There's a widely held assumption that a slight imbalance in male births has its start at the very moment of conception. But researchers say factors later in pregnancy are more likely to explain the phenomenon. CNRI/Science Source hide caption

itoggle caption CNRI/Science Source

Pregnant doctors are less likely than other women to deliver their babies via C-section, recent research suggests. Economists say that may be because the physician patients feel more empowered to question the obstetrician. hide caption

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Infants used to be born at home to traditional midwives. Mónica Ortiz Uribe hide caption

itoggle caption Mónica Ortiz Uribe