Within the inner-city of Johannesburg, only about 90% of women giving birth attended antenatal care – about 5% lower than the national average. Most non-attenders gave birth in the primary health care facility and substantially fewer had HIV testing or a Caesarean section. By not attending ANC, it is not possible to identify women who have high-risk pregnancies and refer them for closer monitoring during childbirth, or for an elective Caesarean section at a secondary or tertiary centre [24]. Thus, not surprisingly, not attending antenatal care was associated with a considerably higher risk for preterm delivery and stillbirths in this population, consistent with previous reports [4, 25,26,27,28]. Similarly, the high levels of maternal mortality in women not attending ANC in the country can likely be ascribed to the women not having attended the appropriate level of care during pregnancy and childbirth, and not having received interventions during pregnancy such antiretroviral treatment [13, 14]. In countries with high HIV prevalence, such as those in eastern and southern Africa, HIV is a leading cause of death among women during pregnancy and the postpartum period [29, 30].
Importantly, the study findings were broadly consistent across the sensitivity analyses done to test the effects of different assumptions about the missing data. Effects sizes in all four multivariate models were similar or even larger than the worst case scenario. The estimates of ANC attendance in the missing-excluded and best case scenario were, however, implausible in many instances (e.g. that 99% of women at SRH had attended ANC).
Despite recommendations for HIV testing in labour or shortly after childbirth in women with an unknown HIV status [31], HIV testing levels were low among women who had not attended ANC. This is true of all levels of care, but most especially at the primary care facility, where only about 10% of non-attenders had an HIV test. Non-attenders should be considered a very high risk group and prioritised for HIV testing around childbirth (HIV positivity rate was two thirds in non-attenders who had an HIV test). Independent of ANC attendance, women who did not have HIV testing had low rates of Caesarean section and markedly poorer birth outcomes than other women. This suggests that women not accessing HIV testing require considerable focused attention, as lack of HIV testing may signal that they have poor access to a range of interventions.
Being an adolescent or a woman living with HIV at the HCHC site lowered the chances of attending antenatal care during pregnancy. Although reasons for poor access were not assessed, likely factors include stigma (real or perceived), and concomitant disrespect and abuse meted out by health workers [32,33,34]. The especially low levels of attendance at HCHC, the Hillbrow site, where most residents are foreign nationals [35], suggests that xenophobia within the health system might be deterring women who are not South African from seeking health care [36, 37]. The Hillbrow site had the lowest levels of ANC attendance and HIV testing, and the highest HIV prevalence, and clearly serves a highly vulnerable and marginalised population who face many obstacles to service attendance.
Having attended ANC, regardless of number of visits, has been used for decades as an important measure of access to maternal health services [38,39,40]. The number of visits made to an antenatal clinic is, however, also a key measure of access, and was unfortunately not collected within birth registers in the study sites. The indicator ‘proportion of women attending four or more visits’ is one of the four indicators used to measure the target 3.8 of SDG 3, Universal Health Coverage of reproductive, maternal, newborn and child health [41, 42]. A multi-country trial led by WHO found that a minimum of four antenatal visits are required to adequately monitor a women’s health during pregnancy, and to complete screening and diagnostic procedures [43]. Additional visits may be necessary for HIV-positive women who initiate antiretroviral therapy during pregnancy and require adherence support and drug toxicity monitoring, for example [2, 19]. Globally, however, only an estimated 53% of women attend four visits and this figure is even lower in most LMICs (36%) [44, 45]. In South Africa, in a population-based survey, of those who attend ANC, 87% had four or more visits [7]. These figures, however, vary considerably between population groups, ranging from 81% in socio-economic quartile I to 97% in quartile IV, and were especially low in those aged below 19 (79%).
