For Participants


If you are planning to have your baby at Mount Sinai Hospital or St. Michael’s Hospital, you may be asked to take part in the Ontario Birth Study. In addition to asking questions about your current pregnancy, the Ontario Birth Study plans to continue to follow-up your child’s health once (s)he is born.

Please read this explanation about the study and its risks and benefits before you decide if you would like to take part. You should take as much time as you need to make your decision. You should ask the study doctor or study staff to explain anything that you do not understand and make sure that all of your questions have been answered before signing the consent form. Before you make your decision, feel free to talk about the Ontario Birth Study with anyone you wish. Participation is voluntary.

Why participate?

Background and purpose
There is a recognized need for long-term evaluation of women’s and infants’ health. This includes better understanding of early life factors that determine health and disease. The overall aim of the Ontario Birth Study is to develop a platform for future research on pregnancy complications and maternal and infant health, and ultimately, to assemble a cohort of studies in the future that investigate the developmental origins of health and disease.

Any information gathered from self-administered online questionnaires, hospital medical charts and biological samples collected for the purposes of the study will be stored in a confidential ‘bank’ of information to which only authorized research personnel can gain access for studies that have passed ethical review.

Ontario Birth Study Design

This study is a form of observational research. It does not involve any drug or treatment interventions. The Ontario Birth Study will collect questionnaire data and biologic specimens at different times throughout and after pregnancy.

Click here for our Ethics statement

Study visits and procedures

As a participant in the Ontario Birth Study, we would ask you to:

  1. Provide us with permission to access your patient chart for medical information about your pregnancy and delivery.
  2. Provide an extra 30-40 cc of blood (about 2-3 tablespoons) and 2 extra vaginal swabs at the time of your routine care. If you have had a previous preterm delivery, you will be asked to provide a total of 4 vaginal swabs at the first collection point. Since these biological samples will be collected at the same time as your routine visit, the study will not require extra visits to the clinic from you.
  3. Twenty-four hours after birth, a blood spot card is routinely collected from your baby using a heel prick. The Ontario Birth Study will ask to collect one extra blood spot card at the same time.
  4. Complete questionnaires about your general lifestyle and diet.

What to expect

The following table illustrates what you can expect to happen at different time points throughout your participation in the Ontario Birth Study. The expected routine care visits are listed by gestational age.

The study questionnaires are self-administered and can be completed using a paper version, online at home or you may borrow a computer from the study to use during your normal appointments.

Your blood samples and swabs will be processed and stored in the Biospecimen Repository at the Lunenfeld Tanenbaum Research Institute of Mount Sinai Hospital.

You may be approached at time of delivery by a research staff member asking if they can collect samples of your placenta. You can choose not to provide these samples without affecting your participation in the Ontario Birth Study.

Please note: All study visits are scheduled to occur at the time you will already be at your obstetrician’s office for routine appointments.

Table of Procedures in Addition to Routine Clinical Care

Time of your routine visitBlood workVaginal SwabsLifestyle QuestionnaireDiet QuestionnaireApproximate Time
Week 11-1430-40 cc2-4 swabs*✔ (LSQ1)-45 min
Week 16 30-40 cc--45 min
Week 2830-40 cc-✔ (LSQ2)-30 min
Week 34-38-2 swabs--10 min
Delivery30 cc;
Infant blood spot card
---10 min
6 weeks after Delivery--✔ (LSQ3)-30 min

*Women with a previous preterm delivery will be asked to provide 2 additional swabs (for a total of 4) at their first vaginal swab collection

Benefits to participation

Although there are no direct benefits to you personally for participating in this study, your participation may help provide new knowledge and invaluable insight into a wide range of pregnancy-related conditions. It may also assist in developing useful recommendations for pregnant women and improved delivery of healthcare. It will also help inform other studies regarding pregnancy and its impact on women’s long-term health as well as that of children.

Your participation is voluntary

Your participation in this study is completely voluntary and you can choose to stop at any time. Refusal to participate or deciding to withdraw from the study will not affect the quality of care that you would normally receive during pregnancy and/or after delivery. Refusal to participate in the Ontario Birth Study will not prevent you from participating in future studies.

Questions about the Ontario Birth Study?

If you have any questions, concerns or would like to speak to the study team for any reason, please contact us.

If you have any questions about your rights as a research participant or have any concerns about this study, please contact the Mount Sinai Hospital Research Ethics Office at 416-586-4875. The REB is a group of people who oversee the ethical conduct of research studies. These people are not part of the study team. Everything that you discuss will be kept confidential.

What about after birth?

To understand how perinatal factors such as parental lifestyle, pregnancy conditions and neonatal medical history may affect children’s growth and neurodevelopment, we continue to follow up children from the OBS mothers at ages 8 months, 24 months, 36 months and 4.5 years. Please see OBS Kids Follow-up for details.

We also encourage you to take part in a research study about your new child’s health called TARGet Kids (Toronto Area Research Group) which is complementary to the OBS Kids follow-up study.

Find out more