#3855 Pregnancy outcomes in chronic hypertensive patients with superimposed preeclampsia: a nephrology outpatient experience

Abstract Background Chronic or pregestational hypertension affects 5%–10% of pregnancies and is associated with adverse maternal and neonatal events. Hypertension in pregnancy is associated with an increased risk of premature birth, low birth weight, and small-for-gestational-age newborns, especially due to a superimposed preeclampsia (PE). Up to 25% of women with chronic hypertension develop PE. Aims To evaluate pregnant women with chronic hypertension followed by a nephrology outpatient clinic and describe those who develop superimposed PE. Method Observational, descriptive, retrospective cohort study of 45 patients with chronic hypertension followed the nephrology hypertension-pregnancy clinic from 2017 to 2022. We analyzed the association between PE and clinical variables using Chi-square, Student's t-test, and ANOVA or their non-parametric equivalents. Results Mean age 36 years +/– 5.8. Caucasian race: 82% (n:37). Comorbidities: smokers (20%, n:9), type 2 Diabetes (8.9%, n:4), chronic hypothyroidism (8.9%, n:4), A family history of hypertension was present in 61.7% (n:21). Obstetric history revealed prior pregnancies in 68.9% (n:31), abortions (48.8%, n:22), and prior PE in 16.1% (n:5). Current pregnancy: first pregnancy (31.11%, n:14), multiple gestation (8.89%, n:4). Assisted reproduction (17.8%, n:8), Gestational diabetes (9.7% n:3). In the table, we compare patients with added PE versus those without it. 20 patients were previously receiving treatment, the most common therapies were ACE inhibitors (60%, n:12), ARBs (25%, n:5), Diuretics (10%, n:2), and B-Blockers (15%, n:1). In the third trimester, 20% (n:9) associated a second antihypertensive, the most used being Labetalol 11.1% (n:5) and 4.44% (n:2) received a third antihypertensive. Conclusion Maternal age, high BP in the first trimester, and the use of 2 or more antihypertensive drugs from the second trimester onwards are risk factors for superimposed PE in patients with chronic hypertension. Superimposed PE increases the risk of premature birth.