<P> While living inside the uterus the baby is enclosed in a fluid - filled membrane called the amniotic sac . Shortly before, at the beginning of, or during labor the sac ruptures . Once the sac ruptures, termed "the water breaks", the baby is at risk for infection and the mother's medical team will assess the need to induce labor if it has not started within the time they believe to be safe for the infant . </P> <P> Many women are known to experience what has been termed the "nesting instinct". Women report a spurt of energy shortly before going into labour . </P> <P> Folklore has long held that most babies are born in the late night or very early morning and recent (2018) research has found this to be correct in the U.S., but only for babies born at home or on Saturday or Sunday . All other births are most likely to occur between 8 a.m. and noon, a reflection of the fact that planned C - sections are generally scheduled for 8 a.m. Likewise, births from induced deliveries rose during the morning hours and peaked at 3 p.m. The most likely day of the week for a baby's birthday in the U.S. is Monday, followed by Tuesday, likely related to scheduled deliveries as well . </P> <P> 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 . </P>

When does internal rotation of the fetal head occur