[Cervical length as a predictor of the latent period and infection in preterm premature membranes rupture].

Purpose: To verify cervical length using transvaginal ultrasonography in pregnant women between 28 and 34 weeks of gestation, correlating it with the latent period and the risk of maternal and neonatal infections.

Methods: 39 pregnant women were evaluated and divided into groups based on their cervical length, using 15, 20 and 25 mm as cut-off points. The latency periods evaluated were three and seven days. Included were pregnant women with live fetuses and gestational age between 28 and 34 weeks, with a confirmed diagnosis on admission of premature rupture of membranes. Patients with chorioamnionitis, multiple gestation, fetal abnormalities, uterine malformations (bicornus septate and didelphic uterus), history of previous surgery on the cervix (conization and cerclage) and cervical dilation greater than 2 cm in nulliparous women and 3 cm in multiparae were excluded from the study.

Results: A <15 mm cervical length was found to be highly related to a latency period of up to 72 hours (p=0.008). A <20 mm cervical length was also associated with a less than 72 hour latency period (p=0.04). A <25 mm cervical length was not found to be statistically associated with a 72 hour latency period (p=0,12). There was also no significant correlation between cervical length and latency period and maternal and neonatal infection.

Conclusion: The presence of a short cervix (<15 mm) was found to be related to a latency period of less than 72 hours, but not to maternal or neonatal infections.