Table 4 Maternal characteristics and pregnancy complications of pregnancies carried to delivery after transferring embryos with or without blastomere loss
|  | Intact embryo group (n = 2962) | Blastomere loss group (n = 407) | p value |
|---|---|---|---|
| Â | No. (%) | No. (%) | |
Maternal socio-demographic characteristics | Â | Â | Â |
 Pre-gestational BMI, mean (SD), kg/m2 | 21.79 ± 2.92 | 21.63 ± 2.66 | 0.265 |
 Education attainment |  |  |  |
  Primary school or lower | 104 (3.5) | 19 (4.7) | 0.487 |
  Middle or high school | 1524 (51.5) | 204 (50.1) | |
  Collage or above | 1334 (45.0) | 184 (45.2) | |
 Maternal smoking during pregnancy | 5 (0.2) | 1 (0.3) | 0.538 |
 Paternal smoking during pregnancy | 379 (12.8) | 71 (17.4) | 0.010 |
History of reproduction | Â | Â | Â |
 Parity | 164 (5.5) | 32 (7.9) |  |
  1 | 155 (5.2) | 30 (7.4) | 0.109 |
   ≥ 2 | 9 (0.3) | 2 (0.5) | |
 Number of previous abortion |  |  |  |
  0 | 1597 (53.9) | 184 (45.2) | 0.004 |
  1–2 | 1095 (37.0) | 180 (44.2) | |
   ≥ 3 | 270 (9.1) | 43 (10.6) | |
 Previous ectopic pregnancy |  |  |  |
  No | 2935 (99.1) | 403 (99.0) | 0.784 |
  Yes | 27 (0.9) | 4 (1.0) | |
 Duration of infertility, year |  |  |  |
   ≤ 2 | 863 (29.1) | 125 (30.7) | 0.795 |
  3–4 | 1008 (34.0) | 137 (33.7) | |
   ≥ 5 | 1091 (36.8) | 145 (35.6) | |
 Primary infertility |  |  |  |
  No | 1555 (52.5) | 179 (44.0) | 0.001 |
  Yes | 1407 (47.5) | 228 (56.0) | |
 Causes of infertility |  |  |  |
  Tubal infertility | 1625 (54.9) | 222 (54.6) | 0.633 |
  Anovulatory | 70 (2.4) | 12 (3.0) | |
 Endometriosis | 60 (2.0) | 8 (2.0) | |
  Male-factor infertility | 549 (18.5) | 78 (19.2) | |
  Unexplained infertility | 87 (2.9) | 6 (1.5) | |
  Combineda | 571 (19.3) | 81 (19.9) | |
 Type of embryo cryopreservation |  |  |  |
  Slowing freezing | 1037 (35.0) | 318 (78.1) | < 0.001 |
  Vitrification | 1925 (65.0) | 89 (21.9) | |
 Type of FET cycle |  |  |  |
  Natural | 1559 (52.6) | 216 (53.1) | 0.435 |
  HRT | 858 (29.0) | 126 (31.0) | |
  OS | 545 (18.4) | 65 (16.0) | |
Pregnancy complications | |||
 Gestational diabetes mellitus |  |  |  |
  No | 2773 (93.6) | 383 (94.1) | 0.707 |
  Yes | 189 (6.4) | 24 (5.9) | |
 Hypertensive disorder |  |  |  |
  No | 2525 (85.3) | 349 (85.8) | 0.994 |
  Gestational hypertension | 201 (6.8) | 27 (6.6) | |
  Mild pre-eclampsia | 166 (5.6) | 22 (5.4) | |
  Wild pre-eclampsia | 70 (2.4) | 9 (2.2) | |
 Intrahepatic cholestasis of pregnancy |  |  |  |
  No | 2856 (96.4) | 388 (95.3) | 0.276 |
  Yes | 106 (3.6) | 19 (4.7) | |
 Amniotic fluid abnormality |  |  |  |
  No | 2842 (96.0) | 388 (95.3) | 0.835 |
  Hydramnios | 46 (1.6) | 7 (1.7) | |
  Oligohydramnios | 74 (2.5) | 12 (3.0) | |
 Preterm delivery b |  |  |  |
  No | 2323 (78.4) | 326 (80.1) | 0.741 |
  Preterm | 546 (18.4) | 69 (17.0) | |
  Very preterm | 93 (3.1) | 12 (3.0) | |
 Mode of delivery |  |  |  |
  Vaginal | 456 (15.4) | 41 (10.1) | 0.005 |
  Cesarean section | 2506 (84.6) | 366 (89.9) | |