Trying to conceive

Pregnancy by the numbers

Did you know pregnancy is 280 days? And your placenta weighs about three pounds—but that's nothing compared to the four extra pounds of blood in your body! This is your pregnancy by numbers.

By Today's Parent
pregnancy-by-numbers Illustration: Nica Patricio

A baby girl in utero has about six million eggs in her ovaries, but she only has about two million when she’s born. Those eggs aren’t mature, and many deteriorate as she grows. By the time a woman reaches puberty, she has about 300,000 eggs left, and only about 400 of those eggs will actually go through ovulation.

Men, on the other hand, are sperm machines. The average man creates 1,500 sperm cells per second. The amount of sperm in a typical ejaculation is about half a teaspoon. That may seem small, but that semen contains anywhere from 40 million to 300 million sperm. Remember, it only takes one sperm and one egg to make a baby!


Your chances of getting pregnant are 25 to 30 percent per menstrual cycle.

According to Health Canada, a 30-year-old woman has a 90 percent chance of getting pregnant. That chance drops to 77 percent by age 35 and 55 percent when she is 40 or older.

Thirty-one percent of first-time moms are between the ages of 30 and 34.


Pregnancy is 40 weeks, or 280 days. Your due date is calculated by counting 40 weeks after the first day of your last period, but only about five percent of babies are born on their actual due dates. Most babies are born between 37 weeks and 41 weeks. One in four babies is born after 41 weeks—that’s when you need to eat spicy food and indulge in some nipple stimulation.

An ultrasound takes about 30 minutes, and you can find out your baby’s sex during your mid-pregnancy ultrasound—this usually takes place between 16 and 20 weeks.

A healthy weight gain during pregnancy is between 25 and 35 pounds. Here’s where the weight you gain goes: placenta, two to three pounds; amniotic fluid, two to three pounds; breast tissue, two to three pounds; blood, four pounds; stored fat for delivery and breastfeeding, five to nine pounds; uterus, two to five pounds; baby, six to eight pounds.

You only need about 300 more calories a day when you’re pregnant, and most of those should be healthy calories (sorry, no extra slice of cake here!).

About 30 percent of babies are breech at 30 to 32 weeks. But there's no need to panic: Most babies eventually turn. Only three percent of babies are breech at term (37 weeks).


In Canada, more than 388,000 babies are born each year. Ontario has the highest birth rate in the country, with more than 140,000 new bundles of joy each year. The Yukon has the lowest, with 440 babies born per year.

Early labour (when the cervix opens and thins out) is usually six to 12 hours long. Active labour (when the cervix dilates to 10 centimetres) can last up to 10 hours. The final stretch—pushing—can last anywhere from a few minutes to a few hours, so start planning your labour-pain management now.

As of 2012, 27 percent of Canadian babies were born via C-section.

The average baby weighs 7.5  pounds and is 20 inches long.

One in six couples struggles with infertility.


The clinical definition of infertility is a couple who has been having unprotected sex for one year and hasn’t conceived. This changes to six months if you are a woman over 35 years old.


This article was originally published on May 27, 2016

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