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This is the peer reviewed version of the following article: Rossen, J., Klungsøyr, K., Albrechtsen, S., Løkkegård, E., Rasmussen, S., Bergholt, T. & Skjeldestad, F.E. (2018). Can oxytocin augmentation modify the risk of epidural analgesia by maternal age in cesarean sections? Acta Obstetricia et Gynecologica Scandinavica, 97(7), 872-879, which has been published in final form at https://doi.org/10.1111/aogs.13341. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. Introduction: Maternal age is an established risk factor for cesarean section; epidural analgesia and oxytocin augmentation may modify this association. We investigated the effects and interactions of oxytocin augmentation, epidural analgesia and maternal age on the risk of cesarean section. Material and methods: In all, 416 386 nulliparous women with spontaneous onset of labor, ≥37 weeks of gestation and singleton infants with a cephalic presentation during 2000–2011 from Norway and Denmark were included [Ten‐group classification system (Robson) group 1]. In this case‐control study the main exposure was maternal age; epidural analgesia, oxytocin augmentation, birthweight and time period were explanatory variables. Chi‐square test and logistic regression were used to estimate associations and interactions. Results: The cesarean section rate increased consistently with advancing maternal age, both overall and in strata of epidural analgesia and oxytocin augmentation. We observed strong interactions between maternal age, oxytocin augmentation and epidural analgesia for the risk of cesarean section. Women with epidural analgesia generally had a reduced adjusted odds ratio when oxytocin was used compared with when it was not used. In Norway, this applied to all maternal age groups but in Denmark only for women ≥30 years. Among women without epidural, oxytocin augmentation was associated with an increased odds ratio for cesarean section in Denmark, whereas no difference was observed in Norway. Conclusions: Oxytocin augmentation in nulliparous women with epidural analgesia is associated with a reduced risk of cesarean section in labor with spontaneous onset.

Anomalous cord insertion is associated with increased risk of adverse maternal and perinatal outcome. Our aim was to study whether anomalous cord insertion is associated with prelabor rupture of membranes (PROM), preterm PROM (pPROM), long or short umbilical cord, and time trend of spontaneous preterm birth (SPTB) and anomalous cord insertion.A population-based register study using data from the Medical Birth Register of Norway including all singleton births (gestational age16 weeks and45 weeks) during 1999-2013 (n = 860 465) to calculate odds ratios (ORs) for PROM, pPROM, SPTB, and cord length (95th or5th centile) according to the cord insertion site by logistic regression with adjustment for possible confounders. We also assessed time trends of SPTB and anomalous cord insertion.Velamentous insertion of the cord was associated with an increased risk of PROM (OR 1.6, 95% CI 1.5-1.7), pPROM (OR 2.7, 95% CI 2.4-3.0), SPTB (OR 2.0, 95% CI 1.9-2.2), and a short cord (OR 1.7, 95% CI 1.5-1.8). Marginal insertion was to a lesser extent associated with these complications. Occurrences of SPTB and anomalous insertion declined. The decline in SPTB persisted after including an interaction term between anomalous insertion and time.Velamentous and, to a lesser extent, marginal cord insertions were associated with increased risk of PROM, pPROM, SPTB, and short cord. This suggests a common pathogenesis behind altered function of the membranes, cord, and placenta. The decline in SPTB could not be explained by the reduction in the occurrence of anomalous cord insertion.

Circadian rhythmicity is fundamental to human physiology, and is present even during fetal life in normal pregnancies. The impact of maternal endocrine disease on the fetal circadian rhythm is not well understood. The present study aimed to determine the fetal circadian rhythm in pregnancies complicated by pregestational diabetes mellitus (PGDM), compare it with a low-risk reference population, and identify the effects of maternal glycemic control and morning cortisol concentrations. Long-term fetal electrocardiogram recordings were made in 40 women with PGDM at 28 and 36 weeks of gestation. Two recordings were made in 18 of the women (45.0%) and one recording was made in 22 (55.0%). The mean fetal heart rate (fHR) and the fHR variation (root mean square of squared differences) were extracted in 1-min epochs, and circadian rhythmicity was detected by cosinor analysis. The study cohort was divided based on HbA1c levels and morning cortisol concentrations. Statistically, significant circadian rhythms in the fHR and the fHR variation were found in 45 (100%) and 44 (95.7%) of the 45 acceptable PGDM recordings, respectively. The rhythms were similar to those of the reference population. However, there was no statistically significant population-mean rhythm in the fHR among PGDM pregnancies at 36 weeks, indicating an increased interindividual variation. The group with higher HbA1c levels (6.0%) had no significant population-mean fHR rhythm at 28 or 36 weeks, and no significant fHR-variation rhythm at 36 weeks. Similarly, the group with a lower morning cortisol concentration (≤8.8 µg/dl) had no significant population-mean fHR-variation rhythm at 28 and 36 weeks. These findings indicate that individual fetal rhythmicity is present in pregnancies complicated by PGDM. However, suboptimal maternal glycemic control and a lower maternal morning cortisol concentration are associated with a less-well-synchronized circadian system of the fetus.

