Etiology and perinatal outcome of periviable fetal growth restriction associated with structural or genetic anomaly

Abstract

Objective To investigate the etiology and perinatal outcome of periviable fetal growth restriction (FGR) associated with a structural defect or genetic anomaly. Methods This was a retrospective study of singleton pregnancies seen at a referral fetal medicine unit between 2005 and 2018, in which FGR (defined as fetal abdominal circumference ≤ 3rd percentile for gestational age) was diagnosed between 22 + 0 and 25 + 6 weeks of gestation. The study group included pregnancies with periviable FGR associated with a genetic or structural anomaly (anomalous FGR), while the control group consisted of structurally and genetically normal pregnancies with periviable FGR (non‐anomalous FGR). Results of genetic testing, TORCH screen and postmortem examination, as well as perinatal outcome, were investigated. Results Of 255 pregnancies complicated by periviable FGR, 188 were eligible; of which 52 (28%) had anomalous FGR and 136 (72%) had non‐anomalous FGR. A confirmed genetic abnormality accounted for 17/52 cases (33%) of anomalous FGR, with trisomy 18 constituting over 50% (9/17; 53%). The most common structural defects associated with FGR were central nervous system abnormalities (13/35; 37%). Overall, 12 (23%) cases of anomalous FGR survived the neonatal period. No differences were found in terms of perinatal survival between pregnancies with anomalous and those with non‐anomalous FGR. Conclusions Most pregnancies complicated by anomalous FGR were associated with a structural defect. The presence of an associated genetic defect was invariably lethal, while those with a structural defect, in the absence of a confirmed genetic abnormality, survived into infancy in over 90% of cases, with an overall one in three chance of perinatal survival. These data can be used for counseling prospective parents. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Infant outcome after active management of early‐onset fetal growth restriction with absent or reversed umbilical artery blood flow

“…Table S2 Mortality and survival without neurodevelopmental impairment (NDI) at or after 2 years of age in the fetal growth restriction (FGR) and non-FGR groups, according to singleton or twin/triplet fetus, fetal sex, gestational age at delivery and time period at delivery Table S3 Perinatal characteristics, mortality and survival at or after 2 years of age in the FGR group, according to Doppler velocimetry in the umbilical artery Table S4 Reports in the literature on the outcome of very preterm growth-restricted fetuses with absent or reversed end-diastolic flow in the umbilical artery 3,6,26,33,34,[40][41][42][43]…”

“… Table S4 Reports in the literature on the outcome of very preterm growth‐restricted fetuses with absent or reversed end‐diastolic flow in the umbilical artery 3,6,26,33,34,40–43 …”

Monitoring, Delivery and Outcome in Early Onset Fetal Growth Restriction

“…With respect to FGR fetuses associated with structural defects or chromosomal abnormalities, to our knowledge, only one case-series has reported the short-term outcomes of 52 anomalous FGR fetuses diagnosed between 22 and 26 weeks of gestation. Within the limitations of the small case-series, the reported perinatal survival was not dissimilar from that of non-anomalous FGR paired for gestational age at diagnosis, even though the diagnosis of a genetic abnormality associated with the fetal smallness proved to be invariably lethal [68]. Of note, in this single-center case-series, the anomalous FGR fetuses accounted for almost one third of all the fetuses identified as FGR at periviable gestation, thus highlighting the importance of a thorough assessment of the fetal anatomy when fetal smallness is diagnosed prior to 26 weeks.…”

Genetics Etiologies Associated with Fetal Growth Restriction

“…6 The most common chromosomal numerical abnormalities associated with FGR were triploid (69,XXX and 69,XXY) and trisomy 18, 21, and 13. 6,7 Trisomy 18 was identified in over 50% of chromosomal numerical abnormalities in severe FGR, defined as AC 3 rd percentile for GA. 8 For FGR associated with fetal structural abnormalities (FGR defined as AC < 5 th percentile for GA), the detection rate of fetal aneuploidy was 21% (4/19), while for isolated FGR diagnosed before 24 weeks of gestational age, the detection rate of fetal aneuploidy was 20% (3/15). 9 Despite the heterogeneity in definitions for FGR, the studies above all indicated that amniocentesis with karyotyping should be offered to rule out chromosomal abnormalities for FGR with fetal structural anomalies, severe FGR defined as AC 3 rd percentile for GA or earlyonset FGR diagnosed before 24 weeks gestational age even if isolated.…”