Fetal growth velocity standards from the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project

Abstract

On behalf of the International Fetal and Newborn Growth Consortium for the 21st Century (INTERGROWTH-21st Project) BACKGROUND: Human growth is susceptible to damage from insults, particularly during periods of rapid growth. Identifying those periods and the normative limits that are compatible with adequate growth and development are the first key steps toward preventing impaired growth. OBJECTIVE: This study aimed to construct international fetal growth velocity increment and conditional velocity standards from 14 to 40 weeks' gestation based on the same cohort that contributed to the INTER-GROWTH-21 st Fetal Growth Standards. STUDY DESIGN: This study was a prospective, longitudinal study of 4321 low-risk pregnancies from 8 geographically diverse populations in the INTERGROWTH-21 st Project with rigorous standardization of all study procedures, equipment, and measurements that were performed by trained ultrasonographers. Gestational age was accurately determined clinically and confirmed by ultrasound measurement of crown-rump length at <14 weeks' gestation. Thereafter, the ultrasonographers, who were masked to the values, measured the fetal head circumference, biparietal diameter, occipitofrontal diameter, abdominal circumference, and femur length in triplicate every 5 weeks (within 1 week either side) using identical ultrasound equipment at each site (4e7 scans per pregnancy). Velocity increments across a range of intervals between measures were modeled using fractional polynomial regression. RESULTS: Peak velocity was observed at a similar gestational age: 16 and 17 weeks' gestation for head circumference (12.2 mm/wk), and 16 weeks' gestation for abdominal circumference (11.8 mm/wk) and femur length (3.2 mm/wk). However, velocity growth slowed down rapidly for head circumference, biparietal diameter, occipitofrontal diameter, and femur length, with an almost linear reduction toward term that was more marked for femur length. Conversely, abdominal circumference velocity remained relatively steady throughout pregnancy. The change in velocity with gestational age was more evident for head circumference, biparietal diameter, occipitofrontal diameter, and femur length than for abdominal circumference when the change was expressed as a percentage of fetal size at 40 weeks' gestation. We have also shown how to obtain accurate conditional fetal velocity based on our previous methodological work. CONCLUSION: The fetal skeleton and abdomen have different velocity growth patterns during intrauterine life. Accordingly, we have produced international Fetal Growth Velocity Increment Standards to complement the INTERGROWTH-21 st Fetal Growth Standards so as to monitor fetal well-being comprehensively worldwide. Fetal growth velocity curves may be valuable if one wants to study the pathophysiology of fetal growth. We provide an application that can be used easily in clinical practice to evaluate changes in fetal size as conditional velocity for a more refined assessment of fetal growth than is possible at present (https://lxi...

Fetal growth velocity references from a Chinese population–based fetal growth study

“…We compared the median fetal velocity curves of our study with those of several previous studies (Fig. 3 ), including the NICHD fetal growth study [ 18 ], INTERGROWTH–21st project [ 19 ], and Guihard–Costa et al [ 15 , 16 ].…”

“…We used the second method to obtain the instantaneous velocity. According to the previous literature, both size curves [ 11 ] and velocity curves [ 19 ] are conditional normal distributions. Therefore, we deduced that the percentile of velocity curves corresponded to the percentile of size curves and then percentiles of fetal growth velocity were obtained based on the exponentiations of the predicted mean and percentiles (the predicted mean and its percentiles were the logarithmic estimates of the original scaled measurements) of the fetal size curves.…”

“…Compared to traditional fetal size curves, fetal growth velocity improved the sensitivity of predictions of antepartum fetal death (26.1 vs. 56.5%) [ 13 ]. Although several fetal growth velocity charts have been published [ 14 – 19 ], there are none specifically intended for the Chinese population. This is the first study to develop a fetal growth velocity chart for the Chinese population.…”

Perinatal Adverse Effects in Newborns with Estimated Loss of Weight Percentile between the Third Trimester Ultrasound and Delivery. The GROWIN Study

“…Fetal growth velocity is defined as the rate of fetal growth over a given time interval and is usually represented as a deviation from growth velocity charts (changes in centiles or Z-score with advancing gestation), which is significant to determine fetal growth [ 1 , 42 ].…”

Índice biométrico integral para evaluar el crecimiento fetal

“…Por otra parte, tomando en cuenta la diferencia entre dos mediciones, el coeficiente de correlación entre estas y el lapso transcurrido entre ambas, es posible calcular una velocidad condicionada de crecimiento, como se sugiere en publicación reciente (23) .…”