Table 1 Sociodemographic and clinical baseline characteristics of the mother-child dyads

Mother’s age (years)^a

32. 8 ± 5.0

32.5 ± 5.2

33.2 ± 4.8

0.02

University studies

239 (55.1%)

103 (47.9%)

136 (62.1%)

0.003

Paid work

315 (72.6%)

150 (69.8%)

165 (75.3%)

0.19

Planned return to work before 6 months

246 (78.1%)

115 (76.7%)

131 (79.4%)

0.34

Number of family-unit members^a

2.5 ± 0.8

2.7 ± 0.8

2.4 ± 0.7

0.002

Living with the partner

411 (94.7%)

200 (93%)

211 (96.4%)

0.12

Has other children

184 (42.4%)

106 (49.3%)

78 (35.6%)

0.004

Dysfunctional family APGAR score

11 (2.5%)

5 (2.3%)

6 (2.7%)

0.78

Income/household member^b

833.3 [500–1250]

750 [500–1167]

833.3 [750–1250]

< 0.001

Spanish

348 (80.2%)

166 (77.2%)

182 (83.1%)

0.12

Maternal BMI (kg/m2)^a

24.8 ± 4.1

25.3 ± 4.4

24.4 ± 3.7

0.05

Maternal smoking

31 (7.1%)

13 (6.0%)

18 (8.2%)

0.38

Gestational age (weeks)^a

39 ± 1.2

39 ± 1.1

39 ± 1.2

0.54

Diseases/clinical problems in pregnancy^c

94 (21.7%)

50 (23.2%)

44 (20.1%)

0.42

Caesarean delivery

88 (20.3%)

41 (19.1%)

47 (21.5%)

0.54

Sex of child (male)

212 (48.8%)

111 (51.6%)

101 (46.1%)

0.25

Apgar score at 1 minute^a

8.9 ± 1

8.8 ± 1

9.0 ± 1

0.56

Weight at birth (kg)^a

3.3 ± 0.4

3.3 ± 0.4

3.3 ± 0.4

0.30

Days of admission of the child^a

3 ± 1.3

3 ± 1.5

3 ± 1

0.30