Reproductive health in state socialism is usually viewed as an area in which the broader contexts of women's lives were disregarded. Focusing on expert efforts to reduce premature births, we show that the social aspects of women's lives received the most attention. In contrast to typical descriptions emphasising technological medicalisation and pharmaceuticalisation, we show that expertise in early socialism was concerned with socio-medical causes of prematurity, particularly work and marriage. The interest in physical work in the 1950s evolved towards a focus on psychological factors in the 1960s and on broader socio-economic conditions in the 1970s. Experts highlighted marital happiness as conducive to healthy birth and considered unwed women more prone to prematurity. By the 1980s, social factors had faded from interest in favour of a bio-medicalised view. Our findings are based on a rigorous comparative analysis of medical journals from Hungary, Poland, Czechoslovakia and East Germany.