If you’re dreaming of pink, a baby girl might top your wish list. Theories on influencing the sex of your child-to-be before conception abound. One of the most persistent ideas proposes that keeping vaginal secretions acidic will benefit the hardier girl sperm, while an alkaline environment will allow the faster, but weaker, boy sperm to speed ahead. Sperm prefer an alkaline environment. Cranberries create an acidic environment in the urine, but their effect on the vaginal tract is less certain. Whether the theory that an acid environment favors girl sperm has any validity is another question.
Acid-Alkaline Food Theories
According to columnist Dr. Gabe Mirkin, the idea that foods help turn any part of your body except your urine acid or alkaline has no validity at all. Mirkin says all foods turn acidic in the stomach because of the high acid content and that all foods -- or what’s left of them in the intestine -- turn alkaline. Cranberries can make your urine more acidic, but they don’t affect other body secretions, including those in the vaginal tract.
Vaginal Acidity or Alkalinity
The acid-alkaline theory follows the Shettles method of determining sex, which has not proven successful in clinical studies. Dr. Landrum Shettles proposed that having sex several days before ovulation, when the vaginal tract is more acidic, favors girl sperm, which live longer, but move more slowly than boy sperm. Near ovulation, the vaginal tract secretes copious amounts of alkaline mucus, which allows sperm to move more quickly through to the egg.
The vagina is normally quite acidic, maintaining a pH of around 3 to 4. Around ovulation, the environment turns much more alkaline, with a pH of between 7 and 14. If you want to see if cranberry tablets keep your vaginal mucus acidic close to ovulation, purchase kits that test pH in the pharmacy. The testing strip will turn color, usually from a yellow to a deep blue, when the mucus becomes more alkaline. PH testing kits are a good way to determine when you’re about to ovulate. If cranberry tablets are keeping the environment acidic, the color won’t change.
When you read success stories of one method or another producing more female or male babies, it’s important to remember that even without any help at all, your chance of having a girl is around 50 percent. If you really want to make sure sperm enter an acidic environment, the Shettles method, even though studies haven’t always shown it to work, is a surer way of ensuring an acidic vaginal environment than taking cranberry supplements. If you really want to have a girl, sex selection done in the laboratory is your best bet if you can afford it.