Fetal sleep states emerge during the third trimester of pregnancy and involve multiple interconnected neuronal networks. We examined whether fetal sleep characteristics predict child and adolescent self-regulation in a non-clinical sample (study group, n=25; reference group, n=48). Combined recordings of three sleep variables (fetal heart rate, body movements and rapid eye movements) were made for 2 h at 36-38 weeks' gestation. Fetuses showing synchronous change of sleep variables (i.e. within 3 min) at transition from quiet into active sleep reached a higher level of effortful control, both at 8-9 and 14-15 years, than fetuses not making synchronous transitions and compared with the reference group. Results are discussed from a Developmental Origins of Behavior, Health and Disease (DOBHaD) point of view. It is concluded that studying sleep ontogeny offers the possibility to gain insight into brain maturational processes and/or environmental adaptive processes that may have long term behavioral developmental consequences.