Summary of findings
I examined Mrs C, a 29-year-old gravida 2 para 1 at 36 weeks by dates. She is not pale, not jaundiced, with mild pitting pedal oedema; her blood pressure is 120/70 mmHg and urinalysis is negative. The abdomen is uniformly enlarged, ovoid and longitudinal, moving with respiration, with a Pfannenstiel scar, linea nigra and striae gravidarum. It is non-tender, with no contractions. The symphysis–fundal height is 35 cm, compatible with the dates. There is a singleton fetus in a longitudinal lie and cephalic presentation, with the back on the left — left occipitoanterior — and the head 4/5 palpable. Liquor volume is clinically adequate and the estimated fetal weight is about 3 kg. The fetal heart is heard in the left lower quadrant at 140 beats per minute, regular. In summary, a singleton pregnancy at 36 weeks with findings compatible with dates in a woman with one previous caesarean section.
Differential diagnoses
| Finding | Causes to offer |
|---|---|
| Fundal height 3 cm or more above dates | Wrong dates, multiple pregnancy, macrosomia (diabetes), polyhydramnios, fibroids, full bladder, maternal obesity |
| Fundal height 3 cm or more below dates | Wrong dates, fetal growth restriction, oligohydramnios, transverse lie, engaged head, fetal death |
| Oblique or transverse lie | Grand multiparity, placenta praevia, polyhydramnios, uterine anomaly or fibroid, twins, contracted pelvis |
| Head not engaged at term in a primigravida | Occipitoposterior position, placenta praevia, cephalopelvic disproportion, deflexed head, polyhydramnios |
| Tense, tender uterus | Placental abruption, labour, chorioamnionitis, red degeneration of a fibroid |
See Large and small for dates and Fetal lie, presentation and position.
Investigations
- Ultrasound: fetal number, biometry and estimated weight, liquor volume, placental site, presentation
- Blood and urine: haemoglobin or packed cell volume, urinalysis, oral glucose tolerance test if large for dates
- Fetal wellbeing: umbilical artery Doppler if growth-restricted, CTG where available
Treatment
Plan the rest of the pregnancy and the delivery around the findings — for example external cephalic version for breech at term, delivery planning for a previous caesarean section, or serial growth scans for small for dates.
Examiner questions
References
- Cunningham FG, Leveno KJ, Dashe JS, Hoffman BL, Spong CY, Casey BM, eds. Williams Obstetrics. 26th ed. New York: McGraw Hill; 2022.
- World Health Organization. WHO recommendations on antenatal care for a positive pregnancy experience. Geneva: WHO; 2016.