Adding a baby to the equation. married and cohabiting women's relationship satisfaction in the transition to parenthood.

The trajectory of relationship satisfaction among married and cohabiting women in their transition to parenthood was compared in a potential sample of 71,504 women taking part in the Norwegian Mother and Child Cohort Study (MoBa). Prospective longitudinal data were collected in 4 waves over a 2-year period starting 6 months prebirth. Results from latent curve models suggested that married and cohabiting women experience similar negative change in relationship satisfaction during the transition to parenthood. However, cohabiting women start off and stay less satisfied throughout the transition period, suggesting the presence of a negative cohabitation effect that prevailed after controlling for various covariates. Extending investigation on the cohabitation effect to the transition to parenthood, and replicating it in a Scandinavian context, is discussed in relation to the understanding of what causes the cohabitation effect, and its clinical implications. © FPI, Inc.