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Objective To determine whether β2-adrenoceptor ( β2 AR) genotype is associated with shortening of the cervix or with preterm birth ( PTB) risk among women with a short cervix in the second trimester. Design A case-control ancillary study to a multicentre randomised controlled trial. Setting Fourteen participating centres of the Maternal-Fetal Medicine Units Network of the Eunice Kennedy Shriver National Institute of Child Health and Human Development. Population Four hundred thirty-nine women, including 315 with short cervix and 124 with normal cervical length. Methods Nulliparous women with cervical length <30 mm upon a 16-22-week transvaginal sonogram and controls frequency-matched for race/ethnicity with cervical lengths ≥40 mm were studied. β2 AR genotype was determined at positions encoding for amino acid residues 16 and 27. Main outcome measures Genotype distributions were compared between case and control groups. Within the short cervix group, pregnancy outcomes were compared by genotype, with a primary outcome of PTB <37 weeks. Results Genotype data were available at position 16 for 433 women and at position 27 for 437. Using a recessive model testing for association between short cervix and genotype, and adjusted for ethnicity, there was no statistical difference between cases and controls for Arg16 homozygosity ( OR 0.7, 95% CI 0.4-1.3) or Gln27 homozygosity ( OR 0.9, 95% CI 0.3-2.7). Among cases, Arg16 homozygosity was not associated with protection from PTB or spontaneous PTB. Gln27 homozygosity was not associated with PTB risk, although sample size was limited. Conclusions β2 AR genotype does not seem to be associated with short cervical length or with PTB following the second-trimester identification of a short cervix. Influences on PTB associated with β2 AR genotype do not appear to involve a short cervix pathway. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Thorp J, Camargo C, McGee P, Harper M, Klebanoff M, Sorokin Y, Varner M, Wapner R, Caritis S, Iams J, Carpenter M, Peaceman A, Mercer B, Sciscione A, Rouse D, Ramin S, Anderson G. Vitamin D status and recurrent preterm birth: a nested case-control study in high-risk women. BJOG 2012;119:1617-1623. Objective To determine whether vitamin D status is associated with recurrent preterm birth, and any interactions between vitamin D levels and fish consumption. Design A nested case-control study, using data from a randomised trial of omega-3 fatty acid supplementation to prevent recurrent preterm birth. Setting Fourteen academic health centres in the USA. Population Women with prior spontaneous preterm birth. Methods In 131 cases (preterm delivery at <35 weeks of gestation) and 134 term controls, we measured serum 25-hydroxyvitamin D [25(OH)D] concentrations by liquid chromatography-tandem mass spectrometry (LC-MS) from samples collected at baseline (16-22 weeks of gestation). Logistic regression models controlled for study centre, maternal age, race/ethnicity, number of prior preterm deliveries, smoking status, body mass index, and treatment. Main outcome measures Recurrent preterm birth at <37 and <32 weeks of gestation. Results The median mid-gestation serum 25(OH)D concentration was 67 nmol/l, and 27% had concentrations of <50 nmol/l. Serum 25(OH)D concentration was not significantly associated with preterm birth (OR 1.33; 95% CI 0.48-3.70 for lowest versus highest quartiles). Likewise, comparing women with 25(OH)D concentrations of 50 nmol/l, or higher, with those with <50 nmol/l generated an odds ratio of 0.80 (95% CI 0.38-1.69). Contrary to our expectation, a negative correlation was observed between fish consumption and serum 25(OH)D concentration (−0.18, P < 0.01). Conclusions In a cohort of women with a prior preterm birth, vitamin D status at mid-pregnancy was not associated with recurrent preterm birth. [ABSTRACT FROM AUTHOR]

Cesarean delivery, the most common surgery performed in the United States, is complicated by adhesion formation in 24-73% of cases. Because adhesions have potential sequelae, different synthetic adhesion barriers are currently heavily marketed as a means of reducing adhesion formation resultant from cesarean delivery. However, their use for this purpose has been studied in only two small, nonblinded and nonrandomized trials, both of which were underpowered and subject to bias. Neither demonstrated improvement in meaningful clinical outcomes. In the only cost-effectiveness analysis of adhesion barriers to date, the use of synthetic adhesion barriers was cost-effective only when the subsequent rate of small bowel obstruction was at least 2.4%, a rate far higher than that associated with cesarean delivery. In fact, intra-abdominal adhesions from prior cesarean delivery rarely cause maternal harm and have not been demonstrated to adversely affect perinatal outcome. Based on our review of the available literature, we think the use of adhesion barriers at the time of cesarean delivery would be ill-advised at the present time. [ABSTRACT FROM AUTHOR]

