Prolonged Labor, Obstructed Labor, Dystocia Caused by Fetal Anomalies PDF

Chapter 27 !"#$#%&'()*+,#"-).,/0"120'()*+,#"-) 34/0#25+)6+1/'(),4)7'0+$)8%#9+$5'/ PROLONGED LABOR...

Chapter 27 !"#$#%&'()*+,#"-).,/0"120'()*+,#"-) 34/0#25+)6+1/'(),4)7'0+$)8%#9+$5'/ PROLONGED LABOR DEFINITION: The labor is said to be prolonged when the combined duration of the first and second stage is more than the arbitrary time limit of 18 hours. The prolongation may be due to protracted cervical dilatation in the first stage and/or inadequate descent of the presenting part during the first or second stage of labor. Labor is considered prolonged when the cervical dilatation rate is less than 1 cm/h and descent of the presenting part is less than 1 cm/h for a period of minimum 4 hours observation (WHO- 1994). Prolonged labor is not synonymous with inefficient uterine contraction. Inefficient uterine contraction can be a cause of prolonged labor, but labor may also be prolonged due to pelvic or fetal factor. PROLONGED LATENT PHASE Latent phase is the preparatory phase of the uterus and the cervix before the actual onset of labor. Mean duration of latent phase is about 8 hours in a primi and 4 hours in a multi. Whether prolonged latent phase has got any adverse effect on the mother or on the fetus, it is not clearly known. A latent phase that exceeds 20 hours in primigravidae or 14 hours in multiparae is abnormal. The causes include: (1) unripe cervix, (2) malposition and malpresentation, (3) cephalopelvic disproportion, (4) premature rupture of the membranes, (5) induction of labor and (6) early onset of regional anesthetic. Prolonged latent phase may be worrisome to the patient but does not endanger the mother or fetus. Management: Expectant management is usually done unless there is any indication (for the fetus or the mother) for expediting the delivery. Rest and analgesic are usually given. When augmentation is decided, medical methods (oxytocin or prostaglandins p. 573) are preferred. Amniotomy is usually avoided. Prolonged latent phase is not an indication for cesarean delivery. CAUSES OF PROLONGED LABOR: Any one or combination of the factors in labor could be responsible. First stage: Failure to dilate the cervix is due to: Fault in power: Abnormal uterine contraction such as uterine inertia (common) or incoordinate uterine contraction Fault in the passage: Contracted pelvis, cervical dystocia, pelvic tumor or even full bladder Fault in the passenger: Malposition (OP) and malpresentation (face, brow), congenital anomalies of the fetus (hydrocephalus). !"#$%&'())***+,- $.+.$/01***0$2/120/*34  464 Textbook of Obstetrics Too often deflexed head, minor degrees of pelvic contraction and disordered uterine action have got sinister effects in causing non-dilatation of the cervix. ! Others: Injudicious (early) administration of sedatives and analgesics before the active labor begins. Second stage: Sluggish or non-descent of the presenting part in the second stage is due to: Fault in the power: (1) Uterine inertia, (2) Inability to bear down, (3) Regional (epidural) analgesia, (4) Constriction ring. Fault in the passage: (1) Cephalopelvic disproportion, android pelvis, contracted pelvis, (2) Undue resistance of the pelvic floor or perineum due to spasm or old scarring, (3) Soft tissue pelvic tumor. Fault in the passenger" (1) Malposition (occipitoposterior), (2) Malpresentation, (3) Big baby (4) Congenital malformation of the baby. DIAGNOSIS: Prolonged labor is not a diagnosis but it is the manifestation of an abnormality, the cause of which should be detected by a thorough abdominal and vaginal examination. During vaginal examination, if a finger is accommodated in between the cervix and the head during uterine contraction pelvic adequacy can be reasonably established. Intranatal imaging (radiography, CT or MRI) is of help in determining the fetal station and position as well as pelvic shape and size. First stage: First stage of labor is considered prolonged when the duration is more than 12 hours. The rate of cervical dilatation is