The temporal relationship between the onset of rapid eye movement period and the first micturition thereafter in the human fetus with advance in gestation.

The objective of this study was to investigate whether micturition occurs, temporally related to the onset of the rapid eye movement (REM) period, in the human fetus. The study was made on 139 fetuses at 33-36 weeks and 153 at 37-41 weeks gestation. The discrepancies between the expected (F(exp)) and observed (F(obs)) frequencies of time lag between the onset of the REM period and the first micturition thereafter were assessed using the goodness-of-fit test. At 33-36 weeks gestation, there was no statistical difference between F(obs) and F(exp) (P greater than 0.05). At 37 weeks onwards, however, significant differences were noted between F(obs) and F(exp) (P less than 0.005). Seventy-two percent of all micturitions occurred within eight minutes after the onset of the REM period. This indicates that there is a temporal relationship between the onset of the REM period and the first micturition thereafter, at term, during 37-41 weeks of gestation.