Bayesian Modelling of the Dynamics of Preeclampsia and Blood Pressure Data of Pregnant Women

Hypertensive disorders of pregnancy pose a significant risk to maternal health, leading to high rates of maternal mortality and severe morbidity. This study aimed to jointly model the longitudinal changes in systolic and diastolic blood pressures and the time to develop preeclampsia among pregnant women. A retrospective study design was employed, collecting data from the medical charts of 549 pregnant women undergoing follow-up at Bishoftu General Hospital. Various methods, including summary statistics measures, individual profile plots, and Kaplan-Meier plots, were used to explore the data. Joint Bayesian multivariate models were employed to obtain inferences of progression of the disease. Among the 549 pregnant women, 10.9% of them were diagnosed with preeclampsia. Out of those diagnosed, unfortunately, 6.7% of women diagnosed with preeclampsia did not survive. Additionally, 10% of the pregnant women underwent pregnancy termination, and among them, 45% of the terminations were due to preeclampsia. There were 17 cases (3.1%) of stillbirths among the total cases, with 13.3% attributed to preeclampsia. Furthermore, 8.38% of pregnant women experienced complications, and among them, 40% of the complications were due to developing preeclampsia.The association parameter suggests that a one-unit increase in systolic blood pressure (SBP) raises the relative risk of developing preeclampsia by approximately 6%, while a one-unit increase in diastolic blood pressure (DBP) increases the relative risk by about 7%, after adjusting for other factors. The study findings indicate that systolic blood pressure and diastolic blood pressure are related to time to developing preeclampsia during pregnancy. Higher baseline blood pressure measurement may indicate an increased time to developing preeclampsia, while lower baseline blood pressure measurement may lead to a higher survival time from preeclampsia. The factors significantly affecting the survival time of developing preeclampsia are mother’s age, weight, family history of blood pressure, previous experience of abortion and gravidity. By monitoring blood pressure status, specifically SBP and DBP, throughout pregnancy period of the mother can minimize the risk of developing preeclampsia, and hence, enhance maternal and infant health.