AIM The knowledge on biological rhythms is rapidly expanding. We aimed to define the longitudinal development of the daily (24-hour) fetal heart rate rhythm in an unrestricted, out-of-hospital setting and to examine the effects of maternal physical activity, season and fetal sex. METHODS We recruited 48 women with low-risk singleton pregnancies. Using a portable monitor for continuous fetal electrocardiography, fetal heart rate recordings were obtained around gestational weeks 24, 28, 32 and 36. Daily rhythms in fetal heart rate and fetal heart rate variation were detected by cosinor analysis; developmental trends were calculated by population-mean cosinor and multilevel analysis. RESULTS For the fetal heart rate and fetal heart rate variation, a significant daily rhythm was present in 122/123 (99.2%) and 116/121 (95.9%) of the individual recordings respectively. The rhythms were best described by combining cosine waves with periods of 24 and 8 hours. With increasing gestational age, the magnitude of the fetal heart rate rhythm increased, and the peak of the fetal heart rate variation rhythm shifted from a mean of 14:25 (24 weeks) to 20:52 (36 weeks). With advancing gestation, the rhythm-adjusted mean value of the fetal heart rate decreased linearly in females (P

To assess whether anomalous cord insertion is associated with risk of complications in the third stage of labor.A population-based study.Norwegian Medical Birth Register.All singleton births (gestational age16 weeks and45 weeks) during the period 1999-2011 (n = 738,443 singletons). Deliveries by cesarean were excluded, leaving 628,680 vaginal singleton deliveries for the analyses.Calculation of odds ratios for complications in the third stage of labor (postpartum hemorrhage, manual delivery of the placenta, curettage) in velamentous and marginal cord insertion by logistic regression with adjustment for confounders.Complications in the third stage of labor, postpartum hemorrhage, manual placental removal and curettage.Anomalous cord insertion was associated with an increased risk of complications in the third stage of labor, the risk being higher for velamentous than for marginal insertion. The risks persisted after adjusting for possible confounding factors. Velamentous cord insertion carried a 5.6% risk of a need for manual removal of the placenta, compared with the risk of 1.1% for nonvelamentous insertion (odds ratio = 5.21, 95% confidence interval 4.71-5.76) in vaginal delivery, and we found increased risks of curettage (odds ratio = 3.29, 95% confidence interval 2.87-3.77) and postpartum hemorrhage (odds ratio = 2.06, 95% confidence interval 1.77-2.39).Marginal and especially velamentous cord insertion is associated with an increased risk of hemorrhage in the third stage of labor, need for manual removal of the placenta and curettage. Anomalous cord insertion can be identified prenatally and so possibly influence obstetric management.

Objective To determine the electrocardiographic performance and neonatal outcome of pregnancies with breech presentation and planned vaginal delivery monitored with ST-waveform analysis (STAN). Design Prospective observational study. Setting University hospital, Norway; 2004–2008. Population Singleton pregnancies with a gestational age above 35 + 6 weeks, breech presentation, selected for vaginal delivery and monitored with STAN. Methods Common clinical guidelines for STAN monitoring were used. An experienced neonatologist graded the symptoms of neonatal encephalopathy. The outcome was compared with STAN-monitored high-risk deliveries in a vertex presentation (n = 5569) using logistic regression analysis. Main outcome measure Frequency of ST events, indications of intervention for fetal distress, and neonatal morbidity and mortality. Results Breech presentation occurred in 750 of 23 219 (3.2%) deliveries, 625 (83%) of which were selected for vaginal delivery. Intrapartum monitoring by STAN was performed in 433 (69%). Compared with vertex presentations, fetuses in breech presentation had a lower risk of baseline T/QRS rise during labour [odds ratio (OR) = 0.7, 95% confidence interval (95% CI) = 0.7–0.9, P = 0.003] and a higher risk for intervention as a result of preterminal cardiotocogram (OR = 2.9, 95% CI = 1.6–5.9, P = 0.001). The risks of perinatal mortality (OR = 1.8, 95% CI = 0.2–15, P = 0.6), cord metabolic acidosis (OR = 0.8, 95% CI = 0.2–3.2, P = 0.7) and moderate or severe neonatal encephalopathy (OR = 1.8, 95% CI = 0.5–6.2, P = 0.3) did not differ significantly between breech and vertex deliveries. Conclusion STAN can be used for the surveillance of breech presentations selected for vaginal delivery with an acceptable neonatal outcome. The electrocardiogram (ECG) pattern during labour varies with the fetal presentation.

Background Providing adequate analgesia and appropriate sedation to high-risk parturients during late second stage labour without compromising foetal safety remains a major challenge, especially in situations when neuraxial block is not applicable. Remifentanil emerged as an option for labour analgesia during the last decade but may be suitable for the facilitation of complicated vaginal deliveries as well. Methods A retrospective chart review of nine labouring women with significant medical and/or obstetrical risk factors was conducted. According to the assessment of an experienced obstetrician, vaginal delivery could only be achieved with profound analgesia, and neuraxial block was not possible because of contraindications, technical failure, or shortage of time. Mode of delivery, need for neonatal resuscitation, maternal and neonatal vital parameters, drug consumption, and personnel resource expenses were recorded. Results Remifentanil target-controlled infusion (TCI) facilitated vaginal delivery in eight out of nine women. No serious adverse events were observed, but three newborns needed initial respiratory support for a few minutes. The total cost of remifentanil TCI administration to facilitate vaginal delivery compared with the estimated additional cost of an emergency caesarean section was negligible. Conclusion This case series suggests that remifentanil TCI may be used to facilitate vaginal delivery in high-risk parturients when other forms of analgesia are limited. However, the small number of patients studied does not allow generalisation of the results; neither can safety concerns be dispelled yet.

