Pathological study of stillbirth placentas at Muhimbili National Hospital, Dar Es Salaam Tanzania

Abstract

Background: World Health Organization (WHO) defines stillbirth as fetal death occurred at gestational age (GA) of equal to or greater than 28 weeks of gestation and/or a birth weight of 1000grams or more. It is a devastating experience for the family and causal identification helps the parents in mourning process, to determine recurrence risk and aids in counseling regarding future pregnancy. The unknown causes of stillbirths range from 3.8-57.4% depending on system used to classify stillbirths. Systems which have pathological examination of the placenta may identify causes of stillbirths in more than 90% of cases, therefore pathological examination of placenta in stillbirths may contribute to significant reduction of unknown cause of stillbirths. To date, clinical assessment is the only evaluation used to find cause of stillbirths at Muhimbili National Hospital (MNH). To our knowledge, this is the first study to be conducted at MNH to evaluate placenta pathologies in stillbirths. Objective: To perform pathological study of placenta to describe placenta pathologies with risk to cause stillbirth at MNH, from June 2018 to December 2018. Methodology: Hospital based, descriptive cross-sectional study, 80 singleton stillbirths placentas delivered from June - December 2018 at MNH labor ward were macroscopically and microscopically examined. Neutral buffered formalin (NBF) 10% was used as a fixative. Placentas were placed immediately (within 30minutes) in a container filled with 10% NBF in a ratio of 1:10 and fixed for 8-12 hours. Grossing of the placenta was according to surgical pathology grossing manual by Tidiane. Placenta pathologies with risk to cause stillbirths were defined according to Amsterdam Placental Workshop Group Consensus. The data were analyzed by using SPSS version 20 computer software and results were summarized in frequencies and proportions. Results: The findings from this descriptive cross sectional study showed that 32 (40%) of stillbirths had unknown clinical diagnosis and 11 (13.8%) of mothers of stillbirths had previous history of adverse pregnancy outcome. Majority of the stillbirth placentas 71 (91%) had either one or combined pathologies with the risk to cause fetal death. Majority of placenta pathologies were combined 45 (56.3%). Maternal vascular malperfusion was the commonest vi pathology 45 (56.25%) among all and it was significantly associated with preterm stillbirths (<37 weeks of gestation). Conclusion: Pathological examination of placenta in stillbirths gives information about intrauterine life, in our study 40% of stillbirths had unknown clinical diagnosis, with detailed pathological examination of placentas 91.3% had either combined or isolated pathologies with risk to cause stillbirths. Pathological examination of placenta in stillbirths and clinical evaluation when used together can significantly reduce the proportion of unknown cause of stillbirths. Recommendations: Pathological examination of placenta should be done in all cases of stillbirths at MNH, especially those with unknown clinical diagnosis. Further studies with the use of proper controls of live births should be done to establish strong causal relationship of placenta pathologies and fetal death. Universal guideline on reporting placenta pathologies should be adopted in order to improve reproducibility of results.