Prevalence, Risk Factors and Timing of Occurrence of Stillbirths Among Patients With Hypertensive Disorders of Pregnancy at Kenyatta National Hospital in 2018-2019; a Cross-sectional Study

Abstract

Background Hypertensive disorders in pregnancy (HDP) such as preeclampsia, eclampsia and chronic hypertension complicate approximately 6.5% of pregnancies in Kenya. About 2.6 million stillbirths occurred globally in 2015, with majority in LMIC, according to WHO. HDP contribute to approximately 16% of stillbirths globally. However, the prevalence of HPD related stillbirths has not been addressed comprehensively in Kenya. Further antepartum, intrapartum, preadmission, or post admission timing of occurrence of stillbirths in HDP, critical for targeted interventions, has not been examined in this setting. Objective To determine the prevalence, risk factors and timing of stillbirth among Kenyan parturients with HDP admitted at Kenyatta National hospital in 2018 and 2019. Methods Study design: A hospital based cross sectional study Study site setting: Kenyatta National Hospital records department Study population: Women aged 15-49 years admitted at Kenyatta National Hospital between 1st January 2018 and 31st December 2019 at 24 and above weeks of gestation or referred after delivery with a verified status of hypertension. Exposure: Hypertensive disorder of pregnancy Outcomes: Birth outcomes (stillbirth or livebirth), Timing of occurrence of stillbirth Study procedure: Simple random sampling was used to identify file of patients who met the eligibility criteria until the desired sample of 404 was reached. Files were allotted numbers and a random number generator used to select the 404 randomly. A pretested questionnaire was used to collect demographic, reproductive, and the medical data relevant to the study. xii Data analysis and management: The prevalence of stillbirth was estimated using the Clopper- Pearson method. The sociodemographic and reproductive factors associated with stillbirth were summarized using frequency distributions and compared using the Chi-square test for categorical variables and Mann-Whitney U test for continuous variables. Bivariate and multivariable logistic regression and corresponding 95% confidence interval were used to obtain odds ratios of these associations. Timing of occurrence of stillbirths was summarised as frequencies and percentages and 95% confidence intervals calculated using the Clopper Pearson method. P value of < 0.01 was statistically significant. Statistical Package for Social Scientists (SPSS) software version 21 was used for analysis. Results: Between 1st January 2018 and 31st December 2019, 450 files were screened of which 404 met the eligibility criteria. Of those ineligible files, 28 had missing laboratory data, 16 were of gestational age less than 24 weeks and 2 had foetal anomalies. The mean maternal age was 29 years (SD ±6) and preeclampsia was the most common HDP (79.2%). The prevalence of stillbirths in HDP was 15.8% (95% CI 12.4-19.8). Determinants of stillbirth were non-ANC attendance (OR 17.48, 95% CI 4.16-85.88), low birth weight (OR 7.78, 95% CI 3.70-16.31), preterm birth (OR 3.99, 95% CI 2.21-7.06), DBP ≥ 110mmHg (OR 2.23, 95% CI 1.24-3.92), low platelet levels (OR 5.95, 95% CI 3.36-10.50), and AST ≥ 2-fold rise (OR 4.93, 95% CI 2.71-8.99). Adjusted odds of SB in vaginal delivery was 13-fold higher than for caesarean, (AOR 13.52, 95% CI 3.69-49.50), 10-fold higher for abnormal resistive index compared to normal (AOR 10.78, 95% CI 2.92-39.78) and 15-fold high for abnormal biophysical profile compared to normal (AOR 15.40, 95% CI 3.75-63.15). Most (73.4%) stillbirths occurred in the antepartum period and 53.1% occurred after admission to KNH. Conclusion: This study revealed a high prevalence of stillbirth in HDP, especially in preeclampsia and eclampsia most occurring in the antepartum period. The mode of delivery, biophysical profile, and resistive index were independent predictors of stillbirths.