Process of labour - Child Delivery Operations
Labour is the expulsion or extraction of viable fetus out of the uterus. Delivery may be vaginal [either spontaneous or aided] or it may be abdominal.
Labour is a series of events that takes in the genital organs in an effort to expel the viable products of conception out of the uterus through the vagina. Usually it occurs between 38-42 weeks of pregnancy. If labour occurs before 37 weeks, it is termed as preterm labour.
Expulsion of conceptual products before 28 weeks is called abortion.
Normal labour (Eutocia) occurs at term and is spontaneous in onset with the fetus presenting by the head. The process is completed within 18 hours and no complications arise. by which the fetus, placenta and membrane are expelled through the birth canal.
Dystocia is the term used to denote a difficult labour
Successful labour depends on the
1. Passages: The passage is the adequate pelvic dimension.
2. Passenger: The passenger is the adequate fetal dimension
3. Powers: Primary powers are the uterine contractions and secondary powers are the maternal efforts taken to expel the fetus with the help of abdominal muscles and the diaphragm.
4. Psyche of the mother: Emotional status of the mother also influences the outcome of labour.
A Initiation of labour pain:
The exact mechanism that initiates labour is unknown.
1. Uterus becomes stretched and the pressure increases causing physiological changes.
2. As pregnancy advances there is a gradual rise in oxytocin level (a hormone which is responsible for uterine contraction).
3. There is increased production of prostaglandin by fetal membranes and uterine decidua.
The mutual coordinated effects of oxytocin and prostaglandin initiate the rhythmic contractions of true labour.
During the last few weeks of pregnancy number of changes occur in women.
1. Lightening: As the presenting part sinks into the true pelvis, the women now breathes easier and experiences a relief.
2. Walking is more difficult as the fetal head enters into the pelvis
3. There is frequency of micturition
4. There is backache due to relaxation of sacroiliac of joints
5. There may be spurious or false pains
Features of true labour pain:
Uterine contractions (labour pains) occur in regular intervals,
Intensity of labour pain increases with time
The labour pain is located in back and abdomen.
Walking intensifies the pain.
Pain is not affected by mild sedatives.
Pain results in progressive, cervical dilation
Stages of labour:
A First stage:
This is the stage of dilatation of the cervical OS. It begins with the onset of true labour contractions to full dilatation of the cervix. Duration of first stage is an average of 13 hours for nullipara and 7.5 hours for multipara.
The first stage is clinically manifested by progressive uterine contraction, progressive taking up of the cervix and ultimate rupture of membranes.
B Second stage:
It is the stage of fetal expulsion. It begins with full dilation of cervical OS and ends with the birth of the baby. Second stage lasts for one to one and half hours for nullipara and 20 to 45 minutes in multipara.
D Third stage:
It is the stage of separation and expulsion of the placenta and membranes. It begins with birth of the baby until the expulsion of placenta and membranes. The third stage may last from few minutes to thirty minutes.
E Fourth stage:
The fourth stage lasts from the delivery of placenta and membranes until the postpartum condition of the women has become stabilized. This stage is usually one hour after delivery. In this stage the mother must start breast-feeding her infant.