Maternal conditions include events occurring from conception to 42 days postpartum. Among these conditions, hemorrhage, sepsis, hypertensive disorders of pregnancy, obstructed labor, and unsafe abortion account for three-quarters of all maternal mortality in developing countries, particularly sub-Saharan Africa (Graham et al., 2006; Musarandega et al., 2021; Oyston and Baker, 2020) According to the 2022 Tanzania Demographic and Health Survey and Malaria Indicator Survey (TDHSMIS), the maternal mortality ratio (MMR) for Tanzania is 104 maternal deaths per 100,000 live births (MoH, 2023). Although the 2022 MMR estimate represents a significant decline from 432 deaths per 100,000 live births in 2012, it remains high, above the agreed sustainable development goal (SDG) target of reducing the MMR to 70 per 100,000 live births by 2030 (Tanzania National Bureau of Statistics, 2013). To sustain current gain in MMR reduction and accelerate efforts toward realizing the SDG target, several measures are being implemented, including strengthening implementing policies and strategies that are more targeted to vulnerable population groups across the country, decentralizing lifesaving comprehensive emergency obstetric care to health centers, strengthening referral systems, and involvement of public-private partnerships (PPP) to ensure a continuum of care, to name just a few (Prasad et al., 2022; Shija et al., 2011).

In the past decade, studies and anecdotal evidence indicated that Tanzanian women are increasingly using traditional medicine as a complementary or alternative healthcare service to manage various maternal conditions. For instance, Dika et al., 2017 reported about a quarter of the pregnant women delivering in tertiary referral hospitals in Mwanza city were using herbal medicines (HMs) as one form of traditional medicine (Dika et al., 2017). Similarly, the prevalence of HMs use during breastfeeding was reported by one out of every two women in the Morogoro region (Millinga et al., 2022). A similar high prevalence of HMs use at 61.2% was reported in the Tabora region (Kessy and Msalale, 2020a). These variations in HMs use across regions in Tanzania pose significant challenges among policymakers, regulators, and healthcare practitioners in designing HMs-related policies and practices aimed at optimizing its contribution to maternal healthcare.

The use of HMs among women for maternal conditions is linked to several factors, such as social status, ethnicity, and cultural traditions. Moreover, the extent of use for the wellbeing of either the mother or the unborn child varies across regions (Illamola et al., 2020). Furthermore, previous studies reported that prevention of incidents of nausea and vomiting, improving abdominal muscle tone and building stamina during labor and delivery, improving the health of the woman, ensuring positive pregnancy outcomes, and easing labor are among the determinants of HMs use (Attah et al., 2012; Felisian et al., 2022; Shewamene et al., 2017). Although studies indicated that the majority of women use HMs for various healthcare needs, there is no accurate national estimate on the prevalence of HMs use for maternal conditions among women in Tanzania. Therefore, we conducted this systematic review to answer the following research questions: (1) what is the average prevalence of HMs use for maternal conditions in Tanzania? (2) what are the major maternal conditions commonly managed by HMs among Tanzanian women? The findings of this review enhanced awareness of the extent to which women of reproductive age use HMs. Bridging this knowledge gap could potentially influence reproductive and child health programs to account for traditional medicine use while planning for interventions to improve maternal health. The improved maternal care outcomes in the form of identifying and addressing potential risks for HMs-conventional medicine interaction could contribute towards accelerating maternal mortality reduction. This reduction is critical in achieving SDG targets.

To the best of our knowledge, this systematic review and meta-analysis is the first to provide qualitative and quantitative synthesis estimates of the national prevalence of and factors influencing HMs use for maternal conditions in Tanzania. The overall national prevalence of HMs use for maternal conditions is 46%. This means that, for every five Tanzanian women, at least two are using HMs for various maternal conditions. This information can assist in the planning of the management of maternal conditions by ensuring that mechanisms are in place to screen women for previous exposure to HMs. Such practice could enhance healthcare professionals’ understanding of the profile of HMs used by women while planning for conventional interventions critical to preventing potential adverse drug-herbal interactions.

