Socioeconomic development predicts a weaker contraceptive effect of breastfeeding

Nicolas Todd, Centre national de la recherche scientifique (CNRS)
Mathias Lerch, Ecole polytechnique fédérale de Lausanne (EPFL)

The contraceptive effect of breastfeeding remains key to control fertility in many developing countries. The extent to which this negative effect of breastfeeding on ovarian activity is sensitive to ecological conditions, notably maternal energetic status, has remained controversial. We assess the relationship between breastfeeding duration and postpartum amenorrhea in 17 WFS and 284 DHS conducted between 1975 and 2019 in 84 low- and middle-income countries, then analyze menses resumption during unsupplemented lactation. We find that a sharp weakening of the breastfeeding – postpartum amenorrhea relationship has globally occurred over the time period analyzed. The slope of the breastfeeding – postpartum amenorrhea relationship is negatively associated with development: higher values of the Human Development Index, urbanization, access to electricity, access to water and education are strongly predictive of a weaker association between breastfeeding and postpartum amenorrhea. The exclusive breastfeeding - amenorrhea relationship in the early postpartum period is also found in rapid decline in Asia, and in moderate decline in Sub-Saharan Africa. These findings indicate the effect of breastfeeding on ovarian function is mediated by external factors that likely include negative maternal energy balance, and support the notion that prolonged breastfeeding significantly helps control fertility only under harsh conditions.

Keywords: Fertility and childbirth

See paper.

  Presented in Session 16. Fertility: Preferences and Intentions