Table 2.

OLS regression model on birthweight

		Coef.	Std. Err.	P-value	[95% Conf.	Interval]
Infant sex	Male	0
	Female	− 124.129	1.243	0.000	− 126.565	−121.694
Birth order	1st	0
	2nd - 3th	96.369	1.360	0.000	93.704	99.035
	4th+	139.752	3.191	0.000	133.497	146.007
Labor complications	No	0
	Yes	31.561	2.141	0.000	27.366	35.757
Caesarean delivery	No	0
	Yes	24.331	1.817	0.000	20.770	27.892
Age of mother	< 20	0
	20–30	53.784	3.665	0.000	46.601	60.967
	31+	44.870	3.925	0.000	37.177	52.562
Marital status of mother	Married	0
	Never married	−5.547	1.454	0.000	−8.397	−2.698
	Separated/Divorced	−8.937	3.167	0.005	−15.144	−2.730
	Widow	−36.169	14.020	0.010	−63.647	−8.691
Education of mother	Primary or less	0
	Lower Secondary	16.919	1.811	0.000	13.369	20.468
	Upper Secondary	18.038	1.940	0.000	14.236	21.840
	University	10.156	2.409	0.000	5.436	14.877
Family class	Manager/Professional	0
	White Collar	−3.126	3.021	0.301	−9.047	2.796
	Service Workers	5.753	2.976	0.053	−0.080	11.586
	Skilled Workers	9.467	3.339	0.005	2.922	16.012
	Unskilled Workers	6.414	3.175	0.043	0.192	12.637
	Inactive	−5.983	2.832	0.035	−11.533	−0.432
Citizenship of mother	Other	0
	Spanish	−31.294	1.725	0.000	−34.676	−27.913
Age of father		0.442	0.104	0.000	0.239	0.645
Migratory status of father	Native	0
	Migrant	22.839	1.558	0.000	19.786	25.893
Origin of Mother	HIC	0
	NHI-EUR	33.208	2.500	0.000	28.307	38.108
	AFC	52.219	2.672	0.000	46.983	57.456
	LAC	57.147	2.143	0.000	52.947	61.347
	ASC	−31.365	3.606	0.000	−38.433	−24.298
Constant		3254.735	5.751	0.000	3243.463	3266.007