For Researchers

The Ontario Birth Study (OBS) is a research platform developed by the Lunenfeld-Tanenbaum Research Institute (LTRI) and Mount Sinai Hospital (MSH). The OBS is an open longitudinal pregnancy cohort designed to serve as a platform for research on pregnancy complications and infant health, and ultimately to assemble a cohort for future studies on the developmental origins of health and disease. One of the goals of the OBS is to streamline research, reducing the burden of research on both clinical care and patients, while increasing research opportunities (lower cost, increased feasibility, and data availability) and enhancing clinical care. The OBS offers collected data and biospecimens to researchers on a cost-recovery basis.


Pregnant individuals are approached by OBS staff at their first ultrasound or prenatal visit at MSH.

Inclusion Criteria

  • Pregnant people less than 17 weeks gestational age
  • At least 18 years of age
  • English speaking
  • Receiving antenatal care at MSH

Exclusion Criteria

  • Non-viable fetus
  • Unable to provide informed consent
  • Known significant fetal abnormalities
Visit TimeBlood WorkQuestionnaireApproximate Time
Weeks 11-1420-40 ccLifestyle Questionnaire 145 minutes
Weeks 15-1920-40 ccDiet History Questionnaire45 minutes
Weeks 24-28 20-40 ccLifestyle Questionnaire 210 minutes
Birth30 cc
Infant Blood Spot Card
30 minutes
6 Weeks PostpartumLifestyle Questionnaire 3 30 minutes

The consent obtained from all participants covers questionnaire data, biospecimens, ultrasounds, and access to clinical records. As outlined in Table 1 below, OBS participants are asked to complete four questionnaires: three lifestyle questionnaires and the past-month web version Canadian Diet History Questionnaire II. The scheduled collection of biospecimens, including participant blood, infant blood spot cards is also shown in the table.

* Vaginal swabs were initially collected at 11-17 and 35-37 weeks. Collection was discontinued as of April 15th, 2021. A limited number of swabs remain available within the Biospecimen Repository.

Clinical Data and Biospecimens

Additional data collected from antenatal records and hospital medical charts are extracted and entered into our REDCap database. Our clinical data is collected in different categories, with their components listed below:


  • Age
  • Height
  • Weight

Medical History

  • Medications
  • Gravidity
  • Parity

Current Pregnancy

  • Blood pressure
  • Blood work
  • Urine test
  • Ultrasound reports
  • Interventions
  • Labour details
  • Infant assessment
  • Gestational age
  • Birth weight
  • Infant sex

Biospecimens are collected and processed at Mount Sinai Hospital’s Biospecimen Repository and Processing Lab. The collection of biological samples includes:

  • Maternal Blood (DNA, Leukocytes, Plasma, Serum)
  • Infant Blood Card (collected 24 hours after birth)
  • Infant Saliva (collected at 24 months and 4.5 years)

The OBS is receptive to prospective studies that need other biospecimens, such as placentas. Interested researchers are invited to contact us to discuss any such requests through Mount Sinai’s Research Centre for Women’s and Infants’ Health (RCWIH) BioBank.

OBS Kids Protocol

Original OBS participants who have agreed to further contact following completion of the initial OBS protocol are invited to continue with the OBS by completing the OBS Kids protocol. The table to the right summarizes the information collected at each OBS Kids follow-up time.

Visit TimeInterview FormatInterview ContentApproximate Time
8 monthsPhoneChild’s sleep, health & breastfeeding;
Childcare arrangements;
Questions about parents
15 minutes
24 months Phone/Home Visit Updates on child health (health & weight);
Collaborative task between parent and child;
Infant saliva sample
45 minutes
36 months PhoneUpdates on child health15 minutes
4.5 yearsPhone/Home VisitUpdates on child health;
Shape and colour matching;
Sibling information; Questions about parents; Parent-child interactive activity
10 minutes

Data Collection Structure

The OBS uses different questionnaires to collect information related to participant demographics, medical history, emotional health, diet, and information related to the children. These questionnaires incorporate various validated screening tools and scales in order to ensure optimum quality. Researchers are encouraged to review all the fields prior to a data inquiry, in order to streamline the data acquisition process as much as possible.

Fee Schedule

The OBS offers samples to researchers on a cost-recovery basis, with fees listed in the document below.

Access OBS/OBS Kids Data and Biospecimens

  1. Complete the Preliminary Data Request Form to determine study feasibility.
  2. If a project is feasible, applicants will receive an invitation to complete the Data and Sample Access Request Form via REDCap. The form requires an explanation of the proposed study, including current ethics approval status, and also records the specific data and/or sample types required.
  3. The application form and any supporting documentation will be reviewed by the OBS Steering Committee within 30 days of submission.
  4. There are possible outcomes after Steering Committee review:
    • Approval: The Steering Committee will notify the applicant of the approval, provide an approval number and Project ID. A research agreement such as a Data/Material Transfer Agreement (DTA, MTA, or DMTA), or another appropriate legal instrument will be issued for all data/samples approved for transfer to external institutions. This agreement will be negotiated between Sinai Health System (SHS) and the approved researcher’s institution prior to execution. Research ethics approval is required before release of any data or biospecimens.
    • Refusal: In the case of a refusal, the applicant will be so notified with reasons for the refusal. In cases of incompleteness or if further information is required, resubmission will be permitted.