The obstetric examination is distinct from other examinations in that you, the clinician, are trying to assess the health of two individuals – the mother and the fetus – simultaneously. From the initial history, you should be able to judge the health of the pregnancy, any risk factors that need to be addressed, and any concerns from the parents. The history is an opportunity for you to find out how much the parents know about pregnancy, labour and delivery and if they have any preferences to which these events are carried out. A carefully taken history will also direct your attention to specific signs during the examination. As such, it is important that you develop a concise and systematic method of taking the history and carrying out the examination so that you do not miss any important information. This article focuses primarily on the examination.
Pregnancy is a sensitive issue, especially for the primigravida’s. Therefore, extra care is needed when you approach a pregnant woman. Always obtain expressed informed consent before examining her and have a chaperone accompany you throughout the examination. A walk-through of what you will be doing is a good way of reassuring the patient and allows the examination to go on smoothly. It is also important to let your patient know that if the examination is too painful, she can stop at any time she wants. Finally, before you begin, you should always wash your hands, especially at an OSCE station.
As with any medical examination, the systematic approach in the obstetric examination follows the basics of:
Before you see the patient, you should have the patients’ details in front of you. Most antenatal clinics routinely measure and plot the mother’s height and weight, her blood pressure and check her urine sample using dipstix before the consultation. This information will be documented in her antenatal notes so you should be familiar with it. Before you begin, the patient should empty her bladder if they have not already done so.
Position the patient as comfortable as possible on the examining couch at an adjusted angle of 30°. In later pregnancy, the pregnant patient should be positioned at a higher angle or in the left-lateral tilt position to avoid aortocaval compression. Expose the abdomen of the patient, ideally from the lower chest (just below the breasts) to the symphysis pubis. Place a sheet over the exposed area when you are not examining her and cover any exposed undergarments to maintain the patient’s dignity.
I - General Examination
The obstetric examination begins by looking at the patient. Pay particular attention to:
- General appearance – fatigue/exhausted, anxious, depressed, nausea
- Does she appear pallor or breathlessness?
- Does she have difficulty getting up and walk from the waiting room to the clinic room?
Measure the mother’s height and weight if this has not been done. Generally:
- Smaller women tend to have smaller babies
- Patients with a high BMI are more likely to develop gestational diabetes, macrosomnia, and polyhydramnios
Measure the mother’s blood pressure and check her urine dipstix if this has not been done. This is to identify:
II - Inspection
On inspection, there are 5 signs that you should focus and comment on (see FIG 1).
- The uterus is normally visible in the abdomen at 12-14 weeks of gestation
- It will reach the level of the umbilicus at around 20 weeks of gestation
- The uterus will reach maximum height at the level of the xiphisternum at 36 weeks
Note: the size and shape of the uterus should be regular and symmetrical unless there are multiple pregnancies or polyhydramnios.
- The most important scar to look for is the Pfannenstiel scar, which is a transverse scar across the lower abdomen. The Pfannenstiel scar indicates a previous Caesarean-section.
- Other scars to look for are laparoscopic scars and laparotomy scars, if indicated in the patient’s previous surgical history.
- Striae gravidarum, or stretch marks, are caused by pregnancy hormones of the current pregnancy. They appear red and inflamed and occur early in the pregnancy. Patients may complain of discomfort and pruritus around the area.
- Striae albicantes are stretch marks from previous pregnancies. They appear as white and silvery. These stretch marks are more common in the lower abdomen, upper thighs and buttocks.
- Linea nigra is the hyperpigmentation of the midline linea alba. Similarly, the hyperpigmentation is caused by the pregnancy hormones of the current pregnancy.
- Fetal movements are visible after 24 weeks – which can be used as a way to confirm viability of the fetus
- The umbilicus becomes flattened as the pregnancy progresses to term (i.e. normal).
- May become flattened and everted in multiple pregnancy and polyhydramnios.
III - Palpation
Palpation of the pregnant abdomen must be gentle and careful, as pregnant woman can be quite sensitive about the health of the fetus. It is quite useful to start with a general palpation of the four quadrants of the abdomen. However, before you place your hands on the abdomen, always ask about areas of pain and tenderness. As a general rule: always palpate these areas last.
