Fertility and pregnancy outcomes in primary hyperparathyroidism: Observations from a large insured population.

ABSTRACT

CONTEXT Primary hyperparathyroidism (PHPT) has initially been implicated in adverse maternal and neonatal outcomes, while subsequent population studies have failed to show an association. OBJECTIVE: To compare maternal, pregnancy, and neonatal outcomes in patients with and without PHPT. DESIGN: Retrospective matched-cohort study (2005-2020). SETTING: An integrated healthcare delivery system in Southern California. PATIENTS Women aged 18-44 years were included. Patients with biochemical diagnosis of PHPT were matched 13 with eucalcemic controls (non-PHPT). MAIN OUTCOME MEASURES: Achievement of pregnancy, pregnancy outcomes (including rates of abortion, maternal complications), and neonatal outcomes (including hypocalcemia, need for intensive care). RESULTS: The cohort comprised 386 women with PHPT and 1158 age-matched controls. Pregnancy rates between PHPT and control groups were similar (10.6% vs 12.8%). The adjusted rate ratio of pregnancy was 0.89 (95% CI 0.64-1.24) (PHPT vs non-PHPT). Twenty-nine pregnancies occurred in women with co-existing PHPT and 191 pregnancies occurred in controls, resulting in 23 (79.3%) and 168 (88.0%) live births, respectively (p=0.023). Neonatal outcomes were similar. Live birth rates were similar (86.4%, 80%, 79.2%) for those undergoing parathyroidectomy prior (n=22), during (n=5), or after pregnancy/never (n=24). Among patients who underwent parathyroidectomy during pregnancy, no spontaneous abortions occurred in women entering pregnancy with peak calcium <11.5 mg/dL [2.9 mmol/L]. CONCLUSIONS: We observed no difference in pregnancy rates between women with or without PHPT. Performing parathyroidectomy before pregnancy or during the second trimester appears to be a safe and successful strategy, and adherence to this strategy may be most critical for patients with higher calcium levels (≥11.5 mg/dL [2.9 mmol/L]).