Prenatal identification of fetal growth restriction and risk of stillbirth

Abstract

The aim of the work is to determine the frequency and impact of prenatal identification of fetal growth restriction (FGR) on obstetric and perinatal outcomes based on a retrospective analysis. Materials and methods. In total, 618 birth histories in singleton normal pregnancies complicated by FGR in the city of Zaporizhzhia were analyzed. Of these, in 546 cases of FGR, women gave birth to live infants (group I), and in 72 such cases, pregnancies ended up in a stillbirth (group II). The mean age of pregnant women in the studied groups was 28.7 ± 3.1 and 31.7 ± 3.1 years and it was significantly greater in group II (p < 0.0001). In all the cases, the gestational age was ≥22 weeks, and the fetal weight was less than the 10th percentile for the relevant gestational age according to the current Order of the Ministry of Health of Ukraine No. 1718 dated 02.10.2023. Growth restriction in newborns was determined according to the criteria of the Consensus Definition (2018) including birth weight the <3rd percentile, or a combination of three of the following criteria: birth weight the <10th percentile; head circumference the <10th percentile; prenatal diagnosis of FGR; prenatal risk factors associated with FGR. A stillbirth was defined as death of a fetus after 22 weeks of gestation without any signs of life. Exclusion criteria from the study were: multiple pregnancy, the presence of a chromosomal abnormality in a fetus, an undetermined gestational age in the 1st trimester. Results. A significant proportion of fetuses with FGR signs has been revealed in group II, which was 17 times more than that in group I. The study data have demonstrated a rather low level of prenatal FGR identification in both groups (35.6 %), while in group II, the diagnosis of FGR was made before delivery only in every fifth case (p < 0.05). Data analysis has shown a higher percentage of preterm births among pregnant women in group II (p < 0.0001) with the maximum number of births in this group at 28- and 36-weeks’ gestation. The average weight percentile was significantly higher in group II, namely 4.12 compared to 3.77 (p < 0.0001), however, the number of fetuses with a weight the <1st percentile occurred significantly more often in group I (p < 0.05). The frequency of fetal distress in group I was greater among fetuses with the birth weight 10th percentile than among those with fetal weight less than the 3rd percentile. Conclusions. The conducted study results have shown a large percentage of FGR fetuses in the structure of stillbirths with no downward trend. A low level of FGR prenatal identification has been found in both groups (35.6 %), while in the group of stillbirths, the indicator was significantly lower and amounted to 22.22 %. The presence of FGR has resulted in a significant increase in the relative risk of stillbirth – 28.4, 95 % CI [21.2; 38.3]. Besides, the additional risk was increased (11.0, 95 % CI [8.7; 13.8]) if FGR was not diagnosed during pregnancy. At the same time, the odds ratio was 32.1, 95 % CI [23.3; 44.1].