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Objective: To evaluate chorionic villus sampling (CVS) as a technique for karyotyping after the first trimester by examining the incidence of result failure, confined placental mosaicism, and false positive or negative results at different gestational ages., Methods: During a nine year period between 1989 and 1997, all results of CVS between 8 and 37 weeks of gestation provided by the Regional Cytogenetics Centre were analysed retrospectively by examining indications for CVS, weights of tissue received, gestational age at sampling and karyotype results., Results: There were 2424 chorionic villus samples analysed by the direct method and/or cell culture. In 1548 cases CVS was performed before 14 weeks (Group 1), in 685 between 15 and 20 weeks (Group 2), in 160 between 21 and 28 weeks (Group 3) and in 31 cases after 29 weeks (Group 4). Although there was a trend for an increasing rate of failed direct preparation results from Groups 1 to 4 which were 3.8%, 4.7%, 5.6% and 6.6%, respectively; these results were not significantly different. There were 19 cases of confined placental mosaicism and the incidence was significantly greater in Group 3 compared with Group 1 (P < 0.05), and in Groups 3 and 4 combined compared with Group 1. There were six false positive and one false negative result following direct analysis with no significant differences between gestationar ages., Conclusions: CVS is a useful test after the first trimester, especially when a fast result is clinically required. However, after 20 weeks, when cordocentesis is available, the higher rate of cytogenetic discordancy between the placenta and the fetus means that cordocentesis may be preferable.

Objective: To determine whether there is a relationship between maternal serum insulin-like growth factor-I and fetal growth, consistent with the hypothesis that insulin-like growth factor-I influences maternal constraint upon fetal growth by controlling placental transfer., Design: A prospective, observational study., Setting: Fetal medicine unit and antenatal clinic of a large teaching hospital., Population: One hundred and forty-one pregnant women identified as having small or normally grown fetuses., Methods: Fetuses were scanned every two weeks with maternal venesection at each visit. Cases (birthweight < 5th centile) were assigned to two groups: fetal growth restriction due to placental dysfunction (umbilical artery Doppler, growth velocity pulsatility index > +2 SD; n = 25) and normal small-for-gestational-age (normal Doppler, growth velocity and amniotic fluid; n = 27). Eighty-nine controls had birthweights between the 5th and the 95th centiles, normal Doppler, growth velocity and amniotic fluid. Insulin-like growth factor-I was measured by radioimmunoassay, and its relationship to gestational age and birthweight was assessed by regression analysis. Comparisons between case groups were made by Student's t test or analysis of covariance to allow for the effect of birthweight., Outcome Measure: The last insulin-like growth factor-I level before delivery within the different subgroups., Results: In controls, maternal insulin-like growth factor-I increased with gestational age (r = 0.40; P = 0.0001) but did not correlate with birthweight. Insulin-like growth factor-I was low in the mothers of growth restricted fetuses (-1.56 SD; P = 0.0001), but not in those with small-for-gestational age fetuses., Conclusions: The control and small-for-gestational-age data suggest that maternal insulin-like growth factor-I is not associated with endocrine control of normal placental function. Low insulin-like growth factor-I relates to poor placental transfer, as indicated by Doppler, rather than to low birthweight. Whether this is a regulatory mechanism, a cause or a consequence of placental dysfunction needs further study.

Objective: To describe the incidence of gastroschisis and to identify possible aetiological factors., Design: A retrospective case review study., Setting: The South West Region of England., Population: All known cases of gastroschisis were identified from the regional fetal medicine, ultrasound, pathology and neonatal surgery, databases. Datasets to be collected were agreed prospectively and included demographic, past medical, family and obstetric information for all pregnancies conceived between January 1987 and December 1995., Results: In the first eight years the incidence was 1.6/10,000 but in 1995 a highly statistically significant rise to 4.4/10,000 was found (P = 0.0009). The increased incidence was not associated with changes in maternal age, proportion of primigravidae, use of tobacco or illicit drugs, conception while taking the oral contraceptive pill, or an increase in the number of teenage pregnancies. The median maternal age at last menstrual period for pregnancies with gastroschisis was 20.4 years which was much younger than the national average of 28 years. Thirty-seven percent of these conceptions occurred during the first quarter of the year compared with the expected 25%., Conclusions: The incidence of gastroschisis has risen to a higher level than previously reported which, despite a marked association with young maternal age at conception, is not due to an increase in the teenage pregnancy rate. As the average length of inpatient stay in the neonatal intensive care unit for cases with this malformation is approximately four weeks, the rise has considerable cost implications. The increasing incidence may also offer opportunities to determine the cause of gastroschisis.

