 The latent phase is generally defined as beginning at the point at which the woman perceives regular uterine contractions.In contrast, Braxton Hicks contractions, which are contractions that may start around 26 weeks gestation and are sometimes called "false labour", are infrequent, irregular, and involve only mild cramping.Cervical effacement, which is the thinning and stretching of the cervix, and cervical dilation occur during the closing weeks of pregnancy.