Maternal serum vitamin D levels at 11-13 weeks of gestation in preeclampsia.

This study is aimed to determine whether the maternal serum levels of vitamin D in the first trimester of pregnancy are altered in cases that develop preeclampsia (PE) and whether the levels are related to biochemical and biophysical markers of impaired placental perfusion and function. Maternal total serum vitamin D, pregnancy-associated plasma protein-A (PAPP-A), uterine artery pulsatility index (PI) and mean arterial pressure (MAP) were measured at 11-13 week gestation in 90 cases that developed PE, including 30 that required delivery before 34 weeks (early PE) and 1000 unaffected controls. The median values of vitamin D, PAPP-A, uterine artery PI and MAP expressed as a multiple of the unaffected median (MoM), in the patients developing early PE and late PE were compared with the controls. There was no significant difference in the median serum vitamin D MoM or raw values within the outcome groups (P=141 and P=0.231, respectively) whereas the median PAPP-A MoM, uterine PI MoM and MAP MoM were significantly different (P=0.031, P=0.001 and P<0.0001, respectively). Serum PAPP-A was decreased in both early PE and late PE (0.54 and 0.88 versus 1.03 MoM, P<0.0001 and P=0.010, respectively), MAP was increased in both early PE and late PE (1.09 and 1.06 versus 0.99 MoM, P<0.0001 and P<0.0001, respectively) and uterine artery PI was increased in early PE but not in late PE (1.32 and 1.12 versus 1.01 MoM, P<0.0001 and P=0.083, respectively). In pregnancies that subsequently develop PE maternal serum total vitamin D levels at 11-13 weeks are not altered.