Women with chronic hypoparathyroidism have low risk of adverse pregnancy outcomes.

OBJECTIVE The aim of this study was to evaluate pregnancy outcome and total number of births in chronic hypoparathyroidism (hypoPT). PATIENTS The Swedish National Patient Register, The Swedish Prescribed Drug Register, Swedish Medical Birth Register and the Total Population Register were used to identify 97 women with chronic hypoPT and 1030 age-matched controls who delivered 139 and 1577 singleton infants, respectively, following diagnosis between 1997 and 2017. RESULTS Women in the chronic hypoPT group had more frequent diabetes (DM) and chronic kidney disease (CKD) compared to women in the control group (p=0.043 and p<0.001, respectively). After adjusting for DM, CKD, maternal age at delivery and calendar year of delivery, chronic hypoPT cases were associated with increased risk of induction of labor (OR 1.82; 95% CI 1.13-2.94) and giving birth to infants with lower birth weight (β-coefficient -188 g; 95% CI -312.2- -63.8) compared to controls. No difference was found in infant length, small for gestational age or head circumference after adjustments. Mean gestational age at delivery after controlling for DM, CKD and pre-eclampsia, was not significantly younger (p=0.119). There was no difference in congenital malformations or perinatal death. There was no difference in the total number of infants born to women with chronic hypoPT and controls (p=0.518). CONCLUSION The majority of women with chronic hypoPT had normal pregnancy outcomes, and the overall risks appear to be low. Maternal chronic hypoPT, is however, associated with a higher risk of induction of labor and slightly lower infant birth weight.