Objective To evaluate the clinical use of ST analysis (STAN) for intrapartum monitoring of high-risk pregnancies. Design Prospective observational study. Setting University hospital, Norway, 2004–2008. Population Singleton pregnancies with a gestational age above 35+6 weeks. Methods Analysis of maternal and neonatal outcomes for all deliveries according to the method of intrapartum monitoring. Main outcome measures Prevalence of cord metabolic acidosis (pH 12 mmol/L). Results Of 23 203 deliveries, 6010 (25.9%) were monitored with STAN. Fetal blood sampling was performed in 146 (2.4%) of the 6010 cases. During the study period, the prevalence of cord metabolic acidosis and moderate cord acidosis (pH

Introduction: The cesarean rates are low but increasing in most Nordic countries. Using the Robson classification, we analyzed which obstetric groups have contributed to the changes in the cesarean rates. Material and methods: Retrospective population-based registry study including all deliveries (3 398 586) between 2000 and 2011 in Denmark, Finland, Iceland, Norway and Sweden. The Robson group distribution, cesarean rate and contribution of each Robson group were analyzed nationally for four 3-year time periods. For each country, we analyzed which groups contributed to the change in the total cesarean rate. Results: Between the first and the last time period studied, the total cesarean rates increased in Denmark (16.4 to 20.7%), Norway (14.4 to 16.5%) and Sweden (15.5 to 17.1%), but towards the end of our study, the cesarean rates stabilized or even decreased. The increase was explained mainly by increases in the absolute contribution from R5 (women with previous cesarean) and R2a (induced labor on nulliparous). In Finland, the cesarean rate decreased slightly (16.5 to 16.2%) mainly due to decrease among R5 and R6-R7 (breech presentation, nulliparous/multiparous). In Iceland, the cesarean rate decreased in all parturient groups (17.6 to 15.3%), most essentially among nulliparous women despite the increased induction rates. Conclusions: The increased total cesarean rates in the Nordic countries are explained by increased cesarean rates among nulliparous women, and by an increased percentage of women with previous cesarean. Meanwhile, induction rates on nulliparous increased significantly, but the impact on the total cesarean rate was unclear. The Robson classification facilitates benchmarking and targeting efforts for lowering the cesarean rates. (Less)

ObjectiveThe English questionnaire Pregnancy-Unique Quantification of Emesis and nausea (PUQE) identifies women with severe Hyperemesis Gravidarum. Our aim was to investigate whether scores from the translated Norwegian version; SUKK (SvangerskapsUtløst Kvalme Kvantifisering) was associated with severity of hyperemesis and nutritional intake.DesignA prospective cohort validation study.SettingHospital cohort of Hyperemesis Gravidarum (HG) patients from western Norway and healthy pregnant women from Bergen, Norway.Sample38 women hospitalized due to HG and 31 healthy pregnant controls attending routine antenatal check-up at health centers.MethodsData were collected May 2013-January 2014. The study participants answered the Norwegian PUQE-questionnaire (scores ranging from 3 to 15) and registered prospectively 24-hours nutritional intake by a food list form.Main outcome measuresDifferences of PUQE-scores, QOL-score and nutritional intake between hyperemesis patients and controls.ResultsHyperemesis patients had shorter gestational age compared to controls (median 9.7 weeks; 95% CI 8.6-10.6 versus 11.9; 95% CI 10.1-12.9, p=0.004), and larger weight-change from pre-pregnant weight (loss of median 3 kg; 95% CI 3-4 versus gain of 2 kg; 95% CI 0.5-2, pConclusionPUQE-scoring has been validated as a robust indicator of severe hyperemesis gravidarum and insufficient nutritional intake in a Norwegian setting.

Background. To evaluate the treatment and neonatal outcome in pregnancies complicated by twin-twin transfusion syndrome (TTS). Material and methods. Twenty-four women with TTS were identified in the period 1993-99 among 34 477 deliveries. We include a retrospective chart review of all twins with TTS. Results. The overall incidence of TTS was 4.75% of all twin pregnancies. The mean gestational age at the time of diagnosing TTS was 23 weeks (range 17.6-38), and the mean gestational age at delivery was 34.6 weeks (range 23.1-38.3). Therapeutic amniocenteses was performed in 21 women. The total volume drained varied from 0.4 to 32.31 with a mean of 2.3 l. Overall perinatal mortality in TTS was 35.4%, as nine donor twins and eight recipient twins died. The main causes for mortality were intrauterine death and prematurity. Conclusion. Twin-twin transfusion syndrome is a severe complication in monochorionic diamniotic twin pregnancies, with high perinatal mortality and morbidity even though amnioreduction prolon...

(2004). Breech birth at term: vaginal delivery or elective cesarean section? A systematic review of the literature by a Norwegian review team. Acta Obstetricia et Gynecologica Scandinavica: Vol. 83, No. 2, pp. 126-130.

