Symphysis-fundus height and pregnancy characteristics in ultrasound-dated pregnancies

OBJECTIVE: To investigate the relation between maternal and pregnancy characteristics and symphysis-fundus height values at term in an obstetric population dated by sonography. METHODS: Three hundred twenty-five women were recruited from the antenatal clinics of the Queen's Medical Centre, Nottingham, United Kingdom for measurement of fundal height and for ultrasound scans. Symphysis-fundus height measurements were analyzed by multivariate regression analysis in relation to gestational age, maternal height and weight, ethnic group, and smoking. RESULTS: Gestational age and maternal characteristics explained nearly half of the variability in symphysis-fundus height. Gestational age was the most important determinant, followed by maternal weight, parity, and sex of the infant. The other variables were not significantly correlated. CONCLUSION: Maternal characteristics had statistically significant effects on the expected symphysis-fundus height, which suggests that individually adjusted fundal height charts may improve the precision of clinical screening for fetal growth restriction.