Maternal Factors for Intrauterine Growth Retardation: Systematic Review and Meta-Analysis of Observational Studies

Intrauterine growth retardation (IUGR) is a major complication of pregnancy and is the second leading cause of perinatal morbidity and mortality. The etiology of IUGR is multifactorial and the maternal factors are easily identifiable and modifiable. The present study aimed to perform a meta-analysis to identify the association between various maternal factors and IUGR. Eight electronic databases (PubMed, Cochrane, Embase, CIHNAL Plus, CNKI, VIP database, CBM, and WanFang database) were searched from their inception until July 2020. Eligibility screening, data extraction, and quality assessment of the retrieved articles were conducted independently by two reviewers. The Newcastle-Ottawa Quality Assessment Form and the Joanna Briggs Institute critical appraisal tool were used to evaluate the quality of included studies. The outcomes of study were calculated by OR with 95%CI. The study protocol was registered with PROSPERO (No. CRD42020210615). A total of 15 studies were included, with a sample size range from 152 to 9372. The quality of included studies ranged from moderate to high. The pooled results identified seven factors: smoking (OR = 1.62, 95%CI 1.38-1.90), primiparity (OR = 1.64, 95%CI 1.20-2.24), and prepregnancy.BMI < 18.5 (OR = 1.98, 95%CI 1.29-3.03), anemia (OR = 2.01, 95%CI 1.44-2.82), hypoproteinemia (OR = 2.91, 95%CI 1.94-4.36), pregnancy-induced hypertension (OR = 3.45, 95%CI 1.80-6.58), and maternal gestational weight gain (OR = 2.51, 95%CI 1.88-3.35). The present study identified several maternal factors for IUGR: smoking, primiparity, prepregnancy BMI < 18.5, poor gestational weight gain, PIH, anemia, and hypoproteinemia. The result could serve to generate risk factors prediction models, improve the management and education for child-bearing or early pregnant women.