Malaria remains a public health threat, with 249 million malaria cases reported in 2022, representing an increase of 5 million cases compared to 2021 [1]. According to the World Health Organization (WHO), the African region bears 95% of the world’s burden of malaria cases, with children under five years and pregnant women being the groups at highest risk [2]. In sub-Saharan Africa, 35.4 million pregnancies were recorded in 2022, of which 12.7 million (36%) pregnancies were exposed to malaria [1]. Malaria in pregnancy (MiP) is responsible for adverse effects both on mothers and their offspring, and these include maternal anemia, pre-term delivery, abortion, stillbirth and low-birth weight (LBW) [3,4]. Without pregnancy-specific intervention in African endemic areas, MiP would have resulted in an additional 521,000 neonates with low-birth weight given the current coverage levels of the main preventive drug-based strategy implemented among pregnant women, i.e., intermittent preventive treatment during pregnancy (IPTp) [1]. In non-endemic areas, falciparum malaria in pregnancy is more likely to lead to overt clinical symptomatology and even severe complications such as cerebral malaria than in the non-pregnant population. In contrast, parasitemic pregnant women are rarely symptomatic, and death from malaria is extremely unusual due to the progressive and relatively rapid acquisition of significant levels of anti-malarial immunity in areas of stable transmission [5]. The risk of malaria and morbidity is higher among primiparous women, adolescents and those co-infected with human immunodeficiency virus (HIV), and malaria-related maternal deaths are estimated to account each year for up to a quarter of all maternal deaths in high-transmission settings [6]. To prevent these adverse effects in areas with moderate-to-high transmission of Plasmodium falciparum (P. falciparum), the WHO recommends a series of interventions. This relies on the promotion and use of long-lasting insecticide-treated nets (LLINs), together with the administration of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP) during pregnancy and appropriate case management through prompt and effective diagnosis and treatment of malaria in pregnant women [7]. However, all of these interventions are delivered through antenatal care (ANC) channels, leaving a great proportion of pregnant women unprotected as a significant proportion may not attend or may delay their initial ANC visits. Malaria occurring early in pregnancy is associated with a higher risk of LBW [8,9]. In Burkina Faso, the permanent secretary for malaria elimination (former National Malaria Control Program, NMCP) recommends for each pregnant woman at least four ANC visits with a minimum of three doses of IPT-SP before delivery [10]. Pregnant women then need to start receiving ANC in early pregnancy to fully benefit from these preventive measures. The WHO has recommended surveillance as an additional tool to control malaria and to monitor trends over time in endemic countries [11]. Groups at risk of malaria should then be identified and resources be allocated for malaria control in high-malaria-burden countries like Burkina Faso [12]. This would require the availability of reliable statistics on the prevalence and risk factors of malaria in pregnancy across the country. In Burkina Faso, several studies on malaria in pregnancy have been conducted to assess the efficacy of anti-malarial drugs during pregnancy but studies characterizing the profile of pregnant women at their first ANC visit are scarce [13]. Characterizing pregnant women attending ANC clinics for the first time can help customize interventions for this specific group. This study was carried out to determine the prevalence of malaria in pregnant women attending ANC clinics for the first time and the associated risk factors.

In this high-endemic malaria setting of Burkina Faso, a high prevalence of malaria-infected pregnant women was documented. This is worrying given the potential adverse effects of malaria during pregnancy [5,19,20,21]. This situation reveals a high level of malaria transmission in this region and a poor uptake of the preventive measures recommended due to late ANC visit attendance [10]. Consequently, a large proportion of pregnant women do not benefit from these preventive measures delivered through antenatal channels. They then carry malaria which will have detrimental consequences both for themselves but also for their offspring, in addition to serving as an important parasite reservoir by sustaining the malaria parasite transmission cycle [22]. In our context, although pregnant women and children under five receive treatment free of charge, cultural beliefs, practices and literacy levels may have contributed to this delayed attendance. Conducting anthropological studies could help uncover the underlying reasons for this delay, enabling the development of effective strategies to address it. The prevalence of malaria in this study was high compared to other studies conducted in neighboring districts. Indeed, Lingani et al. documented a lower prevalence (16.1%) in Yako, an urban area where preventive interventions may be more accessible and utilized effectively. Urban centers generally offer improved healthcare access and infrastructure, supporting greater ANC attendance and malaria prevention compared to rural areas [23]. This difference highlights the need for spatially adaptive intervention strategies, as advocated by the WHO, which recommends targeting high-transmission zones with intensified, tailored measures [24]. Similarly, a study by Yaro et al. in the same epidemiological area documented lower prevalence rates, likely due to its broader inclusion criteria, covering pregnant women at various ANC stages [25]. Many of these women may have already received IPTp-SP, which has been shown to improve pregnancy outcomes due to its efficacy in malaria prevention, and it could have reduced the overall malaria prevalence of the study participants [26,27]. Higher malaria prevalences during first ANC visits were found in various countries, with 31.8% in Zambia [28], 42.2% in Mali and 59.7% in Ghana [29]. However, it is worth noting that our study was conducted after the rainy season, when malaria transmission normally decreases. The decreased incidence found in our data may be partially explained by this seasonal context, since transmission rates are known to vary greatly between rainy and dry seasons. Nonetheless, the high malaria prevalence in our study is alarming and calls for early uptake of the preventive measures available. More than 80% of the study participants reported having an LLIN, but conversely, the prevalence of malaria-infected pregnant women was high in our study, suggesting that coverage alone may not fully capture effective bed net utilization or replacement practices. Family size may influence bed net access, as distribution ratios typically provide one LLIN per two family members, potentially leading to shortages and increased wear. In addition, lower literacy levels and socioeconomic constraints may hinder the effective use of these preventive strategies and further limit the ability of lower-income families to replace worn nets. Misuse, inconsistent use or poor net condition may reduce LLINs’ protective effect, along with issues related to outdoor exposure to mosquitoes due to household activities. In our case, the problem appears to be more related to utilization gaps than to pyrethroid resistance, as LLINs have retained efficacy even in resistant settings [30,31]. While the permanent secretary for malaria elimination offers LLINs through sensitization campaigns, the ownership and likely utilization of the nets remain underexplored. In addition, outdoor mosquito biting remains a problem. This calls for social science studies to investigate in more detail the real state of LLIN utilization and the discrepancies between ownership and real-life utilization.