The palpation of the abdomen serves several purposes; by the end of palpation, you should be able to comment on:
- Fetal growth
- Liquor volume
- Multiple pregnancies
- Fetal lie and presentation
There are 4 steps in palpating the pregnant abdomen (also called Leopold’s Manoeuvers):
First Manoeuver – fundal palpation
- Using both hands, palpate the superior border of the fundus to determine the pole of the fetus in this part of the fundus.
Measuring the fundal height. This is the distance between the symphysis pubis and the superior border of the fundus. This should only be carried out after 20 weeks of gestation, approximately when the fundus reaches the level of the umbilicus.:
- Palpate the superior border of the fundus using the ulnar border of your left hand.
- Feel for the first bony prominence in the midline to identify the symphysis pubis. The fundal height is the distance between these two points (see Fig 2). To avoid discrepancy and bias, always turn the tape measure upside down so that the blank side of the tape faces you.
Interpretation: the fundal height, in centimeters, is equal to the gestation in weeks. It is normal to find a difference of up to 3 cm (i.e. at 30 weeks of gestation, you should expect the fundal height between 27 to 33 cm).
Second Manoeuver – lateral palpation.
- Palpate the patient’s right side with your left hand and the patient’s left side with your right hand.
- Feel for the number of pregnancies.
- Feel for the spine and back of the fetus to determine the fetal lie. This is usually the side of the uterus that feels “full”. Remember that feeling for the fetus is analogous to feeling for an irregularly shaped mass suspended in a bag of water. It is not possible to feel fetal parts directly; hence, the “fullness” on one side of the uterus corresponds to the back of the fetus due to increase resistance.
- Feel and estimate the amount of liquor. This step requires experience and can be difficult to gauge at first. However, as a general tip, if there is an excessive amount of fluid, the uterus will be tense and it will be quite difficult for you to feel for fetal parts.
Interpretation: After this step, you should be able to determine the number of pregnancies, the amount of liquor volume, and the lie of the fetus. The lie of the fetus refers to the position of the fetus in relation to the longitudinal axis of the uterus. Most pregnancies are longitudinal (99%) such that the head and the buttocks are palpable at each end of the uterus. If the fetus lies at a right angle to the axis of the uterus, then the fetus is in a transverse lie. If the head or buttocks are palpable on either side of the iliac fossae, then the fetus is in an oblique lie.
Third and Fourth Manoeuver – presentation palpation.
To determine the presentation of the fetus, two methods are used:
- Using both hands, palpate the lower segment of the pelvis by pressing firmly on either side of the midline just above the symphysis pubis. Use your left hand on the patient’s left side and your right hand on the patient’s right side (i.e. facing the end of the bed).
- Using the thumb and index finger of the right hand, firmly grip the presenting fetal part between the fingers (Pawlik’s grip). Note: this may cause pain and discomfort, so it is advisable to warn your patient beforehand.
- Palpating the presenting part assumes that the fetal lie is longitudinal. By definition, the presenting part can be either breech or cephalic. In cephalic presentation, you can ballot the head by moving the head slightly from side to side. The head is usually quite firm compared to breech. Breech is also harder to feel and cannot be balloted.
- You should also comment on the engagement of the fetal head. This is measured by dividing the fetal head into fifths – if only two-fifths of the head is palpable in the abdomen, this indicates that the head is engaged into the pelvis; the widest diameter has descended into the pelvis. The level at which the head is just engaged (i.e. two-fifths), only the frontal sinciput and the posterior occiput is palpable above the pelvic brim.
IV - Percussion and Auscultation
There is no significance of percussion in the examination. However, if you suspect polyhydramnios, you can confirm by a showing a positive fluid thrill with a negative shifting dullness.
You will need a hand-held Doppler monitor or a Pinard stethoscope (see Fig 4). It is recommended that you should use a Pinard stethoscope after 28 weeks.
- Place the Doppler transducer or the Pinard stethoscope over the anterior shoulder, usually between the symphysis pubis and the umbilicus.
Interpretation: the fetal heart rate is between 110-160 b.p.m. You can simultaneously feel for the maternal’s radial pulse to distinguish between the two individuals.
