Cardiotocography alone vs. cardiotocography with ST segment analysis for intrapartum fetal monitoring in women with late-term pregnancy. A randomized controlled trial.

OBJECTIVES: Randomized studies have obtained conflicting results regarding the usefulness of fetal electrocardiographic (ECG) ST-segment analysis, possibly because these studies included non-homogeneous populations. We designed a study to determine whether this monitoring technique is potentially useful for populations at risk for fetal heart rate alterations during labor, i.e. groups of women who share late-term pregnancy as a risk factor. STUDY DESIGN: This randomized clinical trial recruited women whose pregnancy had lasted more than 290 days. The participants were randomly assigned to continuous fetal cardiotocographic monitoring alone (CTG group) or with fetal ECG ST-segment analysis (ECG-F group). In the CTG group fetal heart rate was interpreted according to guidelines from the National Institute of Child Health and Human Development, whereas in the ECG-F group the tracings were interpreted according the original International Federation of Gynecology and Obstetrics (FIGO) guidelines. The primary outcome measure was neonatal outcome, evaluated as arterial blood pH in neonates after abdominal or vaginal operative delivery indicated because of nonreassuring fetal status. RESULTS: A total of 237 women were randomized, of whom 200 were included in the final analysis (100 in each group). The rate of cesarean delivery was the same in both groups (26%), and the rate of operative delivery due to nonreassuring fetal status did not differ significantly (38% in the CTG group vs. 39% in the ECG-F group). Regarding neonatal outcomes, there was no significant difference between groups in neonatal pH (7.27 [7.23-7.29] and 7.25 [7.21-7.27]). CONCLUSIONS: In a population comprising only late-term pregnancies, fetal ECG monitoring had no benefits for the mother or fetus. Additional studies are needed of protocols for using ST waveform analysis in selected population groups.

Fetal sex and perinatal outcomes.

OBJECTIVE: To evaluate the relationship of fetal sex with obstetric risk factors and perinatal outcomes. MATERIAL AND METHODS: Retrospective study of deliveries during 2003-2009 at a tertiary hospital based on the analysis of obstetric and neonatal risk variables according to neonatal sex. RESULTS: Of the 29,530 deliveries studied, the neonate was a boy in 15,038 (50.92%) and a girl in 14,492 (49.08%). The rates of gestational diabetes, prematurity, true umbilical cord knot and nuchal cord were higher for male newborns, whereas the rate of echographic diagnosis of intrauterine fetal growth retardation was higher for female newborns. Mothers of male fetuses had higher rates of cesarean delivery and instrumental vaginal delivery. The indication for ending labor due to the non-reassuring fetal heart rate was also more frequent among male newborns. This group had higher rates of acidemia, although there were no significant differences between sexes in other short-term neonatal outcomes. In all subgroups analyzed here, fetal weight was higher in male newborns. CONCLUSIONS: Male sex is an independent risk factor for unfavorable outcomes of pregnancy and delivery.