Table 1 Characteristics and sex ratio of singletons at birth (mean ± SD or %).
From: The association of embryo developmental rate and morphological grading with neonatal sex ratio
Characteristics | All infants | Boys | Girls | SSR (%) | P value |
|---|---|---|---|---|---|
Total, n | 4278 | 2293 | 1985 | 53.6 | |
Maternal age (years) | 30.6 ± 4.6 | 30.7 ± 4.5 | 30.6 ± 4.7 | 0.723 | |
Maternal age range, n | 0.266 | ||||
< 35 | 3415 | 1845 | 1570 | 54.0 | |
≥ 35 | 863 | 448 | 415 | 51.9 | |
Body-mass index | 23.2 ± 3.5 | 23.1 ± 3.6 | 23.3 ± 3.5 | 0.244 | |
Paternal age (years) | 32.2 ± 5.3 | 32.2 ± 5.3 | 32.2 ± 5.3 | 0.925 | |
Paternal age range, n | 0.461 | ||||
< 35 | 2970 | 1603 | 1367 | 54.0 | |
≥ 35 | 1308 | 690 | 618 | 52.8 | |
Type of infertility, n | 0.937 | ||||
Primary | 1923 | 1032 | 891 | 53.7 | |
Secondary | 2355 | 1261 | 1094 | 53.5 | |
Type of ovarian stimulation, n protocol, n | 0.873 | ||||
Agonist | 1721 | 925 | 796 | 53.7 | |
Antagonist | 2557 | 1368 | 1189 | 53.5 | |
Methods of sperm separation, n (%) | 0.240 | ||||
Swim-up | 1970 | 1075 | 895 | 54.6 | |
DGC | 2308 | 1218 | 1090 | 52.8 | |
Insemination method, n | 0.298 | ||||
C-IVF | 3323 | 1767 | 1556 | 53.2 | |
ICSI | 955 | 526 | 429 | 55.1 | |
Stage of embryo transferred, n (%) | 0.005 | ||||
Cleavage | 1654 | 842 | 812 | 50.9 | |
Blastocyst | 2624 | 1451 | 1173 | 55.3 | |
Extended culture time, n | 0.152 | ||||
Day 5 | 2291 | 1279 | 1012 | 55.8 | |
Day 6 | 333 | 172 | 161 | 51.7 | |
Type of cycle, n | 0.040 | ||||
Fresh | 1716 | 887 | 829 | 51.7 | |
Frozen | 2562 | 1406 | 1156 | 54.9 |
