Attendance at antenatal clinics in inner-city Johannesburg, South Africa and its associations with birth outcomes: Analysis of data from birth registers at three facilities

Background: Antenatal care (ANC) clinics serve as key gateways to screening and treatment interventions that improve pregnancy outcomes, and are especially important for HIV-infected women. By disaggregating data on access to ANC, we aimed to identify variation in ANC attendance by level of care and across vulnerable groups in inner-city Johannesburg, and document the impact of non-attendance on birth outcomes. Methods: This record review of routine health service data involved manual extraction of 2 years of data from birth registers at a primary-, secondary- and tertiary-level facility within inner-city Johannesburg. Information was gathered on ANC attendance, HIV testing and status, pregnancy duration, delivery mode and birth outcomes. Women with an unknown attendance status were considered as not having attended clinic, but effects of this assumption were tested in sensitivity analyses. Multiple logistic regression was used to identify associations between ANC attendance and birth outcomes. Results: Of 31,179 women who delivered, 88.7% (27,651) had attended ANC (95% CI = 88.3-89.0). Attendance was only 77% at primary care (5813/7543), compared to 89% at secondary (3661/4113) and 93% at tertiary level (18,177/19,523). Adolescents had lower ANC attendance than adults (85%, 1951/2295 versus 89%, 22,039/24,771). Only 37% of women not attending ANC had an HIV test (1308/3528), compared with 93% of ANC attenders (25,756/27,651). Caesarean section rates were considerably higher in women who had attended ANC (40%, 10,866/27,344) than non-attenders (13%, 422/3360). Compared to those who had attended ANC, non-attenders were 1.6 fold more likely to have a preterm delivery (95% CI adjusted odds ratio [aOR] = 1.4-1.8) and 1.4 fold more likely to have a stillbirth (aOR 95% CI = 1.1-1.9). Similar results were seen in analyses where missing data on ANC attendance was classified in different ways. Conclusion: Inner-city Johannesburg has an almost 5% lower ANC attendance rate than national levels. Attendance is particularly concerning in the primary care clinic that serves a predominantly migrant population. Adolescents had especially low rates, perhaps owing to stigma when seeking care. Interventions to raise ANC attendance, especially among adolescents, may help improve birth outcomes and HIV testing rates, bringing the country closer to achieving maternal and child health targets and eliminating HIV in children. The study included the public health facilities where all public-sector births within the inner-city, region F of Johannesburg take place. Specifically, these were: Hillbrow Community Health Centre (HCHC, a primary health clinic), South Rand Hospital (SRH, a secondary-level district hospital and Charlotte Maxeke Johannesburg Academic Hospital (CMJAH, a tertiary-level facility). Private sector hospitals were not included as we believed that it would be difficult to access data from patients at those facilities and they make up a relatively small proportion of all deliveries in the region. We manually extracted data from labour ward registers of all births in 2008 and 2009 at HCHC and SRH. Data were also extracted from birth registers at CMJAH for the years 2011 and 2012. All births are captured in these registers, as well as information on deliveries that occur before the mother and infant arrive at the facility. The registers collate pregnancy, intrapartum and birth outcomes data, and are a rich source of information. A protocol describing the care processes in the region states at which level of care the different patient groups are to receive treatment. In HCHC, nurses and midwives provide care for women with uncomplicated pregnancies. SRH, the secondary level of care is managed by midwives and medical officers who treat women with minor medical complications. At CMJAH all women are assessed by a doctor and there are medical specialists available for more complicated patients. Women are considered to have a complicated pregnancy if they were unwell in a previous pregnancy, or have, for example, co-morbid medical illnesses, multiple gestations or suspected congenital abnormalities. In HCHC and SRH, women do not require a referral letter and can present directly for services when pregnant. CMJAH only provides ANC for women with pregnancy complications and then refers healthy women to lower levels of care. Caesarean sections are only performed at the secondary- and tertiary-level facilities. There are no user fees for HIV, ANC or childbirth services. HIV testing, PMTCT and antiretroviral treatment are available at all facilities. It is important to note that the study setting, region F (inner-city), has several distinctive features which influence the uptake of health services and programme implementation. The inner-city is one of