Preventing term stillbirth: benefits and limitations of using fetal growth reference charts

Abstract

This review examines the variation in clinical practice with regards to ultrasound estimation of fetal weight, as well as calculation of fetal weight centiles from population/customised fetal growth references or fetal growth standards. Recent findingsPlacental dysfunction is associated with fetal smallness from intrauterine malnutrition as well as fetal disability and even stillbirth from hypoxemia. Although estimating fetal weight can be done accurately, the issue of which fetal weight centile chart should be used continues to be a contentious topic. The arguments against local fetal growth charts based on national borders and customization for variables known to be associated with pathology are substantial. As for other human diseases such as hypertension and diabetes, there is a rationale for the use of an international fetal growth reference standard. Irrespective of the choice of fetal growth reference standard, a significant limitation of national SGA detection programs to prevent stillbirth is that the majority of stillborn infants at term were not SGA at the time of demise.

Impact of Selection of Growth Chart in the Diagnosis of Suboptimal Fetal Growth and Neonatal Birthweight and Correlation with Adverse Neonatal Outcomes in a Third Trimester South Indian Antenatal Cohort; A Prospective Cross-Sectional Study

“…Consequently, the Doppler assessment of these vascular territories should be added to the diagnostic workflow. The diagnosis of suboptimal fetal growth should not solely rely on fetal smallness as inferred from the growth charts but should include additional information from the multivessel Doppler and the dynamic changes in the fetal growth velocity [3,8,39,40].…”

“…Growth charts constitute an essential tool in the clinical armamentarium of growth assessment by providing nomograms of biometric variables facilitating the interpretation of their adequacy [7]. Inspite of the progressive understanding of the phenotypes of placenta-based FGR and the introduction of a refined objective criteria for its diagnosis, the choice of fit-for-all growth chart is debatable and elusive [8,9]. The heterogeneity in the design and constructional methodology of growth charts evades the efforts for contriving a universally acceptable standard or reference [10,11].…”

Preventing Stillbirth: A Review of Screening and Prevention Strategies

“…National reference charts correspond to the geography of a particular country and are usually constructed retrospectively based on measured neonatal birthweight rather than EFW by ultrasound assessment. 34 There are two main problems associated with this retrospective approach to establishing fetal size reference charts. First they usually include non-healthy pregnancies with occult morbidities that might impact fetal growth, but not result in fetal demise.…”

“…Both early-and late-onset FGR are associated with significant perinatal morbidity and mortality, but earlyonset FGR fetuses have more severe hypoxia resulting in high morbidity and mortality rates. 21,34,45,46 Early and late-onset FGR are two different presentations of the same disease-placental dysfunction. This can be explained by the changes in fetal nutritional and respiratory demands with advancing gestational age.…”

“…6). 34,47,48 Therefore, early-onset placental dysfunction has a predominant effect on fetal growth before compromising respiratory needs, resulting with fetal stunting as a key feature of the disorder. With early-onset FGR, low fetal respiratory needs can be sustained for several weeks by the dysfunctional placenta.…”