Normal Labour PDF

‫بسم هللا الرحمن الرحيم‬ ‫‪Normal Labour‬‬ Definition: Labour is the process by which the products of conception i.e. the baby the placenta and membranes, are expelled from the uterus after 24 weeks gestation. -Normal labour is the labour which ends without complications to the baby or the...

‫بسم هللا الرحمن الرحيم‬ ‫‪Normal Labour‬‬ Definition: Labour is the process by which the products of conception i.e. the baby the placenta and membranes, are expelled from the uterus after 24 weeks gestation. -Normal labour is the labour which ends without complications to the baby or the mother in terms of morbidity and mortality. The baby should be full term caphalic ,singleton and labour is of spontaneous on set. The participants involved are the powers,the passenger and the passages.  - Premature Labour : Is defined as labour occuring befor 38 weeks gestation. - Prolonged Labour : Is defined as labour lasting more than 12 hours in primigravidum and 6 hours in multigravidum. The stages of labour : 1. The first stage: Commences with the onest of labour and terminate when the cervix is fully dilated. 2. The second stage: starts at full dilatation of the cervix and ends with expulsion of the baby. 3. The third stage “Placental stage”: Begins with the delivery of the baby and ends with the expulsion of the placenta and membranes. 4. The fourth stage: continues for 2 hours after delivery, it is the observation stage labour is also divided in latent phase and active phase which starts after 4 cm dilatation. Onset of Labour: The onset of labour is defined as development of regular uterine contractions which dilate the cervix. Symptoms and signs of labour : - painful regular uterine contractions increasing in intensity ,frequency and duration. -passage of show (mucus with or without streaks of blood ). - passage of liquer (rupture of membranes) -cervical dilatation this is the cardinal sign. Initiation of labour: Factors which initiates labour are not well understood.. But biochemical events occur in a form of a cascade which is controlled by the fetus. - High production of cortisol by the fetal adrenal glands. low production of progesterone (It inhibit uterine contraction )from the placenta. - High prduction of placental oestradiol (stimulates uterine contraction. - placental oesterone stimulates uterine contraction. - All these changes leads to increased production of prostaglanins from the placenta and the myometrium. Prostaglandin increases myometrial activity hence uterine contraction. It releases oxytocin from the posterior lobe of the pitutory gland. - Oxytocin stimulates myometrial activity. - Oxytocin releases calcium ions from the myomerial cell which leads to more uterine musle contractility. Increased myometrial activity causes splitting of adenosine triphosphate thus stimulating the action of actoyosin The Mechanism of Labour : Not all diameters of the fetal head can pass through a normal pelvis. The process of labour ,therefore involves the adaptation of the fetal head to the various segments of the pelvis. The head usually engages in the TRANSVERSE POSITION. Then the passage of the head and trunk through the pelvis follow a well – defined pattern and the following processes occur. 1- Descent : - Descent of the head occurs throughout descent. - Descent of the head is a measure of the progress of labor. 2- Flexion : - Flexion of the head occurs as it descends and meet the pelvic floor bringing the CHIN in contact with the fetal thorax. - Flexion produces a smaller diameter of the presenting part, changing the -occipito – frontal diameter to sub occipito –pregmatic.diameter 3- Internal Rotation : - The head rotates as it strikes the pelvic floor and, normally, the occiput gradually moves from its original lateral position towards the pubic symphysis,and occasionally it moves posteriorly towards the hollow of the sacrum. 4-Extension: The head in flxion.descends to the vulva and the base of the occiput comes into contact with the inferior rami of the pubis. The head now extends until it delivers. The perineum and interoitus are maximally distended by final expulsion of the head – a process that is known as CROWNING. 5- Restitution Following delivery ,the head rotates back to its original position in relation to the shoulders. 6- External Rotation : - When the shoulders reach the pelvic floor, they rotate into the antero-posterior position. - This followed by rotation of the head so that the face looks laterally at the thigh. 7- Delivery of The Shoulder Finally expulsion of the trunk occurs following delivery of the shoulder Lateral flexion of the trunk; Ist posteriorly to delivery the anterior shoulderunder the symphysis public. Then anteriorly disengage the posterior shoulder. That is followed by the rapid expulsion of the remainder of the trunk.  The Third Stage of Labour After delivery of the child ,the uterus contracts separating the placenta off and pushing it into the lower uterine segment. The calssical signs of placental se parations are : 1- gush of bright blood 2- lengthening and descent of the umbilieal cord 3- Raising of the uterine fundus 4- The uterus became globular in shape The whole process of delivery of the placenta and membrances lasts 5-10 minutes.If the placenta is not expelled within 30 minutes, the 3rd stage is considered as and abnormal, partogram