The Impact of Secondary Hypertension in Pregnancy on Maternal and Fetal Outcomes: A 42-Month Observational Study from South India.

Objectives: To examine the prevalence, etiology, and clinical outcomes of secondary hypertension in pregnancy in a high-risk tertiary care hospital.

Study Design: This retrospective study used data from patient records between January 2015 and July 2018. Of 52,293 pregnant women admitted during this period, those with hypertension were included. Patient demographics, diagnosis of secondary hypertension, investigations, suspected etiologies of secondary hypertension, maternal and neonatal outcomes and discharge conditions were included.

Main Outcome Measures: The prevalence of secondary hypertension and causes were measured. Univariate followed by multivariate analyses were done to look for associated maternal and neonatal outcomes.

Results: Among patients with chronic hypertension in pregnancy, 13.7% had secondary causes, of which renal and cardiac causes were the commonest. The incidence of severe pre-eclampsia (40.5%) among patients with secondary hypertension was higher in patients with systolic blood pressures more than 140 mm of Hg than in those with systolic blood pressures lower than 140 mm of Hg (odds ratio [OR]: 4.92, confidence interval [CI]: 1.7-14.16, : 0.002) irrespective of etiology. Pre-eclampsia predisposed to maternal acute kidney injury (OR: 1.23, CI: 1.04-1.45, : 0.003), low birthweight (OR: 4.69, CI: 1.44-11.9, : 0.006), preterm delivery (OR: 4.69, CI: 1.78-12.34, : 0.001), and neonatal death (OR: 5.19, CI: 0.97-27.6, : 0.04).

Conclusion: The prevalence of hypertension in pregnancy was 10.3%; among them, the prevalence of secondary hypertension was 1.46%. Uncontrolled secondary hypertension was associated with poor maternal and neonatal outcomes. Strict control of blood pressure in secondary hypertension in pregnancy ensured better outcomes.