Table 1.
Main demographics and cycle characteristics of patients.
| Characteristics | EP group | Control group | P value |
|---|---|---|---|
| N = 547 | N = 550 | ||
| Maternal age (median and range) | 33 (22–45) | 31 (20–45) | < 0.001 |
| BMI (kg/m2) (mean ± SD) | 21.1 ± 2.4 | 21.2 ± 2.5 | 0.752 |
| Level of education (%) | |||
| Low | 160 (29.3) | 133 (24.2) | 0.058 |
| Middle | 236 (43.1) | 240 (43.6) | 0.869 |
| High | 151 (27.6) | 177 (32.2) | 0.098 |
| Basal serum FSH (IU/L) (mean ± SD) | 8.1 ± 3.2 | 7.8 ± 3.0 | 0.669 |
| Basal serum LH (IU/L) (mean ± SD) | 4.5 ± 2.4 | 4.8 ± 3.6 | 0.629 |
| Basal serum E2 (ng/L) (mean ± SD) | 37.4 ± 21.5 | 40.0 ± 25.2 | 0.658 |
| AFC (median and range) | 7 (1–25) | 9 (1–26) | < 0.001 |
| Cause of infertility (%) | |||
| Tubal factor | 547 (100) | 309 (56.2) | < 0.001 |
| Diminished ovarian reserve | 59 (10.7) | 61 (11.1) | 0.872 |
| Endometrial-uterine factor | 49 (9.0) | 52 (9.5) | 0.776 |
| Male factor | 110 (20.1) | 162 (29.5) | < 0.001 |
| Stimulation protocol (%) | 0.379 | ||
| Long protocol | 282 (51.6) | 293 (53.3) | |
| Short protocol | 104 (19.0) | 93 (16.9) | |
| Micro-stimulation protocol | 91 (16.6) | 106 (19.3) | |
| Others | 70 (12.8) | 58 (10.5) | |
| Duration of stimulation (day) (mean ± SD) | 8.6 ± 2.6 | 8.3 ± 2.9 | 0.091 |
| No. of oocytes retrieved (median and range) | 7 (1–35) | 11 (1–39) | < 0.001 |
| Methods of fertilization (%) | |||
| IVF | 428 (78.2) | 412 (74.9) | 0.192 |
| ICSI | 119 (21.8) | 138 (25.1) | |
| Two pronucleus rate (median and range) | 0.7 (0.1–1) | 0.7 (0.1–1) | 0.362 |
| No. of embryos available (median and range) | 5 (1–21) | 6 (1–29) | < 0.001 |
| Stage of embryos transferred (%) | |||
| Cleavage | 361 (66.0) | 389 (70.7) | 0.092 |
| Blastocyst | 186 (34.0) | 161 (29.3) | |
| No. of embryos transferred (%) | |||
| 1 | 180 (32.9) | 204 (37.1) | 0.146 |
| 2 | 360 (65.8) | 340 (61.8) | 0.169 |
| 3 | 7 (1.3) | 6 (1.1) | 0.773 |
| Time to pregnancy (m) (median and range) | 36 (12–252) | 28 (12–220) | 0.019 |
EP ectopic pregnancy, BMI body mass index, AFC antral follicle count, FSH follicle-stimulating hormone, LH luteinizing hormone, SD standard deviation, IVF in vitro fertilization, ICSI intracytoplasmic sperm injection.