Comparison of adverse perinatal outcomes in late-onset fetal growth restriction with Delphi procedure consensus criteria

The problem of the management of fetal growth restriction (FGR) is in lack of gold standard. Several experts established a consensus definition of FGR through Delphi procedure, while few studies focus on the perinatal outcomes among sub-types of late-onset FGR diagnosed by Delphi procedure consensus criteria. To compare the adverse perinatal outcomes in different subgroups of late-onset FGR according to the Delphi procedure consensus criteria. A retrospective study was conducted between 2013 and 2020 including late-onset FGR diagnosed by Delphi consensus: Group 1, estimated fetal weight (EFW) or abdominal circumference (AC)<3rd centile; Group 2, EFW or AC<10th centile and umbilical artery pulsatility index (UA-PI) > 95th centile; Group 3, EFW or AC<10th centile and EFW or AC crossing centiles > 2 quartiles on growth centiles; Group 4, EFW or AC crossing centiles > 2 quartiles on growth centiles and UA-PI > 95th centile. Adverse perinatal outcomes (APOs) of 1071 late-onset FGR, including cesarean or instrumental delivery for non-reassuring fetal status, acidosis, neonatal hyperbilirubinemia, respiratory problems, and any adverse perinatal outcome, were compared with appropriate gestational age (AGA) group (Group 5, n = 515) as adjusted odds ratio (aOR) and 95% confidence intervals (CI). 1071 subjects with late-onset FGR were included, 371(34.6%), 67(6.3%), 516(48.2%), and 117(10.9%) were classified into four groups respectively according to Delphi standard. All mortalities occurred in fetuses with an EFW < 3rd percentile. Compared with Group 5, Group 1 showed the highest risk concerning any APOs (aOR = 4.91, 95% CI: 3.53–6.84), acidosis (aOR = 5.81, 95% CI: 2.96–11.37), neonatal hyperbilirubinemia (aOR = 4.71, 95% CI: 3.30–6.71) and respiratory problems (aOR = 3.65, 95% CI: 2.31–5.77) in the multivariable-adjusted model. As the risk of APOs in Group 2 (aOR = 2.60, 95% CI: 1.44–4.73) and Group 3 (aOR = 1.55, 95% CI = 1.11–2.16) followed, we did not find an increasing APOs risk in Group 4 (aOR = 0.88, 95% CI: 0.49–1.58). According to the Delphi consensus, the morbidity was inconsistent among different types of late-onset FGR. EFW or AC < 3rd percentile presented the highest risk of APOs. Compared with AGAs, Group 4 was not associated with an increasing risk of APOs. Further study is needed to develop protocols for the risk-stratification management of late-onset FGR.