DOI: 10.3886/icpsr39037.v1
title: Risk Factors for Placental Malaria, Sulfadoxine-pyrimethamine Doses, and Birth Outcomes in a Rural to Urban Prospective Cohort Study on the Bandiagara Escarpment and Bamako, Mali, 2011-2019
title: Version 1

description: Placental malaria is associated with maternal illness and anemia, low birth weight, and preterm birth. Mali has one of the highest malaria case incidence rates globally, according to World Health Organization (WHO) reports on malaria. Using a rural to urban longitudinal cohort of women who initially resided on the Bandiagara Escarpment at study enrollment, this observational study addressed the following questions:

Was risk for placental malaria higher in Bamako (urban) or on the Bandiagara Escarpment (rural)?
What were the maternal risk factors for placental malaria in this cohort?
What was the association between number of intermittent preventative treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP) doses, placental malaria, and birth outcomes?
What factors predicted how many doses women received?

Placental samples (N = 317) and accompanying demographic data were collected from 249 women living on the Bandiagara Escarpment or in the District of Bamako during the years 2011 to 2019. Samples were evaluated by histology to assess placental malaria infection stage and parasite density. Generalized estimating equations (GEE) for logistic regression were used to model the risk factors for placental malaria infection (yes/no) and to assess the characteristics of women who had no doses or fewer doses of SP versus 3 or more doses of SP during pregnancy. Lastly, GEE was used to model birth outcomes as continuous dependent variables (birth weight, birth length, and placenta weight).
description: The purpose of the study was to examine the risk of contracting placental malaria among mothers in Mali and the impact of preventative treatment on birth outcomes.
description: Study participants (N = 832 women) belonging to the Dogon ethnic group were enrolled by the P.I. in a prospective cohort study during infancy or early childhood in 9 rural villages on the plateau of the Bandiagara Escarpment in the Region of Mopti. Enrollment took place from 1998 to 2000 at a mean age of 1.36 years (range 0 to 5 years). Follow-up occurred in 1999, 2000, 2004, 2007, and annually from 2010 through 2019. From 2010 onward, annual follow-up occurred in both the villages and in Bamako, with retention of all but 6% of the migrants to that city.
386 women gave birth, with placental tissue collected and analyzed from 249 who provided a total of 317 placentas from December 2011 to June 2019. Among the 249 mothers, 189 contributed one placenta (total of 189 placentas), 52 contributed two placentas (total of 104 placentas), and 8 contributed 3 placentas (total of 24 placentas). Placentas were collected at either Bamako health facilities or at a rural hospital that serves villages along the Bandiagara Escarpment. Study participants had consented to placental collections prior to going into labor. Specimens were collected from placentas within 30 minutes of placental expulsion. Newborn measurements and placental weight were measured immediately after birth. Other covariates were obtained during annual follow-up of cohort members.
description: Malaria infection stage was classified based on histopathology: no infection, acute, chronic, or past infection. Parasite density was classified as not present, mild, moderate, or severe. Placental weight and number of sulfadoxine-pyrimethamine (SP) doses received were recorded.
Newborn's birth weight and length, sex, and season/year of birth were measured.
Residence was classified as rural if the participant lived in one of the original Bandiagara villages and urban if they had moved to Bamako. Mother's age at child's birth, pre-pregnancy BMI, education level, and wealth (as z-scores) were included. Wealth was determined by approximately 5 judges from each study village who ranked each family's relative wealth to that of other families in the same village.
description: Response Rates: Out of a total of 832 girls enrolled in the cohort, a total of 145 girls died (mostly in infancy and very early childhood), 11 were lost to follow-up, and 676 survived to adolescence and adulthood and remained in the study (retention rate of 81% over 20 years). Among the survivors, 386 gave birth, with placental tissue collected and analyzed from 249 women who provided a total of 317 placentas.
description: The 249 mothers in this study were participants in a prospective cohort study that included the total population of children age 5 years and younger living in 9 villages on the Bandiagara Escarpment in 1998. Newborns were added to the cohort for the next two years (1999 to 2000).
description: Datasets: 
DS1: Risk Factors for Placental Malaria, Sulfadoxine-pyrimethamine Doses, and Birth Outcomes in a Rural to Urban Prospective Cohort Study on the Bandiagara Escarpment and Bamako, Mali, 2011-2019
description: Women participants living on the Bandiagara Escarpment, Mali who were previously enrolled in a prospective cohort study (1998-2000).
description: face-to-face interview; mixed mode