Primary hyperaldosteronism (PHA) is an increasingly identified secondary cause of hypertension. Literature regarding pregnancies in women with PHA have demonstrated poor maternal and fetal outcomes.
We conducted a case-control study to compare the maternal and fetal outcomes of women with PHA (diagnosed pre or post index pregnancy) to matched women at a large metropolitan network of hospitals. Women with PHA were identified from a postnatal database (2015-20) and their matched (1:1) controls from a database of high risk women enrolled in a previous study (2017-19) known not to have PHA. Cases were matched for age, body mass index (BMI), booking blood pressure and where possible parity. Only women with a positive salt infusion test, singleton pregnancy and who delivered after 20 weeks gestation were included. Preeclampsia was defined by SOMANZ criteria and growth restriction as gestation adjusted fetal weight less than the 5th centile. Data analyzed with SPSS v27.
Forty women were included (20 PHA and 20 controls) with no differences in age, BMI, booking blood pressure or parity. Women with PHA took a greater number of pre-pregnancy anti-hypertensive medications (4 taking epleronone)(1 medication vs 0.5 medication,p=0.01) but were equally prophylaxed with aspirin and/or calcium for preeclampsia (95%vs70%,p=0.09). There was no difference in the overall rate, preterm or late preeclampsia (p<0.05 for all). Women with PHA delivered earlier (38vs38.5wks,p=0.02) than controls and their babies were more likely to be admitted to neonatal intensive care (50%vs15%,p=0.04). There was no difference in the women’s length of stay during their delivery admission or method of delivery. Women with PHA took more antihypertensive during pregnancy and post-partum (p=0.001).
Women with PHA require more medication before, during and after pregnancy than other high risk populations. The BMI, booking blood pressure and preeclampsia prophylaxis are better predictors than the PHA for adverse maternal or fetal outcomes.