Total and mature oocyte yields and peak E2 levels by frequency of moving heavy objects, level of physical exertion and typical work among 313 women contributing 462 fresh IVF cycles in the Environment and Reproductive Health (EARTH) Study
| Occupational characteristics (number of fresh IVF cycles) | Total oocyte yield, n | Mature (MII) oocyte yield, n | Peak E2 levels, pmol/L | |||
|---|---|---|---|---|---|---|
| Unadjusted | Adjusted* | Unadjusted | Adjusted* | Unadjusted | Adjusted* | |
| Moving or lifting heavy objects | ||||||
| Never (n=276) | 11.6 (10.8 to 12.4) | 11.4 (10.7 to 12.2) | 9.8 (9.2 to 10.5) | 9.7 (9.1 to 10.3) | 2153 (1424 to 2882) | 2133 (1427 to 2840) |
| Sometimes/often (n=186) | 10.5 (9.7 to 11.5) | 10.4 (9.5 to 11.3) | 8.5 (7.8 to 9.2) | 8.3 (7.7 to 9.0) | 2072 (1177 to 2968) | 2069 (1199 to 2939) |
| p Value | 0.10 | 0.08 | 0.007 | 0.004 | 0.89 | 0.73 |
| Level of physical exertion | ||||||
| Light (n=356) | 11.5 (10.8 to 12.2) | 11.3 (10.7 to 12.0) | 9.5 (9.0 to 10.1) | 9.4 (8.9 to 10.0) | 2153 (1911 to 2394) | 2134 (1897 to 2371) |
| Moderate/heavy (n=106) | 10.1 (9.0 to 11.3) | 9.9 (8.8 to 11.1) | 8.3 (7.4 to 9.3) | 8.1 (7.3 to 9.1) | 2099 (1648 to 2550) | 2103 (1656 to 2551) |
| p Value | 0.05 | 0.04 | 0.03 | 0.02 | 0.70 | 0.82 |
| Typical work shift | ||||||
| Day shift (n=426) | 11.3 (10.7 to 11.9) | 11.2 (10.6 to 11.8) | 9.4 (8.9 to 10.0) | 9.3 (8.9 to 9.8) | 2138 (1941 to 2335) | 2425 (1935 to 2315) |
| Evening/night/rotating shift (n=36) | 9.3 (7.7 to 11.2) | 8.7 (7.3 to 10.5) | 7.5 (6.2 to 9.0) | 7.0 (5.8 to 8.4) | 1917 (1422 to 2411) | 1890 (1404 to 2376) |
| p Value | 0.05 | 0.01 | 0.02 | <0.001 | 0.26 | 0.23 |
*Data are presented as predicted marginal means (95% CI) adjusted for age (continuous), BMI (continuous), education (less than college graduate, college graduate and graduate degree) and infertility diagnosis (male, female and unexplained).
BMI, Body Mass Index; E2, oestradiol; IVF, in vitro fertilisation; MII, metaphase II.