Table 1 Summary statistics of the participating children

Male sex (vs. female)

52.1

Gestational age (weeks)

39.3 (1.7), 28–42

Birth weight (kg)

3.29 (0.50), 0.59–5.01

Maternal age at birth of child (years)

29.4 (4.8), 17–45

Tobacco consumption, %

22.8

Alcohol during pregnancy (drinks/week)

0.54 (1.46), 0–17

Breastfeeding duration (months)

3.4 (3.7), 0–13

Maternal depression during pregnancy, %

21.4

Maternal depression after birth, %

32.4

Family history of language delay, %

13.3

Household income (k€)

2.72 (1.01), 0.23–5.25

Parental education (years)

13.6 (2.3), 9–17

Number of older siblings

0.78 (0.94), 0–7

Maternal cognitive stimulation at 3 years

21.86 (4.84), 5–32

Score for family stimulation at 5.5 years

17.22 (2.29), 7–21

Recruitment center (Nancy)

47.6

Performance IQ

99.30 (13.78), 48–144

 At 3 years

 Semantic fluency (ELOLA)

6.87 (3.91), 0–22

 Word and nonword repetition (ELOLA)

7.63 (3.22), 0–12

 Sentence repetition (NEPSY)

7.19 (3.30), 0–19

 Picture naming (ELOLA)

6.96 (1.90), 0–10

 Comprehension of instructions (NEPSY)

8.47 (2.98), 0–13

 Age of the child at the time of testing (months)

38.05 (0.81), 34.20–42.91

 Non Words Repetition (NEPSY)

28.03 (8.12), 5–45

 Sentence Repetition (NEPSY)

15.42 (4.10), 2–28

 Information (WPPSI-3)

24.96 (2.95), 12–32

 Vocabulary (WPPSI-3)

23.63 (5.65), 5–40

 Word Reasoning (WPPSI-3)

16.07 (4.69), 0–27

 Age of the child at the time of testing (months)

67.89 (1.85), 59.53–82.07

 Emotional symptoms score

6.81 (1.63), 5–14

 Conduct problems score

6.20 (2.01), 3–12

 Hyperactivity/inattention symptoms score

4.48 (2.25), 1–12

 Peer relationship problems score

2.49 (1.50), 0–12

 Prosocial behavior score

12.71 (1.68), 7–15

 Emotional symptoms score

7.13 (1.88), 5–15

 Conduct problems score

5.37 (2.05), 2–13

 Hyperactivity/inattention symptoms score

4.07 (2.42), 0–13

 Peer relationship problems score

2.19 (1.33), 0–9

 Prosocial behavior score

13.37 (1.68), 7–15