Assessing the impact of group antenatal care on gestational length in Rwanda: A cluster-randomized trial

Background Research on group antenatal care in low- and middle-income contexts suggests high acceptability and preliminary implementation success. Methods We studied the effect of group antenatal care on gestational age at birth among women in Rwanda, hypothesizing that participation would increase mean gestational length. For this unblinded cluster randomized trial, 36 health centers were pair-matched and randomized; half continued individual antenatal care (control), half implemented group antenatal care (intervention). Women who initiated antenatal care between May 2017 and December 2018 were invited to participate, and included in analyses if they presented before 24 weeks gestation, attended at least two visits, and their birth outcome was obtained. We used a generalized estimating equations model for analysis. Findings In total, 4091 women in 18 control clusters and 4752 women in 18 intervention clusters were included in the analysis. On average, women attended three total antenatal care visits. Gestational length was equivalent in the intervention and control groups (39.3 weeks (SD 1.6) and 39.3 weeks (SD 1.5)). There were no significant differences between groups in secondary outcomes except that more women in control sites attended postnatal care visits (40.1% versus 29.7%, p = 0.003) and more women in intervention sites attended at least three total antenatal care visits (80.7% versus 71.7%, p = 0.003). No harms were observed. Interpretation Group antenatal care did not result in a difference in gestational length between groups. This may be due to the low intervention dose. We suggest studies of both the effectiveness and costs of higher doses of group antenatal care among women at higher risk of preterm birth. We observed threats to group care due to facility staff shortages; we recommend studies in which antenatal care providers are exclusively allocated to group antenatal care during visits. Trial registration ClinicalTrials.gov NCT03154177 To test the primary hypothesis that group antenatal care would extend gestational length, the Preterm Birth Initiative-Rwanda designed a cluster RCT in which a cluster was defined as a health center and the population served in its catchment area. We chose a clustered design because Rwandan stakeholders preferred to offer all women at each health center the same model of care. Clusters were pair-matched and one of each pair was assigned to continue individual antenatal visits while the other was assigned to provide group antenatal visits. At half of the health centers included in this study we implemented community-based urine pregnancy test by community health workers and basic obstetric ultrasound by nurses and midwives to strengthen gestational age assessment and assess whether these interventions affected the secondary outcomes of attendance at four antenatal care visits and initiation of antenatal care before 14 completed weeks. Health center pairs were matched to similar pairs to ensure balance, and one pair from each quadruple was assigned the additional intervention of basic obstetric ultrasound by nurses and midwives at the health center and community-based urine pregnancy tests administered by community health workers in the catchment area. The intervention group consisted of all health centers providing group antenatal visits; half of these health centers also provided basic obstetric ultrasound and pregnancy testing at community level. The control group consisted of all health centers providing standard individual antenatal visits, half of which also provided basic obstetric ultrasound and pregnancy testing at community level. Ethical approval was granted by the Rwanda National Ethics Committee (No.0034/RNE/2017) and University of California, San Francisco Institutional Review Board (16–21177). Data were collected on women aged 15 and older presenting for antenatal care at the 36 study health care centers who provided written informed consent between May 25, 2017 and December 31, 2018. This study was permitted by the Rwanda National Ethics Committee to waive parental consent for pregnant minors ages 15 and older. No pregnant adolescents younger than 15 years were documented to have been invited to participate in the study. All pregnant women presenting for their first antenatal visit received standard individual care from a provider. Providers invited women to participate in the study and attend future antenatal visits at the study site according to the Rwanda focused antenatal care schedule. At sites randomized to group antenatal care, providers and study staff invited women to participate in group antenatal care; those who declined continued to receive individual care at the study site. After the antenatal care provider estimated the woman’s due date based on the last menstrual period and symphysis-fundal height, study staff assigned the woman to a group of eight to 12 women with similar due dates (preferably within a two-week gestational-age period, with an upper limit of 4 weeks difference). Once the woman was assigned to a group, she was invited to return for three subsequent scheduled group antenatal visits at eight-week intervals, starting at 22–24 weeks gestation, and one postnatal group visit. While group antenatal services were offered to all women at group care