Table 1 Socio-demographic characteristics of the study population

MB-CDI Score

Median [Q1, Q3]

81 [59, 93]

Daily overall temperature^a(Tmean, °C)

Mean [min, max]

12.1 [-20.1, 31.8]

Daily daytime temperature^a(Tmax, °C)

Mean [min, max]

17.3 [-15.7, 42.8]

Daily night-time temperature^a(Tmin, °C)

Mean [min, max]

7.7 [-24.3, 29.1]

Daily PM2.5 concentration^a(µg/m³)

Mean [min, max]

15.3 [0, 108]

Daily PM10 concentration^a(µg/m³)

Mean [min, max]

22.5 [0, 122]

Daily NO2 concentration^a(µg/m³)

Mean [min, max]

20.2 [0, 238]

European Defavor Index of living area

Low: (-9.18,-1.6]

4434 (36.5%)

Medium: (-1.6,2.06]

4194 (34.5%)

High: (2.06,31.9]

3519 (28.9%)

Missing

16 (0.1%)

NDVI^b

Low: (0.0367,0.393]

3732 (30.7%)

Medium: (0.393,0.51]

4066 (33.4%)

High: (0.51,0.89]

4362 (35.9%)

Missing

3 (0.0%)

Size of living area

Rural area or less than 50,000 inhabitants

2447 (20.1%)

50,000 to 500,000 inhabitants

3778 (31.1%)

More than 500,000 inhabitants

5543 (45.6%)

Missing

395 (3.2%)

Mother’s birth place

France

10,903 (89.6%)

Overseas

1185 (9.7%)

Missing

75 (0.6%)

Mother’s history of learning difficulties

No

6715 (55.2%)

Yes

4978 (40.9%)

Missing

470 (3.9%)

Father’s history of learning difficulties

No

4964 (40.8%)

Yes

5017 (41.2%)

Missing

2182 (17.9%)

Level of education (Highest between mother and father)

Primary or secondary school

264 (2.2%)

Highschool

2931 (24.1%)

Undergraduate

2675 (22.0%)

Bachelor

2191 (18.0%)

Postgraduate

3914 (32.2%)

Missing

188 (1.5%)

Mother’s socio-professional category

Craftsmen & merchants

1010 (8.3%)

Executives and higher intellectual professions

3011 (24.8%)

Intermediate professions

1739 (14.3%)

Employees (skilled and unskilled)

4234 (34.8%)

Workers (skilled and unskilled)

1377 (11.3%)

Others

532 (4.4%)

Missing

260 (2.1%)

Parity

Primiparous

5531 (45.5%)

Multiparous

6586 (54.1%)

Missing

46 (0.4%)

Pre-pregnancy Body Mass Index

< 18.5

868 (7.1%)

18.5–25

8053 (66.2%)

25–30

2010 (16.5%)

> 30

1120 (9.2%)

Missing

112 (0.9%)

Mother’s age at conception

25 or below

1139 (9.4%)

26–30

3988 (32.8%)

31–35

4521 (37.2%)

36–40

2046 (16.8%)

41 or above

453 (3.7%)

Missing

16 (0.1%)

Father’s age at conception

25 or below

554 (4.6%)

26–30

2730 (22.4%)

31–35

4332 (35.6%)

36–40

2693 (22.1%)

41–45

1048 (8.6%)

46 or above

463 (3.8%)

Missing

343 (2.8%)

Alcohol consumption during pregnancy

At least once a month

3128 (25.7%)

Never or less than once a month

8955 (73.6%)

Missing

80 (0.7%)

Consumption of tobacco during pregnancy

At least some exposure (passive or active)

3844 (31.6%)

No exposure

7968 (65.5%)

Missing

351 (2.9%)

Coffee consumption during pregnancy

Less than once a day

9966 (81.9%)

Once a day or more

1030 (8.5%)

Missing

1167 (9.6%)

Fish consumption during pregnancy

Never

613 (5.0%)

Less than once a month

1313 (10.8%)

One to three times a month

3294 (27.1%)

Once a week

3714 (30.5%)

Twice a week or more

2160 (17.8%)

Missing

1069 (8.8%)

Vitamin B9 consumption during pregnancy

No

5250 (43.2%)

Yes

6634 (54.5%)

Missing

279 (2.3%)

Omega 3 consumption during pregnancy

Less than once a week

2567 (21.1%)

More than once a week

1796 (14.8%)

Never

5792 (47.6%)

Missing

2008 (16.5%)

Sex of the child

Female

5988 (49.2%)

Male

6175 (50.8%)

Feeding method at 2 months

Breastfeeing only

3963 (32.6%)

Breastfeeing & Bottle feeding

1927 (15.8%)

Bottle feeding only

5987 (49.2%)

Missing

286 (2.4%)

Parental relationship

Separated

690 (5.7%)

Together

11,372 (93.5%)

Missing

101 (0.8%)

Number of languages spoken at home

One

8566 (70.4%)

Two

2525 (20.8%)

Three or more

834 (6.9%)

Missing

238 (2.0%)

Household income

1st quintile

2168 (17.8%)

2nd quintile

2349 (19.3%)

3rd quintile

2286 (18.8%)

4th quintile

2353 (19.3%)

5th quintile

2365 (19.4%)

Missing

642 (5.3%)

Age at MB-CDI test (month)

Mean [min, max]

25.33 [23.00, 28.00]

Missing

101 (0.8%)