This study assessed the factors associated with the knowledge of MTCT of HIV among women of reproductive age in Indonesia. The study found that 72% of women in Indonesia had knowledge of MTCT of HIV. Our study finding is higher than several other studies conducted in Asia and sub-Saharan Africa (SSA). Within the Asian continent, a study conducted in Vietnam reported a knowledge level of 46.83%, which is lower than the present study [18]. Also, within SSA, certain studies from Zimbabwe [21], Tanzania [22], and Ethiopia [17] reported 70.5%, 46%, and 41.1%, respectively. Furthermore, an analysis of 33 sub-Saharan African countries also revealed a knowledge level of 56.21% which is also far lower than the current findings [16]. The higher knowledge level among women in this study could be attributed to the integration of the Prevention of Mother-to-Child Transmission (PMTCT) of HIV program into antenatal care clinics as a part of the national HIV programs by the MOH of Indonesia. In 2017, approximately 664 healthcare facilities were providing PMTCT programs all over Indonesia [23]. The program aimed at creating awareness of MTCT of HIV among reproductive-age women in Indonesia which might have contributed to the knowledge level of women in this study.

The multilevel fixed effects results showed that maternal age, educational level, parity, frequency of reading newspapers or magazines, frequency of using the internet, wealth index, and type of place of residence was associated with knowledge of MTCT of HIV among women of reproductive age in Indonesia.

We found that women’s age was associated with knowledge of MTCT of HIV. In particular, increasing age was associated with higher knowledge of MTCT of HIV. This finding is in line with studies conducted in Zimbabwe [21], Tanzania [22], and Vietnam [18]. The plausible reason for this finding could be that the younger women might not have pregnancy or childbirth experience, so they would be less exposed to this information, usually given during antenatal care or neonatal visits [22]. In Indonesia, youth reproductive health programs that provide information and education on reproductive health, including HIV/AIDS and STI, are included in the Youth Care Health Program (PKPR) service. However, not all public health centers in Indonesia have implemented this service [15]. Our findings suggest that efforts to support the existing program and new strategies to create the awareness of younger women especially those below ages of 20 years on MTCT of HIV are imperative in order to reduce MTCT of HIV.

Evidence shows that higher education is a universal variable for increased knowledge of HIV transmission, and prenatal education [24,25,26]. This study found that the higher the woman’s education, the higher the knowledge of MTCT of HIV. This finding resonates with several other studies conducted in Ethiopia [17, 27, 28], Vietnam [18], Cameroon [29] and Tanzania [22]. Women with higher education has the ability to seek for information and being able to process health information better than women who are not educated [28]. Education of women has the propensity to increase the acquisition of knowledge about maternal health services and enables women to seek and utilize healthcare services [1, 30, 31]. Evidence also shows that educated women who utilize healthcare services such as ANC and health facility delivery are more likely to have PMTCT knowledge [32].

Our study found that multiparous women were more likely to have knowledge of MTCT of HIV compared to nulliparous women. This is in line with several other previous studies [1, 22, 32]. Multiparous women may have received more information on MTCT of HIV during prenatal visits, perhaps leading to improved knowledge.

Furthermore, this study revealed that women who were exposed to mass media were more likely to have knowledge of MTCT of HIV. Precisely women who read newspapers/magazines and the use of the internet in daily bases was associated with knowledge of MTCT of HIV. Our study finding collaborates with findings in Ethiopia [17]. Also our findings resonates with a multi-country study conducted in SSA [16]. In Indonesia, internet users are accelerating yearly; in 2017, internet users were 54.68%, increasing to 77.02%. In 2020, 76.48% of Indonesian women became internet users, and the main reason for internet use was access to social media and news/information [33]. Our findings suggest that mass media outlets are key in the quest to eliminate MTCT of HIV by 2030 if much attention is given to propagating most educative programs on media about MTCT and PMTCT.

Consistent with extent of literature women from higher socioeconomic status are more likely to have higher knowledge of MTCT of HIV [17, 18, 22, 28, 34]. The reason for this finding might be that woman in the lower socioeconomic status might have less access to healthcare services or health facilities due financial barriers and this might impede them from acquiring health information [35]. This will further affect women’s inability to access maternal health services such as antenatal care [36, 37]. Another plausible reason might be that women from higher socioeconomic households are exposed to several opportunities such as access education, health services, and social media to obtain health information on MTCT of HIV [17, 22, 28]. In addition, wealthier women believe health is an investment in the future [18]. Most Indonesian people still view public health services as providing low-quality services from health professionals, complex procedures, and long waiting times. Therefore, high-income Indonesians prefer to go to private health services that provide faster and simple procedure even though they have to spend more money in this facility [38]. For this reason, they will have longer time to discuss with health professionals and have more health information about any health issue they wish to enquire about.

Finally, we found that women from rural settings were less likely to have knowledge about MTCT of HIV. This finding resonates with a recent study conducted in Ethiopia where rural residents were less likely to know about MTCT of HIV [17]. Some other studies have reported that women from urban settings had better knowledge of MTCT of HIV [12, 27, 39]. The plausible reason could be that women from rural settlements might not have access to some key social amenities such healthcare facilities where they can seek health care and possibly receive education on MTCT of HIV. Also, exposure to mass media outlets might have been limited and this could have also limited their knowledge on MTCT of HIV. Although 94% of provinces in Indonesia have met the standards in each district having at least one public health center, the people still have not been able to access it properly [6]. One of the reasons is the geographical difference in Indonesia. As the largest archipelago in the world, many remote islands are difficult to reach [40, 41]. While in urban areas, private health services are also available so that it is easier to access health services, rural areas still rely on public health centers [40]. Geographical conditions also make many rural areas, especially in the eastern region of Indonesia, not to have adequate internet access [42].

The strength of this study is the use of a nationally representative sample to assess women’s knowledge of MTCT of HIV in Indonesia. Using large sample means the study findings are generalizable to the entire reproductive age women in Indonesia. The findings from this study are anticipated to contribute to the designing of new policies and strategies to improve on existing programs on the PMTCT of HIV in order to control the disease in Indonesia. Notwithstanding the strengths, the study is fraught with some limitations. First, due to the cross-sectional nature of the DHS data, we could not draw casual inferences. Lastly, the survey dataset was limited to questions on MTCT did not have a component to assess their knowledge on the prevention of MTCT of HIV.