Table 3.

Potential risk factors for ASD

Geographical region of maternal birth	Other prenatal risk factors (a–c)	Perinatal risk factors (d–g)	Neurodevelopmental disorders in the family (h–i)	Genetic findings/syndromes (j–l)
Eastern Africa	b
Eastern Africa	b		h
Eastern Africa			i	Data missing
Eastern Africa	b	d, g	i
Eastern Africa	b	f
Eastern Africa		d
Eastern Africa	b		i
Eastern Africa	b, c	d, e, f, g	i
Eastern Africa		g	h
Eastern Africa	c		i	Data missing
Eastern Africa	b	d	h, i
Eastern Africa	a	f	i
Northern Africa	c	e, f		k
Northern Africa	b, c	d
South/Eastern Asia	b, c	d	i
South/Eastern Asia	b	d, e, g	i
South/Eastern Asia	b	d
South/Eastern Asia	a, b
South/Eastern Asia	c		h
South/Eastern Asia	b	d
South/Eastern Asia	b			k
Western Asia			i	l
Western Asia	b		i
Western Asia		e
Western Asia		d	i
Western Asia				k, l
Western Asia	b
Western Asia	a
Northern Europe	b		h, i	j, l
Northern Europe	b, c	g	i
Northern Europe	b		i

a Advanced parental age (parental aged ≥ 40)

b Parity (first or ≥ fourth)

c Clustering of pregnancy complications, including maternal health problems, such as gestational diabetes, preeclampsia, abnormal thyroid function, infections, and mental health problem; and maternal prenatal medication, such as antibiotics

d Clustering of birth complications, such as intrauterine hypoxia or birth asphyxia, including 5 min Apgar scores < 7; elective and emergency caesarean section; and assisted birth, including vacuum extraction and forceps

e Preterm birth, gestational age ≤ 36 weeks

f Small size for gestational age (SGA), > 2 SD below the mean birth weight for the gestational age according to Swedish birth weight standards

g Other medical conditions during the neonatal period, such as infections and neonatal jaundice

h A first or second degree relative affected by ASD

i A first or second degree relative affected by other neurodevelopmental disorders

j In SNP array potentials causative copy number variations

k Medical syndrome suspected/Minor physical anomalies (MPA)

l Consanguinity