Controlled trial of fundal height measurement plotted on customised antenatal growth charts.

OBJECTIVE: The purpose of this study was to evaluate the effect of a policy of standard antenatal care which included plotting fundal height measurements on customised antenatal charts in the community.

DESIGN: Prospective, non-randomised, controlled, population-based study.

POPULATION: Two defined and separate referral areas from community to teaching hospital, with similar delivery rates and socioeconomic characteristics. A total of 1272 consecutively booked women with singleton pregnancies and dating ultrasound scans before 22 weeks of gestation.

INTERVENTION: In the study area customised fundal height charts were issued to each mother at the routine hospital booking scan, on which regular fundal height measurements were to be plotted by community midwives. The charts adjusted limits according to maternal characteristics including height, weight, parity and ethnic group. Usual management in the control area included fundal height assessment by abdominal palpation and recording on a standard co-operation card.

OUTCOME MEASURES: Antenatal detection of small and large for gestational age babies; number of antenatal investigations for fetal growth in each group.

RESULTS: The study group had a significantly higher antenatal detection rate of small for gestational age babies (48% vs 29%, odds ratio 2.2, 95% confidence interval 1.1-4.5) and large for gestational age babies (46% vs 24%, OR 2.6, CI 1.3-5.5). There was no increase in the study group in the overall number of scans per pregnancy done in the ultrasound department (1.2 vs 1.3, P = 0.14), but a slight decrease in repeat (two or more) third trimester scans (OR 0.8, CI 0.6-1.0, P = 0.08). Women in the study group had significantly fewer referrals for investigation in a pregnancy assessment centre (OR 0.7, CI 0.5-0.9; P = 0.01) and fewer admissions to the antenatal ward (OR 0.6, CI 0.4-0.7, P < 0.001). There were no differences in perinatal outcome.

CONCLUSIONS: Serial measurement of fundal height plotted on customised charts leads to increased antenatal detection of small and large babies. This is accompanied by fewer investigations, which is likely to represent increased confidence in the community to recognise normal fetal growth. With adjustments for physiological variables, fundal height measurements appear to be a cost effective screening method which can result in substantial improvements in the antenatal assessment of fetal growth.