Does amniotic fluid sludge result in preterm labor in pregnancies after assisted reproduction technology? A nested Case-Control study

Objective to investigate the relationship between the Amniotic fluid Sludge exposure during pregnancy and the Preterm Labor (PTL) in pregnant women who had undergone Assisted Reproductive Technology procedures (ART) in Royan institute. Materials and methods It was a nested case-control study that was conducted on 110 eligible pregnant women who had undergone IVF procedure in Royan institute, Tehran, Iran. The final sample size was 63 subjects with Amniotic fluid Sludge and 67 subjects with normal Amniotic fluid. Delivery before 37 of gestation was considered as PTL. The study was approved by the ethics committee of the Royan institute and the written consent form was filled by participants. Data was entered to the SPSS (version 21, SPSS, Inc.). The baseline characteristics of the participants were described as absolute (n) and relative (%) frequencies for the covariates. Man Whitney and T-Test were used to compare the mean of covariates and the P-value lower than 0.05 was considered significant. The prevalence of the PTL was compared between two groups. Results The mean Gestational Age at delivery in case and control group were 36.46 +/- 3.45 and 38.03 +/- 1.61, respectively which was significant (p = .01). The prevalence of PTL in case and control group were 23.8% and 10.4% respectively which was significant (p = .04). The percentage of cases with cervical length less than 30 (mm) in case and control group were 28.6% and 10.4%, respectively (p = .008) and the percentage of cerclage in case and control group were 33.3% and 7.5% respectively, (p = .00) which were significant statistically. Conclusion The amniotic fluid sludge has a direct effect on the cervical length of pregnancies after ART. In such cases, PTB will be probable in the presence of sludge in spite of preventive treatments such as cerclage.

Automated summary

The study revealed that exposure to amniotic fluid sludge during pregnancy increases the risk of preterm labor in women who have undergone assisted reproductive technology. It may also impact cervical length and predispose to preterm birth even with preventive treatments such as cerclage.