Table 4 Neonatal outcomes of live born infants according to serum progesterone levels on the day of embryo transfer
| Â | Progesterone quartiles (ng/mL) | P-value | |||
|---|---|---|---|---|---|
Q1 (< 7.9) | Q2 (7.9–9.6) | Q3 (9.7–12.0) | Q4 (≥ 12.1) | ||
Singletons | Â | Â | Â | Â | Â |
 No. of children | 232 | 247 | 283 | 278 |  |
 Gestational age (weeks) | 38.6 ± 1.9 | 38.6 ± 1.5 | 38.7 ± 1.4 | 38.5 ± 1.8 | 0.739 |
 Birthweight (g) | 3362.0 ± 537.5 | 3378.5 ± 478.9 | 3406.1 ± 482.3 | 3351.6 ± 538.5 | 0.770 |
 Preterm birth (< 37 weeks), n (%) | 17 (7.3) | 14 (5.7) | 15 (5.3) | 22 (7.9) | 0.549 |
 Low birthweight (< 2500 g), n (%) | 13 (5.6) | 9 (3.6) | 8 (2.8) | 16 (5.8) | 0.262 |
 Major congenital malformations, n (%) | 2 (0.9) | 2 (0.8) | 5 (1.8) | 5 (1.8) | 0.664 |
 Early neonatal death, n (%) | 1 (0.4) | 0 (0) | 0 (0) | 0 (0) | 0.223 |
Twins | Â | Â | Â | Â | Â |
 No. of children | 182 | 174 | 168 | 162 |  |
 Gestational age (weeks) | 35.8 ± 2.4 | 35.6 ± 1.8 | 35.5 ± 2.6 | 35.6 ± 2.4 | 0.377 |
 Birthweight (g) | 2483.3 ± 462.5 | 2475.0 ± 407.5 | 2442.4 ± 526.4 | 2502.6 ± 432.5 | 0.801 |
 Preterm birth (< 37 weeks), n (%) | 92 (50.5) | 102 (58.6) | 92 (54.8) | 78 (48.1) | 0.223 |
 Low birthweight (< 2500 g), n (%) | 69 (37.9) | 78 (44.8) | 74 (44.0) | 65 (40.1) | 0.510 |
 Major congenital malformations, n (%) | 7 (3.8) | 3 (1.7) | 4 (2.4) | 3 (1.9) | 0.618 |
 Early neonatal death, n (%) | 2 (1.1) | 0 (0) | 1 (0.6) | 2 (1.2) | 0.576 |