Birth seasonality in Sub-Saharan Africa

Area of Science:

• Demography
• Human Reproduction
• Population Studies

Background:

• Human reproduction is generally non-seasonal, yet most populations display birth seasonality.
• Birth seasonality is well-documented globally, but understudied in African contexts.
• This study systematically investigates birth seasonality in Sub-Saharan Africa.

Purpose of the Study:

• To systematically test for and document birth seasonality in Sub-Saharan Africa.
• To analyze variations in birth seasonality patterns across different regions and demographic factors.

Main Methods:

• Utilized birth data from Demographic and Health Surveys.
• Aggregated data by country and ecological zone.
• Employed Fourier spectral analysis and regression to identify seasonality in de-trended birth time series.

Main Results:

• Confirmed significant birth seasonality at the national level in most Sub-Saharan African countries.
• Observed wide variation in seasonality amplitude (5-65%) and patterns (unimodal, bimodal).
• Found higher seasonality in West and Central Africa compared to East and Southern Africa, potentially due to heterogeneity.

Conclusions:

• Birth seasonality is a prevalent phenomenon in Sub-Saharan Africa, exhibiting considerable regional and demographic variation.
• Maternal education and rural-urban residence are associated with differing levels of birth seasonality.
• Ecological zone heterogeneity may obscure seasonal patterns in East and Southern Africa.