Questions on Foundations of normal labour Essay

Questions on Foundations of normal labour - Essay Example First stage of labour begins with uterine contractions that are regular and ends with complete dilatation of the cervix, i.e. 10 cm. This stage may be divided into early latent phase, an active phase and a transitional phase. During the latent phase, the uterine contractions are irregular and mild. The cervix begins to shorten and soften. The cervix is dilated 1-4cm. Contractions of the uterus may or may not be regular and may be associated with backache, abdominal cramps, show, rupture of membranes, mucoid vaginal discharge and passage of the mucus plug. Active phase begins when the cervix is 3-4 cm dilated. The dilatation rapidly increases and presenting fetal part descends. The uterine contractions are much stronger and last for longer period, approximately 40-45 seconds. They are also more frequent. Contractions may be accompanied by pain in this stage. The cervix is dilated upto 8cm. This phase is followed by the transitional stage. Cervix dilatation is 8-10cm. The contractions of the uterus are stronger and of longer duration, 50-60seconds. Other symptoms in this stage are discomfort, hiccups, irritable abdomen, behavioural changes, restlessness, nausea and vomiting, increased perspiration, heavy show that is profusely dark, rupture of membranes, low back ache and sensation of stretching in deep pelvis. The first stage of labour ends when the cervix is dilated at 10 cm. ... At term, cortisol production of fetus increases. This causes increase in the production of estrone and estradiol and decreased production of progesterone from placenta. This amounts to increase in uterine activity because, basically, while progesterone suppresses the activity of the uterus, estradiol increases it. Increased production of prostaglandins occurs which contribute to increased activity of the myometrium. All these changes amount to release of oxytocin and other hormones like CRH, activin A, follistatin, relaxin and hCG, which further increase myometrial activity (Fraser and Cooper, 2006). Towards term, softening of cervix occurs due to decrease in collagen and increase in proteolytic enzymes. This partly occurs due to increased production of hyaluronc acid which decreases the affinity between collagen and fibronectin. Due to affinity of hyaluronic acid towards water, the cervix gradually softens and ripens. Even cervix contracts from the point of dilatation of 3-4 cm. How ever, in the active phase of labour, dilatation of cervix mainly occurs due to passive stretching of contractions of the uterus (Fraser and Cooper, 2006). The uterine pressures in first stage of labour rise to 20-30mmHg during contraction. The contractions occur every 10-15 minutes and lasts for 30-40 seconds. The intensity of contractions increases to a maximum of 50mmHg. Pain develops when the amniotic pressures increase beyond 25mmHg. Uterine contractions cause dilatation and effacement of the cervix due to shortening of the fibers of the myometrium in the upper segment of the uterus. This is called retraction. The lower segment of the uterus