Complexities surrounding the diagnosis and management of hypercalcaemia in pregnancy

SUMMARY: Hypercalcaemia in pregnancy is uncommon, with associated adverse obstetric and perinatal outcomes for both the mother and the fetus. Determination of causality is central to its management. Diagnostic imaging techniques are limited during pregnancy and the diagnosis is made more complex by physiological changes in calcium and vitamin D homeostasis in pregnancy. Further, therapeutic options are limited due to safety considerations for the pregnant woman and the developing foetus. Three cases of hypercalcaemia in pregnancy will be presented, highlighting the distinct aetiologies and management strategies for hypercalcaemia in pregnancy and the importance of early measurement of serum calcium in pregnancy screening. LEARNING POINTS: There are complex physiological changes in calcium balance in pregnancy, including increased calcium intestinal absorption and renal excretion. Hypercalcaemia in pregnancy is uncommon but has important potential maternal and foetal complications, making a compelling argument for routine antenatal, calcium screening. Identifying the cause of hypercalcaemia in pregnancy can be challenging due to the complex placental interplay in biochemical test interpretation and due to safety constraints restricting imaging and surgery. Acute medical management of hypercalcaemia must be considered in the context of both maternal and foetal well-being, along with gestational age and specific consideration for the safety of the developing fetus in late gestation.