Strategies to improve antenatal attendance
Clearly, in this setting, interventions to raise ANC attendance are a priority and critical to reducing maternal mortality, stillbirths and paediatric HIV, and to securing access to ART for HIV-infected women [12]. In the country as a whole, failure to address deficiencies in access to ANC, will substantially constrain the ability to further improve national maternal and child health outcomes.
Research identifying the specific demand-side barriers to access in this setting, especially within groups such as adolescents, HIV-positive women and foreigners, could provide actionable information. In other settings, these factors include lack of women’s empowerment and supportive partners [46], perceived poor quality of services [47], having an unintended pregnancy and low socio-economic status [48,49,50]. Demand for antenatal services could be raised through community involvement and activities to raise awareness around these services, including through mass media campaigns [17, 51, 52]. Further strengthening the antenatal care component of the government led MomConnect mHealth intervention might make an important contribution to such initiatives and to raising the number of ANC visits attended [53, 54]. Specific messages on MomConnect, or even a separate mHealth service, could be targeted at immigrants and younger poorer women. Cash transfers have been successfully applied in many settings to incentivise attendance at maternal health services [55]. Currently a cash transfer is given to women in South Africa once a child is born until they are 18 years. Beginning the transfer during pregnancy, as is done in a host of countries, (and not only restricting it to South African women) could raise demand for care (presentation of a ANC patient-held card could be required for enrolment in the scheme, for example) [56].
Supply side actions that have been found to raise attendance include improvements in service quality [57, 58]. More broadly, government should promote adolescent-friendly services and perhaps reserve specific time slots at the clinic for this group [51, 59]. Both within health services and the country as a whole, much more needs to be done to counter the high levels of xenophobia that mark the country and hinder access of migrants to health care [60]. Strategies to achieve this could include training and sensitisation of health workers, monitoring of health workers’ interactions with migrants and strengthening the coordination mechanisms between the multi-sectoral partners who work in this field [61]. Birth registers in areas with high numbers of foreign nationals could include measures of migrant status, such as country of origin and length of time resident in the country, in order to track outcomes of these women and identify any particularly vulnerable sub-groups to be targeted.
Study strengths and limitations
Deficiencies in data quality, especially the gaps in data on ANC attendance at SRH and CMJAH, hinder the ability to interpret the findings. These deficiencies may partly be explained by the data having been collected as part of routine services, where staff have numerous competing priorities. However, regardless of what assumptions were made about the missing data, the direction and size of effect were generally consistent, suggesting that study findings may be robust despite this potential bias. Also, noting these deficiencies in data and the usefulness of the data collected is a key step towards improving data quality in the facilities and other parts of South Africa. Also of note, levels of attendance measured through health service data can differ considerably from coverage measured using population–level data [41]. However, where utilisation of skilled birth attendance is high, health service data, such as used in this study, may approximate antenatal coverage measured in a survey [62]. In Gauteng province, 99% of women deliver with a skilled birth attendant [7], suggesting that our measures of ANC attendance reflect that of population-level coverage.
Number of visits was not recorded in the birth registers, and thus we were unable to differentiate between those who had and had not completed the recommended four visits. Even attendance fewer times than the recommended number offers considerable benefits: the use of point-of-care HIV and syphilis testing, and of same-day initiation of antiretroviral treatment means that women attending even one visit can still access several important services.
The data collection periods differed between facilities. This could have biased the study findings as differences observed in attendance rates between the tertiary facility and other levels may be due to systematic improvements or reductions in ANC utilisation across the facilities, rather than due to the differences between levels of care. Also, patterns of patient referral may have shifted during that period and it is even possible that some women gave birth at the primary or secondary level facility in 2008–2009 and then later at the tertiary centre in 2011. It is likely, however, that the background population living in the study area remained relatively constant across the two periods. Moreover, overall, despite the data gaps and quality concerns, this was the only available data that provides information on this important topic. The use of disaggregated data from this large database is a major strength of the study, allowing us to identify differential access to services and variations in birth outcomes by sub-populations, who can then be targeted.
