Natural gender choice

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The natural gender selection is used by parents to use the non-medical techniques to the gender to influence their children.

For cultural reasons, boys are preferred to girls in many countries . The natural ratio is about 106 newborn boys to 100 girls. There has always been a great deal of interest in attempts to influence the gender of one's own child.

Biological background

The child's sex depends on whether the set of chromosomes of the sperm that fertilizes the egg contains an X chromosome or a Y chromosome . The X chromosome is 164 million base pairs in size, the Y chromosome only 60 million base pairs. It is conceivable that the difference in weight makes the Y-sperm more mobile, which would help explain the low predominance of male newborns. However, the ratio 106: 100 is not constant in terms of time and location.

Derivatives

The notion that Y sperm move faster than X sperm and are less long-lived than X sperm has led to numerous popular recommendations in the past. The best-known representative in the 1970s was the American gynecologist Landrum Shettles (1910-2003) ( How to choose the sex of your baby , 1970), who recommended sexual intercourse immediately after ovulation in order to father a boy. In his scientific study, which included only 43 pairs of parents, 86 percent of the children conceived on the day of ovulation were male. In Germany, the economist Otfried Hatzold also took up the method in a populist way ( Wunschkind Sohn or Daughter , 1970).

Ovulation can be dated with a certain degree of certainty by measuring the body temperature and using the vaginal secretion ( e.g. for symptothermal contraception ). The Australian specialist John Billings gave a complicated, in his opinion more precise, method ( The ovulation method , Melbourne 1964).

Tests on farm animals such as deer and sheep have confirmed that a planned fertilization time can shift the sex ratio of the offspring, but on the other hand this was not possible with cattle (Rorie, 1999). More extensive and more recent studies with human subjects have shown small but significant changes, but contrary to the assumption of Shettles: conceptions near ovulation (± 2 days) led somewhat more frequently to female children; the ratio was then about 55/45 (Gray, 1991).

The book author Elizabeth Whelan ( Boy or girl?, 1984) therefore already recommended the opposite of the Shettles-Billings method: intercourse four to six days before ovulation is supposed to help a boy. From a scientific point of view, this method is only suitable for achieving a slight improvement in chances (55 instead of 50 boys for 100 births). On the other hand, the proposed methods are harmless and can be used without medical assistance.

Current situation

Real certainty of fathering a boy or a girl would only be possible with medical methods such as artificial insemination with separated sperm or in vitro fertilization . The use of such methods for gender selection is considered ethically unjustifiable and is therefore prohibited in Germany ( Embryo Protection Act ) and in other countries.

See also

swell