Role of uteroplacental and fetal Doppler in identifying fetal growth restriction at term

Abstract

Identification of the fetus at risk of adverse outcome at term is a challenge to both clinicians and researchers alike. Despite the fact that fetal growth restriction (FGR) is a known risk factor for stillbirth, at least two thirds of the stillbirth cases at term are not small for gestational age (SGA) -a commonly used proxy for FGR. However, the majority of SGA fetuses are constitutionally small babies and do not suffer from adverse perinatal outcome. Doppler cerebroplacental ratio (CPR) is emerging as a marker of failure to reach growth potential at term. CPR is an independent predictor of intrapartum fetal distress, admission to the neonatal unit at term, stillbirth, perinatal death and neonatal morbidity. Raised uterine artery Doppler resistance in the third trimester is independently associated with significantly lower birthweight and CPR. The combination of the estimated fetal weight, CPR and uterine Doppler in the third trimester can identify the majority of fetuses at risk of stillbirth. HIGHLIGHTS Despite the fact that fetal growth restriction (FGR) is a known risk factor for stillbirth, the majority of fetuses suffering from stillbirth at term are not small for gestational age. Serial measurements to assess growth velocity, combined with fetal Doppler, are preferable than a single point estimate. The cerebroplacental ratio (CPR) is emerging as a marker of failure to reach growth potential at term  The combination of the estimated fetal weight, CPR and uterine Doppler in the third trimester can identify the majority of fetuses at risk of stillbirth Highlights (for review) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 ABSTRACT Identification of the fetus at risk of adverse outcome at term is a challenge to both clinicians and researchers alike. Despite the fact that fetal growth restriction (FGR) is a known risk factor for stillbirth, at least two thirds of the stillbirth cases at term are not small for gestational age (SGA) -a commonly used proxy for FGR. However, the majority of SGA fetuses are constitutionally small babies and do not suffer from adverse perinatal outcome. Doppler cerebroplacental ratio (CPR) is emerging as a marker of failure to reach growth potential at term. CPR is an independent predictor of intrapartum fetal distress, admission to the neonatal unit at term, stillbirth, perinatal death and neonatal morbidity. Raised uterine artery Doppler resistance in the third trimester is independently associated with significantly lower birthweight and CPR. The combination of the estimated fetal weight, CPR and uterine Doppler in the t...

Predictive accuracy of cerebroplacental ratio for adverse perinatal and neurodevelopmental outcomes in suspected fetal growth restriction: systematic review and meta‐analysis

“…Previously, it has been suggested that CPR is a stronger predictor of adverse perinatal outcome in suspected late‐onset FGR than in suspected early‐onset FGR. Unexpectedly, our subgroup analysis showed the opposite; there was a higher predictive accuracy for adverse perinatal outcome in pregnancies with suspected early‐onset FGR.…”

“…In addition, subgroup analyses suggest that the predictive accuracy of CPR is higher in pregnancies with suspected early-onset FGR and when MCA-PI/UA-PI ≤ 1.08 or MCA-RI/UA-RI < 1 or < 1.05 is used as the definition of abnormal CPR. Previously, it has been suggested that CPR is a stronger predictor of adverse perinatal outcome in suspected late-onset FGR than in suspected early-onset FGR 23,[25][26][27] . Unexpectedly, our subgroup analysis showed the opposite; there was a higher predictive accuracy for adverse perinatal outcome in pregnancies with suspected early-onset FGR.…”

A Low Cerebroplacental Ratio at 20-24 Weeks of Gestation Can Predict Reduced Fetal Size Later in Pregnancy or at Birth

“…Similar results were reported by Triunfo et al 58 who showed that a low CPR in the third trimester of pregnancy had a higher association with adverse perinatal outcomes such as, nonreassuring fetal status requiring emergent cesarean section, 5-minute Apgar score <7, or neonatal metabolic acidosis at birth (UA pH ≤7.15 and base excess greater than 12 mEq/L) than EFW. These observations led to the evaluation of the CPR as a screening tool for pregnant women during the third trimester of pregnancy to identify fetuses at risk of late SGA, 5962 stillbirth, low pH in the umbilical cord, low Apgar scores, cesarean delivery for fetal distress, and admission to the neonatal intensive care unit. 60–62 .…”

Intraobserver and interobserver reproducibility of third trimester uterine artery pulsatility index

“…The clinical utility of uterine artery (UtA) Doppler indices assessed during the third trimester of pregnancy in identifying fetuses at risk of adverse outcome is increasingly reported in literature . Several authors have indeed demonstrated that small fetuses with abnormal (≥95th centile) mean UtA pulsatility index (PI) during the third trimester are at increased risk of adverse perinatal outcome and show placental signs of underperfusion .…”

“…The clinical utility of uterine artery (UtA) Doppler indices assessed during the third trimester of pregnancy in identifying fetuses at risk of adverse outcome is increasingly reported in literature. 1 "Reproducibility Issue" in biological sciences. 4 Obstetric measurements, and Doppler in particular, are not immune from these concerns, and a debate is currently ongoing on which cutoffs should be used to interpret reproducibility studies.…”