facilities, only women who consented to study participation, presented for the first antenatal care visit before 24 completed weeks gestation, attended at least two antenatal care visits during pregnancy, and whose birth outcomes were discoverable by study staff were eligible and included in the analyses. The primary analysis included only those women with a gestational length between 24 weeks and 43 weeks, documented by the birth care provider in the birth facility’s maternity register. We included mother-infant units in the primary analysis if the infant’s birth weight fell between the Intergrowth-21st Project’s upper and lower centiles, by sex and gestational length [16]. The Intergrowth-21st Project provides international standards for female and male infants between the 3rd and 97th centiles by gestational length. This study included one primary (group antenatal care) and two secondary (basic obstetric ultrasound and urine pregnancy tests in the community) interventions. These interventions are described below, and more details are available in a separate publication [17]. Each group antenatal visit occurred in a room accommodating eight to 12 pregnant women, one antenatal provider and one community health worker. During the first half of these two-hour sessions, antenatal care providers met with each woman in a semi-private area of the room for brief individual assessments while the group of women socialized and participated in health assessment activities such as weighing one another and taking each other’s blood pressure readings with an electronic cuff, under the supervision of the community health worker. During the second hour of the session, the provider and community health worker co-facilitated a discussion of health-related topics that aligned with the stage of pregnancy and the health issues of highest importance at that time. The full list of visit timing and topics at each visit are described elsewhere [17]. Providers and community health workers elicited concerns and questions from women and encouraged group care participants to share knowledge and support with one another. The Rwanda group antenatal care model was customized by a Technical Working Group convened for this study, composed of representatives from maternal-child health stakeholder organizations in Rwanda [18]. During the study period, the Rwanda Ministry of Health recommended that the group care curriculum follow the four focused antenatal visits model and no more than four antenatal visits per woman could be accommodated by the health system. The Technical Working Group hoped that the social support fostered among women in the same antenatal group would continue into the postnatal period and motivate women to seek care; for this reason, a postnatal group visit was included in the model even though a postnatal visit was not expected to impact the primary outcome (gestational length). Experienced group antenatal care providers from the United States prepared six Rwandan providers with five days of training. These Rwandan providers then trained three antenatal care providers at each health center randomized to group antenatal care, with a three-day group care training session. The Rwandan trainers continued to provide the 18 group antenatal care clusters with targeted training, supervision, and mentoring throughout the study. The Preterm Birth initiative-Rwanda provided one ultrasound machine and 10 days of training for three antenatal care providers per site to the 18 clusters randomized to implement basic obstetric ultrasound. These clusters were asked to conduct a screening ultrasound examination for each woman on the day of her first antenatal visit, or soon after. The Rwanda Society of Radiologist trained these new ultrasound providers who subsequently received mentoring and supervisory visits from radiographers from the nearest district hospital. Community health workers associated with health centers randomized to urine pregnancy tests in the community underwent an eight-hour training and were provided with urine pregnancy test kits. They were instructed to refer women with a positive pregnancy test to the health center for antenatal care services. The Rwanda Biomedical Center trained these community health workers, and each health center’s community health worker supervisor supervised the community health workers in the catchment area. The primary outcome was specified with a testable hypothesis a priori during clinical trial registration (clinicaltrials.gov {“type”:”clinical-trial”,”attrs”:{“text”:”NCT03154177″,”term_id”:”NCT03154177″}}NCT03154177). The primary study hypothesis was that among women who presented for antenatal care at <24 weeks gestation and attended ≥2 antenatal visits documented at the site of study enrollment, antenatal care exposure at sites that offered group antenatal visits would increase mean gestational length by .5 weeks (with a standard deviation no larger than 4.3 weeks) compared to antenatal care exposure at sites that offered standard antenatal visits. Gestational length was assigned by the birth care provider and recorded in the facility’s maternity register. Birth care providers used all available data to make this determination at the time of birth (i.e. last menstrual period, birth weight, infant maturity), but gestational length assignment was not standardized or monitored. Birth weight was recorded by birth providers before leaving