Risk factors for cervical insufficiency after term delivery.

OBJECTIVE: Cervical insufficiency can be unexpected in a woman with a previous term birth. Our objective was to determine what risk factors, if any, place women with a term delivery at risk for cervical insufficiency in a subsequent pregnancy. STUDY DESIGN: Demographic characteristics were collected for a cohort of women with at least 1 previous term birth followed by cervical insufficiency (subject group) and for uncomplicated multiparous women (control group). Multiparous women with cervical insufficiency (subjects; n = 49) were compared with multiparous women who were experiencing repeat term birth with no history of cervical insufficiency (control group; n = 49). RESULTS: Patients with cervical insufficiency were similar to control subjects demographically. No difference was noted in previous cervical procedures or spontaneous preterm deliveries. Multivariate logistic regression analysis identified a history of curettage (odds ratio, 4.6; 95% CI, 1.7-12.5), precipitous delivery (odds ratio, 6.8; 95% CI, 1.6-29.6), and prolonged second stage of labor (odds ratio, 24.9; 95% CI, 2.4-253) as independent predictors of cervical insufficiency. CONCLUSION: Multiparous women who experience cervical insufficiency after a term birth are more likely to have had a previous precipitous delivery, a prolonged second stage of labor, or a previous curettage compared with multiparous women who experience a repeat term birth with no cervical insufficiency.

Risk of third-trimester amniocentesis: a case-control study.

Risks of third-trimester amniocentesis are considered minimal; however, only case series have been reported. We performed a case-control study in which women undergoing third-trimester amniocentesis were matched with controls undergoing antenatal testing for similar indications to determine adverse outcomes associated with the procedure. Cases undergoing amniocentesis at > 32 weeks for fetal lung maturity assessment followed by antepartum testing with nonstress test and amniotic fluid index determination were matched with controls undergoing only antepartum testing based on gestational age at testing and maternal age. The main outcome variable was a composite occurrence of obstetric complications within 48 hours of testing, including urgent delivery, placental abruption, premature rupture of membranes (PROM), perinatal death, or Apgar score at 5 minutes < 7. Statistical analysis included Fisher's exact test and Student T-test, with P < 0.05 considered significant. A total of 167 matched pairs of patients fulfilled the study criteria. Indications for both amniocentesis and antepartum testing, which included diabetes, preterm labor, and cholestasis, were similar in the two groups. As expected, gestational age at sampling/testing (36.4 +/- 1.4 [mean +/- standard deviation] versus 36.6 +/- 1.7 weeks; P = 0.2) and maternal age (31.4 +/- 5.8 versus 31.5 +/- 6.3 years; P = 0.9) were not different between cases and controls. The rate of the main outcome variable within 48 hours of testing was 0 of 167 among cases and 1 of 167 among controls. Amniocentesis in the third trimester is not associated with increased risk of urgent delivery, placental abruption, PROM, Apgar score at 5 minutes < 7, or perinatal death within 48 hours of the procedure.