The Zambian Preterm Birth Prevention Study (ZAPPS): Cohort characteristics at enrollment

Abstract

Sub-Saharan Africa bears a disproportionate burden of preterm Background: birth and other adverse outcomes. Not only is the background rate of preterm birth higher than in North America and Europe, but many facilities lack essential equipment and personnel resources to care for preterm neonates. A better understanding of the demographic, clinical, and biologic underpinnings of preterm birth is urgently needed to plan interventions and inform new discovery.The Zambian Preterm Birth Prevention Study (ZAPPS) is a Methods: prospective antenatal cohort established at the Women and Newborn Hospital of the University Teaching Hospital (UTH) in Lusaka, Zambia. We recruit pregnant women from the antenatal clinics of district health centers and the UTH for study participation. Women undergo ultrasound examination to determine eligibility by gestational age criteria. Enrolled participants receive routine antenatal and postnatal care, lab testing, midtrimester cervical length measurement, serial fetal growth monitoring and careful assessment of birth outcomes.Between August 2015 and September 2017, we screened 1784 Results: women, of whom 1450 (81.2%) met inclusion criteria and were enrolled. The median age at enrollment of study participants is 27 years (IQR 23-32). Participants are enrolled at a median gestational age of 16 weeks (IQR 13-18). Among all parous participants (N=866; 64%), 21% (N=182) reported a prior miscarriage, 49% (N=424) reported a prior preterm birth, and 13% (N=116) reported a prior stillbirth. The HIV seroprevalence in our cohort is 24%.We have established a large antenatal cohort to characterize the Discussion: Gates Open Research epidemiological and biological determinants of adverse birth outcomes in Lusaka, Zambia. Findings from this cohort will help guide future studies, clinical care, and policy in the prevention and treatment of adverse birth outcomes.

Quantifying bias between reported last menstrual period and ultrasonography estimates of gestational age in Lusaka, Zambia

“…The Zambian Prematurity Prevention Study (ZAPPS) is a prospective cohort that enrolls participants prior to 20 weeks of pregnancy from five prenatal care clinics in the Lusaka urban district. 10 For the purposes of enrollment eligibility, gestational age was determined by best obstetric estimate. 9 The data presented in the present study were collected between August 17, 2015, and August 31, 2017.…”

“…1 in the study; (7) willing to be included in at-home follow-up for delivery outcomes if necessary. 10 The University of Zambia biomedical research ethics committee and the University of North Carolina institutional review board granted approval to conduct this research before commencement of data collection. All participants provided individual written informed consent prior to enrollment.…”

“…). Pregnant women who met the following enrollment criteria were eligible for inclusion in the ZAPPS study: (1) aged 18 years or older; (2) viable intrauterine singleton or twin pregnancy; (3) presentation to prenatal care prior to 20 weeks of pregnancy among patients not infected with HIV or 24 weeks if infected; (4) residing within Lusaka with no plans to relocate during the study follow‐up period; (5) willing to provide written, informed consent; (6) willing to allow participation of their neonate(s) in the study; (7) willing to be included in at‐home follow‐up for delivery outcomes if necessary …”

“…The present study included data from an ongoing prenatal cohort in Zambia. The Zambian Prematurity Prevention Study (ZAPPS) is a prospective cohort that enrolls participants prior to 20 weeks of pregnancy from five prenatal care clinics in the Lusaka urban district [10]. For the purposes of enrollment eligibility, gestational age was determined by best obstetric estimate [9].…”

“…Within the ZAPPS cohort, data from three sub-groups were analyzed: all women screened for participation in the ZAPPS study made up the “screening cohort”; those who went on to be enrolled formed the “enrolled cohort”; and those who had delivered by the time of the analysis formed the “delivery cohort” (Figure 1). Pregnant women who met the following enrollment criteria were eligible for inclusion in the ZAPPS study: (1) aged 18 years or older; (2) viable intrauterine singleton or twin pregnancy; (3) presentation to prenatal care prior to 20 weeks of pregnancy among patients not infected with HIV or 24 weeks if infected; (4) residing within Lusaka with no plans to relocate during the study follow-up period; (5) willing to provide written, informed consent; (6) willing to allow participation of their neonate(s) in the study; (7) willing to be included in at-home follow-up for delivery outcomes if necessary [10].…”