Proportion of pregnant women screened for hypertensive disorders in pregnancy and its associated factors within antenatal clinics of Kinshasa, Democratic Republic of Congo

Hypertensive disorders in pregnancy (HDP) are the second most common cause of maternal mortality worldwide [1]. Most deaths are avoidable and occur in low- and middle-income countries (LMIC), due to a lack or a delay in identifying women at high-risk, and in their treatment [2‐5]. HDP screening is an essential element of antenatal care (ANC) that allows the identification of women at high risk of developing HDP or HDP-related complications, and the implementation of preventive interventions for improving perinatal outcomes [6‐12]. Screening for HDP at the first antenatal visit includes blood pressure measurement, urine testing for proteinuria, and identification of maternal risk factors [13‐17]. The National Institute for Health and Clinical Excellence (NICE) and the American College of Obstetricians and Gynecologists (ACOG) have provided a list of maternal risk factors to be assessed at the first antenatal visit [13, 18]. To prevent HDP in LMIC, where biomarkers are not available to identify women at high risk, the International Society for the Study of Hypertension in Pregnancy (ISSHP) recommends the use of low dose aspirin started before 16 weeks of pregnancy in women with any of the following risk factors: previous preeclampsia, chronic hypertension, underlying renal disease, diabetes mellitus, obesity, and antiphospholipid antibody syndrome [17].

In sub-Saharan Africa, while blood pressure is measured in more than half of antenatal attendees, proteinuria testing is performed less frequently [19‐23]. Studies report 10% of women tested for proteinuria in Mozambique [21], 23% in Zambia 23% [19], and 32% in Ethiopia [24]. In a study in six sub-Saharan Africa countries including Tanzania and Rwanda, only 46% of women had a urine test for proteinuria [25]. According to the Demographic and Health Survey (DHS) conducted in 2014 in Democratic Republic of Congo (DRC), urine samples were collected during antenatal visits in 94.1 and 53.1% of women who delivered in the five years preceding the survey in Kinshasa and DRC, respectively [26]. However, laboratory tests performed on these urine samples were not specified. According to the World Health Organization (WHO), the maternal mortality is estimated at 693 deaths per 100,000 live births in the DRC [27]. This is higher than one might expect based on a high rate of antenatal care attendance (89%) and a high rate of skilled attendance at delivery(80%) [26]. According to the DRC’s National Health Information System (NHIS), 561 (52%) of the 1088 cases of preeclampsia reported in Kinshasa in 2017 developed eclampsia [28], making HDP the major cause of adverse pregnancy outcomes. During the first six months of 2018, HDP accounted for 841 (23%) of the 3656 maternal deaths that were reported to the DRC’s maternal death surveillance system [29]. Given that HDP are the second most common cause of maternal mortality in DRC [29], preventing HDP and HDP-related adverse pregnancy outcomes can contribute to the attainment of Sustainable Development Goal 3, which aims to reduce the maternal and neonatal mortality [30]. To our knowledge, no study to date has evaluated the screening for HDP during antenatal care in Kinshasa. We conducted the current study to determine the proportion of pregnant women screened for HDP during their first ANC visit in Kinshasa, and to identify factors associated with HDP screening.

Our study showed a low level of provision of screening for HDP in Kinshasa, with only 26.7% of women fully screened. Nearly all women had their blood pressure checked. The failure of complete HDP screening was a lack of ascertaining risk factors in 40%, and a lack of urine testing for proteinuria in 73%. The latter made the overall gap in the quality of screening so high. Screening for HDP was significantly higher in parous women, in women with a gestational age of at least 20 weeks, in women attending in a private clinic or in a hospital, and when no additional payment was required for proteinuria testing at the clinic.

The prevalence of blood pressure measurement in our study is consistent with those reported in Kenya (96%) and Nigeria (92%); but higher than the range of 45 to 89% reported in other developing countries such as Mozambique and Ethiopia [25, 33‐35]. Our findings regarding proteinuria testing are similar to those reported in Rwanda (31%) and Madagascar (29%), but lower than those reported in Tanzania (40%), in Kenya (59%) and in Ethiopia (66%) [25]. Despite the availability of urine tests in two-thirds of health facilities in Kinshasa, we found a low provision of urine testing for proteinuria. This suggests that other factors were not captured by our study, including poor knowledge among ANC providers or a lack of consistent national guidelines for the screening for HDP [25, 36].

