L32 Abnormal labor

Abnormal labor

1. Abnormal labor

2. Abnormal labor Is any deviation from the normal Normal labor should be spontaneous labor, singleton fetus, cephalic vertex presentation with no intervention , term Abnormal if : poor progress Fetal compromise fetal malpresentation a multiple pregnancy a uterine scar induced labor Progress in labour is dependent on the ‘3 Ps’ as described previously (powers, passages, passenger)

3. abnormal progress in labour

4. Prolonged latent phase Prolonged latent phase occurs when the latent phase is longer than the arbitrary time limits of the normal more common in primiparous women best managed away from the labour suite with simple analgesics, mobilization and reassurance intervention in the form of artificial rupture of membranes (ARM) or oxytocin infusion will increase the likelihood of poor progress later in the labour and the need for caesarean birth

5. Primary arrest poor progress in the active first stage of labour (<2 cm cervical dilatation/4 hours) More in primiparous Causes : inefficient uterine (most common ) CPD Malspresentation

6. Secondary arrest progress in the active first stage is initially good but then slows or stops Same causes of primary arrest

7. Arrest of second stage of labor when delivery is not imminent after the usual interval of pushing in the second stage of labour Causes : inefficient uterine activity malposition malpresentation CPD resistant perineum

8. Poor progress in the first stage of labour defined as cervical dilatation of less than 2 cm in 4 hours , usually associated with failure of descent and rotation of the fetal head Management depends on the cause …3p’s Dysfunctional uterine activity (‘powers’) Cephalopelvic disproportion (‘passages’ and ‘passenger’) Malpresentation (the ‘passenger’)

9. Portogram to assess labor progress Should be used starting from the active phase of first stage of labor; if to be used

10. Dysfunctional uterine activity (‘powers’) weak, irregular and infrequent contractions A frequency of four to five contractions per 10 minutes is usually considered ideal the most common cause of poor progress in labour more common in primigravidae and in older women Management : if confirmed delayed after 4 hours; ARM should be done first and vaginal examination 2 hours later , if still delayed; consider augmentation of contractions by oxytocin infusion If progress fails to occur despite 4–6 hours of augmentation with oxytocin, a caesarean section will usually be recommended

11. Augmentation should be used with caution in multiparous women* Risk of rupture uterus , PPH and other causes to be involved in the delay as malpresentation Augmentation with oxytocin is contraindicated if there are concerns regarding the condition of the fetus Use continuous EFM if augmentation started

12. Cephalopelvic disproportion CPD implies anatomical disproportion between the fetal head and maternal pelvis. Causes : small pelvis in relation to fetal size large fetus fetal neck masses , thyroid goiter macrocephaly , hydrocephaly malposition (relative CPD ) Retrospective diagnosis (failure of vaginal delivery )

13. Findings suggestive of CPD Fetal head is not engaged. Progress is slow or arrests despite efficient uterine contractions. Vaginal examination shows severe moulding and caput formation. Head is poorly applied to the cervix. Haematuria .

14. Clinical pelvimetry Clinical pelvimetry Has less role in assessing for CPD than in the past X ray had a role (radiological pelvimetry ) CPD is considered a retrospective diagnosis after a failure in trial of vaginal delivery

15. Clinical pelvimetry

16. Malpresentation Near term or during labor the fetus normally assumes a vertical orientation and cephalic presentation, with the flexed fetal vertex presenting to the pelvis (95 %) In about 5% of these cases, deviation occurs from this normal presentation called malpresentation Malposition : subtype of malpresentation with cephalic but not vertex presentation as in occipitoposterior Malpresentation suggests the possibilities of adverse consequences and increases the risk for both the mother and fetus

17. Causes and risk factors for malpresentation Diminished vertical polarity of the uterine cavity Increased or decreased fetal mobility Obstructed pelvic inlet, cephalo-pelvic disproportion Polyhydramnios Oligohydramnios Fetal malformation Abnormal placentation Uterine myoma and uterine synechiae Multiparous Idiopathic

18. Abnormal Lie Lie: orientation of the fetal spine relative to the mother’s spine Transverse Oblique Usually transient but if persistent; transverse lie needs cesarean section Occur in 0.3 % Risk factors as : grand-multiparity ,Prematurity, Contraction and deformity of maternal pelvis ,Abnormal placentation

19. Face presentation Is longitudinal lie, full extension of the fetal head on the neck and the occiput against the upper back Anencephaly is found in one third of cases Fetal goiter and neck soft tissue tumors also cause deflection Contracted pelvis or CPD is found in 10-40% of cases

20. Face presentation Dominator is mentum Submento bragmatic is the engagement diameter Mentoanterior : vaginal deliveryand Delivers by flexion ( mento -anterior) Mento posterior : CS

21. Brow presentation Is longitudinal axis with partially deflexed cephalic attitude, midway between full flexion and full extension The frontal bones are the point of designation The  engagement diameter  is the mento -vertical 13.5 cm the incidence is 1 to 1500 deliverers It is more detected in early labor before flexion occurs to normal attitude. Less frequently, further extension results in face presentation Transient; most convert spontaneously by flexion or extension to either vertex or face presentation and are managed accordingly If persist : CS

22. Compound presentation an extremity is found prolapsed beside the main presenting part The combination of an upper extremity and vertex presentation is the most common Prematurity is the most consistent clinical finding fetal risk is associated with birth trauma and cord prolapse

23. the prolapsed extremity should not be manipulated, as it may retract as the major presenting part descends 75% of vertex/upper extremity combinations deliver spontaneously; occult or undetected cord prolapse is possible, therefore continuous CTG is recommended Persistent compound presentation with parts other than vertex and hand in combination in a term-sized infant has poor prognosis for safe vaginal delivery and cesarean section is necessary

24. Breech presentation When the buttocks of the fetus enter the pelvis before the head the presentation is breech Its more common in preterm fetuses because the bulk of each pole is more or less similar Types : 1)Frank breech: the lower extremities are flexed at the hips and extended at the knees. 2)complete breech: the lower extremities are flexed at the hips and one or both knees are flexed. 3)incomplete breech: one or both hips are not flexed and one or both feet are below the breech( footling )

25. Risk factors for breech Gestational age Hydramnios Uterine relaxation Multiple fetuses Oligohydramnios Hydrocephaly, anencephaly Previous breech delivery Uterine anomalies and pelvic tumor

26. Breech delivery Cesarean delivery is commonly but not exclusively used in the following circumstances A large fetus Any degree of contraction or unfavorable shape of the pelvis Hyperextended head When delivery is indicated in the absence of spontaneous labor Methods of delivery ; CS , assisted vaginal delivery , spontaneous vaginal delivery and complete breech extraction in CS or second twin

27. Poor progress in the second stage of labour Delay is diagnosed if delivery is not imminent after 2 hours of pushing in a nulliparous labour and 1 hour for a parous woman Secondary dysfunctional uterine activity (‘powers’) is a common cause of second stage delay Epidural analgesia may delay second stage progress for one hour Operative vaginal delivery maybe done if suitable Oxytocin shouldn’t be started in this stage

28. Vaginal delivery with previous uterine scar VBAC Risk of rupture in previous lower segment cs 1:200 Risk of rupture in previous upper segment cs 2-3 % (classical ) Success rate : 70-80 % and more if previously delivered vaginally Continuous CTG with close observation for signs of rupture uterus Relative contraindications to VBAC Two or more previous caesarean section scars. Need for induction of labour (IOL). Previous labour outcome suggestive of CPD. Previous classical caesarean section is an absolute contraindication.