by Dr. Abayomi Ajayi
Do you know you can choose the s*x of your children before they are
born? Everyone wants a healthy baby and it is normal to have a
preference. Gender selection enables that. It is a procedure that allows
intending parents to choose the sex of their baby.
to as family balancing – is available through special test procedures
in conjunction with IVF/ICSI (In vitro fertilization/ Intracytoplasmic
sperm injection).
Normally, all couples have a 50/50 chance of conceiving a boy or a girl;
however, you might want to stack the odds in your favour, either for
medical or some reasons to balance your family.
You may wish for a specific gender for your child if you wish to prevent inheritance of sex-linked genetic diseases.
There was a time the sex selection process could only be done abroad.
Essentially the primary aim of assisted conception is to help couples
achieve pregnancy, which is a primary and fundamental human requirement.
Research shows that as parents get closer to achieving their total
desired number of children, the gender composition of the children
already born becomes an important determinant of whether you would have
another child.
Under these conditions, sex selection can help maximise your chances of
having a small family size of both sexes. So instead of trying
repeatedly and hoping on chance, a more certain method of selecting the
sex of the child can be considered.
Sex selection is important for medical reasons in order to eliminate
genetic diseases like Haemophila A and Duchenne’s muscular dystrophy
that occur in males but are only carried or transferred by females.
If yours is a family with a history of some of these conditions, you
could prefer to apply gender selection and opt to have only female
children.
Pre-implantation Genetic Diagnosis or PGD is one of the best scientific
methods for selecting the gender of a child. If properly done, PGD is
almost 100 per cent certain of selecting the desired sex. In PGD, the
woman first goes through IVF, where her ovaries are stimulated using
medications to produce eggs.
The eggs are retrieved from her body using a special technique. They are
fertilised using her partner’s sperms and in the resulting embryos,
small cells are removed from each and analysed to determine the gender
of the particular embryo.
Embryos of the desired sex are then transferred into the woman’s womb
with the hope that they will attach to the uterine lining and grow into a
viable pregnancy.
The gender of an embryo is determined by the chromosomes carried by the
sperm. A sperm can carry either the X or the Y chromosome. The woman’s
egg only contributes the X chromosome to the fertilised embryo. The
presence of the Y chromosome in the sperm will create a male baby (XY).
Two X chromosomes – one X from the sperm and one X from the egg – will
produce a female baby (XX).
Another method known as Sperm Sorting/Microsort, involves the sperms
being sorted using fluorescent technology into Y chromosome for the boy
carrying sperms and X chromosome (girl) carrying sperms. The technology
is based on the fact that the X chromosome is substantially larger than
the Y chromosome.
The process uses a fluorescent DNA stain that attaches to the DNA of
each sperm and a sorter to identify and separate the sperms.
However, not all couples are suitable for Microsort. The sperm count of
the male partner must be within normal limits (at least 20 million
sperms per ml with 50 per cent motility). Sperm samples are collected
over a period and banked until a total of about 200 million sperms are
collected. They are frozen and sent for sorting.
The sorted samples are sent back usually within three to four weeks and
depending on the desired gender, the appropriate sperm is used to
inseminate the woman or to fertilise her egg during processes of
assisted reproduction.
The chances that the child will be a boy are up to 80 per cent while the chances that they will be a girl are over 90 per cent.
There are pros and cons. In PGD, the embryos may be damaged during
testing. The desired sex may not be achieved as all the embryos produced
may not be of the desired sex. The Microsort method may also not result
in getting the desired gender as it is not 100 per cent effective.
Microsort method is based on separating sperm according to how much DNA
is in the sperm. If a sperm with extra or less DNA per chromosome
(abnormal sperm) fertilises an egg, it could result in pregnancy failure
or a high risk of miscarriage.
Alongside sex determination, PGD can also check if the embryos are genetically normal.