The overall geometric mean parasite density reported in the present study is similar to those reported by Yaro et al. (777.3/μL) [25] in Burkina Faso and Fana et al. in Nigeria (800/μL) [32], while Lingani et al. reported a slightly higher density in Yako [13]. Factors such as the level of immunity and the uptake of protective measures can explain these differences [33,34]. In addition, this difference can be attributed to the parasite density calculation method used (absolute count of white blood cells versus assumed 8000 WBCs per μL) as there is variation between the two methods [35]. Nonetheless, the same method was used by Lingani et al. [13]. Nearly 20% of pregnant women exhibited signs and symptoms indicative of malaria, with a positivity rate of 40%. A study in Cameroon observed a similar trend, as 21% of febrile pregnant women had a positivity rate of 65% [36]. Given that most pregnant women have asymptomatic presentation of malaria in endemic areas, it is recommended that all pregnant women attending ANC visits be screened for malaria regardless of their symptom status.

Our analysis also highlighted higher malaria susceptibility in younger women (particularly those aged 16–18) and primigravidae (40% of the infected women). In addition, the highest parasite densities were recorded in these groups. These results indicate that younger age (reduced exposure and hence limited immunity) contributes to higher susceptibility to P. falciparum infection in primigravidae compared to multigravidae [37]. Greater risks of infection and adverse outcomes in primigravidae have been attributed to the absence of pregnancy-specific malaria immunity to pregnancy-associated variant surface antigens (VSAPAM) that predispose pregnant women to increased malaria severity [38].

A high prevalence of anemia was found in our study. The same picture of high prevalence of anemia was seen in neighboring countries such as Ghana (70.0%) [39], Benin (67.7%) and Cote d’Ivoire (62.7%) [40], but a lower prevalence was found in southern African countries in a comparative study [41]. The difference in anemia frequency between these two parts of the continent is probably due to the intensity of malaria transmission [42,43] and the high co-existence of soil-infected helminths [44]. Anemia is known to be caused by malaria, especially P. falciparum infections which directly destroy red blood cells and can also impede the formation of new red blood cells by triggering an inflammatory response [45]. Chronic anemia can result from repeated malaria infections over time in areas with high transmission rates, particularly in susceptible populations like children and pregnant women [41]. Additionally, the high co-occurrence of soil-transmitted helminths further exacerbates the prevalence of anemia in West Africa, while conversely, Southern African regions typically report lower helminth infection rates due to different environmental factors, increased healthcare access and the implementation of deworming programs [46]. This lower burden of helminth infections likely contributes to a reduced anemia prevalence compared to West Africa. This is worrying as anemia combined with malaria can negatively impact the course of pregnancy. In the multivariate analysis, the factors associated with the presence of anemia among pregnant women were primigravidae (2.1 times compared to multigravidae), malaria parasites (2.2 times compared to those with negative results) and malaria symptoms (with the presence of symptoms being 1.3 times compared to the absence of symptoms). It is generally assumed that adherence to iron supplementation and ANC service utilization among pregnant women are typically poor in such settings, which are common problems in sub-Saharan Africa [47]. Surprisingly, pregnant women going to school were the most at risk of being anemic. This can be explained by the relatively low number of this subgroup in our study, which could amplify variations in anemia prevalence. However, anemia is known to be a multifactorial phenomenon, and other factors such as low iron or folate levels, as well as infections, genetic predispositions and overall health conditions that were not investigated in the present study, could be another explanation. Moreover, our study design did not allow us to follow pregnant women from their first ANC visit through to delivery. While this approach could have provided deeper insights, it was not feasible within our budget constraints.

The prevalence of malaria during the first ANC visit was high, with one-quarter of women being infected. High parasite densities were found in pregnant women of younger ages. Our study suggests that younger age and lower parity are significant risk factors for malaria, while older and multiparous women are relatively more protected. In addition, a very high proportion of anemic pregnant women was reported, with malaria significantly increasing the odds of developing anemia. Altogether, this suggests that malaria control in Burkinabese pregnant women still faces several challenges, and that there is a need to reinforce malaria and anemia preventive measures through education and sensitization, with special emphasis on increasing early ANC visit attendance.