In an ideal world, we’d all be of ideal weight, pre-pregnancy or otherwise.
But the evidence shows that an estimated 58.4% of UK women are overweight or obese. (Or they were in 2011, at least).
Women who are bigger may face more challenges in getting pregnant. There is an evidenced association between increasing body mass and decreasing fertility; for each BMI point over 29, the chances of falling pregnant decreases by 4%.
Causation or Correlation?
It is not clear whether this relationship is causative; i.e. women find it more difficult to get pregnant because they are overweight, or merely correlative; i.e. women who are overweight also find it more difficult to become pregnant.
Finding a correlation is not surprising if the thing that is stopping you getting pregnant is also affecting your weight! This is particularly relevant to people with PCOS, for whom weight gain and problems with fertility are two of the symptoms of the condition.
That doesn’t mean that you’re guaranteed to struggle with fertility if you’re bigger. I took all this to heart when we were trying for a baby. I’d had the contraceptive implant for years, and had heard that this can affect your chances. I was significantly overweight. Clearly it would probably take months if not years to fall pregnant, if we did at all… And then I got pregnant the third month of trying!
There are a number of studies showing the benefits of losing weight in order to improve the chances of falling pregnant. While this might be the consultants’ preferred solution, it is not always a realistic possibility. I have often said that if I’d waited until I was an ‘ideal’ weight to get pregnant, I’d be too old to conceive!
Overweight women also are likely to have more problems during their pregnancy.
For anyone who is planning to get pregnant, there are certain recommendations specifically aimed at improving pregnancy outcomes.
Please see the pre-pregnancy sub-pages for more in depth info. But please remember, we’re all individuals, with our own individual circumstances. It is perfectly possible to have an easy, happy, healthy pregnancy, whatever your size.