Table 1. Patient characteristics at time of biopsy.
| Characteristic | Value | RIF patients | Controls | P |
|---|---|---|---|---|
| Subjects, n | 43 | 72 | ||
| Female age, mean (range) | 34.0 (27–38) | 34.6 (26–39) | 0.204 | |
| BMI, mean (range) | 23.7 (19–37) | 25.0 (19–53) | 0.288 | |
| Smoking, n (%) | 1 (2) | 8 (11) | 0.087 | |
| Primary infertility, % | 79 | 90 | 0.162 | |
| Cause of infertility, n (%) | Andrological | 28 (65) | 52 (72) | 0.110 |
| Unexplained subfertility | 6 (14) | 15 (21) | ||
| Tubal pathology | 6 (14) | 2 (3) | ||
| Unknown | 3 (7) | 3 (4) | ||
| Treatment history before biopsy | Embryo transfers, mean (range) | 5.3 (3–12) | 2.4 (1–18) | 2.9 × 10−12 |
| Transferred embryos, mean (range) | 7.8 (3–18) | 3.1 (1–30) | 2.8 × 10−13 | |
| Implantations, mean (range) | 0.3 (0–2) | 1.4 (1–3) | 4.0 × 10−15 | |
| Implantation rate, mean % | 3 | 63 | < 2.2 × 10−16 |
Age, age at biopsy; BMI, body mass index; Smoking, number of patients who smoked (range: 1–10 cigarettes); Primary infertility, percentage of patients who were nulliparous at entrance of IVF/ICSI treatment (unknown for 1 patient & 3 controls); Implantation rate, implantations/transferred embryos; Day of biopsy, day of endometrial biopsy after positive LH surge; P was calculated using the Mann-Whitney test for continuous data and Fisher’s exact test for count data (both two-sided).