Pregnancy Without Birth Control: Understanding Fecundity Rates

Question
How common is a pregnacy without any form of birth control? I realize fertility is subjective and different for all partners, but is there any statistics on how often they occur? Like a number/ out of 100 intercourses kind of thing?

Answer
Hello K,

What you are asking for is the "fecundity" rate.  You could probably search the internet for a specific number.  However, the chances for pregnancy per year of trying at various age groups are as follows:

<30     85% per year       18% per month
30-34   60% per year       15% per month
35-36   30% per year        7% per month
37-39   15% per year        5% per month
40-41   10% per year        1% per month
42-43    1% per year        <1% per month
44 on   <1% per year

I hope this helps.

Edward J. Ramirez, M.D., FACOG
Executive Medical Director
The Fertility and Gynecology Center
Monterey Bay IVF Program
www.montereybayivf.com

Monterey, California, U.S.A.