Twin parenthood, but not ART, has a negative impact on the mental health of mothers and fathers during the transition to parenthood. ART parents' mental health was not affected by parity or children's health-related factors.

II-2.

Successful ART did not predict mental health problems during the transition to parenthood. Moreover, ART couples' mental health was remarkably resistant to social and child-related stress during the transition to parenthood.

Pregnancy and early motherhood involve uncertainty and change, which can evoke mental health problems. We identified maternal mental health trajectories in pre-and postnatal period, and examined their association with later child mental health and development. Finnish mothers reported psychological distress (General Health Questionnaire ) and depressive (Beck Depression Inventory ) symptoms in pregnancy (T1; N ¼ 788) and two months (T2; N ¼ 657) and 12 months (T3; N ¼ 545) postpartum. Both parents accounted their child's mental health (Behavior Assessment System for Children [BASC]) and social (Social Skills Rating System [SSRS], Child Behavior Scale [CBS]) and cognitive development (Five to Fifteen [FTF]) when the child was 7-8 years old (T4; N ¼ 485). We identified five trajectories depicting unique timing and course of maternal mental health from pregnancy into 1 year of mothering: Stable low levels of mental health symptoms (75%) and prenatal (6%), early postpartum (9%) and late postpartum (6%) mental health problems. The fifth trajectory, heterogeneous high levels of mental health problems (4%) was an unclassified post hoc class, combining mothers with chronic high or highly variable mental health profiles. Results show some trajectory-related timing effects on children's mental health and cognitive development. The trajectories of early postpartum and heterogeneous high levels of mental health problems predicted higher level of internalizing symptoms as compared to stable low-levels trajectory. The heterogeneous highlevels trajectory predicted higher levels of problems in executive functions than the stable low and late postpartum trajectories, and in memory tasks than children in other trajectories. We discuss the timing and course of maternal mental health from the viewpoint of infant and child development.

Prenatal expectations are important for the future parent-child relationship. The authors examined how maternal and paternal prenatal expectations of the relationship with the child predicted 1st-year parenting stress and whether these expectations were violated over the transition to parenthood. They further examined how former infertility affected these associations. The participants were 745 Finnish couples, 367 having undergone a successful assisted reproductive treatment and 378 conceiving spontaneously. Couples completed a questionnaire of family representations during pregnancy and when the child was 2 and 12 months old and Abidin's Parenting Stress Index at 2 and 12 months postpartum. The hypothesis of moderately high expectations predicting the lowest level of parenting stress was substantiated only concerning paternal expectations of own autonomy with the child. Generally, however, negative expectations of own and spouse's relationship with the child were linearly associated with higher parenting stress. Postnatal representations were more positive or equal to expectations, except for negative violation occurring in maternal expectation of the father-child relationship, especially among normative mothers. The results are discussed in relation to family dynamic considerations and special features of formerly infertile couples.