The results of longitudinal research project are presented. 72 married couples were assessed with interviews, observations and battery of question-naires in late pregnancy and followed up when the children were 6, 18, 42 and 66 months old. 24 married childless couples formed control group. It was found that the decline in marital satisfaction after the birth of a first child could be reduced by preventive intervention. The comparison of patterns of new parents and couples not having a baby showed that their level of adaptation at the beginning of the study explained much more of variation in individual and marital adaptation two years later than did the transition to parenthood. It was possible to identify partners and couples at risk for marital distress from their description of themselves and their marriage before they gave birth. There were links between the quality of parents' relationships and the quality of parent-child interaction and the child's developmental status.