Table 1 Basic characteristics of the study population in relation to asthma at any time among offspring

Primipara

1 039 (39.3)

15 131 (41.3)

0.114

Maternal

Asthma

116 (4.4)

876 (2.4)

<0.001

GDM^a

143 (5.4)

2 314 (6.3)

0.066

Hypertension

76 (2.9)

725 (2.0)

0.002

Preeclampsia

115 (4.4)

1 438 (3.9)

0.217

ART^b

183 (6.9)

1736 (4.7)

<0.001

Maternal age, years

28.7 (5.3)

29 (5.5)

0.313

<25

780 (29.5)

9 944 (27.1)

26-35

1 581 (59.9)

22 049 (60.1)

>35

280 (10.6)

4672 (12.7)

0.001

Mean prepregnancy BMI^c, kg/m²

23.4 (4.5)

23.2 (4.3)

0.020

Mean number of previous pregnancies

1.5 (1.6)

1.4 (1.6)

0.08

Mean number of previous deliveries

1.1 (1.2)

1.0 (1.3)

0.57

Marital status

not married

900 (34.1)

13 238 (36.1)

married

1 741 (65.9)

23 427 (63.9)

0.036

Mode of delivery

Vaginal

2 040 (77.2)

29 925 (81.6)

Cesarean section

601 (22.8)

6 740 (18.4)

<0.001

Single

2 500 (94.7)

35 340 (96.4)

Twins

133 (5.0)

1 258 (3.4)

Triplets

8 (0.3)

67 (0.2)

<0.001

Premature delivery

380 (14.4)

2 594 (7.1)

<0.001

Boy

1 602 (60.7)

18 241 (50.2)

<0.001

Mean gestational age, w

38.4 (3.2)

39.2 (2.1)

<0.001

Apgar score 5 min <7

70 (2.7)

663 (1.8)

0.002

Chorioamnionitis^d

48 (1.8)

414 (1.1)

0.002

Mean follow-up time of children, years*

4.2 (3.6)

9.3 (5.3)

<0.001