Table 1. Participant Characteristics.
| Entire Cohort (n=1654) |
Regularly Cycling Cohort (n=604) |
|
|---|---|---|
| Age, y (mean ±SD; range)a | 28.7 ± 3.5; 23-35 | 29.1 ± 3.4; 23-35 |
| 23-25 | 371 (22.4%) | 108 (17.9%) |
| 26-28 | 417 (25.2%) | 153 (25.3%) |
| 29-31 | 444 (26.8%) | 174 (28.8%) |
| 32-35 | 422 (25.5%) | 169 (28.0%) |
| Body mass index, kg/m2 (median, IQR; range) | 32.4, 26.3-39.5; 15.9-79.4 |
32.9, 26.4-40.0; 15.9-72.9 |
| AMH, ng/mL (median, IQR; range) | 3.18, 1.68-5.33; <0.002-39.4 |
3.35, 1.89-5.49; 0.02-30.4 |
| Education (%) | ||
| High school or less | 22.2 | 23.8 |
| Some college, but no degree | 37.7 | 36.9 |
| Associate or technical degree | 12.3 | 11.6 |
| Bachelor’s degree | 19.4 | 20.2 |
| Graduate degree | 8.4 | 7.5 |
| Gross annual household income (%) | ||
| Less than $20,000 | 46.1 | 45.8 |
| $20,001-50,000 | 36.8 | 37.4 |
| $50,001-100,000 | 14.6 | 15.1 |
| Over $100,000 | 2.5 | 1.7 |
| Currently married or living as though married (%) | 26.8 | 25.7 |
| Age at menarche, y (mean ±SD; range) | 12.0 ± 1.8; 7-19 | 11.9 ± 1.7; 7-18 |
| Pregnancy history | ||
| Never pregnant (%) | 26.7 | 28.0 |
| Previous pregnancy without history of a live birth (%) |
14.0 | 15.2 |
| Previous live birth but no history of breastfeeding (%) |
21.3 | 22.7 |
| Previous live birth with history of breastfeeding (%) |
38.0 | 34.1 |
| Number of pregnancies (mean ±SD range) | 3.1 ± 2.0; 1-15 b | 3.2 ± 2.1; 1-13 c |
| Current hormonal contraception use (%) | 27.5 | --- |
| History of hormonal contraception use (%) | 85.9 | 76.0 |
| Any hormone use in the last 12 months (%) | 39.2 | --- |
| Irregular menses in last 12 months (%)d | 31.6 | --- |
| Menstrual cycle length in last 12 monthsd | ||
| <25 days (%) | 23.4 | --- |
| 25-35 days (%) | 68.4 | 100.0 |
| >35 days (%) | 8.2 | ---- |
| History of polycystic ovarian syndrome (%) | 3.2 | --- |
| History of abnormal menstrual bleeding (%) | 11.5 | 8.5 |
| History of amenorrhea (%) | 4.2 | --- |
| History of endometriosis (%) | 1.8 | 1.0 |
| History of seeking care for difficulty conceiving (%) |
5.8 | 5.5 |
| History of a thyroid condition (%) | 2.9 | --- |
| Smoking status (%) | ||
| Current | 19.2 | 22.5 |
| Former | 7.4 | 7.5 |
| Never | 73.3 | 70.0 |
| Alcohol consumption in last 12 months (%) | ||
| At least weekly | 24.9 | 24.3 |
| Less than weekly | 46.6 | 43.5 |
| Never | 29.5 | 32.1 |
a
Women ages 23-34 were recruited, but some women had turned 35 by the time that all baseline activities and enrollment were completed.
b
Among those with at least 1 previous pregnancy, n=1212
c
Among those with at least 1 previous pregnancy, n=435
d
Among those not using hormonal contraception at any time in the last 12 months, n=953