When Heat Decides Who Is Born 🔥👶 | Climate Change & the Sex Ratio Shock

For centuries, the sex ratio at birth (SRB) was treated as a biological constant—a fixed genetic lottery. But a groundbreaking 2026 study by Abdel-Ghany et al. overturns that assumption.Drawing on 5 million live births across 33 sub-Saharan African countries and India (104 surveys), researchers reveal a striking pattern: when temperatures rise, fewer baby boys are born.In sub-Saharan Africa, first-trimester heat exposure (above 20°C) increases male fetal vulnerability—the “frail male” hypothesis in action. In India, heat reduces male births for a different reason: it disrupts sex-selective abortion practices by limiting income and mobility.From biology to social behavior, climate is shaping who enters the world.Source paper: Temperature and sex ratios at birth. PNAS Vol. 123 | No. 8.#ClimateChange #SexRatio #HumanBiology #MaternalHealth #Demography #EnvironmentalStress #GlobalWarming #SciencePodcast #deepdivelab