Validity of symphysis fundus growth measurements

Abstract

Objectives: Evaluation of symphysis fundus measurements in a large antenatal clinic.

Methods: The obstetrical records were reviewed for all patients that had delivered over a 3-month period. From this group of 1455, a sample of 386 was taken that had a singleton pregnancy, had booked before 24 weeks' gestation and had attended the antenatal clinic at least twice. The study group comprised 65 patients with less than expected symphysis fundus growth and a control group of 249 in whom growth seemed adequate. The remaining 72 subjects' files were either incomplete or the interobserver variation of the symphysis fundus measurements at the end of pregnancy seemed too high.

Results: Deficient intra-uterine growth, as shown by the symphysis fundus measurements, was significantly associated with both low birthweight (< 2500 g) (odds ratio 3.02) and intra-uterine growth retardation (IUGR) (odds ratio 3.43), but no association was found with perinatal mortality. The sensitivity for detecting IUGR was 42%.

Conclusions: Symphysis fundus measurements, as made in our antenatal clinic, seem of limited value. We propose that the number of observers be restricted in order to decrease the interobserver variation.