[Feasibility study of expectant management of different degrees of vaginal fluid in pregnant women with premature rupture of membranes in the second trimester]

Objective: To investigate the feasibility of expectant management of different degrees of vaginal fluid in pregnant women with premature rupture of membranes in the second trimester. Methods: A retrospective cohort study was conducted to collect 103 pregnant women who were diagnosed with premature rupture of membranes in the second trimester of pregnancy and insisted on continuing the pregnancy in Shanxi Bethune Hospital from July 2012 to July 2022. According to the degree of vaginal fluid, pregnant women were divided into rupture group (with typical vaginal fluid, 48 cases) and leakage group (without typical vaginal fluid, 55 cases). The rupture latency (the time from rupture of membranes to termination of pregnancy), gestational weeks of termination, indications and methods of termination of pregnancy, maternal infection related indicators and perinatal outcomes were compared between the two groups. Univariate regression model was used to analyze the correlation between different degrees of vaginal fluid in pregnant women with premature rupture of membranes and maternal and neonatal outcomes. Results: (1) Obstetric indicators: there was no significant difference in the gestational age of rupture of membranes between the two groups (P>0.05). However, the proportion of rupture latency >28 days in the leakage group was significantly higher than that in the rupture group [42% (23/55) vs 13% (6/48); χ2=33.673, P<0.001], and the incidence of pregnancy termination ≥28 weeks was significantly higher [47% (26/55) vs 19% (9/48); χ2=9.295, P=0.002]. (2) Indications and methods of termination: the incidence of progressive reduction of amniotic fluid as the indication for termination in the leakage group was significantly lower than that in the rupture group [22% (12/55) vs 42% (20/48); χ2=4.715, P=0.030], and the incidence of full-term termination in the leakage group was significantly higher than that in the rupture group [31% (17/55) vs 12% (6/48); χ2=5.008, P=0.025], while there were no significant differences in the indications of termination of pregnancy, including amniotic cavity infection, uterine contraction failure and fetal distress between the two groups (all P>0.05). The incidence of induced labor or spontaneous contraction in the leakage group was significantly lower than that in the rupture group [53% (29/55) vs 81% (39/48); χ2=9.295, P=0.002], while the cesarean section rate and vaginal delivery rate were similar between the two groups (both P>0.05). (3) Infection related indicators: the incidence of amniotic cavity infection in the leakage group was significantly higher than that in the rupture group [31% (17/55) vs 13% (6/48); χ2=4.003, P=0.045]. However, there were no significant differences in the elevation of inflammatory indicators, the positive rate of cervical secretion bacterial culture and the incidence of tissue chorioamnionitis between the two groups (all P>0.05). (4) Perinatal outcomes: the live birth rate in the leakage group was significantly higher than that in the rupture group [51% (28/55) vs 27% (13/48); χ2=5.119, P=0.024]. The proportion of live births with 1-minute Apgar score >7 in the leakage group was significantly higher than that in the rupture group [38% (21/55) vs 17% (8/48); χ2=4.850, P=0.028]. However, there were no significant differences in the birth weight of live births and the incidence of neonatal complications between the two groups (all P>0.05). (5) Univariate regression analysis showed that compared with the rupture group, the leakage group had a higher risk of pregnancy termination at ≥28 gestational weeks (RR=2.521, 95%CI: 1.314-4.838; P=0.002), amniotic infection (RR=2.473, 95%CI: 1.061-5.764; P=0.025), perinatal survival (RR=1.880, 95%CI: 1.104-3.199; P=0.014). Conclusion: Compared with pregnant women with typical vaginal fluid in the second trimester of premature rupture of membranes, expectant treatment for pregnant women with atypical vaginal fluid is more feasible, which could effectively prolong the gestational weeks and improve the perinatal live birth rate.