Does the rate of cervical shortening after cerclage predict preterm birth?

Objective: The objective of this study is to evaluate whether the rate of cervical shortening after cerclage can predict spontaneous preterm birth (SPTB).

Methods: Women who had cervical length (CL) assessments after cerclage placement were identified. The rate of cervical shortening and its relationship with SPTB was established using a generalized linear regression model. Secondary outcomes included relationship between cervical shortening and risk of SPTB in those with a post-cerclage CL?<25?mm versus ≥25?mm at 18–20 weeks; and the rate of cervical shortening in women who delivered preterm compared with those who delivered at term.

Results: One hundred thirty-four patients were included and 30 (22.4%) delivered at <36 weeks. A rate of cervical shortening of 1?mm/week conferred a risk of SPTB of 22%. Among women with cerclage who had a CL?<25?mm at 18–20 weeks, 1?mm/week of cervical shortening was associated with a 59% risk of SPTB. Patients with cerclage who delivered at term had a slower rate of cervical shortening compared to those who delivered preterm (0.62?mm versus 1.40?mm per week, p?=?0.008).

Conclusions: The rate of cervical shortening after cerclage placement is associated with the risk of SPTB. Sonographic surveillance of the rate of cervical shortening may be useful in assessing risk for SPTB in patients with cerclage.     

Association between a vasopressin receptor AVPR1A promoter region microsatellite and eating behavior measured by a self-report questionnaire (Eating Attitudes Test) in a family-based study of a nonclinical population

OBJECTIVES: Considerable evidence including twin and family studies suggests that biologic determinants interact with cultural cues in the etiology of anorexia and bulimia nervosa. A gene that makes "biologic sense" in contributing susceptibility to these disorders, and to our knowledge not previously investigated for this phenotype, is the vasopressin receptor (AVPR1A), which we have tested for association with eating pathology. METHODS: We genotyped 280 families with same-sex siblings for two microsatellites in the promoter region of the AVPR1A gene. Siblings completed the 26-item Eating Attitudes Test (EAT) and the Drive for Thinness (DT) and Body Dissatisfaction (BD) subscales of the Eating Disorders Inventory (EDI). The Quantitative Transmission Disequilibrium Test program (QTDT), which employs flexible and powerful variance-components procedures, was used to test for an association between EAT scores and the two AVPR1A promoter region microsatellites, RS1 and RS3. RESULTS: A significant association (p = .036) was detected between the RS3 microsatellite and EAT scores. The strongest association was between RS3 and the Dieting subscale of the EAT (p = .011). A significant association was also observed between the EDI-DT and the RS3 microsatellit (p = .0450). CONCLUSIONS: We demonstrate for the first time an association between a microsatellite polymorphism in the AVPR1A promoter region and scores on the EAT as well as with the EDI-DT. The strongest association was observed between the RS3 microsatellite and the Dieting subscale of the EAT. The relevant phenotype appears to tap severe dietary restriction for weight loss purposes.     

Outcomes after periviable ultrasound-indicated cerclage

Background: Cerclage placed for a sonographically short cervix has been shown to reduce the risk of preterm delivery in women with a history of prior preterm birth. While short cervix is traditionally placed before viability, the threshold gestational age at which viability is achieved continues to decrease, and, as a result, a larger subset of women may be ineligible to receive this potentially beneficial procedure.

Objective: To evaluate the association between obstetric outcomes and perioperative complications after placement of an ultrasound-indicated cerclage at periviability compared to placement in the previable period.

Methods: This retrospective cohort study of patients who underwent ultrasound-indicated cerclage evaluated obstetric outcomes and perioperative complications based on gestational age at cerclage placement. Ultrasound-indicated cerclage was considered to have been placed at periviability if placed at 22 to <24 weeks (exposed) and at previability if placed at 16 to <22 weeks gestational age (unexposed). The primary outcome was preterm delivery <36 weeks. Secondary outcomes included mean gestational age at delivery, preterm delivery <32 weeks, <28, and <24 weeks, preterm premature rupture of membranes (PPROM), chorioamnionitis, and perioperative complications. Adjusted analyses were performed to account for demographic and obstetric factors.

