Table II.
Anthropometric measures at baseline and time to pregnancy
| No. | Cycles | Unadjusted model |
Adjusted modela |
Adjusted modelb |
||||
|---|---|---|---|---|---|---|---|---|
| FR | 95% CI | FR | 95% CI | FR | 95% CI | |||
| BMI, kg/m2 | ||||||||
| <20 | 161 | 843 | 0.95 | 0.78–1.15 | 0.94 | 0.77–1.15 | 1.02 | 0.83–1.27 |
| 20–24 | 666 | 3416 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| 25–29 | 199 | 1178 | 0.83 | 0.70–0.99 | 0.83 | 0.70–1.00 | 0.72 | 0.58–0.90 |
| 30–34 | 85 | 569 | 0.73 | 0.57–0.94 | 0.75 | 0.58–0.97 | 0.60 | 0.42–0.85 |
| ≥35 | 38 | 334 | 0.55 | 0.39–0.78 | 0.61 | 0.42–0.88 | 0.48 | 0.31–0.74 |
| Male partner's BMI, kg/m2 | ||||||||
| <20 | 28 | 168 | 0.85 | 0.56–1.30 | 0.94 | 0.61–1.44 | 0.95 | 0.62–1.46 |
| 20–24 | 611 | 3200 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| 25–29 | 432 | 2423 | 0.93 | 0.81–1.06 | 0.98 | 0.85–1.13 | 0.98 | 0.85–1.13 |
| 30–34 | 60 | 399 | 0.79 | 0.59–1.05 | 0.99 | 0.73–1.35 | 0.97 | 0.72–1.33 |
| ≥35 | 18 | 150 | 0.59 | 0.36–0.98 | 0.72 | 0.43–1.22 | 0.72 | 0.43–1.22 |
| Weight change since age 17 years (kg) | ||||||||
| <−5 | 48 | 242 | 0.91 | 0.65–1.29 | 1.00 | 0.70–1.42 | 1.05 | 0.73–1.52 |
| −5 to 4 | 361 | 1749 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| 5–9 | 330 | 1836 | 0.85 | 0.72–1.00 | 0.91 | 0.77–1.08 | 0.90 | 0.76–1.07 |
| 10–14 | 198 | 1086 | 0.86 | 0.70–1.04 | 0.86 | 0.70–1.05 | 0.86 | 0.70–1.05 |
| ≥15 | 212 | 1427 | 0.68 | 0.57–0.82 | 0.71 | 0.58–0.86 | 0.72 | 0.59–0.88 |
| Waist circumference (cm) | ||||||||
| <74 | 337 | 1941 | 1.00 | (ref.) | 1.00 | (ref) | 1.00 | (ref) |
| 74–79 | 231 | 1231 | 1.04 | 0.83–1.30 | 1.01 | 0.79–1.29 | 1.05 | 0.81–1.36 |
| 80–86 | 259 | 1274 | 1.14 | 0.93–1.39 | 1.10 | 0.89–1.37 | 1.21 | 0.96–1.54 |
| ≥87 | 322 | 1894 | 0.98 | 0.78–1.24 | 1.01 | 0.79–1.29 | 1.44 | 1.03–2.02 |
| WHR | ||||||||
| <0.75 | 274 | 1565 | 1.00 | (ref.) | 1.00 | (ref) | 1.00 | (ref.) |
| 0.75–0.79 | 223 | 1446 | 0.96 | 0.76–1.22 | 0.96 | 0.75–1.22 | 0.98 | 0.77–1.24 |
| 0.80–0.84 | 271 | 1365 | 1.13 | 0.88–1.45 | 1.10 | 0.83–1.45 | 1.15 | 0.88–1.52 |
| ≥0.85 | 381 | 1964 | 1.13 | 0.93–1.37 | 1.15 | 0.89–1.47 | 1.27 | 0.98–1.64 |
| Tendency to gain weight | ||||||||
| Hips/thighs | 307 | 1821 | 0.91 | 0.77–1.09 | 0.86 | 0.72–1.02 | 0.81 | 0.68–0.97 |
| Equally all over | 327 | 1815 | 1.00 | (ref.) | 1.00 | (ref.) | 1.00 | (ref.) |
| Waist/stomach | 447 | 2317 | 1.07 | 0.91–1.26 | 1.06 | 0.90–1.24 | 1.00 | 0.85–1.18 |
| Chest/shoulders | 9 | 66 | 0.75 | 0.37–1.54 | 0.65 | 0.31–1.34 | 0.59 | 0.29–1.24 |
| Do not gain weight | 47 | 239 | 1.06 | 0.76–1.50 | 0.98 | 0.69–1.39 | 0.87 | 0.61–1.26 |
FR = fecundability ratio; CI =confidence interval; No. = number of pregnancies.
aAdjusted for age, partner's age, cycle regularity, cycle length, partner's BMI (in female BMI analysis only), female BMI (in partner's BMI analysis only), physical activity, smoking, alcohol intake, parity and intercourse frequency.
bAdjusted for factors in ‘a’ as well as waist circumference (in BMI analyses), female BMI (in all analyses except weight change) and BMI at age 17 (in weight change analyses).