PURPOSE:
To describe the potential influence of amniotic fluid on the maternal outcome of preterm premature rupture of membranes (PROM).
METHODS:
An observational, retrospective cohort study was conducted between December 2012 and January 2008 on 86 pregnant women with preterm PROM and a gestational age (GA) of 24 to 35 weeks. The amniotic fluid index (AFI) was used to measure aminiotic fluid volume. Pregnant women were compared at two cut-off points: those with AFI <5.0 and ≥5.0 cm and AFI <3.0 and ≥3.0 cm. We excluded women with hypertensive disorders, diabetesmellitus, fetal malformations and a diagnosis of infections at admission. For statistical analysis, we used the χ2test or Fisher's exact test, when appropriate, and simple linear regression analysis, with the level of significance set at 5%. We calculated the Risk Ratio (RR) and its 95% confidence interval (95%CI).
RESULTS:
When maternal outcomes were assessed by comparing ILA ≥5.0versus <5.0 cm, no significant differences were detected. However, when considering ILA <3.0 and ≥3.0 cm, there was an increased risk of chorioamnionitis (36.7 versus10.7%, RR: 3.4, 95%CI 1.4 -8.3, p=0.004), with no significant differences for the other variables. There was also a statistically significant positive correlation between AFI and gestational age at delivery (R2=0.78, p<0.0001).
CONCLUSIONS:
AFI <3.0 cm causes a three-fold increase in the risk for chorioamnionitis; also, the higher the ILA, the higher the gestational age at delivery.
Amniotic fluid; Fetal membranes, premature rupture; Chorioamnionitis; Maternal welfare