OS078. Fetal growth restriction: A marker of severity of early-onset pre-eclampsia?

Abstract

Pre-eclampsia (PE), particularly early-onset PE (PE requiring delivery before 34 weeks), is commonly associated with fetal growth restriction (FGR). The evidence for an association between FGR and a more severe PE phenotype is controversial. The main aim of this study was to investigate whether the presence of FGR in women with early-onset PE is associated with more severe maternal disease compared to those with appropriately grown fetuses (AGA). This was a retrospective cohort study of women with early-onset PE between 2001 and 2010 at University College London Hospital. The diagnosis of PE was made according to the criteria defined by the International Society of the Study of Hypertension in Pregnancy (ISSHP). PE was diagnosed when the systolic blood pressure was 140mmHg or more and/or the diastolic blood pressure 90mmHg or more on at least two occasions four hours apart developing after 20 weeks of gestation in previously normotensive women with proteinuria of 300 mg or more in 24h or two readings of at least ++ on dipstick analysis of midstream or catheter urine specimens if no 24-h collection is available. FGR was defined as birthweight less than the 5th centile, with abnormal umbilical artery Doppler (raised pulsatility index, absent or reversed end-diastolic flow). Maternal, fetal and neonatal data were collected and study groups compared using Chi-square test or Fisher's exact test (categorical variables), and Mann Whitney-U test (continuous variables). Data analysis was performed using SPSS 16.0. In women with early-onset PE (n=134), FGR (n=66, 49%) was associated with significantly higher perinatal mortality (p=0.02). Gestational age at delivery was significantly lower in the FGR group (median, IQR: 29.0 weeks, 28.0-32.8 vs 32.0, 30.0-33.2, p=0.01). However, maternal indicators of PE severity, including blood pressure (3)160mmHg systolic or (3)110mmHg diastolic, ALT>100U/L, platelet count <100×10(9)/L, use of magnesium sulphate or use of antihypertensive therapy, were similar in the two groups. In women with early onset PE, FGR was associated with worse perinatal outcome, but was not associated with a more severe maternal PE phenotype. This may be because the presence of FGR in these women leads to earlier iatrogenic delivery, before the maternal condition deteriorates, but further studies are needed to investigate this.