Table 1:
Number of patients (n) with singleton or multiple pregnancy, and clinical pregnancy rate by follicle number. Including all ages, < 38 years of age, 38–40 years of age, and greater than 40 years of age. Adjusted odds ratio (aOR, 95% CI) indicate the increasing risk of a multiple pregnancy with increasing follicle number, with one follicle as the reference. Generalized estimating equations were used to adjust for multiple cycles per patient. Denominator in the clinical pregnancy ratio represents the total number of patients in that category who had an IUI performed.
| 1 Follicle | 2 Follicles | 3 Follicles | 4 Follicles | 5 Follicles | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| n | % | aOR (95%CI) | n | % | aOR (95%CI) | n | % | aOR (95%CI) | n | % | aOR (95%CI) | n | % | aOR (95%CI) | ||
| All Patients | Singleton | 2094 | 95.8 | 2343 | 87.1 | 1489 | 80.7 | 678 | 76.4 | 243 | 73.0 | |||||
| Multiple | 91 | 4.2 | Referent | 348 | 12.9 | 3.46 (2.72–4.39) | 355 | 19.3 | 5.55 (4.36–7.06) | 210 | 23.6 | 7.21 (5.55–9.37) | 90 | 27.0 | 8.60 (6.23–11.85) | |
| Clinical Pregnancy | 2185/16,837 | 13.0 | Referent | 2691/16598 | 16.2 | 1.30 (1.22–1.38)) | 1844/10534 | 17.5 | 1.42 (1.33–1.52 | 888/4805 | 18.5 | 1.52 (1.39–1.65) | 333/1699 | 19.6 | 1.63 (1.43–1.85) | |
| <38 | Singleton | 1835 | 95.9 | 1989 | 86.8 | 1192 | 79.7 | 499 | 74.3 | 168 | 70.3 | |||||
| Multiple | 78 | 4.1 | Referent | 303 | 13.2 | 3.59 (2.78–4.65) | 303 | 20.3 | 5.99 (4.62–7.77) | 173 | 25.7 | 8.18 (6.15–10.88) | 71 | 29.7 | 9.91 (6.92–14.18) | |
| Clinical Pregnancy | 1913/13077 | 14.6 | Referent | 2292/12612 | 18.2 | 1.30 (1.21–1.39) | 1495/7693 | 19.4 | 1.41 (1.30–1.51) | 672/3341 | 20.1 | 1.46 (1.33–1.61) | 239/1094 | 21.8 | 1.63 (1.40–1.90) | |
| 38–40 | Singleton | 203 | 94.9 | 274 | 88.1 | 229 | 83.6 | 126 | 80.8 | 48 | 78.7 | |||||
| Multiple | 11 | 5.1 | Referent | 37 | 11.9 | 2.49 (1.24–5.00) | 45 | 16.4 | 3.63 (1.83–7.20) | 30 | 19.2 | 4.40 (2.11–9.08) | 13 | 21.3 | 5.00 (2.11–11.83) | |
| Clinical Pregnancy | 214/2373 | 9.0 | Referent | 311/2590 | 12.0 | 1.37 (1.14–1.65) | 274/1901 | 14.4 | 1.70 (1.40–2.05) | 156/947 | 16.5 | 1.98 (1.59–2.48) | 61/361 | 16.9 | 2.03 (1.49–2.77) | |
| >40 | Singleton | 56 | 98.2 | 80 | 90.9 | 68 | 90.7 | 53 | 88.3 | 27 | 81.8 | |||||
| Multiple | 1 | 1.8 | Referent | 8 | 9.1 | 5.60 (0.68–46.04) | 7 | 9.3 | 5.76 (0.69–48.25) | 7 | 11.7 | 7.40 (0.88–62.18) | 6 | 18.2 | 12.46 (1.43–108.77) | |
| Clinical Pregnancy | 57/1385 | 4.1 | Referent | 88/1395 | 6.3 | 1.57 (1.12–2.21) | 75/940 | 8.0 | 2.03 (1.42–2.89) | 60/517 | 11.6 | 3.06 (2.10–4.46) | 33/244 | 13.5 | 3.64 (2.31–5.72) | |