Women With Chronic Hypoparathyroidism Have Low Risk of Adverse Pregnancy Outcomes

Context There are scarce data on the management of chronic hypoparathyroidism (hypoPT) in pregnant women. Objective The aim of this study was to evaluate pregnancy outcome and total number of births in maternal chronic hypoPT. Methods 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 with 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 birth of infants with lower birth weight (β-coefficient −188 g; 95% CI, −312.2 to −63.8) compared with 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 and no difference in the total number of infants born between groups (P = 0.518). Conclusion The majority of women with chronic hypoPT had normal pregnancy outcomes, and the overall risks appear low. Maternal chronic hypoPT is, however, associated with higher risk of induction of labor and slightly lower infant birth weight.