Table 1.
Infant and maternal characteristics among multiples by exposure to ANS (N=6925)
| Characteristic | No. (%) | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| 22 wk | 23 wk | 24 wk | 25 wk | Total 22–28 wk | p-valuea | ||||||
| ANS (n=68) |
No ANS (n=68) |
ANS (n=394) |
No ANS (n=181) |
ANS (n=893) |
No ANS (n=93) |
ANS (n=885) |
No ANS (n=89) |
ANS (n=6094) |
No ANS (n=831) |
||
| Infant | |||||||||||
| BW, mean (SD), g |
511 (75) |
502 (60) |
567 (81) | 574 (87) |
635 (100) |
656 (113) |
746 (118) |
749 (145) |
866 (235) |
794 (251) | <0.001 |
| SGA | 2 (3%) |
1 (1%) |
20 (5%) | 8 (4%) |
67 (8%) | 7 (8%) |
45/883 (5%) |
6 (7%) |
390/6091 (6%) |
50 (6%) |
0.71 |
| Male sex | 33(49%) | 35 (51%) |
213 (54%) |
94 (52%) |
469 (53%) |
53 (57%) |
508/884 (57%) |
45 (51%) |
3238/6092 (53%) |
420 (51%) |
0.16 |
| Twins | 57 (84%) |
61 (90%) |
346 (88%) |
144 (80%) |
751 (84%) |
83 (89%) |
734 (83%) |
82 (92%) |
5034 (83%) |
741 (89%) |
<0.001 |
| Higher orderb | 11 (16%) |
7 (10%) | 48 (12%) |
37 (20%) |
142 (16%) |
10 (11%) |
151 (17%) |
7 (8%) | 1060 (17%) |
90 (11%) | |
| Apgar score ≤3 at 5 min |
21 (31%) |
30/66 (45%) |
104/390 (27%) |
65/175 (37%) |
140 (16%) |
23 (25%) |
81/882 (9%) |
17/88 (19%) |
566 (9%) | 165/820 (20%) |
<0.001 |
| Intubation | 63 (93%) |
45/67 (67%) |
365/393 (93%) |
166/180 (92%) |
816/891 (92%) |
90 (97%) |
719 (81%) |
84 (94%) |
4228/6089 (69%) |
665/829 (80%) |
<0.001 |
| Delivery room resuscitation |
68 (100%) |
67/67 (100%) |
388/393 (99%) |
180/180 (100%) |
892/892 100%) |
93 (100%) |
884 (100%) |
89 (100%) |
6045/6090 (99%) |
828/829 (100%) |
0.04 |
| Surfactant use |
61 (90%) |
41 (60%) |
360 (91%) |
159 (88%) |
843 (94%) |
87 (94%) |
811/884 (92%) |
85 (96%) |
5105/6081 (84%) |
722 (87%) |
0.03 |
| Maternal | |||||||||||
| Age ≤19 y | 4 (6%) |
14 (21%) |
40 (10%) |
12 (7%) |
70 (8%) | 16 (17%) |
51 (6%) | 16 (18%) |
447 (7%) | 98 (12%) | <0.001 |
| Unmarried | 27/66 (41%) |
39/67 (58%) |
159/393 (40%) |
80/180 (44%) |
347/889 (39%) |
55 (59%) |
316/882 (36%) |
62/87 (71%) |
2232/6052 (37%) |
442/820 (54%) |
<0.001 |
| Race/ethnicity | <0.001 | ||||||||||
| Black | 23 (34%) |
41 (60%) |
142/392 (36%) |
73/177 (41%) |
284/877 (32%) |
38 (41%) |
281/880 (32%) |
56 (63%) |
1835/6039 (30%) |
384/825 (47%) |
|
| White | 45 (66%) |
27 (40%) |
231/392 (59%) |
91/177 (51%) |
539/877 (61%) |
55 (59%) |
563/880 (64%) |
32 (36%) |
3868 (64%) |
408 (49%) |
|
| Other | 0 (0%) |
0 (0%) |
19/392 (5%) |
13/177 (7%) |
54/877 (6%) |
0 (0%) |
36/880 (4%) |
1 (1%) |
336 (6%) |
33 (4%) |
|
| Cesarean delivery |
11 (16%) |
12 (18%) |
150 (38%) |
63/180 (35%) |
611/892 (69%) |
60 (65%) |
707/884 (80%) |
61 (69%) |
4661/6092 (77%) |
492/830 (59%) |
<0.001 |
| Diabetes | 0 (0%) |
0/67 (0%) |
7 (2%) |
7 (4%) |
30 (3%) | 3 (3%) |
26/884 (3%) |
3 (3%) |
246/6093 (4%) |
37/830 (4%) |
0.57 |
| Hypertension | 3 (4%) |
4/67 (6%) |
34 (9%) | 21 (12%) |
88 (10%) |
3 (3%) |
116/884 (13%) |
10 (11%) |
870/6091 (14%) |
99/830 (12%) |
0.07 |
| Less than high school degreec |
9/45 (20%) |
3/31 (10%) |
50/273 (18%) |
31/105 (30%) |
104/690 (15%) |
26/70 (37%) |
119/757 (16%) |
27/65 (42%) |
729/4578 (16%) |
164/545 (30%) |
<0.001 |
| Income <$20,000d |
4/7 (57%) |
0/1 (0%) |
13/75 (17%) |
13/28 (46%) |
80/345 (23%) |
16/32 (50%) |
129/473 (27%) |
26/39 (67%) |
576/2021 (29%) |
109/221 (49%) |
<0.001 |
| Medicaidc | 30/52 (58%) |
35/53 (66%) |
148/345 (43%) |
70/129 (54%) |
320/784 (41%) |
50/75 (67%) |
317/825 (38%) |
45/77 (58%) |
2169/5333 (41%) |
369/664 (56%) |
<0.001 |
| Non-speaking Englishe |
0/9 (0%) |
0/6 (0%) |
11/103 (11%) |
3/27 (11%) |
80/426 (19%) |
2/27 (7%) |
65/535 (12%) |
8/46 (17%) |
287/2265 (13%) |
33/230 (14%) |
0.47 |
| Follow-up rate (NDI)f |
9/9 (100%) |
6/7 (86%) |
102/113 (90%) |
23/32 (72%) |
400/464 (86%) |
24/37 (65%) |
508/596 (85%) |
45/48 (94%) |
2134/2509 (85%) |
210/263 (80%) |
0.03 |
Abbreviations: ANS, antenatal corticosteroids; BW, birth weight; GA, gestational age; NDI, neurodevelopmental impairment; SGA, small for gestational age.
P-value comparing total 22–28 wk ANS vs no ANS obtained from Fisher’s exact test for categorical variables and from non-parametric Wilcoxon 2-sample tests for BW and GA
Higher order multiples include: 937 triplets (92% with ANS), 162 quadruplets (96% with ANS), 34 quintuplets (85% with ANS), and 17 sextuplets (100% with ANS).
For infants born from 1998 to 2001, maternal education and Medicaid are only available if provided during follow-up. In 2002, both variables were collected for all infants irrespective of follow-up.
For infants born from 1998 to 2011, income is only available if provided during follow-up. Income was removed entirely in 2012.
Primary language of mother is only available if provided during follow-up.
Follow-up rate based on non missing NDI for 2772 infants, with an overall follow-up rate of 85%. Follow-up is only given for infants born between 1998 and June 2012.