Hyperparathyroidism is rarely encountered in pregnancy; however, the consequence of untreated disease can be significant for both the mother and fetus (increased risk of miscarriage, IUGR, pre-eclampsia, neonatal hypocalcaemia). NICE guidance (May 2019) on the management of PHPT strongly recommends disease control pre-pregnancy, MDT working and offering surgery if cCa is above 2.85 mmol/l. We report a 31-year-old P4 who was referred to our joint endocrine/obstetric clinic at 12 weeks gestation with a history of hypercalcaemia. Two years prior shed been found to have cCa of 2.7 mmol/l and PTH of 8.1 pmol/l, but unfortunately was lost to follow-up. Interestingly shed had 2 early miscarriages since hypercalcaemia detection. She was counselled regarding the risks and advised to avoid dehydration, commence aspirin, undergo regular growth scans and have monthly calcium monitoring. She had negative genetic testing for FHH and PHPT was confirmed. She was asymptomatic and her cCa remained 2.662.76 mmol/l, until a few weeks pre-delivery when it rose to 2.85 mmol/l, so she was not referred for surgery. Her baby interestingly had raised, rather than expected reduced, calcium levels of 3.05 mmol/l and was treated with IV fluids and low calcium formula combined with breast feeding. Postnatally the patient has increased renal stone load and is awaiting both urology and endocrine surgical input, her adjusted calcium fell to 2.62 mmol/l with a PTH of 7 pmol/l during breastfeeding.
Discussion: Antenatally our patient had cCa level <2.85 mmol/l, but it was highest just before delivery. It is thought that active placental transfer of calcium at this stage resulted in the raised level in her daughter. Unfortunately, several opportunities for prenatal counselling and treatment were missed and may have contributed to previous lower birthweight children, miscarriage history and hypercalcaemia seen in her daughter.