38–40-year-old group (n = 147) | 35–37-year-old group (n = 164) | 30-34-year-old group (n = 483) | < 30-year-old group (n = 485) | P value | |
---|---|---|---|---|---|
Positive rate of hCG test%(n) | 59.2(87/147)b, c | 68.3(112/164) | 74.1(358/483) | 73.2(355/485) | 0.003* |
Clinical pregnancy rate%(n) | 47.6(70/147)b, c | 56.1(92/164) | 64.4(311/483) | 62.9(305/485) | 0.001* |
Embryo implantation rate%(n) | 49.7(73/147)b, c | 56.1(92/164) | 65.6(317/483) | 63.9(310/485) | 0.002* |
Biochemical pregnancy rate%(n) | 11.6(17/147) | 12.2(20/164) | 9.7(47/483) | 10.3(50/485) | 0.801 |
Miscarriage rate%(n) | 28.6(20/70) | 22.8(21/92) | 20.9(65/311) | 18.4(56/305) | 0.273 |
Ectopic pregnancy rate%(n) | 0(0/70) | 1.1(1/92) | 0(0/311) | 1.0(3/305) | 0.193 |
Twin pregnancy rate%(n) | 4.3(3/70) | 0(0/92) | 1.9(6/311) | 1.6(5/305) | 0.208 |
Preterm birth rate%(n) | 6.0(3/50) | 11.4(8/70) | 7.7(19/246) | 6.9(17/246) | 0.672 |
Live birth rate%(n) | 34.0(50/147)b, c | 42.7(70/164) | 50.9(246/483) | 50.7(246/485) | 0.001* |
Neonatal birth weight, mean(SD)(g) | 3238.65 ± 606.74 | 3304.26 ± 487.09 | 3303.35 ± 557.21 | 3279.90 ± 521.08 | 0.860 |
Neonatal birth age, mean(SD)(weeks) | 38.95 ± 1.81 | 38.71 ± 1.79d, e | 39.23 ± 1.80 | 39.31 ± 1.88 | 0.089 |
Incidence of macrosomia%(n) | 1.9(1/52) | 7.1(5/70) | 9.6(24/251) | 6.8(17/251) | 0.195 |
Incidence of low birth weight infants%(n) | 7.7(4/52) | 2.9(2/70) | 6.4(16/251) | 8.0(20/251) | 0.439 |
Birth defect rate%(n) | 0(0/52) | 1.4(1/70) | 1.6(4/251) | 0.8(2/251) | 0.799 |
Neonatal sex ratio%(n) | |||||
Male | 67.3(35/52) | 51.4(36/70) | 58.6(147/251) | 53.0(133/251) | 0.181 |
Female | 32.7(17/52) | 48.6(34/70) | 41.4(104/251) | 47.0(118/251) | 0.181 |
Obstetric complications | |||||
Gestational hypertension%(n) | 1.4(1/70) | 3.3(3/92) | 1.0(3/311) | 1.6(5/305) | 0.667 |
GDM%(n) | 7.1(5/70) | 4.4(4/92) | 2.6(8/311) | 3.9(12/305) | 0.373 |