Nine pools were generated for late pregnancy samples (n = 27) and six for lactation samples (n = 18).
For all pregnancy samples, day 0 of pregnancy is the day we observed the vaginal plug.
Significant (p < 0.0001) decreases in the mean overall and daily rate of change in PCB concentrations were observed between the preconception and first pregnancy samples for total (–1.012 and –0.034, respectively), estrogenic (–0.444 and –0.016, respectively), and antiestrogenic (–0.106 and –0.004, respectively) PCBs among women with live births.
In order to detect a possible seroconversion throughout pregnancy, our strategy was to initially analyze the last existing blood sample (for 79 women this was the mid pregnancy sample and for 282 it was the umbilical cord sample).
For all but one male pregnancy sample, it was obvious that the distribution of chromosome X shifted towards the left, while the distributions of chromosomes 21, 18, and 13 for the respective cases of trisomy 21, 18, and 13 shifted towards the right, relative to the distributions of all other chromosomes that were present in two copies.
Pre-pregnancy samples from all of these healthy women were analyzed for gene expression.
Urine samples for pregnancy testing were collected before dosing and at weeks 4, 12 and 24.
Women were asked to notify fieldworkers of missed menstrual periods and to provide urine samples for pregnancy testing by an NM when pregnancy was suspected (QuickVue One-Step hCG Urine Test; bioMérieux).
Female participants also provided a urine sample for pregnancy testing.
At the enrolment visit, participants provided written informed consent, underwent a pelvic examination, provided a blood sample for testing for syphilis (rapid plasma reagin and T pallidum haemagglutinin; Randox Laboratories) and HSV2 (ELISA; FOCUS Diagnostics) and provided a urine sample for pregnancy testing.
