Impact of Perinatal Primary Hyperparathyroidism on Maternal and Fetal and Neonatal Outcomes: Retrospective Case Series.

We sought to describe the maternal, fetal, and neonatal outcomes of primary hyperparathyroidism in a contemporary setting through a retrospective case series conducted in a tertiary referral centre focused on women diagnosed with primary hyperparathyroidism prior to conception, in the antepartum period, or within 6 weeks postpartum.A retrospective chart review was conducted and data were abstracted to case report forms. Summary statistics are reported.From 2000 to 2017, 19 women (23 pregnancies) with primary hyperparathyroidism were identified. Most women (79%) were symptomatic at presentation, though often with non-specific manifestations. While 14% of pregnancies involved maternal/obstetric complications, fetal/neonatal complications were observed in 45%. Mild hypercalcemia was identified in 57% of women, with accompanying hypophosphatemia and hypomagnesemia in 46% and 36% of women, respectively. Surgical intervention was performed for 89% women, and no complications were encountered. Normal calcium levels achieved through treatment before conception did not fully eliminate adverse outcomes.Rates of perinatal complications in our series are more reassuring than the ubiquitously quoted rates from small and dated studies. The diagnosis of primary hyperparathyroidism may be easily missed during pregnancy, owing to its non-specific presentation. A high index of suspicion and measurement of ionized calcium levels is encouraged, especially for patients with excessive nausea and vomiting, nephrolithiasis, atypical presentations of hypertensive disorders, or isolated polyhydramnios. Mild degrees of calcium derangement do not preclude adverse perinatal outcomes. Surgery appears to be safe, even in the third trimester. The attenuated rate of complications noted in our series may have been the result of the high proportion of surgery, though this will require verification via meta-analysis or future prospective work.