Risk factors of HDP can be ascertained by a simple anamnesis of a woman during her ANC consultation [17]. In our study, only 59.8% of pregnant women were assessed for risk factors of HDP. To assess risk factors, providers should be aware of them. In studies from Bangladesh and Nigeria, only 2 and 15% of ANC providers were aware of risk factors for HDP, respectively [37, 38]. The failure to assess women for risk factors of HDP in Kinshasa may be a consequence of providers’ knowledge gaps, but the point needs to be investigated.

The low provision of screening for HDP in Kinshasa (26.7%) may also be due to a lack of consistent national guidelines regarding the prevention of HDP, which can subsequently induce knowledge gaps among health providers [39]. This low provision of screening for HDP raises the issue of the quality of antenatal care services, and implies a missed opportunity to prevent HDP which account for up to 23% of maternal deaths in DRC [29].

Screening for HDP is critically important in PHCs, even if they are generally less equipped, because it allows timely referral of the woman to a higher level facility with more appropriate surveillance tools [2, 17, 40, 41]. Our findings indicate that women having ANC visits in PHCs were less likely to be screened than those in hospitals. This finding is consistent with other studies reporting also a low provision of maternal health services in PHCs compared to hospitals [42]. More efforts should be devoted to promoting systematic screening for HDP in PHCs as they represent the first contact health facility in Kinshasa.

Studies have shown the benefit of aspirin in the prevention of HDP in high-risk women when it is started before 16 weeks of pregnancy, or definitely no later than 20 weeks [6, 17]. To be effective, such prevention requires on one hand that pregnant women book ANC during the first trimester of pregnancy, and that ANC providers systematically screen women to identify those at a high risk of developing HDP, on the other hand. Our study found a high prevalence of late ANC booking (83.3%). This finding is consistent with a previous study from DRC in which the magnitude of late ANC booking was 82.4% [43], suggesting that late ANC booking is a public health issue in DRC. Surprisingly, women booking ANC beyond 20 weeks of pregnancy were more likely to be screened than those booking before 20 weeks. One possible explanation is that preeclampsia, the most prevalent HDP, arises after the 20th week of pregnancy [17]. Hence, ANC providers would be inadvertently more interested in screening women with a gestational age greater than 20 weeks, rather than those with a less advanced pregnancy.

Our findings alert health authorities to the low level of screening for HDP in Kinshasa. With such low provision of screening, it is not surprising that HDP remain a public health problem in Kinshasa [29, 44]. The study highlights the need for improving the provision of screening for HDP in order to contribute to reducing HDP-related morbidity and mortality.

To improve the screening for HDP in Kinshasa, interventions targeting both community and health system are needed. At the community level, pregnant women should be advised to book ANC in an earlier stage of pregnancy, in order to benefit from early screening for HDP [6]. At the health system level, there is a need to update national ANC guidelines and to train health providers accordingly. There is also a need to enhance the availability of urine tests for protein, and without any additional payment from women [45].

The main strength of this study is that data were collected during an actual ANC consultation, avoiding bias due to self-reporting or recall bias. To our knowledge, this is the first study in Kinshasa focusing on the screening for HDP during antenatal care.

Nonetheless, the study has some limitations, as the provision of antenatal service was assessed by direct observation of an antenatal consultation, health providers might have made an extra effort to give their best quality service at the time when the research team visited the clinic. We attempted to mitigate this Hawthorne effect by having data collectors stay of several days, which may have helped to reduce ANC provider awareness of the presence of the data collector.

Our results show that screening for HDP during the first antenatal visit in Kinshasa is not universal. The gap in the quality of screening was in the identification of maternal risk factors, and a lack of urine testing for proteinuria. The factors associated with the screening included maternal as well as clinics’ characteristics. Our study highlights the need to improve the availability and provision of urine testing for proteinuria as well as risk factors assessment during the first ANC visit. More effort should also be made at the women level to increase early ANC booking.