Cervical length and the risk of microbial invasion of the amniotic cavity in women with preterm premature rupture of membranes.

The aims of this study were to determine whether sonographically measured cervical length is of value in the identification of microbial invasion of the amniotic cavity in women with preterm premature rupture of membranes (PPROM) and to compare its performance with maternal blood C-reactive protein (CRP), white blood cell count (WBC), and amniotic fluid (AF) WBC. This prospective observational study enrolled 50 singleton pregnancies with PPROM. Transvaginal ultrasound for measurement of cervical length was performed and maternal blood was collected for the determination of CRP and WBC at the time of amniocentesis. AF obtained by amniocentesis was cultured and WBC determined. The prevalence of a positive amniotic fluid culture was 26% (13/50). Patients with positive amniotic fluid cultures had a significantly shorter median cervical length and higher median CRP, WBC, and AF WBC than did those with negative cultures. Multiple logistic regression indicated that only cervical length had a significant relationship with the log odds of a positive AF culture. Transvaginal sonographic measurement of cervical length is valuable in the identification of microbial invasion of amniotic cavity in women with PPROM. Cervical length performs better than AF WBC, maternal blood CRP, and WBC in the identification of a positive amniotic fluid culture.

Relationship between twin-to-twin delivery interval and umbilical artery acid-base status in the second twin.

The purpose of this study was to determine the effect of twin-to-twin delivery interval on umbilical artery acid-base status of the second twin at birth. This was a retrospective cohort study of all live-born twins with measured acid-base status in umbilical arterial blood who were delivered after 34 weeks' gestation from June 2003 to February 2006. Twins with any maternal or fetal complications were excluded. Subjects were divided into two groups based on the mode of delivery of the first twin: normal cephalic vaginal deliveries (n=40) or cesarean deliveries (n=67). The inter-twin differences in umbilical arterial blood pH, PCO(2), PO(2), and base excess in twin newborns born vaginally were significantly greater than the corresponding differences in those born by cesarean section. A significant positive correlation was found between twin-to-twin delivery interval and inter-twin difference in umbilical arterial blood pH in twin newborns born vaginally. The umbilical arterial blood pH of the second twin was less than 7.0 in 14% (2/14) in cases delivered more than 20 min after the first twin. The umbilical arterial blood gas status of the second twin worsened with increasing twin-to-twin delivery interval, and pathologic fetal acidemia (pH<7.0) might develop in the second twin when the twin-to-twin delivery interval was greater than 20 min.

Prediction of prolonged pregnancy in nulliparous women by transvaginal ultrasonographic measurement of cervical length at 20-24 weeks and 37 weeks.

This study was done to evaluate transvaginal ultrasonographic measurement of cervical length at 20 to 24 weeks and 37 weeks as a predictor of prolonged pregnancy (defined as a pregnancy that extended beyond 41+2 weeks of gestation [289 days]) in nulliparous women. This prospective observational study enrolled 149 consecutive nulliparous women with singleton gestation at 37 weeks. Cervical length was measured by transvaginal ultrasonography at 20 to 24 weeks and 37 weeks. Cervical length at 37 weeks, but not at 20 to 24 weeks, was significantly longer in women delivered at >41+2 weeks than in those delivered at