Results: Of the 426 patients included in the analysis, 94 (22%) had cerclage placed between ≥22 weeks to <24 weeks, while 332 (78%) had cerclage placed at <22 weeks. On univariate analysis, women who had a periviable cerclage placed were less likely to have a recurrent preterm delivery <36 weeks compared to women with previable cerclage placement (26.6 versus 38.3%, respectively, p?=?.04). The adjusted model did not demonstrate a significant difference in risk for preterm delivery <36 weeks associated with periviable versus previable cerclage (odds ratio 0.66, 95%CI 0.37–1.17). Secondary outcomes were similar between the previable and periviable groups, including mean gestational age at delivery (35.1 versus 36.2 weeks, respectively, p?=?.08) and preterm delivery before 32-week gestation (20.7 versus 13.8%, respectively, p?=?.17). Intraoperative and postoperative complications were rare and rates were similar between groups.

Conclusions: Obstetric outcomes between patients receiving periviable and previable cerclage are similar. Ultrasound-indicated cerclage placement is associated with a relatively low rate of complications. Given the evidence supporting benefit of cerclage for women with short ultrasound cervical length and prior preterm birth, our findings demonstrate that benefits of placement at ≥22 weeks to <24 weeks may outweigh risks.     

Prolonged latency of preterm premature rupture of membranes and risk of cerebral palsy*

Objective: To determine whether prolonged latency after preterm premature rupture of membranes (PPROM) is associated with an increased risk of death or moderate-to-severe cerebral palsy (CP).

Study design: This secondary analysis of the randomized controlled trial of magnesium sulfate for the prevention of CP evaluated whether the time interval between diagnosis of PPROM and delivery was associated with increased risk for CP. Prolonged latency was defined as an interval of ≥4 weeks, latency time was also categorized by week of latency for further analysis. The primary outcome was death or moderate-to-severe CP at 2 years of age. Logistic regression was used to control for confounders.

Results: In all, 1522 patients with PPROM were analyzed; of whom, 1328 had a <4-week interval and 194 had an interval of ≥4 weeks. In the unadjusted analysis, the primary outcome was less likely in the PPROM ≥4 weeks group 4.1% versus 8.4%, RR: 0.49, 95% CI: 0.24–0.98. After adjusting for possible confounders, there was no statistical difference associated with PPROM latency ≥4 weeks versus <4 weeks for death or moderate-to-severe CP.

Conclusion: Prolonged exposure to an intrauterine environment of PPROM does not increase risk for CP.     

Activity restriction and risk of preterm delivery*

Purpose: We sought to determine whether activity restriction (AR) in a cohort of women at high risk for preterm delivery is associated with the risk of preterm delivery.

Materials and methods: This is a secondary analysis of the Maternal-Fetal Medicine Units MFMU’s Preterm Prediction Study; a multicenter prospective cohort study designed to identify risk factors of preterm birth (PTB). The study group consisted of women with a singleton gestation that at their first study visit (23–24 weeks) had at least one of the following criteria: patient reported contractions, severe back pain, a cervical length <15?mm, spotting, protruding membranes, or positive fetal fibronectin. Women were assessed for AR at a 27- to 29-week study visit. Associations between AR and preterm delivery (<37 weeks) were examined through logistic regression models before and after adjustment for confounders.

Results: Of the 1086 women that met the inclusion criteria, 16.5% (n?=?179) delivered preterm. In this cohort, 9.7% (n?=?105) of women were recommended AR, with 37.1% (n?=?39) having a PTB. In the group not recommended AR (n?=?981), 14.3% (n?=?140) delivered preterm.

Conclusion: In this cohort of women at high risk for PTB, activity restriction was associated with an increased risk of PTB. The use of AR in this population should be discouraged.