To relate unexplained antepartum fetal death with maternal and fetal characteristics in order to identify risk factors.Population-based study based on records of 1,676,160 singleton births with gestational ageor =28 weeks. Unexplained antepartum fetal death was defined as fetal death before labour without known fetal, placental, or maternal pathology.Although unexplained fetal mortality in general declined from 2.4 per 1000 births in 1967-1976 to 1.6 in 1977-1998, the proportion among all fetal deaths increased from 30% to 43% during the same period of observation. Unexplained fetal death occurred later in gestation than explained. From 39 weeks of gestation, the risk increased progressively to 50/10,000 in women agedor =35 years and10/10,000 in women25 years. In birth orderor =5, the risk was particularly high after 39 weeks of gestation. For birth weight percentile 2.5-9.9 andor =97.5, unexplained fetal death was four and three times more likely to occur, respectively. We found an additive effect of maternal age and birth weight percentile 2.5-9.9. Women with less than 10 years education had higher risk than women with 13 years or more (OR=1.6). Weaker associations were observed with female gender, unmarried mothers, and winter season.Unexplained antepartum fetal death occurred later in gestation than explained and was associated with high maternal age, multiparity, low education, and moderately low and high birth weight percentile. The increased risk in post-term pregnancies and the additive effect of maternal age and birth weight percentile 2.5-9.9 suggests that older women would benefit from monitoring of fetal growth.

Objective. To validate the diagnosis of an unexplained antepartum fetal death in the Medical Birth Registry of Norway against data obtained from hospital records, alone and combined with autopsy data. To compare epidemiologic characteristics of an unexplained fetal death based on cases recorded by the three data sources. Methods. Data on unexplained fetal deaths in the Registry were compared with clinical and autopsy data from 108 457 singletons with a gestational age ≥ 28 weeks or a birthweight ≥ 1000 g delivered in 1985-97 at Haukeland Hospital in Bergen and Aker Hospital in Oslo. Results. Compared with clinical data, the positive and negative predictive values of a Registry diagnosis of an unexplained fetal death were 88% and 86%, respectively, while the sensitivity and specificity were 76% and 93%, respectively. Compared with clinical and autopsy data combined, the positive and negative predictive values of a Registry diagnosis of an unexplained fetal death were 77% and 89%, respectively, while the se...

Introduction The objective of this study was to examine the association between planned mode of delivery and neonatal outcomes in breech deliveries. Material and methods In this retrospective cohort study we studied singleton term breech deliveries in Norway from 1991 to 2011 (n = 30 861) using the Medical Birth Registry of Norway. We compared planned vaginal delivery with planned cesarean delivery across two time periods: from 1 January 1991 to 31 October 2000 (first period) and from 1 November 2000 to 31 December 2011 (second period). Intrapartum and neonatal deaths were validated against source data in medical records, autopsy reports, and other relevant documents. The main outcome measures were intrapartum and neonatal mortality within the first 28 days of life, 5-min Apgar-scores

Background. It is common to admit to hospital or start intensive ambulatory antenatal care of pregnant women with a previous placental abruption using the gestational age of the previous placental abruption as a starting point. In some instances, close surveillance may be commenced much earlier. There is no consensus when in a subsequent pregnancy such measures should be initiated. Objective. The analyses aimed at the prevention of complicated (preterm, small for gestational age, or perinatal death) recurrent placental abruptions, assessing at which time in a subsequent pregnancy special surveillance should start in order to anticipate and prevent a recurrence. Design. A cohort study based on the Medical Birth Registry of Norway. Calculation of gestational age specific risks of placental abruption in a second pregnancy and estimation of when to initiate surveillance in order to reduce an increased risk of recurrent placental abruption to the initial level of initial abruption in the second pregnancy. Resu...

Objectives. To assess secular trends in mortality rates in breech presentation in Norway and the effects of gestational age, birth defects and delivery method. Material and methods. The Medical Birth Registry of Norway 1967-1994, with 45,579 breech presentation births from 24 weeks of gestation onwards, with mortality rate comprising all stillbirths from 24 completed weeks of gestation and all neonatal deaths (extended peri- and neonatal mortality) as main outcome variable. Results. The extended peri- and neonatal mortality rate in breech presentation births declined during the study period from 9.2% in 1967-76 to 5.5% in 1977-86 and to 3.0% in 1987-94. The highest relative risk of mortality in breech presentation versus the total birth population was observed in intrapartum death and in mortality less than 24 hours after delivery. Stillbirth represented about half of the extended peri- and neonatal mortality throughout the study period. Also in infants with birth defects, the survival increased during th...

Objective. To evaluate secular trends in the occurrence of placenta previa and whether placenta previa is associated with the outcome of previous pregnancies, cesarean section, and sociodemographic factors. Design. A cohort study based on the Medical Birth Registry of Norway. Placenta previa in the second pregnancy was investigated for associations with outcomes in the first pregnancy and sociodemographic factors. Results. In birth orders 1 and 2 the occurrence of placenta previa was 1.2 and 2.2 per 1000, respectively, with no secular trend. The occurrence increased with maternal age and was lowest in women aged 20-29 years. The recurrence rate was 23 per 1000 (adjusted odds ratio (OR) of recurrence=9.7). In women with prior delivery at ≤25 gestational weeks the risk of placenta previa was 6.7 per 1000 (adjusted OR=3.0). In women with prior placental abruption the risk was 5.8 per 1000 (OR=2.6). In women with prior perinatal death the risk was 4.4 per 1000 (adjusted OR=1.8). No independent relationship em...

