Association of family history with incidence and gestational hypertension outcomes of preeclampsia

BACKGROUND: Gestational hypertension and preeclampsia are hypertensive disorders related to pregnancy that can cause maternal morbidity and fetal growth retardation. The association of these disorders with family history remains unclear. OBJECTIVES: To examine the degree of family aggregation of preeclampsia and gestational hypertension in Taiwan. METHODS: The study was conducted using the data from the National Health Insurance Database of Taiwan. Delivery events in Taiwan from 1999 to 2013 were collected. Preeclampsia was identified based on the hospital diagnosis of index delivery. The family aggregation pattern of preeclampsia was assessed and analyzed using the relationship registered in the database with the patients. RESULTS: A total of 60,314 preeclampsia events were identified among 4,091,641 deliveries, accounting for 1.5% of the cohort. The incidence of preeclampsia increased with maternal age. A total of 768 preeclampsia events occurred in mothers who had a sororal history of preeclampsia (n = 20,704), accounting for 1.3% of all preeclampsia events (n = 60,314). Mothers who had a sororal history of preeclampsia had a relative risk (RR) of 2.6 (95% confidence interval [CI]: 2.41–2.80) for preeclampsia compared with mothers who did not have a sororal history of preeclampsia. The RR for gestational hypertension was 2.79 (95% CI: 2.36–3.3) in mothers with a positive sororal history of gestational hypertension. CONCLUSIONS: Having a sororal history of preeclampsia was a strong risk factor for preeclampsia and gestational hypertension in mothers in Taiwan. The pattern of family aggregation was similar at all maternal ages.