Defining the residual risk of adverse perinatal outcome in growth-restricted fetuses with normal umbilical artery blood flow.

OBJECTIVE: We sought to determine the cause of adverse perinatal outcome in fetal growth restriction (FGR) where umbilical artery (UA) Doppler was normal, as identified from the Prospective Observational Trial to Optimize Pediatric Health (PORTO). We compared cases of adverse outcome where UA Doppler was normal and abnormal. STUDY DESIGN: The PORTO study was a national multicenter study of >1100 ultrasound-dated singleton pregnancies with an estimated fetal weight <10th centile. Each pregnancy underwent intensive ultrasound, including multivessel Doppler. UA Doppler was considered abnormal when the pulsatility index was >95th centile or end-diastolic flow was absent/reversed. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, or death. RESULTS: In all, 57 (5.0%) of the 1116 fetuses had an adverse perinatal outcome. Nine (1.3%) of 698 fetuses with normal UA Doppler had an adverse outcome, compared with 48 (11.5%) of 418 with abnormal UA Doppler (P < .0001). There were 2 perinatal deaths in the normal group and 6 in the abnormal group (P = .01). The perinatal deaths in the normal group were 1 case of pulmonary hypoplasia after prolonged preterm rupture of the membranes from 12 weeks' gestation and a case of placental abruption. Gestation at delivery was 33 ± 3 vs 31 ± 4 weeks (P = .05) and mean birthweight was 1830 ± 737 vs 1146 ± 508 g (P = .001) in the respective groups. Neonatal sepsis was the commonest adverse outcome in both groups: 0.1% and 0.4%, respectively (P = .01). CONCLUSION: Adverse perinatal outcome is uncommon in FGR with normal UA Doppler. The cases we identified were associated with heterogenous pathologies. FGR with normal UA blood flow is a largely benign condition.

The role of brain sparing in the prediction of adverse outcomes in intrauterine growth restriction: results of the multicenter PORTO Study.

OBJECTIVE: The aim of the Prospective Observational Trial to Optimize Pediatric Health in IUGR Study was to evaluate the optimal management of fetuses with an estimated fetal weight less than the 10th centile. The objective of this secondary analysis was to describe the role of the cerebroplacental ratio (CPR) in the prediction of adverse perinatal outcome. STUDY DESIGN: More than 1100 consecutive singleton pregnancies with intrauterine growth restriction (IUGR) were recruited over 2 years at 7 centers, undergoing serial sonographic evaluation including multivessel Doppler measurement. CPR was calculated using the pulsatility and resistance indices of the middle cerebral and umbilical artery. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death. RESULTS: Data for CPR calculation was available in 881 cases, which was performed at a mean gestational age of 33 weeks (interquarile range, 28.7-35.9). Of the 146 cases with CPR less than 1, 18% (n = 27) had an adverse perinatal outcome. This conferred an 11-fold increased risk (odds ratio, 11.7; P < .0001) when compared with cases with normal CPR (2%; 14 of 735). An abnormal CPR was present in all 3 cases of mortality. Prediction of adverse outcomes was comparable when using all definitions of abnormal CPR. CONCLUSION: Irrespective of the CPR calculation used, brain sparing is significantly associated with an adverse perinatal outcome in IUGR. This adds further weight to integrating CPR evaluation into the clinical assessment of IUGR pregnancies. The impact of this finding on long-term neurodevelopmental outcomes in this patient cohort is underway.

Optimizing the definition of intrauterine growth restriction: the multicenter prospective PORTO Study.

OBJECTIVE: The objective of the Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction (IUGR) (PORTO Study), a national prospective observational multicenter study, was to evaluate which sonographic findings were associated with perinatal morbidity and mortality in pregnancies affected by growth restriction, originally defined as estimated fetal weight (EFW) <10th centile. STUDY DESIGN: Over 1100 consecutive ultrasound-dated singleton pregnancies with EFW <10th centile were recruited from January 2010 through June 2012. A range of IUGR definitions were used, including EFW or abdominal circumference <10th, <5th, or <3rd centiles, with or without oligohydramnios and with or without abnormal umbilical arterial Doppler (pulsatility index >95th centile, absent or reversed end-diastolic flow). Adverse perinatal outcome, defined as a composite outcome of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death was documented for all cases. RESULTS: Of 1116 fetuses, 312 (28%) were admitted to neonatal intensive care unit and 58 (5.2%) were affected by adverse perinatal outcome including 8 mortalities (0.7%). The presence of abnormal umbilical Doppler was significantly associated with adverse outcome, irrespective of EFW or abdominal circumference measurement. The only sonographic weight-related definition consistently associated with adverse outcome was EFW <3rd centile (P = .0131); all mortalities had EFW <3rd centile. Presence of oligohydramnios was clinically important when combined with EFW <3rd centile (P = .0066). CONCLUSION: Abnormal umbilical artery Doppler and EFW <3rd centile were strongly and most consistently associated with adverse perinatal outcome. Our data call into question the current definitions of IUGR used. Future studies may address whether using stricter IUGR cutoffs comparing various definitions and management strategies has implications on resource allocation and pregnancy outcome.

The customized fetal growth potential: a standard for Ireland.

OBJECTIVE: To identify maternal and pregnancy-related physiological and pathological variables associated with fetal growth and birthweight in Ireland and to develop customized birthweight centile charts for the Irish population that will aid in appropriate identification and selection of growth-restricted fetuses requiring increased antenatal surveillance. STUDY DESIGN: Prospectively collected outcome data of 11,973 consecutive ultrasound-dated singleton pregnancies between 2008 and 2009 from six maternity units in Ireland (Dublin, Galway, Limerick and Belfast) were included for analysis. Maternal weight and height at booking, parity and ethnicity were recorded and combined with birthweight, fetal gender and pregnancy outcomes. Coefficients were derived by backward multiple regression using a stepwise backward elimination approach. RESULTS: A total of 11,973 ultrasound-dated singleton pregnancies were included in the analysis. Over 90% of women (n=10,850) were of Irish or European descent, 3.4% (n=407) were African or African Caribbean, 1.7% (n=208) were Indian; 42.2% (n=5057) were nulliparous, 32.8% (n=3923) had one previous delivery after 24 weeks' gestation, 15.6% (n=1872) had two previous deliveries and 9.4% (n=1121) had three or more previous deliveries. Mean term birthweight for a standard Irish mother was 3491 grams. Babies of all other ethnic origins were smaller than their Irish counterparts. African Caribbean, Bangladeshi, Indian and Pakistani babies were on average 237 g, 196 g, 181 g and 181 g lighter, respectively, when compared to the average Irish offspring. Pathological factors significantly affecting term birthweight were pre-gestational diabetes (+137 g; p<0.001), smoking (-225 g; p<0.001), pregnancy-induced hypertension (-37.6g; p=0.009) and maternal obesity (-41.6g; p=0.012). CONCLUSION: Birthweight in this Irish maternity population is subject to similar influences to those observed in studies from the UK, Sweden, USA and Australasia. The derived coefficients can be used for customized assessment of fetal growth potential in Ireland. The implementation of these customized centile charts and their free online availability will aid clinicians in Ireland in the interpretation of fetal weight estimation.