Is height related to fertility? An evaluation of women from low- and middle-income countries

Objectives To present an empirical description of the association between height and lifetime fertility in women from low- and middle-income countries, allowing for flexible functional relationships. Methods A pooled sample (N = 846 257) of women ages 35-49 in Demographic and Health Surveys (DHS) from 64 countries, with regional samples for Latin America, South Asia, and sub-Saharan Africa. Flexibly-estimated structured additive regression models estimate variations in the height-fertility relationship over the height distribution. Results Across samples, height is shown to have nonlinear relationships with number of children ever born and age at first birth. Number of children increases with height until a maximum below average height, after which the number of children decreases. Age at first marriage decreases with height until a minimum below average height, and then increases. Except at the shortest heights, much of the variation in fertility is suggested to reflect socioeconomic differences across heights. At the shortest heights, variation is suggested to reflect later ages at first birth, except for women in sub-Saharan Africa. Conclusion A nonlinear relationship is indicated between height and fertility. Much of the relationship is suggested to reflect height-variations in socioeconomic status and age at first birth.