Jaundice babies and ASD research

Among 13 included studies, there was a statistically significant association between neonatal jaundice and ASD

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4285414/

Using guidelines of the Meta-analysis of Observational Studies in Epidemiology Group, we systematically reviewed the literature on neonatal jaundice (unconjugated hyperbilirubinemia) and Autism Spectrum Disorder (ASD) in term and preterm infants.

Thirteen studies were included in a meta-analysis. Most used retrospective matched case–control designs. There was significant heterogeneity (Q = 31, p = 0.002) and no evidence of publication bias (p = 0.12). Overall, jaundice, assessed by total serum bilirubin (TSB), was associated with ASD (OR, 1.43, 95% CI 1.22–1.67, random effect model).

This association was not found in preterms (OR 0.7, 95% CI 0.38–1.02) but deserves further investigation since other measures of bilirubin such as unbound unconjugated bilirubin may be better predictors of neurotoxicity than TSB in preterms.

Two things I found interesting. Jaundice is an indication of brain trauma (neurotoxicity). And this is seen more in term babies than in preterm. Does the size of the baby matter? Does going full term have an increased risk for ASD.

Also, do we actually know when a baby is a full term or not. As women's cycles vary shouldn't gestation?