seven regions within the district called City of Johannesburg. In turn, the City of Johannesburg is one of five districts of the Gauteng Province, the economic hub of the country. The inner-city is densely populated, consisting of the flatland areas of Hillbrow and Berea, as well as the Johannesburg Central Business District. It is estimated that the region contains about 15% of the 4 million people who live in the city of Johannesburg [21]. However, it is likely that this figure is well above 15% as the majority of the large transient population in the inner-city area are not included in those estimates. The inner-city is a uniquely complex and dynamic environment that has undergone major demographic, social and economic shifts over the last few decades. Many of its inhabitants are immigrants, both South Africans from other provinces of the country as well as foreigners. About a quarter of adults in the area are unemployed [21]. The inner-city houses several large taxi hubs and 800,000 commuters are said to pass through the city daily. Informal trading is the dominant economic activity. Unfortunately, the area is plagued with high levels of crime and drug dealing [22]. Not surprisingly, the area has a high burden of HIV: the antenatal HIV prevalence in Gauteng Province as a whole was 29.9% in the most recent national survey (2012), with a similar level in the City of Johannesburg (29.6%). Corresponding figures for Herpes Simplex Virus type-2 were 58.4% and 58.5% [23]. The following variables were manually extracted from the labour ward registers into a Microsoft Excel database: ANC attendance (having attended at least one ANC visit), maternal age (not available at SRH), gravidity and parity (only available at CMJAH), HIV testing uptake and status, mode of delivery, infant gender, gestation at childbirth and stillbirths. Patient names or other identifiers were not collected. Adolescents were divided into younger and older groups (10–16 years and 17–19 years), which correspond broadly to the ages of those in primary or secondary school (10–16 years), and those in the final years of school or post-school (17–19 years). Adults were groups into 5-year age bands. As about 4% of data were missing on whether women had attended ANC, we performed a sensitivity analysis in which we reclassified the missing data in one of three ways. Firstly, in a worst case scenario, women whose attendance status was unknown were classified as not having attended ANC. In the second scenario, a ‘missing excluded’ analysis, we excluded all women where it was unknown whether or not they had attended ANC. The third scenario, the best case, classifies women with unknown attendance as having attended ANC. Findings across the three scenarios were compared for effect size and direction. The associations reported in the paper are drawn primarily from the worst case scenario, as we considered it most likely that where attendance was unknown, patients had not actually attended care. Also, many of the figures in the other two scenarios were implausible. Figures for HCHC were unchanged across the scenarios as data were not missing on ANC attendance at that site. Newborns were classified as preterm (under 37 weeks gestation), term (37 to 41 weeks) and post-term (42 or more weeks). Stillbirths included some deaths that occurred shortly after birth as the birth records did not differentiate between those deaths and actual stillbirths. Data were recoded and analysed using STATA version 12 (STATA Corporation, College Station, Texas, USA). Chi-square tests were used to detect associations between categorical variables and Wilcoxon Rank sum tests were used for analysis of continuous variables. Pearson Chi-square test for trend assessed associations between ordinal exposure categories and binary outcomes. Multiple logistic regression models examined whether ANC attendance was associated with two dependent variables assessing service access (HIV testing and Caesarean section delivery) and two birth outcomes (preterm births and stillbirth). These models included the variable site, and other potential confounding variables associated with the outcome in univariate analysis or in analysis stratified by site (P < 0.10). The exposure variable antenatal attendance was included in the multivariate model assessing factors associated with the outcome preterm delivery (attendance was associated with preterm delivery in all three facilities, even though not associated with the outcome when data from all sites were pooled). For similar reasons, the exposure variable delivery mode was included in the multivariate model assessing factors associated with the outcome stillbirths. Potential confounders varied by outcome variable, with, for example, infant sex not included in the outcome HIV testing, as there was no plausible causal pathway between these variables. Infant sex, however, and HIV status were considered potential confounders for the remaining three models.