Study Goals

Our goals are:

• To determine if the PBDE and PFC levels in women’s blood are related to thyroid hormone levels during pregnancy. Chemical levels will be measured in women’s blood collected during mid-pregnancy, and thyroid hormone levels will be measured in women’s blood and in umbilical cord blood collected just after delivery
• To identify the ways in which pregnant women become exposed to PBDEs and PFCs. This information will be gathered using 2 questionnaires, to collect information about personal characteristics, the diet, and the home and workplace environment. The first questionnaire will be done on the internet (web), and the second one will take place inside each woman's home
• To measure the levels of PBDEs and PFCs in indoor air, outdoor air, dust, and dryer lint collected from women’s homes
• To investigate which chemicals in the family of PFCs can cross the placenta

Study Procedures

Update, summer 2008: Please note that we have finished enrolling women for the CHirP study. Please contact us if you would like to receive a summary of the study results in early 2009!

Starting in October 2006, we will enroll 150 pregnant women into the study. The study will follow a four-step process, with an optional fifth step:

Step 1: Collecting maternal blood

If you decide to join the study, two small blood samples (about 1 Tablespoon each) will be collected at 15 and 18 weeks of your pregnancy. To minimize inconvenience to you, one of these samples may be taken at the same time as the Triple Marker Screen, an optional blood test to screen for conditions such as Down’s syndrome. You may still participate in this study if you choose not to have the Triple Marker Screen test. Both blood samples will be taken at BC Children’s and Women’s Hospital by trained hospital staff. This blood collection will not harm you or your baby.

Step 2: Web-based Questionnaire

Soon after the second blood test, we will email a web-based questionnaire to you. This questionnaire will ask about your home, your use of certain products and your transportation habits. The questionnaire should take about 20-30 minutes to complete, and can be done at a time that is convenient to you.

Step 3: In-home Questionnaire and Home Sampling

Soon after the second blood test, you will also be invited to take part in a 1-hour interview in your home, conducted by a member of the research team. This questionnaire will collect information about the foods you typically eat, your job history, personal characteristics, and other factors. Both questionnaires will help us to identify potential sources of PBDEs and PFCs in the home and workplace environment.

After the interview, we will collect a dust sample from your home vacuum cleaner. For some women only, we will also take samples of dryer lint (collected for 2 weeks before the interview), and set up air sampling equipment in the main bedroom. The air sampling equipment is silent and will be left in the room for approximately 1 month. Air sampling equipment will also be set up outside of a few homes, to measure PBDE and PFC levels in the outdoor air. Because of budget constraints, the air and lint samples will only be collected in the first 60 homes.

Step 4: Cord Blood collection

Just after your baby is delivered, a small sample of blood (about 1.5 Tablespoons) will be collected from the umbilical cord after it has been cut. This blood collection will not harm you or your baby. The cord blood sample will be collected by your doctor or midwife. No one from the CHirP study will be present at your delivery. We respect all of your choices about your birth plan - please discuss any wishes with your caregiver! If you wish to bank your baby's cord blood with a private company you can still participate in the CHirP study. In this case, a cord blood sample will not be collected for this project. Please contact us if you have any questions about this part of the study!

Step 5: (Optional) Tissue-Banking Program

You may also choose to take part in an optional tissue-banking program. This program will store left-over maternal and cord blood samples for future studies. With your permission, a small maternal hair sample will also be collected at the home interview, and stored for future research. Participation in the tissue-banking program is entirely optional, and you may decide to withdraw your samples at any time.

The tissue-banking program would allow us to conduct future studies on environmental chemicals, pregnancy, and child health, which may be difficult or impossible to do without stored samples. For example, a future study might investigate whether other chemical exposures in the womb are related to child development. These studies may help us to sustain the health and development of future generations.

We have finished enrolling women for the CHirP study. Please contact us if you would like to receive a summary of the study results in early 2009!