Gender Selection


Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
ISSUE 3 Topic guide What is sex selection? Usually the gender of a baby is the result of a random sperm lottery, with a fairly even chance of getting a boy or a girl (see Big Picture on Sex and Gender for further details). Sex selection is the process of biasing this lottery in favour of one or other sex. People may want to do this either for medical reasons (in order to avoid serious genetic disorders) or for social reasons (where they have a strong desire for a child of a particular sex). How do you choose a baby’s sex? All eggs carry an X chromosome, while sperm carry either an X chromosome or a Y chromosome. An egg fertilised by an X-bearing sperm creates a girl, while a Y-bearing sperm will produce a boy. ‘Natural’ methods The X chromosome contains more genetic material than the Y chromosome. As a result, X-bearing sperm are heavier and are therefore slower swimmers. Some people think that parents can capitalise on this difference to influence the sex of their offspring by, for example, changing the timing of intercourse relative to ovulation. Recent books such as Taking Charge of Your Fertility promote such ‘natural’ methods to parents, although several studies have found that they have almost no effect on a baby’s sex. Sperm sorting The weight differential between X and Y chromosomes is the basis for sperm sorting. This is a physical technique in which slower-swimming X-bearing sperm are separated from Y-bearing sperm. However, while sperm sorting can increase the likelihood of giving birth to a boy or a girl, this cannot be guaranteed. More recently, a fluorescent dye has been used, which binds to DNA and shows up X chromosomes as bigger patches of fluorescence. Although this is more accurate, it is still not completely dependable and the success rate is higher for selecting girls as opposed to boys. One study found that the success rate was 91 per cent for those seeking girls and 76 per cent for boys. Preimplantation genetic diagnosis (PGD) PGD involves a single cell being plucked from an IVF embryo while it is still at the eight-cell stage. The cell can then be analysed so that an embryo with, for example, a serious genetic disorder is not implanted in the womb. As well as enabling testing for numerous hereditary diseases, PGD also makes it possible to find out the sex of an embryo. PGD is available on the NHS, but it is tightly controlled by the Human Fertilisation and Embryology Authority (HFEA) and only allowed under certain medical conditions. The likelihood of becoming pregnant after a PGD cycle is usually less than 20 per cent, slightly lower than for IVF. Abortion Most women receive an ultrasound scan between weeks 18 and 20 of pregnancy, and by this stage it is possible to determine the sex of their baby. Some doctors have expressed concern about informing parents of their child’s sex at this early stage. They fear that some parents who are disappointed that their child is not the sex that they wanted might seek an abortion. Abortion is legal in the UK up until week 24 of pregnancy. DEBATING SEX
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 09/22/2008 for the course HD 115 taught by Professor Schelhas-miller during the Fall '08 term at Cornell.

Page1 / 6


This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online