Screening for Small for Gestational Age Fetus: Are we Succeeding? an Audit of Performance at a Regional Hospital

Abstract

Background: Fetal growth restriction affects perinatal morbidity and mortality and in practice. symphysis fundal height measurement only identifies 17.3-24.8% of Small for Gestational Age (SGA) fetuses. Plotting on a growth chart and observation of trends has been reported to increase detection rate. Failure to diagnose such fetuses is a recurrent issue at the hospital. Aims: To determine rate of detection of SGA fetuses during the antenatal period and to determine effect of maternal factors on the detection rate. Materials and Methods: This was a retrospective chart review of all babies born at Ipswich General Hospital from 2016 to 2018 in singleton pregnancies with birthweight below the tenth percentile and born ≥28 weeks gestation confirmed by first trimester dating ultrasound. Results: Over 3 years, 760 singleton SGA infants were born. 86.4% had at least 3 antenatal visits after 20 weeks gestation. Although at some stage in pregnancy 52.5% had a symphysis fundal height (SFH) measurement ≥3cm less than gestational age, in only 273 (36%) this resulted in a request for an ultrasound scan to confirm SGA fetus. This happened 53.1% of women who had a scan. Statistical analysis showed the only factor to affect SFH measurement and ultrasound diagnosis of SGA was maternal BMI while maternal age, parity and smoking status had no significant effect. Conclusion: The rate of detection of SGA is low but may be improved with the introduction of a new program of education and plotting of SFH on charts to assess trend. Keywords: Small for gestational age; Symphysis-Fundal height; Antenatal care; Ultrasound