Sunnybrook Twins Research Centre

Just found out you are expecting twins? You’re in the right place!

The Sunnybrook Twins Research Centre is committed to improving outcomes for twin pregnancies through research, education, and evidence-based care. Drawing on the expertise of Canada’s first and largest Twins Clinic, we provide families and care providers with reliable information and clinical tools grounded in our research.

A twin pregnancy often comes as a surprise, and it’s normal to feel overwhelmed by questions. What do all these medical terms mean? What tests will I have? How will my babies be delivered? This site brings together everything we’ve learned from caring for hundreds of twin pregnancies each year and from our research program, explained in plain language. Explore the sections below to find what you need.

The Sunnybrook Twins Research Centre is part of the DAN Women & Babies Program and is supported by the Waugh Family Foundation.

For Families

Just found out you’re having twins? Start here.

A twin pregnancy involves considerations that differ from a single pregnancy. We have developed a comprehensive, plain-language resource covering what to expect throughout a twin pregnancy, including common terminology, prenatal screening, the risks specific to twins and how they are managed, and guidance on labour and delivery.

Clinical Tools

Tools for your pregnancy: Most pregnancy calculators are based on single pregnancies and may not be accurate for twins. We have developed a set of evidence-based tools specific to twin pregnancies – for estimating fetal growth percentiles, monitoring gestational weight gain, assessing protein requirements, and evaluating delivery-related risks. These tools are used in our clinic and are available here for families and care providers.

Our Research

Our research: The Twins Centre has published more than 140 peer-reviewed studies on twin pregnancies, contributing to national and international guidelines on fetal growth, gestational diabetes, weight gain, and the timing and mode of delivery. Each study on this site is accompanied by a plain-language summary explaining its findings and relevance.

Patient Experiences

Stories from other twin families. You’re not alone. Families who have experienced a twin pregnancy can share their experience with us, and read about the experiences of others. These accounts help inform our care and may be of value to families navigating a twin pregnancy.