Association between unexplained recurrent pregnancy loss history and adverse neonatal outcomes among infertile women...

Does maternal history of unexplained recurrent pregnancy loss (RPL) increase the risk for adverse neonatal outcomes after assisted reproductive technology (ART)?

Embryo transfer cycles with singleton live births (n = 37,703) were included from three fertility centres between 2014 and 2021. Infertile patients were divided into three groups according to their pregnancy loss history: two or more; one; and none (control group). A range of neonatal outcomes were followed up by telephone interviews using standardized questionnaires. Multivariate logistic regression analysis was used to control for potential confounders, and subgroup analyses were conducted for primary and secondary RPL.

A total of 925 patients experienced RPL (one pregnancy loss n = 3466; no pregnancy losses after exclusion n = 33312). Compared with the patients without pregnancy loss, the RPL group had significantly higher risks of preterm birth (adjusted odds ratio [aOR] 1.25, 95% CI 1.01 to 1.56) and low birth weight (aOR 1.32, 95% CI 1.00 to 1.74). No significant associations were observed between RPL and other neonatal outcomes. Patients who had experienced only one loss had no increased risk of adverse neonatal outcomes versus those without losses. In subgroup analyses, no differences in neonatal outcomes were observed between the primary and secondary RPL.

Among infertile patients undergoing ART, a history of unexplained RPL was associated with an increased risk of preterm birth and low birth weight in neonates. Absolute risk increments were small, and the clinical significance of these findings should be interpreted with caution.