|
|
Singletons
(N=1,246 mothers) |
Multiple births
(N=238 mothers with 256 fetuses/neonates) |
p |
| |
|
|
|
N |
% |
N |
% |
Method of treatment |
IVF |
308 |
24.7 |
66 |
27.7 |
|
| |
ICSI |
300 |
24.1 |
63 |
26.5 |
|
| |
IVF and ICSI |
42 |
3.4 |
12 |
5.0 |
|
| |
Frozen embryo transfer |
594 |
47.7 |
97 |
40.8 |
n.s. |
| |
Unknown/missing values |
2 |
0.2 |
0 |
0.0 |
|
Blastocyst transfer |
Yes |
660 |
53.0 |
98 |
41.2 |
|
| |
No |
580 |
46.5 |
137 |
57.6 |
<0.01 |
| |
Unknown/missing values |
6 |
0.5 |
3 |
1.3 |
|
Maternal age |
Range |
|
23-46 |
|
25-43 |
|
| |
Mean±SD |
|
35.2±4.1 | |
33.8±3.8 |
<0.001 |
| |
Median |
|
35.0 | |
34.0 |
|
Gestational weeks |
Range |
|
10-42 | |
12-41 |
|
| |
Mean±SD |
|
36.5±5.8 | |
34.4±4.9 |
<0.001 |
| |
Median |
|
38.0 | |
36.0 |
|
| |
Unknown/missing values |
153 |
12.3 |
5 |
2.1 |
|
Sex |
Male |
595 |
47.8 |
131 |
51.2 |
|
(fetuses/neonates) |
Female |
474 |
38.0 |
100 |
39.1 |
n.s. |
| |
Unknown/missing values |
177 |
14.2 |
25 |
9.8 |
|
Perinatal outcome |
Abortion (< 22 weeks)b |
73 |
5.9 |
13 |
5.1 |
n.s. |
(fetuses/neonates) |
Stillbirths ( 22 ≤ weeks)b |
24 |
1.9 |
6 |
2.3 |
|
| |
Live births |
1024 |
82.2 |
235 |
91.8 |
|
| |
Unknown/missing values |
125 |
10.0 |
2 |
0.8 |
|
Abortion |
Spontaneous |
3 |
4.1 |
0 |
|
|
| |
Artificial |
51 |
69.9 |
11 |
84.6 |
|
| |
Unknown/missing values |
19 |
26.0 |
2 |
15.4 |
|
Early neonatal death (neonatal death up to day 6 after birth) |
Yes |
32 |
3.1 |
22 |
9.4 |
<0.001 |
No |
716 |
69.9 |
174 |
74.0 |
|
|
Unknown/missing values |
276 |
27.0 |
39 |
16.6 |
a: Percentage of singletons and multiples within each year were calculated. |
b: Abortion was defined as occurring under 22 weeks of gestation and stillbirth was defined as occurring at 22 or more weeks of gestation in the original data. |
Unknown/missing values were excluded in the statistical tests. |