Objective To determine the incidence and complications related to manual removal of the placenta. Methods Review of hospital medical records from 1990 throughout 1994. One thousand five hundred and two vaginal deliveries from 1984 1992 were used for comparisons. Results A total of 24,750 deliveries were registered during the five year study period. Placenta was removed manually in 165 women (0.6%). The use of general anesthesia for manual removal of placenta decreased from 74% in 1990 to 19% in 1994. Spinal analgesia was applied from 1993, and it was used in 42% of the women in 1994. Of 74 parous women, 12 (16%) had experienced retained placenta before. The average difference in the hemoglobin concentration between the prenatal and the postoperative values was 3.4 g/dl among the patients, and 10% required blood transfusion (1-4 units). Among the controls, there was no decrease in the average hemoglobin concentration, and only 0.5 needed blood transfusion. Endometritis following manual removal was detected in 1.8% of the patients and 1.5% among the controls. Despite manual removal, five women (3%) were considered to have retained placental fragments two days or later after delivery, which required curettage. Conclusions Placenta needed to be removed manually in 0.60% of all deliveries in our department. It was associated with increased incidence of hemorrhage and consequently low hemoglobin values. Women with a history of retained placenta have an increased risk of recurrence of retained placenta in subsequent deliveries.

Objective: To assess subsequent pregnancy rates and recurrence of breech, as well as interpregnancy interval after a breech presentation. Methods: We conducted a national population registry-based study using data from 1967 to 1994, with maternal record linkage of sibships, comprising the first to the fourth birth of a mother. Results: The subsequent pregnancy rate after a surviving breech birth was lower than after a surviving nonbreech birth. Women with two births, of which one was a perinatal loss, had a higher subsequent pregnancy rate, compared with those who had surviving infants. The subsequent pregnancy rate was lower after a cesarean delivery irrespective of presentation. The interpregnancy interval was shorter if the previous infant died, whereas presentation did not influence the interval. The adjusted odds ratio of recurrence of breech increased from 4.32 (95% confidence interval [CI] 4.08, 4.59) after one previous breech delivery to 28.1 (95% CI 12.2, 64.8) after three. Conclusion: Breech and cesarean delivery lowered the subsequent pregnancy rate, probably because of the women’s decision not to reproduce. Thus, preconceptional counseling with information, support, and reassurance regarding future pregnancies and deliveries might reduce the discouraging effect. A high odds ratio of recurrence of breech suggests effects of recurring specific causal factors of either genetic or more permanent environmental origin.

Background. To study factors influencing delivery method in breech presentation. Methods. Population based cohort study from The Medical Birth Registry of Norway, comprising all singleton deliveries in Norway, 1967-1994, 1,592,064 deliveries of which 45,921 (2.9%) were in breech presentation. Results. The proportion of cesarean section in breech presentation increased from 3.6 per 100 in 1969 to 58.8 in 1994. The relative risk for delivery by cesarean section in breech presentation compared to the nonbreech population increased from 2.0 (95% CI 1.5-2.7) in 1967 to 5.9 (95% CI 5.6-6.2) in 1994. It declined by maternal age, increased by gestational age and was lowest among mothers with urban residence. A negative association was observed between the annual number of births at the delivery department and the cesarean section proportion. However, during the observation period, the centralization of breech deliveries to the largest departments was reduced. Conclusions. Vaginal delivery in breech presentation was particularly observed in large delivery departments and among mothers with urban residence. Since experience and practical competence are prerequisites for successful vaginal delivery, this centralization seems justified. Further centralization of all breech presentation births should be pursued. However, preparedness as to vaginal delivery should be established also at the smaller units, e.g. by a routine providing periodical centralized training for obstetricians working in smaller institutions.

Background. To study the occurrence of breech presentation and its association with demographic and geographic variables. Method. Population based cohort study from the Medical Birth Registry of Norway comprising all singleton deliveries 1967-1994, a total of 1,592,064 deliveries. Of these, 45,921 in breech presentation. Results. From 1967 through 1994, the breech presentation proportion increased from 2.2%, (95% CI 2.1-2.3) to 3.4% (95% Cl 3.2-3.5). Breech presentation was associated with high maternal age and low birth order, as well as low gestational age and birthweight. The secular trend was mainly due to demographic changes in terms of increasing proportions of births with low birth order and high maternal age. Breech presentation was most frequent in urban areas. Conclusions. Strong associations were observed between breech presentation and low birth order as well as high maternal age. The findings are compatible with both intrinsic as well as environmental mechanisms. A full understanding of the birth order effect necessitates further studies based on sibship data. Prevention of premature delivery would be an effective measure for reducing the breech presentation proportion.