the delivery room using an analog infant scale; this measurement was abstracted from the maternity register at each facility. Birth care providers were not informed about the study’s primary hypothesis nor primary outcome. The secondary outcomes were adherence to the recommended four antenatal visits, gestational length at first antenatal visit, incidence of preterm birth, proportion of women delivering by caesarean section, proportion identified as at risk during antenatal care, and adherence to six-week postnatal visit. We intended to examine newborn morbidities but our data sources were not adequate to do so. Antenatal visits were counted in the longitudinal antenatal register at each facility. Gestational length at the time of the first antenatal visit was documented by the antenatal provider in the facility antenatal register. Preterm birth was assigned to any infant whose gestational length was recorded in the maternity register as less than 37 weeks. We also examined the effect of group antenatal care on mode of birth and the effect of basic obstetric ultrasound and community-level urine pregnancy tests on antenatal care attendance. Gestational length at the time of the first antenatal visit was documented by the antenatal care provider in the facility antenatal register. Antenatal visits were reported in the pre-existing longitudinal antenatal register at each facility. Postnatal visits were reported in the recently established postnatal register at each facility. On the day women consented to study participation, immediately after the first antenatal visit, all study participants completed an enrollment questionnaire about socio-economic and health history, which was administered by a health provider or study staff member. Data were entered directly on mobile tablets by data collectors into an encrypted, web-based system called Research Electronic Data Capture (REDCap) platform [19]. Study staff abstracted all data from standard Ministry of Health primary (paper) data sources located in the study facilities. These included antenatal, birth, neonatal, and postnatal registers, and individual longitudinal antenatal and postnatal records. Birth registers were reviewed at all 36 health center study sites and the six district hospitals to which those health centers referred women for higher-level care. Study staff were instructed to extract newborn morbidities from health center data drawn from community health worker SMS reports, but in practice these data were not available. The study initially created and used a multisite Research Electronic Data Capture database. However, due to poor connectivity and the quantity of data collected per participant (367 variables), the process of syncing or uploading data from the tablets to the server was frequently disrupted. The disruption led to many duplications and erroneous linkage of study events. Upon discovery of this error, the study team substantially revised the database and conducted a thorough process to rectify any errors and retain the most complete record for each patient. Unrectified records were excluded from the final datasets. The electronic data were maintained on secure systems with access limited to the principal investigators, study epidemiologist, and designated study staff. The data were converted into SPSS for Windows version 25 [20] and STATA SE version 16 [21] for analyses. At the design stage of this trial, we assumed an ICC of 0.01, and a possible effect size of half a week in gestational length based on a Cochrane review of conventional versus group antenatal care [22]. We assumed a loss-to-follow-up rate of 30%, based on the assumptions that 10–15% of all pregnancies end in miscarriage and 15–20% of women might deliver at another location. We calculated that for a two-tailed test, α = 0.05, 1-β = 80%, and a balanced 1:1 ratio of intervention (group antenatal care) to control (standard antenatal care) study participants, a minimum sample of n = 1,163 eligible women per study group (intervention and control) was required. The sample size was increased to account for a cluster design effect of 3.21 (cluster randomization to study group by health center rather than by individual) and to account for a loss to follow-up rate of up to 50%, for a total required sample size per study group of 3,640, or an average of 202 women per health center at 36 health centers [23]. As descriptive outcomes, the secondary outcomes were assessed in the available sample without hypothesis testing or multiple comparisons adjustment. Five of 30 districts in Rwanda, including Burera, Bugesera, Nyamasheke, Rubavu, and Nyarugenge, were selected by the Ministry of Health as locations for this cluster RCT based on their service capacity and need. To gather information that would inform study site selection, data collectors visited all 55 public health centers in the study districts and interviewed staff about the facility itself, human and material resources, and client volumes. We selected 36 health centers for inclusion that 1) had historical volumes of women that made organizing groups feasible (35–125 births at the health center per month); 2) reported at least two antenatal care providers per day when antenatal care was offered, to increase the likelihood that one antenatal care provider could be exclusively allocated to scheduled group visits; and 3) had a room sufficiently large for group visits.