Cephalopelvic Disproportion-1 PDF

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Cephalo pelvic disproportion
Rajah Amina Suleiman, RN, RM, RNE, BNSc.,MSc....

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CEPHALOPELVIC DISPROPORTION (CPD) LECTURE NOTE BY RAJAH AMINA SULEIMAN (RN, RM, BNSc.) Definition This is a disparity between the fetal head and the maternal pelvis. Cephalopelvic disproportion (CPD) is a condition in which the presenting part of the fetus (usually the head) is too large to pass through the woman’s pelvis. It means that the particular head is too big for the particular pelvis through which it must pass, it may be due to:-

A contracted pelvis with a normal sized head.

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A normal pelvis with a large baby ,or

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A combination of a large baby and a contracted pelvis

Cephalopelvic disproportion cannot be diagnosed before the 36th week of pregnancy because before then the fetal head is too small for comparison with the pelvis but at 36th week the fetus would have reached its maximum size. Disproportion There are three degrees of disproportion 1. Minor degree: Here, the head does not engage or pass through the pelvic brim but it may be possible to push it through the brim. The head is at the same level with the anterior boarder of the symphysis pubis. With good uterine contractions the head may be able to push through the brim. 2. Moderate degree: - Here, the head cannot be made to engage at the pelvic brim, the head slightly overlaps the anterior edge of the symphysis pubis. 3. Major degree:- Here, the head greatly overlaps the anterior edge of the symphysis pubis Causes Fetal Causes:  Malposition  Malpresentation  Hydrocephaly  Macrosomia Maternal causes  Contracted Pelvis e.g. Deformed through Rickets 1

 Pelvic tumour  Stenosis or scarring of cervix  Vaginal stenosis Diagnosis of CPD CPD can rarely be diagnosed before labor begins. During labor, the baby’s head molds and the pelvis joints spread, creating more room for the baby to pass through the pelvis. Ultrasound is used in estimating fetal size but not totally reliable for determining fetal weight. A physical examination that measures pelvic size can often be the most accurate method for diagnosing CPD. 1. Disproportion should be suspected in short primigravidae less than 150cm or 5ft and a woman with a very small shoe size 2. It is uncommon in multigravidae women with a previous history of spontaneous vaginal delivery of babies weighing more than 3.4kg. 3. A pendulous abdomen should lead to the suspicion of disproportion. 4. If at 38th weeks of pregnancy, the head cannot be made to engage 5. Non engagement of the head in a primigravida at 36wks in 6. Diagnosis can be made by assessing:  The degree of overlap of the head over the pelvic brim at the symphysis pubis 

Internal pelvic and external pelvic examination: The internal examination should be gentle, thorough, methodical and purposeful. 

Sacrum: The sacrum is smooth, well curved and usually inaccessible beyond lower three pieces. The length, breadth and its curvature from above down and side to side are to be noted.

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Sacrosciatic notch: The notch is sufficiently wide so that two fingers can be easily placed over the sacrospinous ligament covering the notch. The configuration of the notch denotes the capacity of the posterior segment of the pelvis and the side walls of the lower pelvis.

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Ischial spines: Spines are usually smooth and difficult to palpate. They may be prominent and encroach to the cavity thereby diminishing the available space in the mid pelvis.

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Sidewalls — Normally they are not easily palpable by the sweeping fingers unless convergent.

 X-ray Pelvimetry which is done at 38 weeks of pregnancy.

Management Major & moderate degrees of disproportion are delivered by elective caesarean section; patients with minor degrees of cephalo pelvic disproportion are allowed trial of labour with the aim of achieving vaginal delivery. Trial of labour: A test carried out in the presence of minor degree of cephalo pelvic disproportion to see if vaginal delivery will be possible. It is done in an equipped and staffed hospital for operative procedures in case vaginal delivery fails. The success of trial of labor depends on: 1. The effectiveness of uterine contraction 2. The flexibility or “give” of the pelvic joints 3. Flexion of the fetal head. 4. The degree of moulding of the fetal head.  Ambulation and upright positions can be adopted to promote effective uterine contraction cervical dilatation and flexion of the head 3

 Mc Roberts position and Squatting position aids to increase pelvic capacity by around 30%  Progress of labour is recorded on a partograph, continuous fetal monitoring is used to assess fetal well being.  The aim of trial labor is to ensure a successful outcome of labour, if dilatation is slow and the head fails to descend, despite good uterine contractions, the decision must be made whether or not to allow labour to continue. If at any stage during this labour the mother or the fetus is under stress a caesarean section will be performed. -

Symphysiotomy

Complications of CPD. 1. Prolonged or obstructed labour 2. Vesico vaginal Fistula and Recto vaginal fistula. 3. Rupture of uterus due to thinning of the lower uterine segment. 4. Birth asphyxia 5. Brain damage due to severe Birth asphyxia 6. Ascending infection if ruptured membranes occurs for a long period 7. Hypostatic pneumonia and respiratory distress. 8. Venous thrombosis.

Nursing Diagnosis Anxiety related to unknown outcome of labour evidenced by patient’s verbalization Pain related to uterine contraction evidenced by patient’s verbalization Risk for Maternal Injury related to CPD Risk for Fetal Injury related to CPD Risk for Fluid Volume Deficit related to CPD

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