NORMAL LABOUR Defined as: Presence of regular painful uterine contractions becoming progressively stronger and more frequent accompanied by effacement and progressive dilatation of the cervix and decent of the presenting part. At its onset its usually accompanied by bloody mucoid vaginal discharge called show . The process culminates in expulsion of the baby and other products of conception.
The course of normal labour
1. The 1 st stage of labour the latent phase This is the period from 0 – 3 cm dilatation of the cervix. Its duration can not be easily determined but perhaps around 8 hrs.
(b) The active phase This is the period from 3 – 10 cm (full dilatation) dilation of the cervix . In this stage the woman is said to be in established labour. The cervix dilates at the rate of about 1 cm/hour It may be a little faster esp. in multiparous women or little slower esp. in primigravida, giving an average duration of labour of about 12 hrs.
2. The 2 nd stage of labour This is the stage from full dilatation of the cervix to the delivery of the baby. It takes 1 hour in primigravidas 30 minutes in multigravidas
The 3 rd stage of labour This is the stage of labour after delivery of the baby to the delivery of the placenta and membranes. It usually takes 15 minutes
The 4 th stage of labour This is the stage in the first 24 hours after delivery This is the period where majority of maternal deaths occurs It needs close monitoring of the mother in the hospital esp. for PPH, Eclampsia etc..
PROLONGED LABOUR L abour is said prolonged when it has lasted for over 12 hours since its establishment. However since it may not be possible to know exactly when it started in a particular women, failure to progress may be more significant than the actual duration.
CAUSES OF PROLONGED LABOUR It is due to fault with the Passage Passenger Powers psyche
Passenger infant size and fetal presentation, e.g., in cephalic-occiput anterior or occiput posterior vs. breech or transverse)
passage Pelvis size and adequacy of the bony pelvis as well as soft tissues Conditions associated with faulty passage or passenger will usually lead to mechanical obstruction due to disproportion btw foetus and the maternal pelvis.
Power Faulty powers means that the expulsive forces are ineffective to overcome the normal resistance of the birth canal.
OBSTRUCTED LABOUR Failure of progressive descent of the presenting part , despite adequate uterine contractions. It implies mechanical obstruction Cervical dilatation is usually arrested or occurs much slower.
CAUSES Cephalopelvic disproportional (CPD) Small pelvis with a normal baby Big baby Shoulder dystocia Deformed pelvis (rickets, polio, Tb spine, fracture)
Abnormal presentation/position Brow Face Breech especially after coming head OPP
Soft tissue abnormalities Myoma in the lower segment or cervix Cervical stenosis Vaginal stenosis
ANTICIPATION OF OBSTRUCTION DURING LABOR Close surveillance of a woman in labor will identify obstruction before it advances to cause maternal and/or fetal complications
The following parameters should raise suspicion Failure of progressive descent of the presenting part and/ or stagnation or slow dilatation of the cervix Cervix that is poorly applied to the fetal presenting part Incoordinate uterine action Early rupture of membranes Reduced pelvic diameters Diagonal conjugates of less than 11cm Flat sacral curve Prominent ischial spine Narrow subpubic angle or pubic arc.
NEGLECTED OBSTRUCTED LABUR When labour is obstructed the uterus continues to contract long after. In neglected obstruction the duration of labour will be prolonged First stage will have lasted for many hours above the average of 12 hours and/or the second stage will have lasted for over an hour
Most of the complications we encounter in obstructed labor are a result of neglects The obstruction is prolonged resulting in short and long term complications. The major immediate causes of death in obstructed labour are sepsis , and haemorrhage from uterine rupture . Sepsis is more common in primigravida women, and uterine rupture in parous women.
in primigravida women, the uterus probably stops contracting because of myometrial acidification . This acidification results from local myometrial energy depletion, anaerobic metabolism, and systemic ketosis. In parous women, perhaps the myometrium becomes tolerant to the effects of acidification by an unknown mechanism and does not stop contracting. Continued contractions in the presence of myometrial energy depletion and hypoxia are likely to lead to myometrial oedema and necrosis contributing to uterine rupture .
