Obestetric history and examination

Examination

Basic principles of infection control
Hospital acquired infection has been a major problem for some groups of patients.
While the incidence among the obstetric population is small, adherence to the principles of infection reduction are vital.

In any clinical setting you must remove any wristwatches or rings with stones. You should have bare arms from the elbow down. You should ensure that you use alcohol gel when moving from one clinical area to another (e.g. between wards) and always wash hands or use gel before and after any patient contact. The patient should see you do this before you examine them so that they are confident that you have done so.

Maternal weight and height

The measurement of weight at the initial examination
is important to identify women who are significantly
underweight or overweight. Women with a body
mass index (BMI) [weight (kg)/height (m2)] of less than 20
are at higher risk of fetal growth restriction and
increased perinatal mortality. This is particularly the
case if weight gain in pregnancy is poor. Repeated
weighing of underweight women during pregnancy
will identify that group of women at increased risk
for adverse perinatal outcome due to poor weight
gain.


In the obese woman (BMI> 30), the risks of
gestational diabetes and hypertension are increased.
Additionally, fetal assessment, both by palpation and ultrasound, is more difficult. besity is also associated
with increased birthweight and a higher perinatal
mortality rate.

Height should be measured at booking to assist with BMI assessment.

Short women are significantly more likely to have problems in labour, but these are generally unpredictable during pregnancy.

Blood pressure evaluation

The first recording of blood pressure should be made as early as possible in pregnancy. Hypertension diagnosed for the first time in early pregnancy (blood pressure140/90 mmHg on two separate occasions at least 4 hours apart) should prompt a search for underlying
causes, i.e. renal, endocrine and collagen-vascular disease. Although 90 per cent of cases will be due to
essential hypertension, this is a diagnosis of exclusion
and can only be confidently made when other secondary
causes have been excluded.

Blood pressure measurement is one of the few aspects of antenatal care that is truly

beneficial. It should be performed at every visit.
Measure the blood pressure with the woman
seated or semi-recumbent. Do not lie her in the left
lateral position, as this will lead to under-reading of
the blood pressure.


Convention is to use Korotkoff V (i.e. disappearance of sounds), as this is more reproducible than Korotkoff IV.
If the Vth sound is heard to near zero, give the values for the IVth and Vth sounds.

Urinary examination

Screening of midstream urine for asymptomatic
bacteriuria in pregnancy is of proven benefi t. The
risk of ascending urinary tract infection in pregnancy
is much higher than in the non-pregnant state. Acute
pyelonephritis increases the risk of pregnancy loss/
premature labour, and is associated with considerable
maternal morbidity. Additionally, persistent proteinuria
or haematuria may be an indicator of underlying renal
disease, prompting further investigation.

General medical examination

Cardiovascular examination
Routine auscultation for maternal heart sounds
in asymptomatic women with no cardiac history
is unnecessary. Flow murmurs can be heard in
approximately 80 per cent of women at the end of the
first trimester. Studies suggest that women coming
from areas where rheumatic heart disease is prevalent
and those with signifi cant symptoms or a known history
of heart murmur or heart disease should undergo
cardiovascular examination during pregnancy


Abdomen
To examine the abdomen of a pregnant woman, place her in a semi-recumbent position on a couch or bed.
Women in late pregnancy or with multiple pregnancies may not be able to lie very flat.
Cover the woman’s legs with a sheet and make sure she is comfortable before you start.

Inspection

• Assess the shape of the uterus and note any
asymmetry.
• Look for fetal movements.
• Look for scars (women often forget to mention
previous surgical procedures if they were
performed long ago). The common areas to find
scars are:

• suprapubic (Caesarean section, laparotomy for

ectopic pregnancy or ovarian masses);
• sub-umbilical (laparoscopy);
• right iliac fossa (appendicectomy);
• right upper quadrant (cholycystectomy).
Note any striae gravidarum or linea nigra (the
faint brown line running from the umbilicus to
the symphysis pubis)


Palpation
Symphysis–fundal height measurement
First, measure the symphysis–fundal height (SFH).
This will give you a clue regarding potential problems such as polyhydramnios, multiple pregnancy or growth restriction before you start to palpate.

