and its effect on Gender
Research supporting Timing’s effect on gender determination:
O + 12
The only day on which more girls than boys were conceived was the day following ovulation.
The New Zealand Study has spun out the “O + 12 Method”, basically flipping the script of the Shettles Method. It is a method specifically for conceiving a girl and was developed not by a doctor or researcher but a mother of six sons who desired to have a girl. A 1984 New Zealand Study set out to test the Shettles Method. That study found that most conceptions occurring 3-5 days before ovulation were actually boys not girls, as the Shettles Method advised. The mother of the six sons noticed that the only day where more girls than boys were conceived was the day after ovulation.
Further instruction on the O + 12 Method includes abstaining from all ejaculation for a minimum of a week prior to the “conception sex,” and preferably longer. Have sex only once 8-20 hours after ovulation. Abstain or use a condom until you are fertile again, because the “fresher” batch will have more Y-producing boy sperm.
There are a variety of methods for trying to pinpoint the exact timing of ovulation, involving basal body temperature and mucus, as well as home testing kits. For best results, a combination of methods should be employed plus careful observation of the woman’s individual patterns.
Nineteen conceptions occurred on peak day or peak plus one, 37% of these were male and 63% were female.
This is opposite to the predicted results for the Shettles method or as suggested in the Atlas of the Billings Ovulation Method, where a male child is predicted to be more likely, if intercourse is restricted to the peak day or the day following and a female child is more likely from intercourse at the beginning of the mucus phase with abstinence until the fourth day after peak.
This is an account of Dr Leonie Mc Sweeney’s prospective study of sex preselection in Nigerian women using the Billings‘ Method.
Dr Mc Sweeney advised couples who wished to have a male child, to abstain from the onset of the mucus symptom and then to have intercourse on the morning of the second day after peak symptom day.
If conception had not occurred after several cycles, the couple were recommended to have intercourse on the night of the first day after peak, and intercourse again on the morning of the second day after peak.
She reported a male birth rate of 96.3%. A success rate of 88.9% for a female child was obtained with pre-ovulatory intercourse postponed until the appearance of the slippery mucus days prior to peak, and then abstinence until the 4th day after peak. Day 2 prior to peak appeared to be the preferable day for a female child.
These results are at variance with those of other studies on the timing of intercourse at the time of peak fertility and sex outcome. Overall, these other studies reported little difference in sex outcome compared to the usually accepted 107/100 male to female ratio.
Source: Dr Barbara Gross, B Pharm Msc PhD.,
Senior Scientific Officer, Department of Clinical Endocrinology, Westmead Hospital Sydney, Australia
The Shettles Method
The most read about method is the “Timing Method” which was developed by Doctor Shettles and called the Shettles method. Parents are asked to try for boys during ovulation and girls 3 days before ovulation.
Dr. Landrum Shettles and David Rorvik, who wrote How to Choose the Sex of Your Baby, claim that because Y-chromosomes (for boys) move faster but don’t last as long as X-chromosomes (for girls), it makes sense to have sex as close as possible to ovulation if a boy is what you want. If you try to conceive two to four days before you ovulate, you’ll most likely have a girl.
According to Dr. Ravnikar, the Shettles method, and others similar to it, could be sound in suggesting that couples try for a boy baby closer to ovulation since Y-chromosome-bearing sperm is lighter but more fragile than those that carry X-chromosomes. If you want a girl you should not have sex during ovulation but a few days before as the x can live longer that the y chromosome sperm.
Dr Shettles, was criticized for his non biological assumptions. To quote a couple of the many reviews, RH Gray, in a 1991 article in American Journal of Obstetrics and Gynecology says that the Shettles method is contradicted by scientific data. In a 1995 study published in the New England Journal of Medicine, researchers Allen Wilcox, Clarice Weinberg and Donna Baird say that “the timing of sexual intercourse in relation to ovulation has no bearing on the sex of the baby”.
It is wrongly assumed that the Y chromosome (boy) provides a lighter sperm which races to the egg faster than the heavier X sperm. As we explained the difference in weight or size is negligible and the speed of delivery of thousands of sperm in a small space does not allow for these ideological theories. It is not a credible situation.
Sperm rarely stay or live on and remain fertile for more than 2 days, so users cannot easily be blessed with girls or even a baby if the only time to try is “3 days prior” to ovulation! It would create much stress as mothers who today mostly want a little girl would have great problems in the difficult task of predicting a future ovulation to the exact day. Boys are made on day of ovulation or day before and so are girls !
The method has popular appeal and is well introduced by hundreds of existing fertility service companies specializing in selling various kits such as ovulation predictors. They have no idea who uses the kits for gender selection or the results.
The method looses credibility as there are as many women as men around! The method has been available for 25 years with no known success statistics. There is no register of users so there is no possibility of measuring the success rate.
Dr Shettles finally advised different diets for each gender as well and he was right to do so as the “race” idea is not a biological solution.
Timing ALONE is one of the least effective ways to influence gender.