Expansion
Fundal height, lie, presentation, engagement and fetal heart
Expansion
Position: semi-recumbent with a left lateral tilt after 20 weeks, to avoid aortocaval compression.
Inspection: distension, linea nigra, striae, scars (especially previous caesarean), fetal movements.
Palpation
- Symphysis fundal height: measured from the symphysis pubis to the fundus. From about 24 weeks it approximates gestation in weeks plus or minus 2 cm
- Lie: longitudinal, transverse or oblique
- Presentation: cephalic or breech
- Engagement: recorded in fifths palpable above the pelvic brim. Engaged means 2 out of 5 or fewer
- Liquor volume and estimated fetal size
Auscultation: fetal heart with a Pinard stethoscope or handheld Doppler, normal rate 110 to 160.
Complete with blood pressure, urinalysis for protein, and ankle oedema, since these screen for pre-eclampsia.
Discrepancy between fundal height and dates is the key finding: large suggests wrong dates, multiple pregnancy, polyhydramnios, macrosomia or fibroids; small suggests wrong dates, fetal growth restriction, oligohydramnios or an abnormal lie. It prompts ultrasound assessment.