Indicators of neglected obstructed labour Metabolic changes Hypoglycemia Metabolic acidosis Dehydration Electrolyte imbalance Ketonuria &Oliguria
Other features Maternal exhaustion Fever tachycardia Fetal distress and/or IUFD Formation of bandl’s ring or peanut shaped uterus Tonic inertia of the uterus Excessive Caput formation Excessive molding Vulvae oedema
MANAGEMENT OF OBSTRUCTED LABOUR initial assessment of the patient Pallor, pulse, blood pressure, dehydration Fundal height, foetal lie, foetal presentation, foetal heart rate, state of the uterus and bladder. Level of presenting part, cervical dilatation, caput formation and moulding. Do pelvic assessment and note the measurements and the presence of infected liquour. Access urine Blood group and X match
(b) resuscitate the patient IV fluids at least 3L stat. Give dextrose saline for hypoglycemia initially then ringers lactate (c) control infection Give broad spectrum IV antibiotics Stat dose of Ampicillin 1g and chloramphenicol 1g IV (d) check if the foetus is alive and decide mode of delivery (e) empty bladder with self retaining catheter
Principles of management Relieve the obstruction the earliest Pain relief Combat dehydration Prevent sepsis. Correct hypoglycemia Correct electrolyte imbalance.
MODE OF DELIVERY (a) If the foetus is alive delivery should be accomplished by caesarean section. Swab of the amniotic fluid should be taken for bacteriological analysis If the head is deep in the pelvis it should be pushed up from the vagina by an assistant after opening of the uterus. (b) If the foetus is dead and the cervix is fully dilated a destructive procedure may be fully undertaken. However if the cervix is not fully dilated C/S should be done
Post delivery care Continue monitoring of temperature, pulse, Bp urine output and color Monitor abdominal distension Continue antibiotics Continuous bladder drainage for at least 10days Check for perineal nerve damage and rehabilitate accordingly Bear in mind possibility of Secondary PPH Counseling for future pregnancies and deliveries
anticipation of obs labor during ANC Short stature particularly in primes <150cm Large fetuses >4.0 kg Obvious pelvic/spinal deformities Gynetresia.(at least one pelvic exam be done at ANC Uterine myomas in lower segment or Cervix Abnormal lie Severe degree of overlap at pelvic brim
PROLONGED LABOUR DUE TO FAULTY POWERS The expulsive force during labour is comprised of: Uterine contractions Maternal efforts As reflex action coinciding with contractions As a deliberate effort by the mother to bear down When the normal expulsive forces are too weak to overcome the normal resistance from the birth canal labour fail to progress and becomes prolonged.
Normal myometrial contraction and retraction leads to stretching of the lower segment and thickening of the upper segment. This coordination leads to fundal dominance and a resultant downward force during the process of child birth. Lack of coordination of the upper segment and lower segment leads to lack of fundal dominance hence abnormal uterine action.
Three types of abnormal uterine action have been recognized. Incoordinate action Uterine hypotonia (primary/ secondary) Hypertonic dysfunction
Incoordinate action Diagnosis Infrequent irregular contractions Cervix fails to dilate or stagnates Severe colicky pain persisting even after the contraction have passed High intrauterine pressure >24 mmHg (persistently) leading to interference with placental circulation and causes foetal hypoxia and distress
Uterine hypotonia Urine contractions are of insufficient force and infrequent. There could be complete inertia Common causes include: Over sedation Overdistention of the uterus eg . In multiple pregnancy, polyhaydromnious and big baby. Secondary inertia in primigravidae could be due to obstructed labour.
Treatment In both incoordinate dysfunction and uterine hypotonia, as long as obstruction is ruled out give: Dilute IV oxytocin e.g.: 5 IU in 500 mls . of normal saline (20,30,40,50,60 drops/min) Care must be taken with oxytocin in multiparous women as the response of oxytocin might violent enough to cause uterine rupture
Complications of prolonged labour without obstruction Sepsis – both maternal and foetal Maternal exhaustion Fetal hypoxia or distress PPH – both primary and secondary