Vitamin D Deficiency Is Associated With Poor Ovarian Stimulation Outcome in PCOS but Not Unexplained Infertility

The impact of vitamin D deficiency on the success of ovarian stimulation according to underlying infertility diagnosis has not been investigated.

To evaluate the relationship between vitamin D deficiency and reproductive outcomes after ovarian stimulation in women with either polycystic ovary syndrome (PCOS) or unexplained infertility.

Retrospective cohort study.

Analysis of randomized controlled trial (RCT) data.

Participants from the Pregnancy in Polycystic Ovary Syndrome II (PPCOS II) RCT (n = 607); participants from the Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) RCT of unexplained infertility (n = 647).

Serum 25(OH)D levels measured in banked sera.

Primary: live birth; secondary: ovulation (PPCOS II), pregnancy, and early pregnancy loss.

In PPCOS II, subjects with vitamin D deficiency [25(OH)D < 20 ng/mL or 50 nmol/L] were less likely to ovulate (adjusted OR, 0.82; 95% CI, 0.68 to 0.99; P = 0.04) and experienced a 40% lower chance of live birth (adjusted OR, 0.63; 95% CI, 0.41 to 0.98; P = 0.04) than those not deficient. In AMIGOS, no significant association between vitamin D deficiency and live birth was noted. In pregnant subjects from both studies, vitamin D deficiency was associated with elevated risk of early pregnancy loss (OR, 1.6; 95% CI, 1.0 to 2.6; P = 0.05).

In this investigation of women pursuing ovarian stimulation, the association between vitamin D deficiency and diminished live birth relied on carrying the diagnosis of PCOS and was not observed in unexplained infertility. Given the generally modest success of ovarian stimulation, addressing vitamin D deficiency may prove an important treatment adjunct for many infertile women.