Objective: To compare rates of preterm birth before 35 weeks based on cervical length measurement at 16-20 weeks in women with twin gestations who received 17-α hydroxyprogesterone caproate (17OHPC) or placebo.Methods: This is a secondary analysis of a randomised, double-blind, placebo-controlled trial of twin gestations exposed to 17OHPC or placebo. Baseline transvaginal ultrasound evaluation of cervical length was performed prior to treatment assignment at 16-20 weeks. Cervical length measurements were categorised according to the 10th, 25th, 50th and 75th percentiles in the women studied. The effect of 17OHPC administration in women with a short (25th percentile) and long (75th percentile) cervix was evaluated.Results: Of 661 twin gestations studied, 221 (33.4%) women enrolled at 11 centers underwent cervical length measurement. The 10th, 25th, 50th, 75th percentiles for cervical length at 16-20 weeks were 32, 36, 40 and 44 mm, respectively. The risk of preterm birth <35 weeks was increased in women with a cervical length <25th percentile (55.8 vs. 36.9%, p=0.02). However, a cervical length >75th percentile at this gestational age interval was not protective for preterm birth (36.5 vs. 42.9%, p=0.42). Administration of 17OHPC did not reduce preterm birth before 35 weeks among those with either a short or a long cervix (64.3 vs. 45.8%, p=0.18 and 38.1 vs. 35.5%, p=0.85, respectively).Conclusion: Women with twin gestations and a cervical length below the 25th percentile at 16-20 weeks had higher rates of preterm birth. In this subgroup of women, 17 OHPC did not prevent preterm birth before 35 weeks gestation. A cervical length above the 75th percentile at 16-20 weeks did not significantly reduce the risk of preterm birth in this high risk population. [ABSTRACT FROM AUTHOR]

Objective: To estimate the effects of chlorhexidine vaginal and baby wipes on fetal and neonatal mortality, respectively, and infection-related morbidity.Methods: We performed a placebo-controlled, randomized trial of chlorhexidine vaginal and neonatal wipes to reduce neonatal sepsis and mortality in three hospitals in Pakistan. The primary study outcome was a composite of neonatal sepsis or 7-day perinatal mortality.Results: From 2005 to 2008, 5,008 laboring women and their neonates were randomly assigned to receive either chlorhexidine wipes (n=2,505) or wipes with a saline placebo (n=2,503). The primary outcome was similar in the chlorhexidine and control groups (3.1% compared with 3.4%; relative risk 0.91, 95% confidence interval 0.67-1.24) as was the composite rate of neonatal sepsis or 28-day perinatal mortality (3.8% compared with 3.9%, relative risk 0.96, 95% confidence interval 0.73-1.27). At day 7, the chlorhexidine group had a lower rate of neonatal skin infection (3.3% compared with 8.2%, P<.001). With the exception of less frequent 7-day hospitalization in the chlorhexidine group, there were no significant differences in maternal outcomes between the groups.Conclusion: Using maternal chlorhexidine vaginal wipes during labor and neonatal chlorhexidine wipes does not reduce maternal and perinatal mortality or neonatal sepsis. The finding of reduced superficial skin infections on day 7 without change in sepsis or mortality suggests that this difference, although statistically significant, may not be of major importance.Level Of Evidence: I. [ABSTRACT FROM AUTHOR]

Objective: To assess whether 17 alpha-hydroxyprogesterone caproate reduces the rate of preterm birth in women carrying triplets.Methods: We performed this randomized, double-blinded, placebo-controlled trial in 14 centers. Healthy women with triplets were randomly assigned to weekly intramuscular injections of either 250 mg of 17 alpha-hydroxyprogesterone caproate or matching placebo, starting at 16-20 weeks and ending at delivery or 35 weeks of gestation. The primary study outcome was delivery or fetal loss before 35 weeks.Results: One hundred thirty-four women were assigned, 71 to 17 alpha-hydroxyprogesterone caproate and 63 to placebo; none were lost to follow-up. Baseline demographic data were similar in the two groups. The proportion of women experiencing the primary outcome (a composite of delivery or fetal loss before 35 0/7 weeks) was similar in the two treatment groups: 83% of pregnancies in the 17 alpha-hydroxyprogesterone caproate group and 84% in the placebo group, relative risk 1.0, 95% confidence interval 0.9-1.1. The lack of benefit of 17 alpha-hydroxyprogesterone caproate was evident regardless of the conception method or whether a gestational age cutoff for delivery was set at 32 or 28 weeks.Conclusion: Treatment with 17 alpha-hydroxyprogesterone caproate did not reduce the rate of preterm birth in women with triplet gestations.Clinical Trial Registration: ClinicalTrials.gov, www.clinicaltrials.gov, NCT00099164Level Of Evidence: I. [ABSTRACT FROM AUTHOR]

