Association Between Pre-eclampsia and Patterns of Early Pregnancy Bleeding Seen Amongst Postnatal Women Treated at the Kenyatta National Hospital, Nairobi, Kenya.a Case Control Study

Abstract

Background: Vaginal bleeding in early pregnancy is a common event estimated to occur in up to 40% of all pregnancies. The leading cause of such bleeding is miscarriage,affecting 16-25% of pregnancies. Suchbleeding is thought to occur due to abnormal functioningor development of the placenta and has been associated with an increased incidence of various adverse pregnancy outcomes among those pregnancies that proceed beyond 20 weeks of gestation.The outcome of interest for our study is preeclampsia. Pre-eclampsia is a rare condition estimated to complicate about 5-10% of pregnancies globally. The onset of pre-eclampsia cannot be reliably predicted,and this remains an area of ongoing research. The results of observational studies have been conflicting on the association between vaginal bleeding in early pregnancy and pre-eclampsia. Study Objective:To study the association between vaginal bleeding in early pregnancy and the risk ofsubsequent pre-eclampsia. Methods: We conducted our study at the Kenyatta National Hospital in Nairobi, Kenya. Our study was an unmatched case control study. Our sampling frame was all post-natal mothers within the first 72 hours after delivery treated at KNH. We stratified study participants into cases (post-natal mothers with pre-eclampsia in pregnancy) and controls (postnatal mothers without pre-eclampsia in pregnancy) and compared them with regards to history of per vaginal bleeding during the first 20 weeks of gestation. Study participants were identified from records in the post-natal wards. After obtaining informed consent from eligible participants, the information of interest was obtained using a structured study questionnaire administered by trained research assistants with verification of information given from patient case notes. The bleeding characteristics assessed were any bleeding in the first 20 weeks of pregnancy, maximal intensity of bleeding, duration of bleeding and number of episodes of bleeding. Descriptive statistics and regression analyses were used for data analysis using SPSS version 26 software. Results: The study comprised 304 participants. 152 cases and 152 controls. Bleeding in early pregnancy was significantly associated with increased risk of subsequent pre-eclampsia (OR 2.110, 95% CI 1.184-3.763, p value 0.011). Conclusion: Vaginal bleeding in early pregnancy is a common event and is associated with pre-eclampsia. The results of studies on this association are mixed. Further studies, especially in African populations whose risks have been found to vary from those of Indo-European populations, would shed further light on this issue. Study significance: Few studies have been done globally looking at the association between early pregnancy bleeding and pre-eclampsia. No such study had been done previously on an African population though epidemiological data has shown racial disparities in risk of pre-eclampsia, with Africans having higher risk. Our study is the first of its kind carried out in a pre-dominantly African population and sheds light on early pregnancy bleeding patterns and their associated risk for pre-eclampsia. Our findings will inform future research on this topic in Africa.