Objective: To assess the ability of noninvasive tests of fetal wellbeing to predict hypoxic morbidity independent of fetal size., Design: A prospectively planned, longitudinal, observational study., Setting: Fetal Surveillance Unit, King's College Hospital, London., Subjects: One hundred and ninety-one pregnant women with singleton pregnancies who were delivered after 32 weeks' gestation who were seen in the Fetal Surveillance Unit within seven days of delivery., Interventions: Fetal surveillance by fetal abdominal circumference, heart rate variability (mean range), biophysical profile score and umbilical artery pulsatility index measurements., Main Outcome Measures: Birthweight was classified as > or < or = 2.5th centile (AGA or SGA) for gestational age and sex. Morbidity was defined as at least one of the following at birth: delivery by emergency caesarean section for fetal distress, umbilical venous blood pH less than 7.15, 5 min Apgar score less than 7 or admission to the Special Care Baby Unit (SCBU)., Results: Fetal abdominal circumference was the best indicator of which fetuses (n = 30) would be SGA. Fourteen of the 30 (47%) SGA fetuses had morbidity at birth and abnormal umbilical Doppler studies significantly predicted this (chi 2 = 2.93, P = 0.003). By contrast, fetal heart rate variability and the biophysical profile score did not. Twenty-seven of the 161 (17%) AGA fetuses had morbidity at birth, but this was not significantly predicted by heart rate variability, biophysical profile score or umbilical Doppler studies., Conclusions: None of the antenatal testing techniques studied predicted morbidity in normally grown fetuses but Doppler studies indicated whether a small fetus was 'sick small' or 'normal small'.

Objective: To compare computer cardiotocographic (CTG) analysis with clinical visual analysis., Design: A retrospective blind comparison of the two techniques of CTG assessment., Setting: Fetal Assessment Unit, King's College Hospital, London., Subjects: One hundred CTG traces of women referred to the unit were studied; the traces were taken after 32 weeks' gestation, within 10 days of delivery and where outcome was known., Interventions: The CTG traces were assessed both by the computer (System 8000 computerised CTG analyser, Oxford Sonicaid Ltd) and visually, by one of us., Main Outcome: Computer mean range from 0 to 80 in ms clinical visual CTG score from 0 to 80 (arbitrary units). A score < 20 is ominous; suspicious when between 20 and 30; and normal when > 30., Results: There was close correlation between the computer mean range and clinical visual assessment (r = 0.78, n = 100, P = 0.001). However, there were 13 occasions where the computer classified the trace as abnormal when clinical visual assessment was normal, indicating computer false positives. All these pregnancies had normal outcomes. There were no traces where computer analysis was normal and clinical visual assessment abnormal., Conclusions: Computerised CTG analysis gives an objective assessment which agrees closely with experienced visual assessment. It also provides a number which can be used to assess the value of fetal heart rate analysis.

Objective: To investigate whether Doppler studies of placental perfusion and antenatal tests for fetal hypoxia can identify reduced placental functional reserve in women with unexplained antepartum haemorrhage (APH)., Design: A prospective, longitudinal study., Setting: Fetal Surveillance Unit, King's College Hospital, London., Subjects: 48 women with bleeding from the genital tract after 26 weeks gestation without a clinical diagnosis of abruption or ultrasound evidence of placenta praevia., Interventions: Fetal surveillance by Doppler measurements of the umbilical and uterine arteries, biophysical profile scoring and computerized measurement of the mean minute range of FHR variation., Main Outcome Measures: A poor outcome was defined by one or more of the following: (i) birthweight greater than 2SD below the normal mean for gestational age and sex, (ii) abnormal FHR pattern in labour resulting in operative delivery, (iii) umbilical vein blood pH at delivery less than 7.15, (iv) a 5-min Apgar score less than 7., Results: Fifteen of the 48 pregnancies had a poor outcome; seven occurred in the 10 women delivered preterm (less than 37 weeks) and eight in the 36 women delivered between 37 and 42 weeks. Two women were delivered after 42 weeks and both infants had a good outcome. The results of Doppler studies of uterine and umbilical arteries, fetal biophysical profile or FHR variation were not significantly different between the two outcome groups. The 36 pregnancies delivered between 37 and 42 weeks were matched retrospectively for maternal age, parity and race with 36 pregnancies without APH; there was no significant difference in outcome between the women with unexplained APH and the matched comparison group., Conclusion: Morbidity related to unexplained APH is associated with preterm delivery rather than with damage to utero-placental function.

Amniotic fluid temperature in first trimester pregnancies and fetal subcutaneous tissue and amniotic fluid temperature in second trimester pregnancies, measured by a thermocouple probe, did not increase during sector, linear-array or Doppler ultrasound scanning. The mean fetal muscle temperature was higher (36.9 degrees C) than mean amniotic fluid temperature (36.6 degrees C) during the second trimester.

Histology reports of endometrial curettage and hysterectomy specimens were compared in patients with stage 1 uterine malignancy. In 63 of 117 (54%) the tumour grade or type reported in the curettage specimen differed from that described in the hysterectomy specimen; the grading was as likely to be more as less well differentiated at hysterectomy. The differences were not related to endometrial sampling technique or pre-operative intracavity radiotherapy. The results suggest that if decisions about patient management continue to be based on histological grading of tumours in endometrial curettage samples, unnecessary morbidity will be caused to some patients and inadequate treatment will be given to others.

In 79 pregnancies with erythroblastosis fetalis, fetal blood was sampled to assess the level of anaemia. Significant correlations were found between the haemoglobin concentration and umbilical artery pH, bicarbonate concentration and base excess. Compensatory mechanisms help to maintain oxygen supply in anaemia but their failure is associated with hydrops fetalis.