Our aim was to study the inter-correlations and developmental pathways of mothers' and fathers' social and emotional loneliness during pregnancy (20th pregnancy week), infancy (child aged 8 months), and early childhood (child aged 18 months). Moreover, we aimed to study whether mothers and fathers who have different developmental profiles (identified by latent growth curve mixture models) differ in their experiences of marital dissatisfaction (RDAS), social phobia (SPIN) and depression (BDI) during pregnancy. Both mothers' social and emotional loneliness and fathers' social and emotional loneliness were highly stable, and within individuals these loneliness factors were strongly correlated. However, the correlations between mothers' loneliness experiences and fathers' loneliness experiences were weaker than expected. Separate latent growth curve groups were identified, which differed in feelings of marital dissatisfaction, social phobia, and depression. These groupings revealed that the higher the loneliness was, the more the parents experience these other psychosocial problems.