Table 1.

Characteristics of the study population by origin

	Native Spanish	High-income countries	Non-high-income European countries	Africa	Latin America	Asia	All migrant born
Singleton births	2,401,964	65,220	100,773	127,040	223,162	25,942	542,137
%	82%	12%	19%	23%	41%	5%	100.0%
Mean Birthweight	3281.7	3318.1	3368.3	3407.4	3390.1	3320.7	3378.1
Infant sex %
Male	51.3	51.0	51.5	51.7	51.2	52.0	51.4
Female	48.7	49.0	48.5	48.3	48.8	48.0	48.6
Birth order %
1st	54.4	53.9	58.0	38.4	49.0	44.4	48.5
2nd - 3th	44.1	44.0	40.1	52.0	47.1	51.0	46.8
4th+	1.5	2.1	1.9	9.6	3.9	4.5	4.7
Labor complications %
Yes	13.1	13.9	12.2	14.2	15.9	11.6	14.4
No	86.9	86.1	87.8	85.8	84.1	88.4	85.6
Caesarean delivery %
Yes	22.9	22.5	18.4	20.2	24.8	20.7	22.1
No	77.1	77.6	81.6	79.8	75.2	79.3	77.9
Age of mother %
< 20	1.5	1.2	3.9	3.1	4.1	1.3	3.4
20–30	30.2	28.3	58.8	56.1	45.1	63.2	49.1
31+	68.3	70.6	37.3	40.8	50.8	35.5	47.6
Marital status of mother %
Married/Partner	62.7	52.7	55.0	83.3	45.9	70.0	58.3
Never married	33.7	42.8	39.4	14.8	48.3	28.2	37.2
Separated/Divorced	3.4	4.2	5.3	1.8	5.6	1.7	4.3
Widow	0.2	0.2	0.2	0.2	0.2	0.1	0.2
Education of mother %
Primary or less	8.4	7.5	18.0	61.1	14.9	41.1	26.6
Lower Secondary	20.4	17.7	33.8	20.9	32.4	31.1	28.1
Upper Secondary	30.1	30.6	30.5	12.5	33.6	18.5	27.0
University	41.1	44.3	17.8	5.5	19.2	9.3	18.3
Family class %
Manager/Professional	16.2	19.6	5.6	1.8	7.9	3.9	7.2
White Collar	26.0	27.4	9.4	3.3	12.2	4.6	11.0
Service Workers	17.3	18.4	15.8	8.6	20.1	41.3	17.4
Skilled Workers	15.4	9.4	13.1	8.7	7.8	3.6	9.0
Unskilled Workers	7.4	6.6	19.6	15.1	11.5	9.6	13.2
Inactive	17.7	18.7	36.6	62.6	40.6	37.0	42.2
Citizenship of mother %
Spanish	99.8	38.9	1.5	6.8	31.8	5.2	19.9
Other	0.2	61.1	98.5	93.2	68.2	94.9	80.1
Mean Age of father	34.4	35.3	33.0	36.8	33.5	32.5	34.3
Migratory status of father
Native	94.3	64.3	24.7	7.7	34.6	6.9	28.7
Migrant	5.7	35.7	75.4	92.3	65.4	93.2	71.3