A Meta-Analysis for Association of ACE I/D Polymorphism with Susceptibility to Preterm Birth

Preterm birth is one of the main contributors to newborn mortality, morbidity, and hospitalization in the first year of life globally. To date, several numbers of studies have reported that Angiotensin-Converting enzyme Insertion/Deletion polymorphism (ACE I/D) is linked with preterm birth. But those results are conflicting. Thus, we carried out this meta-analysis to summarize the existing data and evaluated the association.

All eligible studies were collected from PubMed, Scopus, SciELO, MedRxiv, SID, China National Knowledge Infrastructure (CNKI), and Chinese Biomedical Literature Database (CBLD) up to 01 March 2021. The pooled odds ratios (ORs) and 95% confidence interval (CIs) under all five genetic models were calculated using either random-effects or fixed-effects models dependent on study heterogeneity.

A total of five case-control studies with 480 preterm birth cases and 702 healthy subjects were included. Pooled data showed that the ACE I/D polymorphism was significantly associated with increased risk of preterm birth under the allele model (I vs. D: OR = 1.219, 95% CI 1.023-1.453, P = 0.027), homozygote model (II vs. DD: OR = 0.662, 95% CI 1.149-2.385, P = 0.007), and recessive model (DD vs. DI+II: OR = 0.707, 95% CI 1.082-1.948, P = 0.013). Stratified analysis by ethnicity indicated that the ACE I/D polymorphism was significantly associated with preterm birth in Caucasian descendants.

Our pooled data revealed that ACE I/D polymorphism is associated with the risk of preterm birth. However, larger and more rigorous studies among different populations are needed to evaluate the association with preterm birth.