Incidence and Outcomes of Abnormal Placentation at Kenyatta National Hospital-a 3 Year Retrospective Descriptive Study

Abstract

Background: Global incidence of Abnormal Placentation: Placenta previa and Placenta accreta spectrum is 0.6% and 0.17% respectively. Presence of at least one previous caesarean scar increases the relative risk of Placenta previa by 1.5-5 and Placenta accreta spectrum by 2.95 to 7. In Africa, countries like Egypt with caesarean section rates of 52% the prevalence of Placenta Accreta spectrum is 0.3-0.9% and Placenta previa prevalence rate is 1.7%. Ultrasound is comparable to Magnetic resonance imaging in detecting Abnormal Placentation from 20 weeks gestation. In high income countries upto 20-30 % of cases of Abnormal Placentation remain undiagnosed until delivery. Upto a third of patients with Abnormal Placentation experience intra-partum haemorrhage, leading to postpartum haemorrhage and adverse perinatal and maternal outcomes such as preterm births, stillbirths, low APGAR scores and increased need for transfusion, emergency peripartum hysterectomy and severe postpartum maternal anaemia. Incidence and outcomes of Abnormal Placentation have not been previously evaluated in Kenya. Study objective: To determine the incidence, maternal and perinatal outcomes due to Abnormal Placentation at Kenyatta National Hospital between January 2017 to December 2019. Methodology: This was a 3-year retrospective descriptive study in which files of patients with an ICD-10 diagnosis of antepartum haemorrhage and third stage haemorrhage were retrieved. Eligible files had either an antenatal or intrapartum ultrasound and/or those diagnosed with Abnormal Placentation for the first time during surgery also known as the clinical intra-operative group were included, 168 patient files fit the criteria and their information filled in a mobile based data extraction tool (Open data kit, ODK). Their socio-demographic characteristics, adverse maternal and perinatal outcomes were compared based on whether the diagnosis of Abnormal Placentation (Placenta previa/Placenta accreta spectrum) was made via ultrasound antenatally or intrapartum versus clinical intra-operative diagnosis. Data collected was cleaned and analysed using SPSS version 21. Results: Between January 2017 to December 2019, there were 168 cases of Abnormal Placentation out of 40,673 deliveries giving an incidence of 0.4% at 95% CI (0.0035, 0.0048). Of these, 112 (66.7%) had ante-natal/intrapartum ultrasound diagnosis while 56 (33.3%) had clinical intraoperative diagnosis. Sociodemographic, clinical and obstetric characteristics were comparable between the two groups. The mean age was 30.2 years (SD-5.7), most were married (79.2%), majority were multipara (73.2%), most had no history of prior caesarean delivery (69.3%) nor miscarriage (79.8%) and upto xi half (50.6%) were referred from other medical facilities. The use of ante-natal or intrapartum ultrasound in diagnosis of Abnormal Placentation reduced adverse maternal outcomes by 23% RR 0.77[0.58, 1.03] though this was not statistically significant. Similarly, adverse perinatal outcomes was reduced by 24% among patients with an ante-natal/intrapartum ultrasound diagnosis of Abnormal Placentation this was also not statistically significant. Conclusion: Early ante-natal/intrapartum ultrasound diagnosis of Abnormal Placentation is associated with less composite maternal and perinatal morbidity.