Postnatal depression and reproductive success in modern, low-fertility contexts

摘要

Background and objectives: Postnatal depression (PND) presents a puzzling phenomenon to evolutionaryudanthropologists as it is highly prevalent and yet detrimental to child development and maternaludhealth. Adaptive explanations have been proposed, but have not been tested with data that directly linkudPND to female fertility.ududMethodology: A survey was designed to gather complete reproductive histories and retrospective measuresudof PND to measure the effects of PND on fitness. Respondents were born between 1930 and 1967,udwith the majority based in the UK during their childrearing years. The hypothesis that PND is detrimentaludto fitness is assessed using Mann–Whitney U tests on completed fertility. Binary logistic regressionudmodelling is used to test the hypothesis that PND reduces the likelihood of parity progression.ududResults: Women experiencing PND at their first or second birth have lower completed fertility, with PNDudat the first birth leading to lowered fertility. Logistic regression analyses show that this is the result ofudreductions in the likelihood of parity progression to a third birth when PND is experienced at the firstudbirth or when repeat bouts occur.ududConclusions and implications: Our results call into question adaptationist arguments, contribute to theudgrowing understanding of the importance of emotional wellbeing to fertility decision making, and givenudthe economic consequences of markedly below replacement fertility, highlight a potential new source ofudfinancial incentive to invest in screening and preventative measures to ensure good maternal mentaludhealth.