Relationship Between Vitamin D Level and Preterm Labor in Pregnant Women in Zahedan, Iran

Abstract

Background: Preterm labor (PL) is a leading cause of perinatal morbidity and mortality. Different factors can result in preterm labor, including maternal vitamin D. Objectives: This study aimed to evaluate the level of vitamin D in pregnant women with PL. Methods: This case-control study was conducted on 156 pregnant women (52 cases with PL and 104 controls without PL) in Ali Ibn Abitaleb Hospital, Zahedan, Iran, in 2018. Results: The age was 30.92 ± 5.21 and 29.39 ± 4.86 years in the case and control groups, respectively. There were no significant (P-value > 0.05) differences between the two groups in baseline variables. Vitamin D supplement consumption (P-value = 0.128), sun exposure time (P-value = 0.304), history of admission in pregnancy (P-value = 0.608), and history of vaginal infection (P-value = 0.100) were not significantly different between the two groups. The mean vitamin D level was 30.88 and 31.93 ng/mL in pregnant women with and without PL, respectively, with no significant difference (P-value = 0.591). The mean babies' weight was significantly (P-value > 0.001) higher in the control group than in PL women (3338.75 ± 466.16 vs. 2655.76 ± 393.36 g). Conclusions: Although this study showed no association between vitamin D levels and PL, abnormal vitamin D levels might be related to PL in pregnant women with other comorbidities or risk factors.