Background: In singleton gestations, 17 alpha-hydroxyprogesterone caproate (17P) has been shown to reduce the rate of recurrent preterm birth. This study was undertaken to evaluate whether 17P would reduce the rate of preterm birth in twin gestations.Methods: We performed a randomized, double-blind, placebo-controlled trial in 14 centers. Healthy women with twin gestations were assigned to weekly intramuscular injections of 250 mg of 17P or matching placebo, starting at 16 to 20 weeks of gestation and ending at 35 weeks. The primary study outcome was delivery or fetal death before 35 weeks of gestation.Results: Six hundred sixty-one women were randomly assigned to treatment. Baseline demographic data were similar in the two study groups. Six women were lost to follow-up; data from 655 were analyzed (325 in the 17P group and 330 in the placebo group). Delivery or fetal death before 35 weeks occurred in 41.5% of pregnancies in the 17P group and 37.3% of those in the placebo group (relative risk, 1.1; 95% confidence interval [CI], 0.9 to 1.3). The rate of the prespecified composite outcome of serious adverse fetal or neonatal events was 20.2% in the 17P group and 18.0% in the placebo group (relative risk, 1.1; 95% CI, 0.9 to 1.5). Side effects of the injections were frequent in both groups, occurring in 65.9% and 64.4% of subjects, respectively (P=0.69), but were generally mild and limited to the injection site.Conclusions: Treatment with 17 alpha-hydroxyprogesterone caproate did not reduce the rate of preterm birth in women with twin gestations. (ClinicalTrials.gov number, NCT00099164 [ClinicalTrials.gov].). [ABSTRACT FROM AUTHOR]

OBJECTIVE: This study was undertaken to investigate the association among plurality (number of fetuses per pregnancy), abruptio placenta, and perinatal mortality. STUDY DESIGN: A retrospective cohort study on 15,051,872 singletons, 413,619 twins, and 22,585 triplets delivered in the United States between 1995 and 1998 was conducted. We compared the occurrence of perinatal death between pregnancies complicated by abruptio placenta and those without with the use of adjusted odds ratios. The generalized estimating equations framework was applied to adjust for intracluster correlations among multiples. RESULTS: Placental abruption occurred among 93,968 singletons (6.2 per 1000), 5051 twin (12.2 per 1000), and 353 triplet (15.6 per 1000) gestations ( P for trend<.0001). Placental abruption was associated with significant risk of mortality irrespective of the plurality subtype. Perinatal mortality was greatest among singletons (adjusted odds ratio [95% CI]=14.3[13.2-15.4]), followed by twins (4.4[3.9-4.9]) and least among triplets (3.0[2.0-4.6]) ( P for trend<.0001). CONCLUSION: As plurality increases from 1 to 3, the risk of placental abruption rises, whereas the risk of abruptio-associated perinatal mortality declines. [ABSTRACT FROM AUTHOR]

OBJECTIVE: The purpose of this study was to evaluate the relationship between chorioamnionitis and its duration to adverse maternal, fetal, and neonatal outcomes. STUDY DESIGN: This was a 13-university center, prospective observational study. All women at term carrying a singleton gestation who underwent primary cesarean from January 1, 1999 to December 31, 2000 were eligible. Data abstraction was systematic and performed by trained research nurses. Selected adverse outcomes were compared between pregnancies with, and without, clinically diagnosed chorioamnionitis using relative risks (RRs) and 95% CIs. The duration of chorioamnionitis was stratified into 5 intervals (3-6 h,>6-9 h,>9-12 h, and>12 h), and respective outcomes compared by Mantel-Haenszel test for trend. Additionally, regression analysis was used to compute odds ratios (ORs) and 95% CIs for chorioamnionitis duration length as a continuous explanatory variable. RESULTS: 16,650 pregnancies were analyzed, 1965 (12%) with chorioamnionitis, which was associated with significantly increased risks of maternal blood transfusion, uterine atony, septic pelvic thrombophlebitis, and pelvic abscess (RR 2.3-3.7), as well as 5-minute Apgar

