Fagbamigbe Adeniyi Francis, Idemudia Erhabor Sunday
School of Research and Postgraduate Studies, Faculty of Human and Social Sciences, North West University, Mafikeng, South Africa.
Department of Epidemiology and Medical Statistics, Faculty of Public Health, College of Medicine, University of Ibadan, Ibadan, Nigeria.
BMC Pregnancy Childbirth. 2016 May 13;16:102. doi: 10.1186/s12884-016-0895-y.
First childbirth in a woman's life is one of the most important events in her life. It marks a turnaround when she might have to drop roles of career building and education, for motherhood and parenthood. The timing of the commencement of these roles affects the child bearing behavior of women as they progress in their reproductive ages. Prevalent early first childbirth in Nigeria has been reported as the main cause of high population growth and high fertility, mortality and morbidity among women, but little has been documented on the progression into first birth as well as factors affecting it in Nigeria. This paper modelled timing of first birth among women in Nigeria and determined socio-demographic and other factors affecting its timing.
We hypothesized that background characteristics of a woman will influence her progression into having first birth. We developed and fitted a survival analysis model to understand the timing of first birth among women in Nigeria using a national representative 2013 NDHS data. Women with no children were right censored as of the date of the survey. The Kaplan Meier survival function was used to estimate the probabilities of first birth not occurring until certain ages of women while Cox proportional hazard regression was used to model the timing of first births at 5 % significance level.
About 75.7 % of the respondents had given birth in the Northern region of Nigerian compared with 63.8 % in the South. Half (50.1 %) of the first childbirth occurred within the 15-19 years age bracket and 38.1 % within 20-29 years. The overall median survival time to first birth was 20 years (North 19, South 22), 27 years among women with higher education and 18 years for those with no formal education. The adjusted hazard of first birth was higher in the Northern region of Nigeria than in the South (aHR = 1.24, 95 % CI: 1.20-1.27), and higher in rural areas than in urban areas (aHR = 1.15, 95 % CI: 1.12-1.19). Also, hazard of earlier first birth tripled among women with no education (aHR = 3.36, 95 % CI: 3.17-3.55) compared to women with higher education. The significant factors affecting age at first birth are education, place and zone of residence, age at first marriage, religion, ethnicity and use of contraceptives.
This study showed that progression into early first birth is most affected by the education standing of women as well as age at first marriage. Delay of first childbirths as a strategy for fertility reduction and maternal health improvement can be achieved if women are empowered early in life with quality education. Stakeholders should therefore, give adequate attention to educating the girl child. Adverse socio-cultural norms of betrothing and marrying young girls should be abrogated, while health education and promotion of need to delay child bearing must be intensified especially among rural dwellers and also in Northern Nigeria.
女性的首次生育是其人生中最重要的事件之一。这标志着一个转变，即她可能不得不放下职业发展和教育的角色，转而承担起母亲和家长的角色。这些角色开始的时间会影响女性在生育年龄阶段的生育行为。据报道，尼日利亚普遍的早育是人口高增长以及女性高生育率、高死亡率和高发病率的主要原因，但关于尼日利亚女性首次生育的进展情况及其影响因素的记录却很少。本文对尼日利亚女性首次生育的时间进行了建模，并确定了影响其时间的社会人口学因素及其他因素。
我们假设女性的背景特征会影响其首次生育的进程。我们利用2013年全国代表性的尼日利亚人口与健康调查（NDHS）数据，开发并拟合了一个生存分析模型，以了解尼日利亚女性首次生育的时间。截至调查日期，没有孩子的女性被视为右删失。使用Kaplan - Meier生存函数来估计女性在特定年龄之前未生育第一胎的概率，而Cox比例风险回归则用于在5%的显著性水平下对首次生育的时间进行建模。
约75.7%的受访者在尼日利亚北部地区生育，而南部地区这一比例为63.8%。一半（50.1%）的首次生育发生在15 - 19岁年龄组，38.1%发生在20 - 29岁。首次生育的总体中位生存时间为20年（北部19年，南部22年），受过高等教育的女性为27年，未受过正规教育的女性为18年。尼日利亚北部地区首次生育的调整后风险高于南部地区（风险比 = 1.24，95%置信区间：1.20 - 1.27），农村地区高于城市地区（风险比 = 1.15，95%置信区间：1.12 - 1.19）。此外，与受过高等教育的女性相比，未受过教育的女性早育的风险增加了两倍（风险比 = 3.36，95%置信区间：3.17 - 3.55）。影响首次生育年龄的重要因素包括教育程度、居住地点和区域、初婚年龄、宗教、种族以及避孕措施的使用。
本研究表明，女性首次生育过早的进程受教育程度和初婚年龄的影响最大。如果女性在年轻时能接受优质教育，那么推迟首次生育作为降低生育率和改善孕产妇健康的策略是可以实现的。因此，利益相关者应充分重视女童教育。应废除过早许配和嫁女童的不良社会文化规范，同时必须加强健康教育，并强化推迟生育必要性的宣传，特别是在农村居民以及尼日利亚北部地区。
