This study examined levels, trends, and factors influencing male fertility in Nigeria using data from four Demographic and Health Surveys between 2003-2018. The average birth rate declined from 9.5 to 8.7 during this period, though one region saw an increase. Male fertility was lower among those with secondary education or from wealthy households. Polygamy and multiple partners contributed to higher fertility. The study found marital postponement was associated with lower fertility even after accounting for education and wealth. It recommends policies address polygamy, partners, and promote education to further reduce Nigeria's high fertility rates.

1. Group 3
Male fertility in Nigeria
1. Obiageli Onwusaka . university of ibadan : ochiezey@yahoo.com
2. Elizabeth Nji . University of Calabar: elizabethbeshel92@gmail.com
3. Ofori Victoria. University of Ghana: oforivictoria55@gmail.com
4. Rapahael Ojo Joseph. University of Ghana: drgreatjoe@gmail.com

2. Executive summary
• Nigeria is among the top ten high-fertility countries worldwide. High fertility drives population growth and
has negative impact on socio-economic advancement of any nation. In Nigeria, men tend to exercise
dominance over women especially on reproductive health issues including fertility. Recent advances in
fertility estimation requires the inclusion of data from men. However, the available fertility metrics have
been primarily based on women alone. Therefore, objective assessment of fertility trends in Nigeria
necessitates the estimation of male fertility indices.
• This study investigated levels, trends, and differentials in male fertility in Nigeria, an issue scarcely addressed
in the demographic literature. Using data from four rounds of Demographic and Health surveys collected
using a cross-sectional study design between 2003 and 2018, male fertility rates and differences in fertility
levels by selected socio- demographic characteristics were examined

3. Background
• In Nigeria, achievement of fertility reduction has been at a slow pace, fertility
reduced from 6.2 births per woman in 1990 to 5.3 births per woman in 2018
(National Population Commission (NPC) [Nigeria] and ICF Macro, 2019).
• However, fertility levels vary widely among Nigeria's regions, with the Total
Fertility Rate ranging from 6.1 to 3.9 in the south west (National Population
Commission (NPC) [Nigeria] and ICF Macro, 2019).
• The persistent high fertility rate has been identified among other drivers of
unacceptable high population growth rate in Nigeria.
• The population researchers are becoming apprehensive about the trend and
projected future fertility situation in Nigeria amidst poverty, social vices and poor
state of the economy because of their negative implications for sustainable
development and economic growth.

4. Methodology
• This study used male datasets from four waves of Nigeria Demographic and
Health Survey (NDHS) for 2003 (n1=2,346), 2008 (n2=15,486), 2013 (n3=17,359)
and 2018 (n4=13,311). Male Total fertility Rate (mTFR) representing the total
number of children a man will have if he experiences fertility at the prevailing
fertility schedule throughout his reproductive period, was estimated.
• Factors affecting male fertility were also examined

5. Results and discussion
• The average birth rate declined from 9.5 in 2003 to 8.7 in 2018 and all six geopolitical regions experienced a similar
downward trend except the North-West where it rose from 11.1 in 2003 to 12.3 in 2018.
• Males with at least secondary education (IRR=0.99 CI=0.88-0.91) and those from rich households (IRR=0.93
CI=0.91-0.94) had significantly lower fertility. IRR for males who postponed marriage (age ≥30 years) increased
from 0.7 (95% CI= 0.6-0.8) in 2003 to 0.93 (95% CI= 0.90-0.97) in 2008. Decomposition analysis showed that
polygamy accounted for 39.9%, 47.2%, 25.8% and 35.2% of the differential in children-ever-born between
polygamous and non-polygamous males in 2003, 2008, 2013 and 2018, respectively.
• Also, this study ascertains that having multiple sexual partners and practicing polygamy were factors that predispose men to high
fertility in Nigeria. The study also identifies men’s level education as well as Household wealth index and significant drivers of male
fertility level. Each of these correlates were found to have varying degrees of influence across the geo-political zones.

6. Implications and recommendations
• The level of male fertility in Nigeria is high but has begun to decline. However, the pace of
reduction is slow and varies across the regions in the country. Age, education, and wealth index
are important predictors of male fertility across the regions in Nigeria. This study established an
increasing trend in the levels of Polygyny and multi-partnered fertility among males in Nigeria
• Polygamous marriages and multi-partnered relationships promote high fertility among Nigerian
men. The older men still contribute to male fertility and marital postponement is an important
factor associated with fertility reduction in Nigeria. This study also highlighted the importance of
education in marital postponement and established that when the effect of educational
attainment and wealth index were controlled, marital postponement was still significantly
associated with fertility.
• This study also explored the distributional effect of polygamy and marital postponement on
fertility outcomes. It established the role Polygamy and multi-partnered fertility play which could
potentially lead to sustained fertility rates and affect population dynamics. This study also
identified a slowly occurring divergence in family patterns, which is a shift in family timing – an
increase in the proportion of men who postpone marriage and childbearing. It is pertinent that
makers of population and reproductive health policies begin to take cognizance of these findings
if Nigeria must attain demographic transition.

7. • Polygamous marriages and multi-partnered relationships promote high fertility among Nigerian men. The
older men still contribute to male fertility and marital postponement is an important factor associated with
fertility reduction in Nigeria. This study also highlighted the importance of education in marital
postponement and established that when the effect of educational attainment and wealth index were
controlled, marital postponement was still significantly associated with fertility. This study also explored the
distributional effect of polygamy and marital postponement on fertility outcomes. It established the role
Polygamy and multi-partnered fertility play which could potentially lead to sustained fertility rates and affect
population dynamics. This study also identified a slowly occurring divergence in family patterns, which is a
shift in family timing – an increase in the proportion of men who postpone marriage and childbearing. It is
pertinent that makers of population and reproductive health policies begin to take cognizance of these
findings if Nigeria must attain demographic transition.

8. References
• National Population Commission (NPC) [Nigeria] and ICF International. (2019). Nigeria Demographic and
Health Survey 2018. Abuja, Nigeria, and Rockville, Maryland, USA: NPC and ICF International.
• National Population Commission (NPC) [Nigeria] and ICF International. (2014). Nigeria Demographic and
Health Survey 2013. Abuja, Nigeria, and Rockville, Maryland, USA: NPC and ICF International.
• Contacts
1. Obiageli Onwusaka . university of ibadan : ochiezey@yahoo.com
2. Elizabeth Nji . University of Calabar: elizabethbeshel92@gmail.com
3. Ofori Victoria. Universisty of Ghana: oforivictoria55@gmail.com
4. Rapahael Ojo Joseph. University of Ghana: drgreatjoe@gmail.com