Institut Supérieur des Sciences de la Population
West Africa has one of the highest fertility rates in Africa and in the world.1 Several factors, including the persistence of subsistence farming and cultural and social norms that place a premium on having children, have contributed to a higher desire for children and higher fertility rates.2 However, different forms of marriage, including polygamy, have also contributed to the current landscape of fertility intentions in West Africa.
Recent Demographic and Health Surveys (DHS) data reveal that polygamy rates are high in most countries in the region (Figure 1), with the proportion of women in polygamous unions at or above 30% in eight countries and below 30%in two countries (Côte d’Ivoire and Ghana).
Sources: Data from DHS for various years: Benin (2017-18), Burkina Faso (2010), Côte d’Ivoire (2011-12), Ghana (2014), Guinea (2018), Mali (2018), Niger (2012), Nigeria (2018), Senegal (2019), and Togo (2013-14), https://dhsprogram.com/.
Several socioeconomic and cultural factors promote the practice of polygamy in West Africa, including:
While several studies have highlighted the decline in entry into marriage in West Africa and its impact on fertility decline, little attention has been given to the role of polygamy in maintaining high fertility and family planning use.6 To better understand the role of polygamy in fertility and to ensure that the needs of women in polygamous unions are addressed, it is therefore important to assess the impact of polygamy on fertility intentions and family planning use. This study addresses the topic of polygamy through three main questions:
To provide scientific answers to these questions, data from recent DHS in 10 West African countries were used as a framework for analysis: Benin (DHS 2017-18), Burkina Faso (2010), Côte d’Ivoire (2011-12), Ghana (2014), Guinea (2018), Mali (2018), Niger (2012), Nigeria (2018), Senegal (2019), and Togo (2013-14). We used this data to construct descriptive statistics and implement multivariate regressions to estimate the impact of polygamy on fertility, the average ideal number of children, and the proportion of women using family planning. Control variables included age, area of residence, household wealth quintile, level of education, occupation, number of co-wives, and ranking of wives. For additional information on our methodologies, please refer to Annex 1.
The figure below shows the descriptive analysis of the total fertility rate (TFR) for women in monogamous unions and women in polygamous unions. This represents the average number of children a woman would have during her reproductive life if current fertility rates held steady. The data shows no significant difference in fertility rates between women in polygamous unions and those in monogamous households in almost all countries.
Regarding the socioeconomic characteristics of women, women in polygamous unions living in rural areas have significantly more children than those in urban areas. In addition, the TFR of women in polygamous and monogamous unions decreases as their standard of living and level of education increases. Our analysis also shows that women in the labor force have a significantly lower fertility rates than unemployed women, regardless of type of union (Annex 2).
Considering the rank of wife and the number of co-wives, the descriptive results show that in polygamous unions, the level of fertility decreases as the rank of wife decreases (for example, third wife compared to second wife) and as the number of co-wives increases.
Source : EDS.
Estimating the average ideal number of children per woman (Figure 4) reveals that, in most countries, women in polygamous unions have a higher average ideal number of children than women in monogamous unions. The results of our analysis of the average ideal number of children by type of union reveal that women in polygamous unions are 28 percent more likely to want an additional child than women in monogamous households (Annex 3). Also, the results show that married women with primary or secondary and higher education, as well as those living in middle-income or wealthy households, have lower fertility intentions than those with no education (Annex 3).
Descriptive analysis of family planning use by type of union reveals that the proportion of women using a contraceptive method is lower among women in polygamous unions than among women in monogamous unions (Figure 5). In addition, multivariate analysis reveals that, other things being equal, women in polygamous unions are 14% less likely to use a family planning method than women in monogamous unions. Considering other factors associated with family planning use, a higher ideal number of children per woman, older partner age, and rural residence reduce the likelihood of using family planning; if the woman is employed, the likelihood increases. The probability of using family planning also increases with the standard of living and the level of education of women in union. (Annex 4).
Women in polygamous unions are also found to have lower percentages of demand for family planning satisfied by modern methods than those in monogamous unions (Figure 6). However, in Niger and Senegal, the results show little difference between women in polygamous unions and those in monogamous unions. Other findings indicate that the percentage of current family planning users who make decisions with their husbands is lower among women in polygamous unions than those in monogamous unions.
This analysis deepens our understanding of the role of polygamy in fertility, fertility intentions, and family planning use in West Africa. While fertility rates do not vary significantly between women in polygamous and monogamous unions, those in polygamous unions have a higher desire for children and are less likely to use family planning compared to women in monogamous unions. These findings build on previous population-specific analyses of the impact of polygamy on fertility, fertility intentions, and family planning and apply them more broadly to the West African region.
