This study set out with the aim of identifying the determinants of multiple partner fertility among males in Uganda. Secondary data obtained from the Uganda Demographic and Household Survey (UDHS) of 2016 were applied to this study.
The results of this study indicated that the probability of fathering children with multiple women increased with increase in one’s age. This result was consistent with the findings of the study by Logan et al.  who observed a steady increase in the proportion of males fathering children with multiple women from 5% by the age of 25 to 15% by the age of 40. A possible explanation for this result may be attributed to the longer duration of time that older men have had to move from one relationship to another, compared to younger men . Secondly, older men tend to have more resources than younger men  and they are therefore in a better position to have another child from a different relationship.
It is interesting to note that males in the Western region had lower odds of fathering children with multiple partners compared to males in the Central region. This can be attributed to the fact that the Central region is more urbanized than the Western region of Uganda. According to the 2014 National Population and Housing Census report, at least half of the twenty largest urban centers were located in Central Uganda and only three in Western Uganda . Also, findings from the UDHS report by UBOS and ICF  indicated that 36.2% of urban males compared to 28.4% of rural males reported having sex in the past 12 months with a person who was neither their wife nor lived with them. Therefore, given that males in urban areas tended to have multiple sexual partners, this may explain the higher odds of male multiple partner fertility in the more urbanized Central region compared to the Western region.
As expected, this study demonstrated that the Muslim men had greater odds of multiple partner fertility than men belonging to the Anglican religion. This result can be attributed to the teachings in the Quran (4:1) which do not prohibit a man from having more than one wife . For this reason, the men are at liberty to marry more than one wife and have children with them. Religiosity has an impact on the attitude of an individual towards different aspects of marriage such as divorce and commitment and longevity [18, 19].
The findings from the analysis of the data in this study showed that males who were cohabiting or married had lower odds of fathering children with more than one woman compared to the males who were not in union. Males who were divorced or separated had higher odds of fathering children with more than one woman compared to males who were not in union. Although people who are cohabiting are in less legalized relationships and are less bound to commit to a single relationship , the findings of the study could be attributed to partners in this case looking at cohabitation as a step towards getting married . Therefore, males who are cohabiting may demonstrate the same level of commitment to a specific partner even though the relationship isn’t yet formalized by getting married. The males who are divorced or separated are at greater liberty to start another relationship and have children with the women in the new relationship compared to males who are not divorced.
Another important finding in the study was that the odds of male multiple partner fertility increased with decrease in age of first sex. The result in this study was in agreement with Logan et al.’s  study who found out that 27, 16 and 6% of males whose age of first sex was by 15, 17 and 19 respectively had fathered children with more than one woman. Early sexual debut is linked to increased risk of involvement in risky sexual behaviors such as having unprotected sex, unstable sexual partners and unwanted pregnancies [22,23,24]. In addition, the men who birthed their first child at an early age were less likely to be married at the time which reduced their likelihood of committing to just one woman, the mother of their first child . The increased odds of multiple partner fertility among males with many wives/partners is expected since having more children is one of the reasons for males getting other wives or partners especially in developing countries [25,26,27]. Finally, the odds of fathering children with multiple women increased with increase in number of lifetime sex partners. This could be due to the increased tendency by males to use protection against pregnancy less reliably as their number of sexual partners increases . Ashenhurst et al.’s  study found that people with multiple partners over time had the highest odds of reporting sex with no protection against STIs and pregnancy compared to those who had one partner over time.
The most important limitation of this study lies in the fact that data in the UDHS is dependent on the participant’s responses which may be affected by recall, reporter or response bias. Also, the men may not be in the know of the actual number of children they have fathered outside their current union and with how many partners . These affect the accuracy of the information given. Secondly, this was a cross-sectional study which limits the research to description of the association and not the cause-effect relationship between male multiple partner fertility and identified factors. Thirdly, since secondary data were used, some key variables were left out of the study given that they weren’t captured. These included marital status of one’s parents at their birth, family structure, number of siblings and education level of their parents etc. .