V - Internal Examination
Vaginal examination should only be carried out in later pregnancy to allow assessment of the favourability of the cervix for labour and delivery. In early pregnancy, vaginal examination not only increases the risk of ascending infection but also may cause antepartum haemorrhage (e.g., in the case of placentae praevia).
- Inspect the vulva. Examine for any vaginal discharge and note any abnormalities such as varicosities.
- Examine the vagina and cervix using a sterile Cusco’s speculum through an aseptic technique.
- Identify the cervix and determine:
- Dilation of the cervix – assess using examining fingers. This is one of the examinations where knowing the breadth of your finger comes into use. Note the breadth of your index finger on your examining hand. Generally, it is about 1 – 1.5 centimeters.
- Cervical length – normally, the cervix is about 3 – 3.5 cm. However, during labor, the cervix effaces and contracts, which shortens the overall length.
- Consistency – describes the softness of the cervix: firm, medium, or soft.
- Position – the position of the cervix changes during labour as it effaces and contracts. The cervix is pulled anteriorly as labour progresses.
- Station – refers to the level of the presenting part in relation to the ischial spines. The station is negative if it is above the ischial spines and positive if it is below the ischial spines (e.g., -3 means that the level of the head is 3 cm above the ischial spines; whereas, +3 means the head is 3 cm below). The station of the presenting part should coincide with the engagement of the head determined in the Third Manoeuver.
Interpretation: the Bishop score, which encompasses the 5 characteristics mentioned, is used as an assessment tool to evaluate the favourability of the cervix for vaginal delivery. Be familiar with the Bishop scoring system, although it is unlikely that you will be asked to perform an internal examination of the vagina.
- Introduce yourself and obtain consent. Wash your hands at the same time.
- Measure the patient’s height and weight, if it has not been done so.
- Measure the patient’s blood pressure, if it has not been done so.
- Offer the patient a chance to empty her bladder and leave a urine sample specimen for a dipstix testing.
- Obtain a chaperone for assistance.
- Position the patient on the examining cough and expose the abdomen from the lower chest to the symphysis pubis.
- Begin with a general inspection at the end of the bed. Comment on:
- General appearance
- Pallor and anaemia
- Difficulty walking and getting up from waiting room.
- Inspection – see Fig 1.
- Size of the uterus and shape
- Pfannenstiel scars and other surgical scars
- Skin changes
- Fetal Movements
- Measure the fundal height – see Fig 2.
- First Manoeuver – fundal palpation (see Fig 3).
- Second Manoeuver – lateral palpation: to determine lie, number of pregnancies and liquor volume (see Fig 3).
- Third Manoeuver and Pawlik’s grip: to determine the presentation and engagement of the presenting part (see Fig 3).
11. Auscultation – see Fig 4
- Listen over the anterior shoulder. Normal = 110 – 160 bpm.
12. Internal examination of the vagina and cervix.
- Inspect the vulva
- Determine: dilation, length, consistency, station and position of the cervix to assess the favourability of the cervix.
- When you first approach a pregnant woman, be kind and gentle. Remember, most pregnant women are very sensitive and protective of their abdomen and fetus. It may not be easy for you to gain consent.
- Examination of a pregnant woman can be quite difficult at first. Like all examinations, the more you practice, the easier it gets. At first, I strongly recommend that you ask for guidance from an experienced senior colleague. This is not only for your own benefit but it also reassures the patient. Always make sure you verify your findings so that you learn how each fetal part feels like.
- Auscultation of the fetal heart requires a lot of patience. Do not be discouraged if you cannot find it at first – it takes a lot of practice before you can actually find it.
- In an OSCE station, never forget to wash your hands and obtain consent. Always offer a chaperone, especially if you are told to perform any internal examination.
- Thank the patient once you have finished and wash your hands afterwards. Assist the patient if necessary, especially from getting up from the examination couch.
- Douglas G, Nicol F, Robertson C (eds). Macleod’s Clinical Examination. 11th ed. Churchill Livingstone. 2009
- Impey L, Child T. Obstetrics and Gynaecology. 3rd ed. Wiley Blackwell: London. 2008
- Beckman C, Ling F et al [in collaboration with ACOG]. Obstetrics and Gynecology. 6th ed. Lippincott Williams and Wilkins. 2009