Table 1 Characteristics of the study participants.
From: DNA methylation in newborns conceived by assisted reproductive technology
Characteristics | Naturally conceived (n = 983) | ART conceived (n = 962) | P valuea |
|---|---|---|---|
Maternal age at delivery, mean (SD) | 30.0 (4.6) | 33.2 (3.6) | <0.001 |
Paternal age at delivery, mean (SD) | 32.6 (5.4) | 35.8 (5.4) | <0.001 |
Maternal parity, No. (%) | |||
Nulliparous | 461 (46.9) | 673 (70.0) | <0.001 |
Multiparous | 522 (53.1) | 289 (30.0) | |
Maternal educational level, No. (%) | |||
Less than high school | 71 (7.2) | 48 (5.0) | 0.001 |
High school | 299 (30.4) | 232 (24.1) | |
Up to 4 years of college | 386 (39.3) | 418 (43.5) | |
More than 4 years of college | 225 (22.9) | 258 (26.8) | |
Missing | 2 (0.2) | 6 (0.6) | |
Paternal educational level, No. (%) | |||
Less than high school | 98 (10.0) | 72 (7.5) | 0.004 |
High school | 398 (40.5) | 333 (34.6) | |
Up to 4 years of college | 249 (25.3) | 296 (30.8) | |
More than 4 years of college | 209 (21.3) | 235 (24.4) | |
Missing | 29 (3.0) | 26 (2.7) | |
Maternal pre-pregnancy BMI, mean (SD) | 24.3 (4.5) | 24.3 (4.0) | 0.572 |
Missing, No. (%) | 14 (1.4) | 17 (1.8) | |
Paternal pre-pregnancy BMI, mean (SD) | 25.9 (3.2) | 26.4 (3.5) | 0.002 |
Missing, No. (%) | 23 (2.3) | 20 (2.1) | |
Maternal smoking during pregnancy, No. (%) | |||
Never | 490 (49.8) | 494 (51.4) | <0.001 |
Former | 253 (25.7) | 358 (37.2) | |
Quit before 18 gestational weeks | 132 (13.4) | 62 (6.4) | |
Continued after 18 gestational weeks | 104 (10.6) | 44 (4.6) | |
Missing | 4 (0.6) | 4 (0.6) | |
Paternal smoking, No. (%) | |||
No | 747 (76.0) | 737 (76.6) | 0.459 |
Yes | 234 (23.8) | 220 (22.9) | |
Missing | 2 (0.2) | 5 (0.5) | |
Child sex, No. (%) | |||
Male | 470 (47.8) | 505 (52.5) | 0.073 |
Female | 513 (52.2) | 457 (47.5) | |
Child gestational age, mean (SD) | 39.6 (1.6) | 39.4 (1.7) | 0.210 |
Missing, No. (%) | 4 (0.4) | 0 (0) | |
Child birthweight, mean (SD) | 3649 (526) | 3526 (539) | <0.001 |
Missing, No. (%) | 0 (0) | 1 (0.1) | |
Time to pregnancy, No. (%) | |||
No information | 179 (18.2) | NA | |
<3 months | 417 (42.4) | NA | |
3–8 months | 256 (26.0) | NA | |
9–12 months | 52 (5.3) | NA | |
>12 months | 79 (8.0) | NA | |
Type of ART, No. (%) | |||
Fresh embryo transfer IVF | NA | 437 (45.4) | |
Fresh embryo transfer ICSI | NA | 327 (34.0) | |
Frozen embryo transfer IVF | NA | 87 (9.0) | |
Frozen embryo transfer ICSI | NA | 39 (4.1) | |
Combination/unspecified | NA | 72 (7.5) | |
