What is Preterm Birth?

What is Preterm Birth?

• Most pregnancies end around 40 weeks.

• Babies that are born at or after 37 weeks are considered to be full term.

• Babies that are born before 37 weeks are considered to be PRETERM or PREMATURE.

• In Canada, 7-10% of all babies are born prematurely.

• Babies born preterm are at risk for serious health problems and even death. Those born the earliest are at greatest risk. This is because the earlier a baby is born, the less the baby will weigh, and the less developed the organs will be. Therefore, more complications can occur.

• Preterm babies must stay in the Neonatal Intensive Care Unit (NICU), which has special equipment and staff to deal with the multiple problems of being premature: breathing, keeping warm, feeding, and many others.

• Very premature babies and very sick babies are at risk of long lasting problems such as developmental delays, physical handicaps, lung and gastrointestinal problems, vision and hearing loss.

What Are the Categories of Preterm Birth?

Preterm Birth is classified into two categories:

I. Iatrogenic: refers to situations where your doctor decides to deliver the baby early because of complications with the mother and/or the baby.
This is the cause of ~30% of cases of preterm birth.

II. Spontaneous: refers to situations where your body decides to deliver the baby early, and makes up the other ~70% of cases of preterm birth.

There are three important conditions that can result in this:

A. Preterm Labour: uterine contractions begin too early and this causes the cervix to open.
B. Preterm Premature Rupture of the Membranes (PPROM): the membranes (or the “water sac”) may break, but this is not accompanied by uterine contractions or cervical changes.
C. Cervical Incompetence: the cervix opens without uterine contractions at all. When this happens, a small baby can easily pass through.

Special Pregnancy Program

Referrals »

Fetal Medicine: 416-586-4800 x 7756
Fax: 416-586-3216

Maternal Medicine: 416-586-4800 x 7000
Fax: 416-586-5109

Main clinic hours: Monday to Friday, 8am to 4pm

Prenatal Diagnosis & Medical Genetics

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phone: 416-586-4800 x 4523
fax numbers:
416-586-4723 or 416-586-8384

Perinatal Mental Health

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Phone: 416-586-4800 x 8325
Fax: 416-586-8596