Table 2. Childbearing parameters of the study sample by high school BMI a.
| < 18.5 kg/m2 underweight (n=535) | 18.5-24.9 kg/m2 normal (n=2246) | 25.0-29.9 kg/m2 overweight (n=276) | ≥ 30.0 kg/m2 obese (n=97) | P value | |
|---|---|---|---|---|---|
| Number of children | 2.2 (1.4) | 2.0 (1.4) | 2.1 (1.5) | 1.6 (1.5) | <0.01 |
| Nulliparity | 68 (12.7) | 376 (16.7) | 53 (19.2) | 30 (30.9) | <0.01 |
| Number of pregnancies | 3.1 (2.0) | 2.9 (1.9) | 2.9 (2.1) | 2.3 (2.1) | <0.01 |
| Nulligravidity | 42 (7.9) | 233 (10.4) | 39 (14.1) | 26 (26.8) | <0.01 |
| Spontaneous abortion(s) | |||||
| One or more | 149 (27.8) | 596 (26.5) | 83 (30.1) | 27 (27.8) | 0.62 |
| Two or more | 51 (9.5) | 167 (7.4) | 25 (9.1) | 6 (6.2) | 0.32 |
| Three or more | 21 (3.9) | 53 (2.4) | 9 (3.30 | 3 (3.1) | 0.19 |
| Induced abortion(s) | 154 (28.8) | 670 (29.8) | 67 (24.3) | 21 (21.7) | 0.09 |
| Medical factors potentially affecting fertility | |||||
| Amenorrhea b | 70 (13.2) | 345 (15.4) | 59 (21.5) | 30 (30.9) | <0.01 |
| Continuous OCP use c | 36 (6.8) | 186 (8.3) | 20 (7.3) | 9 (9.4) | 0.61 |
| Report of infertility d | 131 (25.2) | 513 (23.5) | 64 (24.0) | 24 (25.3) | 0.85 |
| Salpingitis | 19 (3.6) | 106 (4.8) | 11 (4.0) | 5 (5.3) | 0.65 |
| Eating disorders | 10 (1.9) | 26 (1.2) | 2 (0.7) | 1 (1.0) | 0.48 |
| Fertility medications e | 22 (4.2) | 124 (5.5) | 11 (4.0) | 4 (4.1) | 0.50 |
| Social factors potentially affecting fertility | |||||
| Preference for sex with women | 5 (1.0) | 28 (1.3) | 8 (3.0) | 2 (2.1) | 0.12 |
| Did not try to get pregnant | 1 (0.2) | 14 (0.6) | 7 (2.6) | 2 (2.1) | 0.02 |
Unless otherwise indicated, continuous variables presented as mean (SD) with P values calculated by Kruskal- Wallis tests. Categorical variables presented as n (percent) with P values calculated by χ2 or Fisher's exact test as appropriate.
Non-gestational amenorrhea was defined as experiencing a time interval of 3 months or greater without a menstrual period that was not due to pregnancy or breast-feeding since the age 18
Participants who took oral contraceptive pills all the time without a break from age 25 to 35
Infertility was defined by the question “Have you ever had a period of 12 months when you could not get pregnant although you were attempting to get pregnant or were letting yourself get pregnant?”
Use of fertility medications such as clomiphene citrate