9/1/10
Dear Dr. Kate, Can You Affect the Sex of Your Baby?

photo by gniliep

Dr. Kate is an OB/GYN at one of the largest teaching hospitals in New York City and she answers your medical questions here once a week. To ask her your own question, click here.

Dear Dr. Kate,

When trying to conceive, are there things you can do to try to tip the scales in the direction of one sex or the other, i.e. so if you wanted a baby girl you could increase your odds and vice versa?

— Gender Bender

Dear GB,

There are some theories about trying for a girl or a boy, famously laid out in Dr. Shettles’ book, How to Choose the Sex of Your Baby. These ideas haven’t been tested in large-scale studies (though that would be interesting!), so I’d file this advice in your doesn’t-hurt-to-try-it folder.

Male sperm are thought to be faster but weaker swimmers, so to try for a boy, you want to have sex as close to the time of ovulation as possible. Have sex the day before and the day of ovulation, if you can. And the best positions are ones that get the deepest penetration—him entering her from behind, or on her back with her legs pulled back—to deliver the sperm closest to the uterus. Best of all, female orgasm helps move those little guy swimmers towards the egg, so she should try to climax around the time that he does.

Female sperm, on the other hand, are slower but heartier, so to try for a girl, you want the male sperm to have swum off (or died off!), leaving only the female ones behind. The best times to have sex are two or three days before you ovulate. Your guy should pull out slightly when he comes; this makes the sperm have to travel the length of the vagina, increasing the chances that the stronger female sperm will make it. And the woman should try not to have an orgasm when trying for a girl (oh, the irony).

— Dr. Kate
Gynotalk

dr_kate_100Dr. Kate is an OB/GYN at one of the largest teaching hospitals in New York City. She also lectures nationally on women’s health issues and conducts research on reproductive health. Check out more of her advice and ask her a question at Gynotalk.com.



4 Comments

  1. I heard ( and not from a doctor ) that though men are the only ones that have the chromosome that decides the gender of the baby, that some women’s bodies are more prone to attack the male sperm or female sperm? It was argued that women also help in gender of the baby. Supposedly the research is recent, but I tried to Google the information and have difficulties finding anything.

  2. Actual experiance shows that female sperm are more prevalent in Testes when mean temperatures are deliberately kept lower for the month Prior to Conception. Higher temp.=boys, lower temp.=girls. drJ

  3. Please correct me if I’m wrong, but isn’t there some treatment for a man that would make him stop producing male/female sperm? From what I heard about it, and this was AGES ago, it was permanent. Is this true?

  4. “Best of all, female orgasm helps move those little guy swimmers towards the egg, so she should try to climax around the time that he does. […] the woman should try not to have an orgasm when trying for a girl”

    Didn’t Masters and Johnson disprove this theory about female orgasm? I believe they called it the ‘up-suck’ theory.

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