This article is from the Big Folks Health FAQ, by email@example.com (Sharon Curtis) with numerous contributions by others.
A common misconception is that fat women are often infertile and/or
don't get their periods. If you are having trouble getting pregnant, have
a doctor try to figure out what is going on. Lots of other fat women have
become pregnant; almost certainly, a woman who is fatter than you has become
pregnant. There are lots of reasons that one might not become pregnant
A reference is [Zaa+], which
found that a larger waist-hip ratio had a negative impact on fertility
in women. Average-size and obese women had similar conception rates, but
underweight and very obese (BMI > 38) women were slower to conceive.