Table 2 Clinical treatment characteristics according to serum uric acid quartiles
|  | Quartile 1 (n = 3240) | Quartile 2 (n = 3329) | Quartile 3 (n = 3422) | Quartile 4 (n = 3334) | Ptrend |
|---|---|---|---|---|---|
Ovarian stimulation protocol, n (%) | Â | Â | Â | Â | 0.523 |
 GnRH agonist | 3124 (96.4) | 3204 (96.3) | 3311 (96.8) | 3219 (96.6) |  |
 GnRH antagonist | 116 (3.6) | 125 (3.8) | 111 (3.2) | 115 (3.5) |  |
Stimulation duration (days) | 11 (10–12) | 11 (10–12) | 11 (10–12) | 11 (10–12) | 0.439 |
Total gonadotropin dose (IU) | 2025.0 (1500.0-2700.0) | 2025.0 (1550.0-2668.8) | 2025.0 (1550.0-2662.5) | 2100.0 (1650.0-2700.0) | < 0.001 |
E2 level on trigger day (pg/mL) | 1966.5 (1394.1-2701.5) | 1946.0 (1384.0-2701.0) | 1909.0 (1331.0-2613.0) | 1711.4 (1186.0-2411.8) | < 0.001 |
LH level on trigger day (mIU/mL) | 1.1 (0.7–1.6) | 1.0 (0.8–1.6) | 1.0 (0.7–1.6) | 0.9 (0.6–1.4) | < 0.001 |
P level on trigger day (ng/mL) | 0.6 (0.4–0.9) | 0.7 (0.5–0.9) | 0.6 (0.4–0.9) | 0.6 (0.4–0.9) | 0.024 |
Endometrial thickness on trigger day (mm) | 10.9 (9.3–12.7) | 10.9 (9.4–12.6) | 10.9 (9.3–12.6) | 10.8 (9.2–12.6) | 0.054 |
No. of oocyte retrieved | 11 (8–14) | 11 (8–15) | 11 (8–15) | 11 (8–14) | 0.130 |
Fertilization type, n (%) | Â | Â | Â | Â | 0.043 |
 IVF | 2502 (77.2) | 2616 (78.6) | 2753 (80.5) | 2667 (80.0) |  |
 ICSI | 530 (16.4) | 516 (15.5) | 486 (14.2) | 484 (14.5) |  |
 IVF + ICSI | 208 (6.4) | 197 (5.9) | 183 (5.4) | 183 (5.5) |  |
No. of embryos transferred, n (%) | Â | Â | Â | Â | 0.001 |
 Single | 866 (26.7) | 838 (25.2) | 845 (24.7) | 773 (23.2) |  |
 Double | 2374 (73.3) | 2491 (74.8) | 2577 (75.3) | 2561 (76.8) |  |
Embryo stage at transfer, n (%) | Â | Â | Â | Â | 0.390 |
 Cleavage | 2799 (86.4) | 2882 (86.6) | 2958 (86.4) | 2907 (87.2) |  |
 Blastocyst | 441 (13.6) | 447 (13.4) | 464 (13.6) | 427 (12.8) |  |
Transfer at least 1 good-quality embryo, n (%) | 2579 (79.6) | 2667 (80.1) | 2736 (80.0) | 2564 (76.9) | 0.009 |