PELVIC ASSESSMENT

This is an examination done on a pregnant mother to know whether the pelvis is adequate.

CLINICAL ASSESSMENT OF THE PELVIS:

To find out whether the mother will manage to deliver normally in assessing the pelvis the midwife must observe the following:

External Pelvic Assessment:

On Inspection

• Mother’s stature (small and short), gait (limping), shoe size 4 or less and height less than 152 cm.

History Taking

• Mother age not less than 17 years or over 35 years, race or tribe, Baganda and Basoga have small pelvis.
• Mother may give history of medical or surgical condition which adversely affects the diameter of the pelvis e.g. medical history poliomyelitis, TB of the hips, spine or legs. NB: These observations give a general impression of the mother e.g. very tall women with tiny feet are not well proportioned neither, a very short woman especially if she also has broad shoulder and thick hip. Midwife has to be alert for the patient who walks with a limp or has muscle wasting of the legs which may occur due to congenital hip deformity or poliomyelitis.

OBSTETRICAL HISTORY

Careful history should be taken of previous labors and deliveries.

• If she had previously got normal labor at 40 weeks gestation and infant weighing at least 3 kg. This indicates adequate pelvis but it should be remembered that subsequent babies may be larger and cause problems.
• A primigravida who has not delivered a fair sized infant or has a history of previous instrumental delivery e.g. forceps, vacuum extraction, difficult labor and had a still birth or caesarean section due to cephalopelvic disproportion. It can be assumed that the pelvis is inadequate or multigravida with the above history is likely to have contracted pelvis.

ON PALPATION OF ABDOMEN (ABDOMINAL EXAM)

• The head is very high and free or head fitting from 36 weeks onwards, the abdomen is palpated to see if the widest transverse diameter of the fetal head can be made to be engaged in the pelvic brim or the fetal head is engaged in the pelvic brim, there may be no overlapping of the fetal head over the symphysis pubis.

INTERNAL PELVIC ASSESSMENT Vaginal examination:

This is more accurate method and gives a good indication of the size and shape of the pelvis unless there is a previous history of abortion the doctor usually performs a vaginal examination on every woman attending antenatal clinic.

• To confirm pregnancy.
• To exclude abnormalities of the pelvis and further examination is done to assess the pelvic brim, cavity, and outlet at 36–37 weeks of pregnancy.

SIZE: The size of the brim measured by the diagonal conjugate.

DIAGONAL CONJUGATE

This is measured from the lower border of the symphysis pubis to the center of the sacral promontory and usually 12–13 cm (measured vaginally to brim) 1.9–2 cm is subtracted from the diagonal conjugate for the fetus to get obstetrical conjugate.

METHOD:

• Empty the bladder, tell the patient what you are going to do put her in dorsal position with the knees drawn up.
• Scrub hands and put on sterile gloves.
• Swab the vulva with antiseptic lotion with the right hand.
• Lubricate the 1st and 2nd fingers with the obstetrical cream.
• Insert the two fingers into the vagina.
• Then the effort is made to reach the sacral promontory. If the sacral promontory is not reached then the brim is said to be adequate.
• The point where the hand is in contact with the lower border of the symphysis pubis is marked by the fore finger. After withdrawing the finger the distance between that point and the tip of the middle finger is obtained. If the sacral promontory was reached, then the points are measured with a ruler. When the finger is withdrawn usually the sacral promontory is not reached by the examining fingers.
• The hollow of sacrum is assessed and should be well curved in the normal pelvis.
• The ischial spines are felt and the degree of their prominence is observed.
• The subpubic rami. The pubic arch should admit about 2½ fingers.
• The distance between the ischial tuberosities is also measured by putting the knuckles between the tuberosities and should accommodate 4 knuckles.
• It’s done when the mother is in dorsal position. Clean the patient and leave her dry and comfortable, chart and report all your findings including abnormalities found.

X-RAY PELVIMETRY This is the most accurate method to estimate the relationship between the maternal pelvis and the fetal skull.

Qn.(1) In case they ask you to Describe

(a) The female pelvis,

(b) True pelvis,

(c) Gynecological pelvis?

You have to define, size, shape, situation, division of the pelvis i.e. brim, cavity and outlet by drawing diagrams.

Qn (2) In case they have given you Question which says describe

The bony pelvis you have to talk about definition, size, shape, situation, the 2 innominate bones, one sacrum, one coccyx by drawing diagrams.