Table 4.
Association of categorical AMH with follicular phase lengtha, long follicular phase, and short follicular phase
| AMH (ng/mL) | No. of cycles | Adjustedb Δ follicular phase length, days (95% CI) | P value | Adjustedc Δ in follicular phase length, days (95% CI) | P value | Adjustedd Δ in follicular phase length, days (95% CI) | P value | |
|---|---|---|---|---|---|---|---|---|
| <1.6 | 326 | –1.59 (–2.52, –0.65) | .001 | –1.58 (–2.53, –0.63) | 0.001 | –1.45 (–2.66, –0.24) | .019 | |
| 1.6-3.4 | 343 | Reference | ||||||
| >3.4-8 | 338 | 0.43 (–0.47, 1.32) | .354 | 0.47 (–0.44, 1.37) | 0.311 | 0.53 (–0.62, 1.68) | .367 | |
| >8 | 120 | 2.02 (0.78, 3.27) | .001 | 2.00 (0.77, 3.24) | 0.001 | 0.63 (–1.08, 2.34) | .471 | |
| Long follicular phase (≥18 days) | aOR (95% CI) b | aOR (95% CI) c | aOR (95% CI) d | aOR (95% CI) e | ||||
| <1.6 | 284 | 0.48 (0.28, 0.83) | — | 0.44 (0.25, 0.79) | — | 0.45 (0.19, 1.09) | — | 0.33 (0.16, 0.69) |
| 1.6-3.4 | 314 | Reference | ||||||
| >3.4-8 | 320 | 1.41 (0.90, 2.20) | — | 1.43 (0.89, 2.30) | — | 2.30 (1.10, 4.82) | — | 0.87 (0.47, 1.61) |
| >8 | 117 | 2.28 (1.37, 3.79) | — | 2.52 (1.48, 4.28) | — | 3.65 (1.54, 8.67) | — | 1.39 (0.73, 2.62) |
| Short follicular phase (≤ 10 days) | aOR (95% CI) b | aOR (95% CI) c | aOR (95% CI) d | aOR (95% CI) e | ||||
| <1.6 | 287 | 1.20 (0.69, 2.08) | — | 1.28 (0.74, 2.24) | — | 1.68 (0.67, 4.26) | — | 1.58 (0.74, 3.39) |
| 1.6-3.4 | 261 | Reference | ||||||
| >3.4-8 | 236 | 0.72 (0.37, 1.38) | — | 0.72 (0.36, 1.43) | — | 1.05 (0.31, 3.58) | — | 0.67 (0.27, 1.64) |
| >8 | 72 | 0.36 (0.11, 1.19) | — | 0.33 (0.10, 1.11) | — | 0.71 (0.08, 6.68) | — | 0.46 (0.12, 1.79) |
Results are displayed as change in phase in days for a given AMH category, compared to the reference group.
a To achieve normality of the model residuals, the continuous analysis was limited to phases between 5 and 45 days long.
b Adjusted for age.
c Adjusted for age, race, education, BMI, time since oral contraceptive use, alcohol, smoking, and caffeine consumption.
d Sensitivity analysis of follicular phase length with ovulation determined by OPK (cycle N = 592).
e Sensitivity analysis the association of categorical AMH with long and short cycles weighted by the inverse of cycles contributed by each woman.