How Risky for Pregnancies Is Having Both PCOS and GDM?

TOPLINE:
Polycystic ovary syndrome (PCOS) and gestation diabetes mellitus (GDM) are both associated with adverse pregnancy outcomes, but having the combination of the two conditions does not elevate the risks beyond that of having GDM alone, according to a cohort study of nearly 300,000 Swedish births.
METHODOLOGY:
This was a population-based retrospective cohort of 281,806 births from 1997 to 2015.
Five different Swedish registries were used to calculate the risks for adverse pregnancy outcomes adjusted for maternal characteristics.
The primary outcomes were four adverse maternal outcomes and 13 adverse neonatal outcomes.
The analysis was designed to assess whether risks, expressed as odds ratios with confidence intervals, were additive with the two conditions or interactive.
TAKEAWAY:
The study compared risks for (1) controls with neither PCOS nor GDM (n = 238,262); (2) PCOS-only risks (n = 40,272); (3) GDM-only risks (n = 2236); (4) PCOS + GDM risks (n = 1036); and (5) the interaction of PCOS + GDM.
PCOS-only carried elevated risks for two of four adverse maternal outcomes (gestational hypertension, and preeclampsia) and eight of 13 adverse neonatal outcomes (including stillbirth and spontaneous preterm birth).
The combination of PCOS and GDM is not associated with excess risks for GDM alone.For example, PCOS is linked to an 18% higher risk for preeclampsia over control participants (adjusted odds ratio, 1.18; 95% CI, 1.11-1.26), but the additive combination of PCOS and GDM (adjusted odds ratio, 1.86; 95% CI, 1.46-2.36) and the interactive combination (adjusted odds ratio, 0.89; 95% CI, 0.65-1.22) are not significantly greater than GDM-only (adjusted odds ratio, 1.77; 95% CI, 1.45-2.15).
For example, PCOS is linked to an 18% higher risk for preeclampsia over control participants (adjusted odds ratio, 1.18; 95% CI, 1.11-1.26), but the additive combination of PCOS and GDM (adjusted odds ratio, 1.86; 95% CI, 1.46-2.36) and the interactive combination (adjusted odds ratio, 0.89; 95% CI, 0.65-1.22) are not significantly greater than GDM-only (adjusted odds ratio, 1.77; 95% CI, 1.45-2.15).
IN PRACTICE
The authors concluded that even though the combined risks are not additive or multiplicative, PCOS “is still an unrecognised risk factor in pregnancy…”
SOURCE:
The lead and corresponding author is Ragnheidur Valdimarsdottir of Uppsala University, Uppsala, Sweden. The study appeared in Acta Obstetricia et Gynecologica Scandinavica.
LIMITATIONS:
Limitations included the study’s retrospective observational design.
DISCLOSURES:
Two of eight authors declared competing interests. Funding for the study came from the Perinatal Foundation and the Swedish Research Council.
 
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