Objective To assess the effect of the time interval from indication of hypoxia to delivery on neonatal outcome in high-risk pregnancies monitored with cardiotocography (CTG) and ST-waveform analysis. Design Prospective observational study. Setting University hospital, Norway, 2004–08. Population Singleton high-risk births with a gestational age above 35+6 weeks, monitored with CTG and ST-waveform analysis. Methods Logistic regression analysis and Kaplan–Meier survival plots. Main outcome measure Neonatal morbidity in relation to the rapidity of intervention. Results Of 6010 deliveries monitored with ST-waveform analysis, 1131 (19%) had an indication to intervene for fetal distress according to clinical guidelines. Those fetuses were at increased risk of an adverse neonatal outcome, and if delivered later than 20 min after the indication of hypoxia their risk increased further; i.e. transfer to the neonatal intensive care unit (NICU) from an odds ratio of 1.6 (95% confidence interval 1.2–2.2) to an odds ratio of 3.3 (95% confidence interval 2.5–4.3). The indication-to-delivery interval was longer for neonates with a 5-min Apgar score of

ObjectivesTo determine the prevalence of, and risk factors for anomalous insertions of the umbilical cord, and the risk for adverse outcomes of these pregnancies.DesignPopulation-based registry study.SettingMedical Birth Registry of Norway 1999-2009.PopulationAll births (gestational age >16 weeks to MethodsDescriptive statistics and odds ratios (ORs) for risk factors and adverse outcomes based on logistic regressions adjusted for confounders.Main outcome measuresVelamentous or marginal cord insertion. Abruption of the placenta, placenta praevia, pre-eclampsia, preterm birth, operative delivery, low Apgar score, transferral to neonatal intensive care unit (NICU), malformations, birthweight, and perinatal death.ResultsThe prevalence of abnormal cord insertion was 7.8% (1.5% velamentous, 6.3% marginal) in singleton pregnancies and 16.9% (6% velamentous, 10.9% marginal) in twins. The two conditions shared risk factors; twin gestation and pregnancies conceived with the aid of assisted reproductive technology were the most important, while bleeding in pregnancy, advanced maternal age, maternal chronic disease, female foetus and previous pregnancy with anomalous cord insertion were other risk factors. Velamentous and marginal insertion was associated with an increased risk of adverse outcomes such as placenta praevia (OR = 3.7, (95% CI = 3.1-4.6)), and placental abruption (OR = 2.6, (95% CI = 2.1-3.2)). The risk of pre-eclampsia, preterm birth and delivery by acute caesarean was doubled, as was the risk of low Apgar score, transferral to NICU, low birthweight and malformations. For velamentous insertion the risk of perinatal death at term was tripled, OR = 3.3 (95% CI = 2.5-4.3).ConclusionThe prevalence of velamentous and marginal insertions of the umbilical cord was 7.8% in singletons and 16.9% in twin gestations, with marginal insertion being more common than velamentous. The conditions were associated with common risk factors and an increased risk of adverse perinatal outcomes; these risks were greater for velamentous than for marginal insertion.

To evaluate the clinical use of ST analysis (STAN) for intrapartum monitoring of high-risk pregnancies.Prospective observational study.University hospital, Norway, 2004-2008.Singleton pregnancies with a gestational age above 35(+6) weeks.Analysis of maternal and neonatal outcomes for all deliveries according to the method of intrapartum monitoring.Prevalence of cord metabolic acidosis (pH7.05, extracellular fluid base deficit (extracellular fluid)12 mmol/L).Of 23 203 deliveries, 6010 (25.9%) were monitored with STAN. Fetal blood sampling was performed in 146 (2.4%) of the 6010 cases. During the study period, the prevalence of cord metabolic acidosis and moderate cord acidosis (pH7.15) decreased in STAN-monitored deliveries from 1.4 to 0.3% (p = 0.01) and from 16.4 to 11.7% (p = 0.001), respectively. The prevalence of moderate and severe neonatal encephalopathy was 0.38%. In the birth population, the proportion of cesarean deliveries decreased from 10.1 to 8.8%. The risk of emergency cesarean section after STAN monitoring compared with those monitored with auscultation/cardiotocography was high (odds ratio 5.4, 95% confidence interval = 4.9-6.1) but remained stable during the study period.ST analysis is a useful tool for identification of fetuses at risk of intrapartum hypoxia. Despite the restricted use of fetal blood sampling, we found a low proportion of cord metabolic acidosis and newborn morbidity.

Objectives To examine the consequences of cervical conisation in terms of adverse outcome in subsequent pregnancies. Design Population based cohort study. Data sources Data on cervical conisation derived from the Cancer Registry of Norway and on pregnancy outcome from the Medical Birth Registry of Norway, 1967-2003. 15 108 births occurred in women who had previously undergone cervical conisation and 57 136 who subsequently underwent cervical conisation. In the same period there were 2 164 006 births to women who had not undergone relevant treatment (control). Results The proportion of preterm delivery was 17.2% in women who gave birth after cervical conisation versus 6.7% in women who gave birth before cervical conisation and 6.2% in women who had not undergone cervical conisation. The relative risk of a late abortion (

Objective: To investigate intergenerational recurrence of breech delivery, with a hypothesis that both women and men delivered in breech presentation contribute to increased risk of breech delivery in their offspring. Design: Population based cohort study for two generations. Setting: Data from the medical birth registry of Norway, based on all births in Norway 1967-2004 (2.2 million births). Participants: Generational data were provided through linkage by national identification numbers, forming 451 393 mother-offspring units and 295 253 fatheroffspring units.We included units where both parents and offspring were singletons and offspring were first born, forming 232 704 mother-offspring units and 154 851 father-offspring units for our analyses. Main outcome measure: Breech delivery in the second generation. Results: Men and women who themselves were delivered in breech presentation had more than twice the risk of breech delivery in their own first pregnancies compared with men and women who had been cephalic presentations (odds ratios 2.2, 95% confidence interval 1.8 to 2.7, and 2.2, 1.9 to 2.5, for men and women, respectively). The strongest risks of recurrence were found for vaginally delivered offspring and were equally strong formenand women. Increased risk of recurrence of breech delivery in offspring was present only for parents delivered at term. Conclusion: Intergenerational recurrence risk of breech delivery in offspring was equally high when transmitted through fathers and mothers. It seems reasonable to attribute the observed pattern of familial predisposition to term breech delivery to genetic inheritance, predominantly through the fetus. publishedVersion

