Discussion
The current analysis was done to understand the association between ultrasound based fetal anthropometric parameters and neurodevelopmental outcomes at 24 months of age. We did not find any significant association with parameters at 26–28 weeks gestation, except for a positive association of TCD with motor composite scores. None of the fetal anthropometric parameters were associated with a risk of moderate to severe development delay.Transcerebellar diameter is considered as a marker of cerebellar growth. Between 24 to 40 weeks of gestation the cerebellar volume increases by almost 500% [For some of the other fetal anthropometric parameters (AC, HC/AC, FL/BPD) measured in the second or third trimester, associations with neurodevelopment in early childhood have been found [In the Generation R study, an increase in AC z score and a decrease in HC/AC z score was associated with lesser risk of optimal neuromotor development [To the best of our knowledge, this is the only population based study done in South Asia which examines the association between fetal anthropometric variables and neurodevelopmental outcomes beyond infancy. A major strength of this study is that it was population based (in apparently healthy low risk women) with a large sample size of around 1500 mother child dyads. The fetal anthropometric variables were measured by well-trained sonographers using INTERGROWTH 21 standards. Trained psychologists conducted the neurodevelopmental assessments using the globally accepted Bayley-III scales. We carefully selected variables for adjustment in the model. However, there still remains a possibility that some factors such as postnatal nutrition, morbidity, quality of child care and parenting may have influenced the neurodevelopmental outcomes.