Is low vitamin D status in pregnancy associated with adverse outcomes? ：a prospective cohort study

Abstract

Objectives: The relative contributions of vitamin D status to pregnancy complications are not fully understood. We investigated the correlation between vitamin D status and pregnancy outcomes. Design: Prospective analysis of cases Setting: China Population or Sample: A total of 1766 pregnant women admitted to The Eighth Affiliated Hospital, Sun Yat-sen University and Guangdong Women and Children Hospital between January 2019 and December 2020. Methods: This prospective cohort study was performed on women who paid antennal visits during their whole gestation. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were measured among women before 24 weeks of gestation. Associations between maternal vitamin D status, maternal characteristics, and pregnancy outcomes were assessed. The adjusted odds ratio (OR) for adverse pregnancy outcomes was calculated using the logistic regression analysis. Results: Among all the participants ,192(10.87%), 1023(57.93%) and 551(31.20%) were defined as vitamin D sufficiency, insufficiency, and deficiency, respectively. There was no significant difference in vitamin D between pregnant women with adverse pregnancy outcomes and those without adverse pregnancy outcome. Neither vitamin D deficiency nor insufficiency was associated with adverse pregnancy outcomes compared with vitamin D sufficiency. Risks of adverse outcomes were as follows: GDM (OR=0.72 95%CI 0.46-1.14; OR=0.86 95%CI 0.57-1.30), SGA (OR=1.38 95%CI 0.73-2.60; OR=1.28 95%CI 0.70-2.34), early preterm delivery (OR=0.59 95%CI 0.13-2.70; OR=0.84 95%CI 0.23-3.00), PE (OR=3.44 95%CI 0.43-27.52; OR=2.40 95%CI 0.31-18.50), and postpartum hemorrhage (OR=0.58 95%CI 0.33-1.03; OR=0.81 95%CI 0.49-1.35). Conclusions: Low vitamin D status may not be associated with adverse pregnancy outcomes. Vitamin D screening in all pregnant women seems not reasonable.