No statistically significant associations were observed between DDT/DDE and IVF outcomes or between HCB and chemical pregnancy or spontaneous abortion.
Of the 2,350 couples in the main study, 765 women were selected by the outcome of their first IVF cycle (failed implantation, chemical pregnancy, spontaneous abortion, or live birth).
A chemical pregnancy was defined by a post-ET hCG measurement of [greater than or equal to] 5.
Whenever a woman was at risk of a cycle failure because of implantation failure, chemical pregnancy, or spontaneous abortion in each cycle, a binary outcome (1 = failure, 0 = not a failure) was recorded.
There were 541 total cycle failures, of which 490 were included in the analysis and consisted of implantation failure (209), chemical pregnancy (161), and spontaneous abortion (120).
001 Chemical pregnancy Q1 189 204 47 Referent 197 209 Q2 181 203 41 0.
29 Chemical pregnancy Q1 188 204 43 Referent 195 209 Q2 184 203 45 1.
A chemical pregnancy was defined by a luteal hCG measurement of [greater than or equal to] 5.
failed implantation, chemical pregnancy, and spontaneous abortion) to improve statistical power.
In each cycle, whenever a woman was at risk of having a failure due to implantation failure, chemical pregnancy, or spontaneous abortion, a binary outcome (Y) was recorded (1 = failure, 0 = not a failure).