Smoking During Pregnancy

What is it?

Smoking during pregnancy is based on the percent (rate) of mothers who reported smoking at any time during pregnancy. Any smoking refers to smoking any amount of cigarettes during pregnancy, including those who did not know how many cigarettes were smoked.

Why is it important?

Smoking during pregnancy can harm a developing baby. Cigarette smoking is the main cause of low birth weight in developed countries and has been linked to many other adverse pregnancy and birth outcomes, including spontaneous abortion, premature delivery and stillbirth. Long-term adverse effects on children born to mothers who smoked during pregnancy include poor cognitive performance and decreased physical growth.

What does it mean?

The vast majority of mothers of newborns in Toronto did not smoke during pregnancy. Figure 2 shows that 3.9% of mothers reported smoking during pregnancy, which is significantly lower than the Ontario rate (10.6%). The Toronto rate is similar to the public health unit with the lowest rate and significantly less than the public health unit with the highest rate. Figure 3 shows that younger mothers were significantly more likely to report smoking during pregnancy, as compared to mothers 25 years and older. There was no significant difference in the rate of smoking between mothers less than 20 and those 20 to 24 years of age.

Smoking during pregnancy


the risk of infant admission
to the Neonatal Intensive Care Unit.