Table 1.
Basic characteristics of the study population in relation to asthma at any time among offspring
| Asthma* | No asthma* | p-value** | |
|---|---|---|---|
| n = 2641 (6.7 %) | n = 36 665 (93.3 %) | ||
| Primipara | 1 039 (39.3) | 15 131 (41.3) | 0.114 |
| Maternal | |||
| Asthma | 116 (4.4) | 876 (2.4) | <0.001 |
| GDMa | 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 |
| ARTb | 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 BMIc, 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 |
| Chorioamnionitisd | 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 |
*Values are mean (±2 SD) or N (%)
** p-value obtained in univariate model
aGestational diabetes mellitus
bART (assisted reprodution technology), including IVF (in-vitro fertilization), ICSI (intracytoplasmic sperm injection), insemination and ovulation induction by clomiphene and other medicines
cData missing in 1984 (4.5 %) cases
dData missing in 7 (0 %) cases