Second stage of labor and intraventricular hemorrhage in early preterm infants in the vertex presentation.

OBJECTIVE: To investigate the association between exposure to second stage of labor and duration of second stage, and risk of intraventricular hemorrhage (IVH) among infants delivered <30 weeks of gestation. METHODS: We conducted a retrospective cohort study among 158 singleton vertex deliveries (97 vaginal and 61 cesarean). Multivariable logistic regression was used to evaluate the risk of IVH related to second stage. RESULTS: Infants exposed to second stage as compared to those not exposed to second stage irrespective of their mode of delivery had increased risk of mild IVH (odds ratio [OR] 2.69; 95% confidence interval [CI] 1.15, 6.29) but not of severe IVH (OR 1.14; 95% CI 0.33, 3.84). No relation with risk of mild (OR 0.98; 95% CI 0.95, 1.01) and severe (OR 1.00; 95% CI 0.95, 1.05) IVH was observed for each 1 min increase in duration of second stage. We also observed no significant association between quartiles of duration of second stage and risk of mild (p = 0.20) and severe (p = 0.29) IVH. We did not observe any significant interaction by gestational age, chorioamnionitis, birth weight or presenting complaint on admission. CONCLUSION: The risk of mild IVH was increased in those exposed to a second stage of labor. However, no clear association was observed between duration of second stage and mild or severe IVH.

Concentrations of serum total activin A and inhibin A in preterm and term labor patients: a cross-sectional study.

OBJECTIVE: To compare maternal serum levels of total activin A and inhibin A in preterm and term patients who are in labor or not in labor. METHODS: A cross-sectional study compared activin A and inhibin A in the following groups of patients: preterm and in labor (n = 65), preterm and not in labor (n = 96), term and in labor (n = 65), and term and not in labor (n = 65). Preterm was defined as 23-34 weeks' gestation and term as 37-42 weeks' gestation. Labor was defined as regular contractions with progressive cervical change or an initial examination revealing cervical dilation of 1-3 cm with 50% effacement or more. Follistatin levels were analyzed in a subset of 12 patients from each group. Analytes were measured by two-site enzyme-linked immunosorbent assays. RESULTS: Activin A levels were higher in the preterm labor group (median 1.38 multiples of the median [MoM], interquartile range [IQR] 1.01 MoM) compared with the preterm nonlabor group (median 1.0 MoM, IQR 0.78 MoM, P <.05) and in the term labor group (median 1.37 MoM, IQR 1.74 MoM) compared with the term nonlabor group (median 1.0 MoM, IQR 0.87 MoM, P <.05). Inhibin A levels were higher in the preterm labor group (median 1.27 MoM, IQR 0.73 MoM) compared with the preterm nonlabor group (median 1.0 MoM, IQR 0.58 MoM, P <.05). Post-hoc analysis of activin A and inhibin A elevations in the preterm labor group revealed a significant effect only during 31-34 weeks' gestation. The total activin A:follistatin ratio, an indirect measure of free activin A, was similar between labor and nonlabor gestational age-matched patient groups. CONCLUSIONS: Levels of total activin A and inhibin A were increased in patients during labor; however, based on the moderate degree and narrow gestational age range of the increased levels, these analytes are not likely to be clinically useful in predicting preterm labor.