Table 1 Characteristics of mothers and infants in the BD and the non-clinical sample

Maternal age at inclusion, in years, mean ± SD; range

30.5 ± 4.7; 22–37

33.5 ± 5.1; 27–44

0.03^*

n

%

n

%

Parity

0.43

 Primiparous

13

50

17

61

 Multiparous

13

50

11

39

Completed education

< 0.001*

 Primary school

8

31

1

4

 Secondary school

5

19

4

14

 Bachelor’s degree

11

42

7

25

 Master’s degree

2

8

16

57

Employment status when not pregnant

0.003*

 Working full-time

12

46

21

75

 Working part-time ± receiving benefits

4

15

2

7

 Receiving benefits only

8

31

0

 Unemployed

1

4

1

4

 School

1

4

4

14

Infant gender

0.95

 Girl

10

38

11

39

 Boy

16

62

17

61

Infant birth weight, in g, mean ± SD; range

3632 ± 507; 2905-5085

3692 ± 424; 2911–4715

0.64

Infant gestational age, in months, mean ± SD; range

39.5 ± 1.2; 37.2-41.6

40 ± 1.2; 37–42

0.17

Clinical characteristics of BD sample

 Primary diagnosis

  BD I

7

27

Not applicable

  BD II

19

73

 Symptom load^a at 3 months

  Euthymia

8

31

Not applicable

  Mild depressive

6

23

  Moderate depressive

5

19

  Severe depressive

4

15

  Hypomania

2

8

  Mixed state^b (mild)

1

4

 Symptom load^a at 12 months

  Euthymia

8

31

Not applicable

  Mild depressive

4

15

  Moderate depressive

6

23

  Severe depressive

6

23

  Mania^c

1

4

  Mixed state^d (severe)

1

4