The following is a summary of “Reduced fetal growth velocity and weight loss are associated with adverse perinatal outcome in fetuses at risk of growth restriction,” published in the January 2023 issue of Obstetrics and Gynecology by Stampalija, et al.

Although there was a link between fetal size and poor perinatal outcomes, the connection between fetal growth rate and poor perinatal outcomes was less evident. For a study, researchers sought to assess the link between fetal growth rate and indications of redistributed cerebral blood flow, as well as their correlation with low birthweight and poor perinatal outcome.

The TRUFFLE-2 multicenter observational prospective feasibility study of fetuses at risk of fetal growth restriction between 32⁺⁰ and 36⁺⁶ weeks of gestation (n=856), assessed by ultrasound biometry and umbilical and middle cerebral artery Doppler, served as the basis for the secondary analysis. Individual fetal growth velocity was computed using linear regression of all available estimated fetal weight data and the difference between birthweight and estimated fetal weight at 3, 2, and 1 week before to delivery. For statistical purposes, birthweight and estimated fetal weight were presented as absolute values and multiples of the median. The final umbilical-cerebral ratio was shown against the coefficients of the individual linear regression of estimated fetal weight measurements (growth velocity; g/wk), with subclassification for the perinatal outcome. It was evaluated if these parameters were related to poor perinatal outcomes. The unfavorable perinatal outcome was a combination of significant neonatal illness or an aberrant condition at delivery.

Regardless of any indications of redistribution of cerebral blood flow, worse perinatal outcomes were more common in fetuses whose prenatal growth was <100 g/wk. Infants born with birthweights that were < 0.65 multiples of the median were recruited earlier, had the slowest fetal growth rates, had greater umbilical-cerebral ratios, and were more likely to experience unfavorable perinatal outcomes. In 163 (19%) women with an estimated fetal weight multiple of <-0.025, higher umbilical-cerebral ratio values, and more often occurring poor perinatal outcomes, a declining fetal development velocity was seen; 67 (41%; 8% of the total sample) of these women showed negative growth velocity. The logistic regression-estimated fetal weight, umbilical-cerebral ratio, and fetal growth rate together demonstrated a stronger correlation with a worse perinatal outcome than any of the individual indicators (relative risk, 3.3; 95% CI, 2.3-4.8).

Reduced growth velocity was linked to a higher likelihood of a poor perinatal outcome in fetuses at risk for late preterm fetal growth restriction, regardless of any evidence of cerebral blood flow redistribution. Some embryos had negative growth velocities, which was consistent with catabolic metabolism.

Reference: ajog.org/article/S0002-9378(22)00477-X/fulltext