Burden and outcomes of hypertensive disorders of pregnancy in Kazakhstan: A national population-based analysis using the National Electronic Healthcare System

Introduction: Hypertensive disorders of pregnancy (HDP) remain a significant global health burden, complicating up to 16% of all pregnancies, and significantly contributing to maternal morbidity and mortality. This study aimed to analyze the epidemiology, clinical characteristics, and outcomes of HDP in Kazakhstan. Materials and methods: This population-based retrospective cohort study included all pregnant women diagnosed with HDP across Kazakhstan during the period of 6 years (2014-2019). Data from the Unified Nationwide Electronic Health System (UNEHS) were analyzed. The International Classification of Diseases (ICD) 10th edition was used for coding diagnoses. Statistical analyses assessed prevalence trends, risk factors, associated complications, and survival. Results: A total of 215,972 women with HDP were identified, with an overall prevalence of 9%, increasing from 8.2% in 2014 to 10.1% in 2019. The most common HDP subtype was gestational hypertension (52%), followed by severe and mild preeclampsia (22% and 18%, respectively). Eclampsia was the most lethal HDP subtype (adj.HR = 8.67 compared to the least lethal gestational hypertension). The median maternal age was 29.3 years (IQR 24.4, 34.7), with the majority of cases occurring in women aged 20-34 years. Cesarean delivery was performed in 19.7% of HDP cases. Complications included cephalopelvic disproportion (3.7%), premature rupture of membranes (1.5%), and postpartum hemorrhage (0.2%). Conclusion: HDP remains a huge health burden for pregnant women associated with a high proportion of cesarean delivery and increased rates of morbidity and mortality. Understanding the current situation with pregnancy complications among HDP patients highlights potential gaps in obstetric care that require further investigation. These findings provide valuable epidemiological insights to inform national policies and improve maternal health outcomes.