Polygamy is a form of marriage involving multiple spouses. It may occur as polygyny (when a man has multiple wives concurrently, and less commonly, as polyandry (when a woman has multiple husbands concurrently) and as polygynandry (concurrent marriage of two or more wives to two or more husbands) [1,2,3,4].
Polygyny is the commonest form of polygamy. It existed historically in more than 80% of preindustrial societies [5]. Although the global prevalence of polygyny is small, more than a third of the world’s population lives in a community that permits it [6]. The history of polygyny has been practiced for many centuries by various cultures in the world. It has existed as a fundamental part of family law in most African countries. With the arrival of Christianity and colonists, however, it came to be considered as a form of slavery that needed to be eliminated. As a result, its prevalence has been diminishing for decades. Nevertheless, it remains more common in Sub-Saharan Africa (SSA) than anywhere else [7]. The highest prevalence of polygyny in Africa is found across the so-called ‘polygyny belt’ stretching from Senegal in West Africa to Tanzania in East Africa [8]. As the Demographic and Health Survey (DHS) data show, 11, 27, and 53% of marriages in Zimbabwe, Ivory Coast, and Guinea were polygynous respectively [9]. Another DHS reported that polygyny represents 25% of all marriages in the Democratic Republic of Congo (DRC), 47% in Sierra Leone, and 53% in The Gambia [10].
In Ethiopia, although polygyny has declined in recent decades, the national average of polygyny among currently married men was 11% in 2016 and ranged from 1% in the Amhara region to 29% in the Somali region [11, 12].
There are several possible reasons for the persistence of polygyny in Ethiopia. Demographic factors such as high infant and child mortality, high male mortality and out-migration, and potentially lethal activities performed by men such as hunting and military combat resulting in a surplus of women and shortage of men, all of which can encourage polygyny [13, 14]. Religions, mainly Mormonism and Islam, have increased the prevalence of polygyny. Polygyny among Mormons is encouraged whereas, in Islam, it is merely permitted [13, 15]. The prevalence of polygyny is also affected by age, place of residence, and household wealth [16, 17]. Culture and tradition are the other main factors contributing to the acceptance of polygyny. Polygyny in many African cultures is considered to be a solution for women’s infertility and menopause. It also allows men to satisfy sexual needs while their wives are pregnant since sexual relations during pregnancy are taboo in some cultures. Some believe that it is important for a man to continue his family name in future generations. In agricultural societies, polygyny leads to more children who can work in housework, farming, and cattle herding [4, 7, 18, 19].
Polygyny is legally prohibited in Ethiopia by the revised family code proclamation since it undermines women’s self-worth, violates gender equality and women’s rights, both of which are protected under the Convention on the Elimination of All Forms of Discrimination Against Women (CEDAW) and the Universal Declaration of Human Rights (UDHR) [20]. These legal restrictions on polygyny, however, are rarely enforced.
In addition, polygyny increases the spread of HIV/AIDS and other Sexually Transmitted Diseases (STDs) [21,22,23]. Men in a polygynous marriage were 2.6 times more likely to be HIV positive than monogamous men [24] and 2.9 times more likely to be infected with Herpes Simplex Virus (HSV)-2 [25]. Moreover, polygyny is associated with a higher incidence of infant and child mortality [26, 27]. Children from polygynous families experience ill health and early childhood death as a result of malnutrition and HIV/AIDS [28,29,30]. Adolescents in polygynous families are more likely to have lower self-esteem [31] and poor academic outcomes compared to adolescents from monogamous families [2, 32,33,34]. Polygyny is also a source of emotional distress and depression imposing detrimental effects on the mental health of wives [35,36,37].
Identifying the determinants of polygyny is important to meet Sustainable Development Goal (SDG) 3 (to end the HIV epidemic and to decrease neonatal mortality below 12 per 1000 live births by 2030), SDG 5 (to achieve gender equality and empower all women and girls by 2030) [38] and Ethiopian Health Sector Transformation Plan (HSTP) IV (to decrease the under-five mortality rate from 64 to 30 per 1000 live births, to reduce adult HIV incidence by 60% below 2010 incidence, and to achieve zero new HIV infections among children by 2020) [39].
The reasons for polygyny are multifaceted and vary within and across countries. However, the polygyny practice is more prevalent in sub-Saharan African countries than other world sub-regions [40]. The problems associated with polygyny are numerous, especially in a less developed country like Ethiopia where there is poverty and majority of families earn less than $1 per day [41]. Polygyny has been implicated in many studies as one of the factors that promote early marriage, domestic violence, harmful traditional practices, and high fertility [42,43,44,45]. Despite the public health importance of polygyny, it is often less studied in Ethiopia. This study aimed to determine individual and community-level factors associated with polygyny among married men in Ethiopia.