External cephalic version could be an alternative to either vaginal delivery or caesarean section in breech presentation at term.A systematic literature review about external cephalic version in breech presentation.The numbers of breech presentation delivered by caesarean section could probably be reduced in Norway by offering version, but this would not affect perinatal mortality.

To determine whether proportionate or disproportionate foetal smallness at 17 to 19 weeks of gestation in low-risk pregnancies was associated with size, body constitution, and adverse outcome at birth.We included ultrasound measurements at 17-19 weeks of gestation in 7285 uncomplicated pregnancies with reliable information on last menstrual period. We considered a foetus with both mean abdominal diameter (MAD) and biparietal diameter (BPD) below the 10th percentile for gestational age, gender, and parity as symmetrically small. Those who had MAD below the 10th percentile and BPD at or above the 10th percentile were asymmetrically small (thin and small).The occurrence of small for gestational age (SGA) (birth weight below the 10th percentile) decreased with increasing second trimester MAD percentile (P0.0001). The risk in foetuses which were both thin and extremely small (MAD below the 2.5th percentile) of having weight, ponderal index, crown-heel length, or head circumference below the 10th percentile at birth was 19-28%. The risk of perinatal composite outcome (prenatal death, Apgar score after 5 minor =7, birth weight below the 10th percentile, or1500 g, or preterm birth) was 37%. Apgar score ofor =7 at 5 min and explained foetal death both occurred in 7%, which was significantly higher than those with larger MAD.Asymmetric as well as symmetric foetal smallness may start early in pregnancy. Symmetric and particularly asymmetric small foetuses at 17-19 weeks of gestation were generally lighter, shorter, and thinner at birth and had more often adverse perinatal outcome.

To evaluate the treatment and neonatal outcome in pregnancies complicated by twin-twin transfusion syndrome (TTS).Twenty-four women with TTS were identified in the period 1993-99 among 34477 deliveries. We include a retrospective chart review of all twins with TTS.The overall incidence of TTS was 4.75% of all twin pregnancies. The mean gestational age at the time of diagnosing TTS was 23 weeks (range 17.6-38), and the mean gestational age at delivery was 34.6 weeks (range 23.1-38.3). Therapeutic amniocenteses was performed in 21 women. The total volume drained varied from 0.4 to 32.31 with a mean of 2.3 l. Overall perinatal mortality in TTS was 35.4%, as nine donor twins and eight recipient twins died. The main causes for mortality were intrauterine death and prematurity.Twin-twin transfusion syndrome is a severe complication in monochorionic diamniotic twin pregnancies, with high perinatal mortality and morbidity even though amnioreduction prolonged the pregnancies leading to better neonatal outcome.

report and has obvious clinical relevance. We combined in one analysis the dyskinetic and quadriplegic subtypes to yield a significant proportional distribution between GMFCS level I to III and levels IV to V. This was in addition to significant proportional distributions when these subtypes were evaluated for proportions independently. The rationale for doing the additional combination proportions was to address difficulties in the clinic at times in terms of distinguishing children with spastic quadriplegic or dyskinetic or mixed subtypes of CP. We did detect a lower proportion of non-ambulatory (i.e. GMFCS level IV or V) children with spastic diplegia than that noted by Gorter et al. in another Canadian sample. Two possibilities to explain this difference come to mind. The first is that our sample was collected between the ages of 2 and 5 and there may be a ‘deterioration’ in GMFCS level over time as the child becomes older, and seemingly, the population studied by Gorter et al. was one drawn entirely from paediatric rehabilitation centers, whereas our population was drawn both from paediatric rehabilitation centers and assessment centers. There may be a subset of children with diplegic CP who do not require ongoing rehabilitation intervention as a result of their lack of significant functional impairment. I wish to emphasize that only the simultaneous application of varied and complementary classification approaches offers any hope of capturing in an accurate way the heterogeneity that is CP. The relationships noted between these various classification approaches only serve to reinforce their intrinsic individual validity and value. I would hope that a multimodal approach would be a definite goal of our future care efforts.

Objective: To evaluate the effect of low birth weight adjusted for gestational age in first pregnancies on preeclampsia in second pregnancies and to estimate the proportion of preeclampsia in second pregnancies attributable to histories of LBW for gestational age. Methods: We conducted a cohort study based on linked data from the Medical Birth Registry of Norway, which covered all births in 1967–1992. Results: Women who delivered infants under the third percentile birth weight were three times more likely to have initial or recurrent preeclampsia in second pregnancies than those who delivered infants at or above the tenth percentile. After adjusting for maternal age, year of birth, interpregnancy interval, education, chronic hypertension, diabetes mellitus, and change of partner, the increased risk persisted. Birth weight below the tenth percentile in the first delivery accounted for 10% of the total cases of preeclampsia in the second pregnancy and 30% of recurrent cases. Conclusion: A history of low birth weight adjusted for gestational age is associated significantly with subsequent occurrence as well as recurrence of preeclampsia. These findings are consistent with the hypothesis of a shared etiologic factor or recurrent pathophysiologic mechanism for preeclampsia and fetal growth restriction. A history of fetal smallness for gestational age is found in a substantial proportion of all cases of preeclampsia and thus seems to be important in the etiology of preeclampsia.

