This study confirms that kolanut is frequently consumed at relatively high quantity by pregnant women. The most reported reasons for use were for the prevention of excessive salivation, nausea, and vomiting. Factors that remained significantly associated with current use of kolanut were ethnicity, with the highest use among Yoruba women, those with lower educational levels and those attending antenatal care at primary health care centers or TBAs.
A significant number of studies that have reported higher risk of adverse pregnancy outcomes such as miscarriages (14–18), among pregnant women consuming high levels of caffeine-containing substances in pregnancy. Caffeine can cross the placenta into the amniotic fluid and the fetus, resulting in adverse pregnancy outcomes (19), such as small for gestational age birth (20), and a delay in neuronal migration and gliosis (21), caused by kolanut. An understanding of patterns of kolanut use and associated factors as provided from our findings will support the design of interventions that could target pregnant women with kolanut use in pregnancy in Nigeria. The current study showed a prevalence of 33.9% of kolanut consumption in previous pregnancy and 29.3% reported use in the current pregnancy, this shows a high consumption of kolanut in pregnancy. However, other Nigerian studies that collected kolanut consumption data among pregnant women reported lower prevalence of kolanut use, this could be because kolanut consumption in pregnancy was not their primary focus. An exception to this is a study conducted in Jos, North Central Nigeria (22), that reported a prevalence of 61.9%. Studies with less emphasis on kolanut use by Fawale and his colleagues (23), who investigated Restless Legs Syndrome in Hausa/Fulani women in Northern Nigeria and reported a prevalence of 8.4%. Another Nigerian study (24) of self-medication among women in South-South Nigeria found that only 1% of women reported kolanut intake in pregnancy. Ifesanya and Oke (9) reported a prevalence of 44.2% of kolanut/bitter kola consumption in pregnancy while looking at adverse gingival conditions among pregnant women in South-West Nigeria. In Ghana, a neighbouring West African country, Abu et., al (25), in a study of pica use found that 3.6% of women reported kolanut use. The present study showed a higher rate of kolanut use compared to those in Northern and South-South Nigeria with Yoruba women, constituting 82% of the sample while the study in North-Central Nigeria (22) with a much higher prevalence than the present study did not report the ethnicity of the women studied. Also, the higher proportion of use found in the present study could be because of kolanut use being the focus of this study while it was not of primary interest in the ones cited.
Even though there is a limited number of studies on kolanut consumption in pregnancy, several studies have examined psychoactive substances use among secondary school students with lifetime use as high as 86% (26) and 63.5% (27) in South-West and South-East Nigeria, respectively. Another study of students however reported 18.8% from the South-East (28). Further, a prevalence of 15.8% has been reported among commercial motorcyclists in Zaria, Northern Nigeria (29). Altogether, these studies of kolanut use in diverse populations suggest that kolanut use is popular in Nigeria and as stated by previous authors, some of the reasons for this include that it is cheap, readily available, and socially acceptable (22, 26).
In contrast to the findings from this study, other studies outside Nigeria focusing on caffeine use and not kolanut specifically report that almost all women take caffeine containing foods for different reasons at different points of pregnancy (16, 30, 31). For example, an Ethiopian study (30) investigated the consumption of caffeinated beverages and foods in a community sample of pregnant women and found that 98.2% of the beverages and foods had caffeine; with 17.6% of the women reporting excessive caffeine intake. These studies of caffeine use that are not restricted to kolanut alone highlight the possibility of greater caffeine consumption in pregnancy due to other sources such as coffee, energy drinks, soda such as Coca cola, and tea.
Kolanut use in this study was most frequently reported in the first trimester (32.1%). Most women studied reported medium (thrice in a week) or high frequency (daily) kolanut use, while most women also reported high (at least 1 nut at once) or medium (half to less than 1 lobe) quantity. These findings suggest that users tend to consume significant quantities relatively frequently and highlight the need for efforts to identify these women and offer interventions that will get them to discontinue use. Health providers have a crucial role to play in this regard, especially given that history of kolanut use may not be routinely asked during antenatal care, a concern similarly shared by other authors (32, 33). Additionally, women who are managed for nausea and vomiting, have a greater chance of using kolanut for treatment and could be important targets for identifying those who may be using kolanut. Hämeen-Anttila et.al., (34) showed that the need for health information was significantly higher among pregnant women using herbal preparations, supporting the argument for the provision of health information to women who may be using substances like kolanut.
The most common reason for kolanut use was the prevention of excessive salivation, nausea and vomiting, reported in about 56% and 37% respectively of women that reported ever using kolanut. In support of the importance of nausea and vomiting warranting kolanut use, a study in North Central Nigeria reported that preventing nausea and vomiting was the reason mentioned by all women reporting kolanut use in pregnancy (22). It is noteworthy that in contrast to the reasons for kolanut use in pregnancy, students and commercial motorcyclists populations are more likely to report use for staying awake, suppression of fatigue and peer group pressure (26, 29).
It was also noted that kolanut use was significantly higher among women with lower educational level, women attending primary health care centers and TBA clinics, after adjusting for other demographic characteristics and reproductive health related variables. The higher amount of kolanut use among Yoruba women compared to other ethnic groups in Nigeria has been discussed earlier when comparing the findings from this study to others from other regions of the country. The reasons for ethnic differences in kolanut use could include the availability of kolanut in some regions compared to others and cultural beliefs that could promote use in pregnancy. However, the ethnic differences found in this study must be interpreted with caution given the inadequate sample sizes for non-Yoruba ethnic groups. The higher rates among women with lower education could be due to poor knowledge of foods safe for consumption in pregnancy (35), compared to more educated women. It could also reflect poor socioeconomic status of women with lower education who may lack funds to seek healthcare for treatment of symptoms such as nausea and vomiting, thereby, visiting PHCs and TBA clinics, resulting in higher amount of kolanut use in these centers. In addition to women with excessive salivation and nausea and vomiting, interventions aimed at reducing kolanut use in pregnancy need to target women in PHCs or TBA clinics, Yoruba women, and those with lower education. There were no significant differences in kolanut use by age or parity, although nulliparous women were less likely to currently use kolanut. However, the very small number of nulliparous women casts doubt on the results. The non-significant difference in kolanut use by age has been reported in another study(22).
Limitations Of The Study
The limitations of this study include the potential for recall bias concerning kola nut use in previous pregnancies. Additionally, some of the women studied in the first and second trimester could use kolanut later in their pregnancy, potentially underestimating kolanut use. However, majority of the women studied were in the third trimester and most current kolanut use would have been captured. In addition, the assessment of ever-use of kolanut is likely to capture most women that use the substance. Other limitations include the inability to quantitatively estimate the amount of the kolanut use as there are currently no guidelines for determining levels that are likely to result in adverse outcomes. This contrasts with caffeine-containing foods in the developed world such as coffee and soda that have been extensively studied.
Recommendations
Studies designed with large sample sizes of the ethnic groups and including qualitative methodology are needed to understand kolanut use patterns in pregnancy by ethnicity. Also, multiple sources of caffeine in the Nigerian context and estimation of total caffeine intake through kolanut should be studied. Furthermore, health information about hazards of substances like kolanut should be included in routine counseling in ANC clinics. Finally, further studies with a wider coverage within the country should be considered as this would give a better picture of kolanut consumption among pregnant women.