Primary Hyperparathyroidism in Pregnancy: Maternofetal Outcomes at a Quaternary Referral Obstetric Hospital, 2000 Through 2015

Context: Primary hyperparathyroidism (PHPT) in pregnancy has historically been associated with substantial maternofetal morbidity and mortality rates. The optimal treatment and timing of surgical intervention in pregnancy remain contested.

Objective: To compare maternofetal outcomes of medically and surgically treated patients with PHPT in pregnancy.

Design: Retrospective chart review.

Setting: Quaternary referral hospital.

Patients: Women with PHPT in pregnancy treated between 1 January 2000 and 31 December 2015.

Interventions: Medical therapy or parathyroid surgery.

Main Outcomes Measured: Timing of diagnosis; maternal corrected serum calcium concentrations; gestation, indication and mode of delivery; complications attributable to PHPT; birth weight; and admission to the neonatal intensive care unit (NICU).

Results: Twenty-two pregnancies were managed medically, and six patients underwent parathyroidectomy in pregnancy (five in trimester 2, and one at 32 weeks gestation). Most patients treated medically either had a corrected serum calcium concentration <2.85 mmol/L in early pregnancy or had PHPT diagnosed in trimester 3. Of viable medically managed pregnancies, 30% were complicated by preeclampsia, and preterm delivery occurred in 66% of this group. All preterm neonates required admission to the NICU for complications related to prematurity. All surgically treated patients delivered their babies at term, and there were no complications of parathyroid surgery.

Conclusion: Maternofetal outcomes have improved relative to that reported in early medical literature in patients treated medically and surgically, but the rates of preeclampsia and preterm delivery were higher in medically treated patients. The study was limited by its retrospective design and small sample sizes.