The results indicate no significant difference in current fertility rates between women in polygamous and monogamous unions in most countries, which is similar to the results of previous studies in Nigeria.7 Our analysis validates these results for other countries in West Africa.
In addition, other studies similarly indicate that fertility intentions are higher among women in polygamous unions than among those in monogamous unions. This finding may be related to competition for fertility among co-wives. For example, studies of the Yoruba people in western Nigeria have shown that in polygamous couples, younger wives with lower status have a greater desire to improve their status by having a male child or by giving birth to more children than older wives.8 Other research has shown that competition between wives intensifies when women are more directly dependent on their husbands for emotional fulfillment or access to resources.9
In most of the countries in this study, women in polygamous unions are less likely to use contraception than women in monogamous unions. While an earlier study in Nigeria found a different result10, our result could be explained in part by the fact that women in polygamous unions may be reluctant to use contraceptive methods because a high desire to have more children. In addition, the low autonomy of women in polygamous unions, which makes it difficult for couples to negotiate access to family planning, could help explain this difference.11
Future research could build on this analysis by addressing some of the existing limitations. The first limitation relates to the lack of qualitative anthropological data that could help us understand certain behaviors in society that might have an impact on fertility rates. For example, in a society where there is a preference for boys, co-wives who do not yet have a boy might tend to compete for the birth of the husband’s “heir.” Another limitation of our analysis is the endogeneity between polygamy, fertility, and fertility intentions. Indeed, low fertility could encourage a man to take new co-wives. Finally, our study is limited by the absence of some variables that are strongly correlated with fertility, such as the wife’s perception of her husband’s fertility desires.
This study does not address all the sociocultural, economic, or other factors that might add important context to differences in fertility desires, nor does it attempt to explain all contributing factors. Explorations of other factors, such as ethnicity or religiosity, may be the subject of future research in this area in order to understand the implications of fertility desires among women in polygamous unions. Another aspect not included in this study is the role of the husband in decision-making in couples or polygamous unions, and the husband’s role as family decisionmaker on fertility or contraceptive use. The role of the husband and other factors influencing fertility choices among women in polygamous unions merits further exploration for programmatic and policy implications.
In the West African countries in this study, there are no specific policies or programs to address the family planning needs of polygamous couples. Apart from the legal status of polygamy in each country, it is important to recognize the extent of the practice in the region and to consider polygamy as one of the factors influencing levels of access to sexual and reproductive health care and services. This study demonstrates that there are identifiable differences in fertility desires and contraceptive use between women in polygamous and monogamous unions that deserve to be incorporated into programs and awareness campaigns.
With a deeper understanding of the sociocultural, religious, and gendered elements of decision-making in polygamous unions, policymakers and program managers responsible for access to sexual and reproductive health care and services should:
2 John Bongaarts, “The Measurement of Wanted Fertility,” Population and Development Review 16, no. 3 (1990): 487-506; John C. Caldwell and Pat Caldwell, “The Cultural Context of High Fertility in Sub-Saharan Africa,” Population and Development Review 13, no. 3 (1987): 409-37.
5 Fatou Binetou Dial, “Divorce, remariage et polygamie à Dakar,” [Divorce, Remarriage and Polygamy in Dakar] Le mariage en Afrique. Pluralité des formes et des modèles matrimoniaux [Marriage in Africa: Plurality of Matrimonial Forms and Models] (Québec: Presses de l’Université du Québec, 2014): 250-65; Gning and Antoine, “Polygamy and the Elderly in Senegal. “
6 Shelley Clark, Alissa Koski, and Emily Smith‐Greenaway, “Recent Trends in Premarital Fertility Across Sub‐Saharan Africa,” Studies in Family Planning 48, no. 1 (2017): 3-22; Barbara S. Mensch, Monica J. Grant, and Ann K. Blanc, “The Changing Context of Sexual Initiation in Sub‐Saharan Africa,” Population and Development Review 32, no. 4 (2006): 699-727.
7 Jelaludin Ahmed, “Polygyny and Fertility Differentials Among the Yoruba of Western Nigeria,” Journal of Biosocial Science 18, no. 1 (1986): 63-74; Helen Chojnacka, “Polygyny and the Rate of Population Growth,” Population Studies, 34, no. 1 (1980): 91-107.
8 P. O. Olusanya, “The Problem of Multiple Causation in Population Analysis, With Particular Reference to the Polygamy-Fertility Hypothesis,” The Sociological Review, 19, no. 2 (1971): 165-78; Osei-Mensah Aborampah, “Plural Marriage and Fertility Differentials: A Study of the Yoruba of Western Nigeria,” Human Organization 46, no. 1 (1987): 29-38.
11 Abdellatif Lfarakh, “Préférences, comportements et besoins non satisfaits en matière de planification familiale,” [Unmet Family Planning Preferences, Behaviors and Needs] (2005).