Labor

Onset of child birth is initiated by the increase of irregular uterine contractions The contractions push the head of the fetus towards the cervix Contractions begin about once every 30 minutes and become closer and closer with time

Stage One - Dilation of Cervix Cervix becomes soft, allowing it to dialate to the size of the fetus’s head (nearly 10cm) longest stage of labor ( hours) uterine contractions begin to push the head toward the cervix (increase in frequency and regularity)

As the contractions become more forceful the amnion (the innermost fluid-filled sac) in the uterus that contains the fetus breaks Fluid and the cervical mucus plug are then expelled Uterine contractions increase, with relaxation after each contraction to supply fresh blood to the fetus in the uterus

Stage Two - Regular Contractions and Expulsion of the Fetus head moves into the birth canal (vagina) and the fetus is expelled can take from several minutes to several hours and can be painful depending on the mother’s preparedness, emotional state, and cultural conditioning

Stage Three - Afterbirth During next minutes the uterus contracts to near its normal size This causes the placenta to sheer off and be expelled

Hormones Involved in Labor Relaxin - produced by the placenta –causes the softening of the cervix, which is important for the first stage of labor –allows the cervix to dilate –also softens the ligament of the pubic symphosis allowing the fetus to move with greater ease through the pelvic bone structure

Estrogen and Progesterone From the seventh month onward there is a decreased level of progesterone and an increased level of estrogen Progesterone prevents uterine contractions throughout the pregnancy

Oxytocin increases uterine contractions. Stretching of the cervix will stimulate the pituitary gland to release more oxytocin