To study the occurrence of breech presentation and its association with demographic and geographic variables.Population based cohort study from the Medical Birth Registry of Norway comprising all singleton deliveries 1967-1994, a total of 1,592,064 deliveries. Of these, 45,921 in breech presentation.From 1967 through 1994, the breech presentation proportion increased from 2.2% (95% CI 2.1-2.3) to 3.4% (95% CI 3.2-3.5). Breech presentation was associated with high maternal age and low birth order, as well as low gestational age and birthweight. The secular trend was mainly due to demographic changes in terms of increasing proportions of births with low birth order and high maternal age. Breech presentation was most frequent in urban areas.Strong associations were observed between breech presentation and low birth order as well as high maternal age. The findings are compatible with both intrinsic as well as environmental mechanisms. A full understanding of the birth order effect necessitates further studies based on sibship data. Prevention of premature delivery would be an effective measure for reducing the breech presentation proportion.

Retinal detachment is a rare complication of preeclampsia, eclampsia and abruptio placentae. We report a case of bilateral retinal detachment in association with severe preeclampsia complicated with abruptio placentae, Intrauterine fetal death and disseminated intravascular coagulation. In obstetric complications, placental thromboplastin may release into maternal circulation and activate the extrinsic coagulation system with resultant disseminated intravascular coagulation. This may be responsible for choroidal ischemia and consequent serous retinal detachment.

Placental abruption tends to recur in later pregnancies, but its time of onset is unpredictable. Women with a past history of abruption frequently are admitted, or else begin intensive ambulatory antenatal care, using thegestational age of the previous episode as a starting point. The goal of this cohort study was to determine the best time during a subsequent pregnancy to begin intensive surveillance to prevent recurrent abruption. More than 1.8 million births in Norway from 1967 through 1998, representing 928,779 women, were included in the study if the pregnancy lasted at least 16 completed weeks. A total of 492,861 women were followed through their first two deliveries. Four cohorts were assessed: 1) women with a complicated placental abruption, 2) uncomplicated abruption, 3) complicated birth without placental abruption, and 4) uncomplicated birth without abruption. A complicated birth with or without placental abruption was defined as a case with preterm delivery, fetal growth restriction, or perinatal death. Placental abruption complicated 6.4 per 1000 deliveries in birth order 1 and 6.2 per 1000 in birth order 2. The 104 recurrent abruptions represented 38 per 1000 deliveries. The recurrence rate in cohort 4 was 4.6 per 1000, and that in cohort 3 was 8.8 per 1000 deliveries. Analysis of cohort 1 disclosed recurrent placental abruption in 41 per 1000 deliveries. In this group it was estimated that 27 complicated abruptions would have occurred outside the hospital or before starting special observation at the gestational age of the initial episode, compared with only 3 if observation began 12 weeks before. Cohort 2 had recurrences at a rate of 30 per 1000. Starting surveillance 12 weeks earlier would reduce the expected number of complicated abruptions from 14 to 3. When there is a past history of placental abruption complicated by preterm delivery, a small-for-gestationalage infant, or perinatal death, observation starting 6 weeks before the gestational age of the initial event may reduce the risk of recurrence to one approaching the initial risk. An even longer surveillance time may be appropriate after an uncomplicated term placental abruption.

CD and CD for NRFS alone or in combination with MCA Doppler was assessed by decision tree analysis. Results: Retrograde net blood flow in aortic isthmus was observed in 8.3% (14/169) of the cases and only within the group of fetuses with MCA vasodilation (PI < 5th centile). Among the overall study population, cases with reversed aortic isthmus blood flow were associated with a significantly higher risk of CD (85.7% vs. 36.8%, P < 0.001) and CD for NRFS (85.7% vs. 24.5%, P < 0.001) than those with antegrade blood flow. Decision tree analysis indicated that incorporation of aortic isthmus showed an additional predictive value to brain Doppler abnormalities. Among the group with MCA vasodilation, reversed aortic isthmus blood flow allowed discrimination of cases with high or moderate risk of CD (85.7% vs. 54.5%, P < 0.01) and CD for NRFS (85.7% vs. 40.9%, P < 0.05). Conclusions: Identification of aortic isthmus reversed blood flow identifies a subgroup of term SGA fetuses with middle cerebral artery vasodilation with the highest risk of emergency cesarean delivery for non-reassuring fetal status.

Objects. Pregnancy and delivery in two laryngectomized women.Results. One woman had a pregnancy complicated by hypothyroidism and stenosis of the tracheostoma, she was delivered by cesarean section. The other had an uneventful pregnancy and a spontaneous vaginal delivery.Conclusions. Individualized handling of the delivery. By modifying the technique of bearing down spontaneous vaginal delivery is possible.