Table 2.

 Maternal characteristics in full cohort and sibling cohort in analysis of association between fetal and childhood exposure to antibiotics and development of asthma

	Full cohort			Sibling cohort
	No of children	No (%) with asthma		No of children	No (%) with asthma
Total No of children	493 785	29 753 (6.0)		180 894	11 260 (6.2)
Mode of delivery:
Vaginal	366 662	20 712 (5.7)		136 452	7 870 (5.8)
Instrumental	38 333	2235 (5.8)		12 746	814 (6.4)
Elective caesarean section	37 934	2911 (7.7)		17 893	1 054 (7.7)
Emergency caesarean section	50 569	3880 (7.7)		13 687	1 518 (8.5)
Missing	287	15 (5.2)		116	4 (3.5)
Smoking during pregnancy:
No	439 962	25 516 (5.8)		162 490	9 806 (6.0)
Yes	32 743	2766 (8.5)		10 184	877 (8.6)
Missing	21 080	1471 (7.0)		8 220	577 (7.0)
Age at delivery (years):
<19	7746	462 (6.0)		1 972	149 (7.6)
19-24	61 960	3954 (6.4)		23 118	1 660 (7.2)
25-29	140 790	8873 (6.3)		56 079	3 727 (6.7)
30-34	173 923	10 395 (6.0)		66 494	3 907 (5.9)
≥35	109 366	6069 (5.6)		33 231	1 817 (5.5)
Parity (at current delivery):
1	216 643	11 869 (5.5)		65 781	4 287 (6.5)
2	181 919	11 805 (6.5)		80 583	4 767 (5.9)
3	66 979	4200 (6.3)		22 647	1 386 (6.1)
≥4	28 244	1879 (6.7)		11 883	820 (6.9)
Family situation:
Mother and father cohabit	444 030	26 454 (6.0)		165 892	10 205 (6.2)
Mother lives alone, other	27 164	1761 (6.5)		6 279	452 (7.2)
Missing	22 591	1538 (6.8)		8 723	603 (6.9)
Country of birth:
Sweden	393 578	25 007 (6.4)		148 548	9 562 (6.4)
Other Nordic countries	7561	448 (5.9)		2 649	174 (6.6)
Other	92 646	4298 (4.6)		29 697	1 524 (5.1)
Parents’ highest level of education (years):
0-9	24 141	1576 (6.5)		8 023	557 (6.9)
10-12	180 539	12 239 (6.8)		62 781	4 305 (6.9)
>12	286 922	15 874 (5.5)		109 666	6 386 (5.8)
Missing	2183	64 (2.9)		424	12 (2.8)
Maternal asthma:
No	453 278	24 733 (5.5)		162 887	9 113 (5.6)
Yes	40 507	5020 (12.4)		18 007	2 147 (11.9)