Feel carefully for the top of the fundus. This

is rarely in the midline. Make a mental note of
where it is. Now feel very carefully and gently for
the upper border of the symphysis pubis. Place the
tape measure on the symphysis pubis and, with
the centimetre marks face down, measure to the
previously noted top of the fundus. Turn the tape
measure over and read the measurement. Plot the
measurement on an SFH chart

Fetal lie, presentation and engagement

Before you start to palpate, you will have an idea
about any potential problems. A large SFH raises the
possibility of:
• macrosomia;
• multiple pregnancy;
• polyhydramnios.
Rarely, a twin is missed on ultrasound!
A small SFH could represent:
• FGR;
• oligohydramnios.


After you have measured the SFH, palpate to
count the number of fetal poles . A pole
is a head or a bottom. If you can feel one or two, it is likely to be a singleton pregnancy. If you can feel three or four, a twin pregnancy is likely.
Sometimes large fibroids can mimic a fetal pole; remember this if there is a history of fibroids.

Now you can assess the lie. This is only necessary as the likelihood of labour increases, i.e. after 34–36 weeks in an uncomplicated pregnancy.
If there is a pole over the pelvis, the lie is
longitudinal regardless of whether the other pole is lying more to the left or right

An oblique lie is where the leading pole does not lie over the pelvis, but just to one side; a transverse lie is where the fetus lies directly
across the abdomen.

Once you have established that there is a pole over the pelvis, if the gestation is 34 weeks or more, you need to establish what the presentation is. It will be either cephalic (head down or breech (bottom/feet down).

Using a two-handed approach and watching the woman’s face, gently feel for the presenting part. The head is generally much firmer than the bottom, although even in experienced
hands it can sometimes be very difficult to tell. As you are feeling the presenting part in this way, assess whether it is engaged or not.

If you can feel the whole of the fetal head and it is easily movable, the head is likely to be ‘free’. This equates to 5/5th palpable and is
recorded as 5/5. As the head descends into the pelvis, less can be felt. When the head is no longer movable, it has ‘engaged’ and only 1/5th or 2/5th will be palpable

If the SFH is large and the fetal parts very diffi cult to feel, there may be polyhydramnios present. If the SFH is small and the fetal parts very easy to feel, oligohydramnios may be the problem.


Auscultation
If the fetus has been active during your examination and the mother reports that the baby is active, it is not necessary to auscultate the fetal heart.
If you are using a Pinard stethoscope, position it over the fetal shoulder (

Pelvic examination

Routine pelvic examination is not necessary. Given
that as many as 18 per cent of women think that a
pelvic examination can cause miscarriage, and at least 55 per cent fi nd it an unpleasant experience
However, there are circumstances in which a vaginal examination is necessary (in most cases a speculum examination is all that is needed). These include:

• excessive or offensive discharge;

• vaginal bleeding (in the known absence of a
placenta praevia);
• to perform a cervical smear;
• to confi rm potential rupture of membranes.
A digital examination may be undertaken
to perform a membrane sweep at term, prior to
induction of labour.

The contraindications to digital examination are:

• known placenta praevia or vaginal bleeding when the placental site is unknown and the presenting part unengaged;
• prelabour rupture of the membranes (increased risk of ascending infection).


A digital examination may be performed when an assessment of the cervix is required. This can provide information about the consistency and effacement of the cervix that is not obtainable from a speculum examination.
Examining from the patient’s right, two fingers of
the gloved right hand are gently introduced into the
vagina and advanced until the cervix is palpated.
Prior to induction of labour, a full assessment of the
Bishop score can be made

3
2
1
0

5 or more

3 or 4
1 or 2
0
Dilation of cervix (cm)

soft

medium
firm
Consistency of cervix
Less than 0.5
1- 0.5
2-1
more than 2
Length of cervical canal


Anterior
Central
Posterior
Position
below
1 or 0
2
3
Station of presenting part (cm above
ischial spine)

Always introduce yourself and say who you are.

• Make sure you are wearing your identity badge.
• Wash your hands or use alcohol gel.
• Be courteous and gentle.
• Always ensure the patient is comfortable and warm.
• Always have a chaperone present when you examine
patients.
• Tailor your history and examination to fi nd the key
information you need.
• Adapt to new fi ndings as you go along.
• Present in a clear way.
• Be aware of giving sensitive information in a public
setting.