Objective: The purpose of this study was to determine, among women without evidence of gestational diabetes mellitus during their first pregnancy, the likelihood of, and associated risk factors for, the development of gestational diabetes mellitus in the subsequent pregnancy.Study Design: This was a retrospective cohort study, with a time frame of 1991 to 1999.Results: Of 3710 women without gestational diabetes mellitus in the first pregnancy, 1% (37 women) were subsequently diagnosed with gestational diabetes mellitus in the second pregnancy. These 37 women, when compared (by means) to women without gestational diabetes mellitus in their second pregnancy, were more likely to be older (age 21 years vs 19 years) and obese (first visit body mass index, 28 kg/m(2) vs 25 kg/m(2)) and to have an interpregnancy weight gain of >5 kg (93% vs 49%) and a longer mean interpregnancy interval (33 months vs 24 months). Regression analysis revealed that, during the first pregnancy, a first visit body mass index of >29 kg/m(2) (odds ratio, 2.2; 95% CI, 1.1-4.5) and a serum glucose screen of >101 mg/dL (odds ratio, 8.3; 95% CI, 2.5-27.9) were associated significantly with the development of gestational diabetes mellitus in the second pregnancy, as was an interpregnancy weight gain of >5 kg (odds ratio, 10.8; 95% CI, 2.5-46.3). All women who subsequently had gestational diabetes mellitus had at least one of these risk factors.Conclusion: Among women without gestational diabetes mellitus in the first pregnancy, the risk of gestational diabetes mellitus in a second pregnancy is low. Therefore, screening all such women in the second pregnancy may not be justified. [ABSTRACT FROM AUTHOR]

Context: Antenatal corticosteroids for fetal maturation have been underused, despite evidence for their benefits in cases of preterm birth.Objective: To evaluate dissemination strategies aimed at increasing appropriate use of this therapy.Design and Setting: Twenty-seven tertiary care institutions were randomly assigned to either usual dissemination of practice recommendations (n = 14) or usual dissemination plus an active, focused dissemination effort (n = 13).Subjects: Obstetricians and their preterm delivery cases at participating hospitals.Intervention: Recommendations by a National Institutes of Health (NIH) Consensus Conference held in late February-early March 1994 were disseminated in early May 1994. Usual dissemination was publication of the recommendations and endorsement by the American College of Obstetricians and Gynecologists. Active dissemination was a year-long educational effort led by an influential physician and a nurse coordinator at each facility, consisting of grand rounds, a chart reminder system, group discussion of case scenarios, monitoring, and feedback.Main Outcome Measure: Use or nonuse of antenatal corticosteroids was abstracted from medical records of eligible women delivering at the participating hospitals in the 12 months immediately prior to release of the NIH recommendations (average number of records abstracted, 130) and in the 12 months following their release (average number of records abstracted, 122).Results: Active dissemination significantly increased the odds of corticosteroid use after the conference. Use increased from 33.0% of eligible patients receiving corticosteroids to 57.6%, or by 75% over baseline, in usual dissemination hospitals. Use increased from 32.9% to 68.3%, oran 108% increase, in active dissemination hospitals. Gestational age and maternal diagnosis affected use of the therapy in complex ways.Conclusion: An active, focused dissemination effort increased the effectiveness of usual dissemination methods when combined with key principles to change physician practices. [ABSTRACT FROM AUTHOR]

Objective: To quantitate the potential effectiveness and monetary costs of a policy of elective cesarean delivery for fetal macrosomia diagnosed by ultrasound.Design: A decision analytic model was constructed to compare 3 policies: (1) management without ultrasound; (2) ultrasound and elective cesarean delivery for estimated fetal weight of 4000 g or more (4000-g policy); and (3) ultrasound and elective cesarean delivery for estimated fetal weight of 4500 g or more (4500-g policy). The impact of maternal diabetes was analyzed separately. Probability data used in the decision analytic model were summarized from the literature and supplemented with unpublished data from the Collaborative Trial of Preterm Birth Prevention. Costs were estimated from the literature, regional reimbursements, and clinical practice data.Main Outcome Measures: Rates of shoulder dystocia and permanent brachial plexus injury, and both the number of additional cesarean births and monetary costs per permanent brachial plexus injury averted.Results: In the baseline analysis for nondiabetic women, the ultrasound policies increased both the cesarean delivery rate and costs, while decreasing the rate of shoulder dystocia and brachial plexus injury. For each permanent brachial plexus injury prevented by the 4500-g policy, 3695 cesarean deliveries were performed at an additional cost of $8.7 million, vs 2345 cesarean deliveries and $4.9 million with the 4000-g policy. In the baseline analysis for diabetic women, with all 3 policies, rates of cesarean delivery, shoulder dystocia and brachial plexus injury, and total costs were higher than for nondiabetic women. However, more favorable ratios for both cesarean deliveries and cost per permanent injury avoided were observed: 443 deliveries and $930 000, respectively, with the 4500-g policy, and 489 deliveries and $880 000, respectively, with the 4000-g policy. Sensitivity analysis confirmed the general robustness of these findings.Conclusions: For the 97% of pregnant women who are not diabetic, a policy of elective cesarean delivery for ultrasonographically diagnosed fetal macrosomia is medically and economically unsound. In pregnancies complicated by diabetes, such a policy appears to be more tenable, although the merits of such an approach are debatable. [ABSTRACT FROM AUTHOR]