Amnioinfusion vs. standard management for the second trimester PPROM: a systematic review and meta-analysis of observational studies and RCTs.

Objective: This meta-analysis aims to review the effect of serial transabdominal amnioinfusion (TAI) on short-term and long-term perinatal outcomes in mid-trimester preterm premature rupture of membranes (PPROM).

Methods: Literature searches of PubMed, Web of Sciences, Scopus, and Cochrane Library were performed from their inception to April 2022. Studies comparing conventional treatment with serial TAI in women with proven PPROM at less than 26 + 0 weeks of gestation with oligohydramnios were included. Studies that included oligohydramnios due to other reasons such as fetal growth retardation or renal anomalies were excluded. Risk of bias in observational studies was assessed using the tool of the Cochrane Review group identified as risk of bias in non-randomized studies - of interventions. The risk of bias assessments for RCTs were performed according to the Cochrane risk-of-bias tool for randomized trials. An score was used to assess the heterogeneity of included studies. The analyses were performed by using random-effect model, and the results were expressed as relative risk (RR) or mean difference with 95% confidence intervals (CIs).

Results: Overall, eight relevant studies including five observational studies ( = 252; 130 women allocated to the intervention) and three RCTs ( = 183; 93 women allocated to the intervention) were eligible. The pooled latency period was 21.9 days (95% CI, 13.1-30.8) and 5.8 days (95% CI, -11.6-23.2) longer in the TAI group in the observational studies and RCTs, respectively. The perinatal mortality rate reduced in the intervention group when tested in observational studies (RR 0.68; 95% CI, 0.51-0.92), but not in RCTs (RR 0.79; 95% CI, 0.56-1.13). The rate of long-term healthy survival was higher in the children whose mothers were treated with the TAI (35.7%) than those were treated with the standard management (28.6%) (RR 1.30, 95% CI 0.47-3.60, "best case scenario").

Conclusions: The efficacy of serial TA on early PPROM associated morbidity and mortality is not attested. Additional randomized control trials with adequate power are needed.