While this is the first systematic review in the East African region, our findings are congruent with those reported in Ethiopia, where about 47.77% of women use HMs (Adane et al., 2020). The similarity observed between the two countries could indicate the shared socio-cultural beliefs and practices as these countries are located proximal to each other in the Eastern and north-eastern African regions. Regarding the maternal periods, contrary to our findings that the pooled prevalence of HMs use during pregnancy is 45%, a systematic review and meta-analysis of the prevalence of HMs use during pregnancy globally revealed an average of 32.4% (Heydarpour et al., 2022). The differences observed between the two systematic reviews could reflect the diverse socio-cultural context of the study population. While our systematic review focused on national prevalence from data on the same country, the latter pooled prevalence across countries with diverse cultural backgrounds. Nonetheless, these findings corroborate previous findings that women are increasingly using HMs during pregnancy (El Hajj and Holst, 2020; John and Shantakumari, 2015). In recognition of the high demand for HMs among Tanzanian communities and the potential contribution of HMs to accelerate the realization of universal health coverage, in 2022, the Government of Tanzania, through its ministry responsible for health, launched a pilot integration of traditional medicine in a formal healthcare system where HMs for selected diseases are dispensed at formal health facilities (MoH, 2022). This integration has been implemented for more than a year with satisfactory performance, but it has not provided guidelines for HMs to manage maternal conditions. Hence, the findings of this systematic review and meta-analysis could inform integration efforts on the possibility of expanding its scope to include maternal conditions frequently managed by HMs.

While several communities regard HMs as natural and may not harm pregnant women, recent studies have indicated some adverse effects associated with the use of certain HMs during pregnancy (Sarecka-hujar, 2022). Thus, the higher prevalence of HMs used during pregnancy in our study calls for deliberate efforts to identify and understand their safety and efficacy in humans.

The grounds for the frequent usage of HMs could be attributed to culture and beliefs, poverty, long distance to health facilities, high cost of conventional medicines, easy accessibility, and acceptability of HMs (Mudonhi and Nunu, 2022; Peprah et al., 2019). Again, the popularity of HMs use among women in maternal conditions could be mainly attributed to the belief that herbal products are natural and safe, with fewer adverse events compared to conventional drugs (Barnes et al., 2018; Ernst, 2002). In the current study, cultural and traditional customs, strong ties to local knowledge, low level of education and illiteracy, influence from older family members (e.g., elders), distance from health facilities, place of residence (e.g., rural), increasing age, low economic status, presence of traditional birth attendants (TBAs), and perceived safety of herbs are the driving factors for the usage of HMs among women.

There is an unequal distribution of HMs used among women in maternal conditions across different regions in Tanzania. Furthermore, when compared to other regions in Tanzania, Iringa and Manyara had the highest prevalence of HMs use for maternal conditions, accounting for more than 73.5 percent. This implies that efforts to create awareness among healthcare professionals of the substantial use of HMs by women for various maternal conditions have become the need of the hour. Interestingly, Zanzibar had the lowest prevalence, accounting for eight percent; this does not necessarily mean that the prevalence is lower in that archipelago; it might be because of the dearth of studies investigating HMs use for maternal conditions as only one study contributed to the overall pooled prevalence.

Contrary to the belief that the general population in Tanzania is increasingly using HMs for healthcare needs, our findings revealed a decreasing trend in the use of HMs for maternal conditions. However, the observed trend was not statistically significant and could likely be explained by the variation in a number of studies over time and settings or the growing inaccessibility of HMs in recent years. Nevertheless, such a decreasing trend raised critical research questions that call for researchers to assess the national prevalence of HMs use among women for maternal conditions using an appropriate sample size to validate the observed trend and also to determine barriers and facilitators of use.

Our systematic review and meta-analysis included data from sixteen out of thirty-one administrative regions in Tanzania. This may have led to insufficient representation from other regions, potentially underestimating the current national estimate. The missing regions likely represent populations with different practices regarding HMs use. However, the current national estimate offers a baseline that can serve in the absence of reliable national prevalence data for planning and managing maternal conditions. Additionally, the meta-analysis used survey data that could have been affected by biases such as social desirability and self-reporting, which might have influenced the national estimate. Nevertheless, efforts were made to assess bias risk, and only studies designed to minimize bias were included. Some relevant studies were excluded because the authors did not respond to follow-up emails despite three reminders over 2 months, which may have slightly limited our review scope. The lack of data from other regions highlights the need for further research on documenting HMs use among local communities to achieve better representation. Due to the limited availability of high-quality studies, some included studies had a significant risk of bias. This could affect the reliability of the overall findings, so the results should be interpreted carefully. However, their inclusion was deemed necessary to ensure comprehensive coverage of existing evidence. Furthermore, the narrative synthesis method used in identifying factors influencing the use of HMs among women did not support causal inference. The synthesis captured perceived or reported associations rather than statistically validated relationships. The results should therefore be interpreted as indicative of commonly reported influences within the available literature, not as definitive or causal effects.

Based on our findings, about 46% of women in Tanzania use some form of HMs to manage maternal conditions, and more women use them during delivery/labor and after delivery. Furthermore, the most commonly and frequently cited maternal condition managed by HMs is labor induction. Policymakers and healthcare professionals could use the national estimate of HMs use for planning the management of maternal conditions in Tanzania. However, data from better-designed ethnomedical surveys from all regions are still needed for a robust, generalizable estimate.