The role of uterine closure in the risk of uterine rupture.

OBJECTIVE: To evaluate the effects of prior single-layer compared with double-layer closure on the risk of uterine rupture. METHODS: A multicenter, case-control study was performed on women with a single, prior, low-transverse cesarean who experienced complete uterine rupture during a trial of labor. For each case, three women who underwent a trial of labor without uterine rupture after a prior low-transverse cesarean delivery were selected as control participants. Risk factors such as prior uterine closure, suture material, diabetes, prior vaginal delivery, labor induction, cervical ripening, birth weight, prostaglandin use, maternal age, gestational age, and interdelivery interval were compared between groups. Conditional logistic regression analyses were conducted. RESULTS: Ninety-six cases of uterine rupture, including 28 with adverse neonatal outcome, and 288 control participants were assessed. The rate of single-layer closure was 36% (35 of 96) in the case group and 20% (58 of 288) in the control group (P<.01). In multivariable analysis, single-layer closure (odds ratio [OR] 2.69; 95% confidence interval [CI] 1.37-5.28) and birth weight greater than 3,500 g (OR 2.03; 95% CI 1.21-3.38) were linked with increased rates of uterine rupture, whereas prior vaginal birth was a protective factor (OR 0.47; 95% CI 0.24-0.93). Single-layer closure was also related to uterine rupture associated with adverse neonatal outcome (OR 2.89; 95% CI 1.01-8.27). CONCLUSION: Prior single-layer closure carries more than twice the risk of uterine rupture compared with double-layer closure. Single-layer closure should be avoided in women who could contemplate future vaginal birth after cesarean delivery. LEVEL OF EVIDENCE: II.

A randomized cross over trial of tolerability and compliance of a micronutrient supplement with low iron separated from calcium vs high iron combined with calcium in pregnant women [ISRCTN56071145].

BACKGROUND: Prenatal micronutrient combinations with high iron content are associated with high rates of gastrointestinal symptoms. This coupled with nausea and vomiting of pregnancy results in women often discontinuing their multivitamins. A new prescription supplement (PregVit) that separates iron from calcium in two tablets--morning and evening, has lower elemental iron content (35 mg), but results in similar extent of iron absorption when compared to another supplement containing (60 mg) of elemental iron (Materna). The objectives of this study were to compare tolerability and compliance with PregVit vs. a supplement with high iron content (Materna), in pregnant women. METHODS: Randomized, crossover open labeled study in 135 pregnant women attending outpatient clinics in Ontario and Quebec. RESULTS: Use of PregVit was associated with a 30% reduction in constipation rate as compared to Materna. Both products demonstrated similar compliance rates. Compliance of Materna was negatively associated with the severity of nausea and vomiting of pregnancy. No such correlation was found for PregVvit. CONCLUSION: PregVit, a supplement with lower iron content (35 mg), has significantly decreased constipation rates as compared to 60 mg iron--Materna and has similar compliance rates. High iron content in multivitamin supplements is associated with adverse effects in pregnancy.