Table 2. List of the non-shared variables and categories included in the cumulative load of early medical events and intra-pair differences in MZ pairs qualitative discordant for ASD (n=13 pairs).

Categories	Wilcoxon sign-rank test	Variables	McNemar's/Wilcoxon sign-rank test
Delivery related factors	Z=−1.34 P=0.180	Apgar 5 min	—
		Fetal distress	—
		Breech birth	P=0.625
Minor medical neonatal factors	Z=−1.51 P=0.131	Hypoglycemia	—
		Hyperbilirubinemia	P=1.00
		Oxygen treatment	—
		Iron depletion	—
		Thrombocytopenia	—
Growth at birth	—	Birth weight	Z=−2.20 P=0.028*
Microcephaly	—	Head circumference relative to length	P=0.219
Minor and frequent infections	Z=−0.58 P=0.564	Frequent ear infections	P=1.00
		Infections asthma before 5 y	P=1.00
		Gastroenteritis <2 y	—
Serious infections <2 y	Z=0.00 P=1.00	Pyelonephritis <2 y	—
		Septicemia <2 y	P=1.00
Total allergy	—	Eczema <5 y	P=1.00
		Allergy <5 y	—
Total epilepsy <5 y	Z=−1.41 P=0.157	Epilepsy <5 y	—
		Seizures first year	P=0.50
Serious medical conditions first year	Z=−1.00 P=0.317	Cerebral hemorrhage	P=1.00
		Cerebral paresis	—
		Hydrocephalus	—
Congenital heart and vessel malformations	—	Heart and large vessels malformation, Cerebral AVM	—
Brain atrophy	—	Brain atrophy	—
Head contusion	—	Head contusion <3 y	—
Visual impairments	—	Glasses	P=1.00
Dysregulation <1 y	Z=−2.56 P=0.011*	Poor sleep	P=0.063
		Feeding disabilities	P=0.125
		Frequent vomiting	—
		Crying a lot	P=0.250
		Worried <1 y	—
The cumulative load of early medical events	Z=−2.85 P=0.004**	Including all above-listed variables

Abbreviations: ASD, autism spectrum disorder; AVM, arteriovenous malformation; MZ, monozygotic; y, year.

*P<0.05, **P<0.01.