The relationship between maternal vitamin D deficiency and glycolipid metabolism and adverse pregnancy outcome.

OBJECTIVE: Maternal vitamin D deficiency is associated with glucose and lipid metabolism in the mother and offspring. Meanwhile, it can also lead to adverse pregnancy outcomes. The aim of this case-control study was to document maternal, umbilical arterial glucose and lipid metabolic levels and correlations in pregnancies with or without vitamin D deficiency, while also investigating adverse pregnancy outcomes.

DESIGN/PARTICIPANTS/MEASUREMENTS: A total of 425 pregnant women who received antenatal care and delivered at Wenzhou People's Hospital were enrolled. According to their serum 25-hydroxyvitamin D [25(OH)D] level, the pregnant women were divided into the vitamin D deficiency group [25(OH)D < 20 ng/mL, 185 participants] and the control group [25(OH)D ≥ 20 ng/mL, 240 participants]. Maternal blood samples were collected at 24~28 weeks of gestation and delivery for 75-g oral glucose tolerance test (OGTT), and measurements of glucose and lipid metabolite levels and 25(OH)D levels. Umbilical arterial samples were collected during delivery (33.57~41.43 gestational weeks).

RESULTS: Compared with control participants, vitamin D deficiency women had significantly higher concentrations of fasting blood-glucose (P < 0.01), 1-h OGTT plasma glucose (P < 0.01), 2-h OGTT plasma glucose (P < 0.01), insulin (P < 0.01), HOMA-IR (P < 0.01), LDL (P < 0.01), and triglycerides (P = 0.02) and lower concentrations of HOMA-S (P < 0.01). Compared with the control group, vitamin D deficiency women had higher concentrations of triglycerides (P < 0.01) and lower concentrations of HDL-C (P < 0.01) and HOMA-β (P = 0.01) in infant umbilical arterial blood. Pearson's correlation analysis demonstrated that the maternal 25(OH)D level was negatively correlated with maternal plasma glucose, insulin, LDL-C, cholesterol, triglyceride, and HOMA-IR (r = -0.38, -0.27, -0.2, -0.11, -0.11, -0.33, and 0.11; P < 0.01, < 0.01, < 0.01, < 0.05, < 0.05, and < 0.01, respectively), while there was a positive correlation between maternal serum 25(OH)D and HOMA-S (r = 0.11, P < 0.05). The triglyceride level in the umbilical artery was negatively correlated with maternal serum 25(OH)D concentration (r= -0.286, P < 0.01), while the HDL-C and HOMA-β in umbilical artery were positively related (r = 0.154, 0.103, P < 0.01). Compared with the control group, the incidences of preeclampsia [4.8% (9/185) vs 1.25% (3/240), P = 0.03], gestational diabetes mellitus [19.45% (36/185) vs 12.08% (29/240), P = 0.04], and premature rupture of membranes [15.68% (29/185) vs 5.42% (13/240), P < 0.01] were higher in the vitamin D deficiency group.

CONCLUSION: Vitamin D deficiency during pregnancy is associated with maternal glucose and lipid metabolism and pregnancy outcomes. Therefore, it is worth recommending to maintain maintain vitamin D status at an optimal level in pregnant women to prevent metabolic disorders and pregnancy complications.