Postpartum uterine response to oxytocin and carbetocin.

OBJECTIVE: To obtain quantitative data on uterine contractility postpartum and compare the response of intramuscular oxytocin to carbetocin. STUDY DESIGN: A prospective study using an intrauterine pressure transducer (IUPT) to measure frequency, amplitude, and duration of contractions following the administration of either oxytocin (10 U) or carbetocin (30 microg). RESULTS: The IUPT was tolerated by all subjects and generated useful data 90% of the time in most subjects (12/16). Both drugs generated hypertonic uterine activity with contractions of similar duration. However, carbetocin resulted in contractions of sustained higher amplitude and frequency and therefore higher uterine performance as expressed by Montevideo units. This uterotonic effect of carbetocin lasted for 3 hours. CONCLUSION: IUPT monitoring generated quantitative data on postpartum uterine activity. When compared to high-dose oxytocin, a low dose of carbetocin has a more prolonged effect on uterine activity both in terms of a higher amplitude and frequency of contractions.

The association between early membrane rupture, latency, clinical chorioamnionitis, neonatal infection, and adverse perinatal outcomes in twin pregnancies complicated by preterm prelabour rupture of membranes.

The objective of this study was to evaluate associations between adverse outcomes in twin pregnancies and preterm prelabour rupture of membranes (PPROM). A chart review of 246 consecutive twin pregnancies with confirmed PPROM was conducted. Regression analysis (beta [natural log of the odds ratio] and odds ratio [OR]) was performed to identify independent predictors. Two hundred and forty-six twin pregnancies, 492 liveborns, and 20 neonatal deaths. Mean (SD) PPROM gestational age (GA): 31.3 (3.8) wk; delivery GA: 32.0 (3.3) wk. PPROM < 30 wk was associated with increased parity (OR: 2.66), and log (admission leukocyte count) (OR: 9.99). Shortened latency was associated with PPROM GA (beta = -0.17) and chorioamnionitis (beta = 0.95). Neonatal sepsis was predicted by lower delivery GA (OR: 2.04). Adverse perinatal outcomes were protected against by older GA at PPROM (OR 0.53) and shortened latency (OR 0.73). It was concluded that increased leukocytosis and parity implies an infectious aetiology in earlier PPROM. Increased risk for neonatal sepsis at earlier delivery GA is consistent with gestation-dependent fetal immunocompetence. Early PPROM and long latencies were associated with increased adverse perinatal outcomes.