Gender Selection in Cyprus

What Is Gender Selection?

Gender selection means determining the sex of a baby before pregnancy begins. Today this is done with genetic tests performed on embryos created during IVF. Genetic testing of embryos has become widespread since the 2000s.

The subject has long been debated on ethical grounds, and its legal status differs from country to country. In many countries, sex determination is limited to medical needs.

What Is Family Balancing?

"Family balancing" is a term describing the wish to have a child of the other sex when a family has children of only one sex. It is also called sex selection or sex determination.

How Is a Baby's Sex Determined?

The sex of an embryo is determined by the chromosome carried by the sperm. A woman's egg always carries an X chromosome; sperm can carry either an X or a Y chromosome.

• Y chromosome from the sperm → baby boy (XY)
• X chromosome from the sperm → baby girl (XX)

Naturally, this probability is about 50% in each pregnancy.

How Is an Embryo's Sex Identified with PGT?

An embryo's sex can only be reliably identified through genetic testing combined with IVF treatment. The process generally consists of the following stages:

1. Initial assessment

The intended mother has an ultrasound assessment of the uterus and ovaries, an HSG (uterine X-ray) if necessary, and blood tests (blood count, clotting, thyroid and infectious disease tests). A semen analysis is performed for the intended father. If there is a genetic disease in the family, additional tests are planned; some genetic test results can take 30-45 days.

2. Ovarian stimulation

Medication starts on day 2 or 3 of the cycle. The injections are given under the skin, usually at home, and the follicles are monitored by ultrasound several times. When the follicles reach about 20 mm, a trigger injection (hCG) is given.

3. Egg collection and microinjection (ICSI)

Egg collection is performed under anaesthesia 35-36 hours after the trigger injection and takes about 15 minutes. Mature (MII) eggs are fertilised the same day by microinjection.

4. Embryo biopsy and genetic testing

When the embryos reach day 5 (blastocyst stage), a few cells are taken from the outer layer (trophectoderm), which will later form the placenta. This does not harm the inner cell mass that will form the baby. Day 5 biopsy is considered more reliable than day 3 biopsy.

5. Embryo transfer and freezing

Healthy embryos are selected according to the genetic results. One or two embryos are transferred to avoid multiple pregnancy; the remaining healthy embryos can be frozen for later use.

Sex Determination for Medical Reasons

Some hereditary diseases are passed on via the X chromosome and appear mostly in boys. Haemophilia is one example. In families at risk of such sex-linked diseases, genetic testing of embryos can increase the chance of having a healthy baby.

PGT may also be considered in the following situations:

• A known genetic disease in one or both partners (for example thalassaemia)
• Recurrent pregnancy loss
• Repeated IVF failure
• Identifying embryos with chromosomal abnormalities at advanced maternal age

Genetic Testing Methods for Embryos

• FISH (fluorescence in situ hybridisation): The cell nucleus is labelled with special dyes and examined under a fluorescence microscope. Usually chromosomes X, Y, 13, 18 and 21 are examined; it requires experience.
• PCR (polymerase chain reaction): Used to screen for single-gene diseases such as thalassaemia and haemophilia. The mutation in the intended parents must be known in advance.
• Array-CGH: Examines all 24 chromosomes to detect chromosome number abnormalities.
• NGS (next-generation sequencing): One of the most advanced genetic diagnostic methods used today; it is used to diagnose hereditary diseases in embryos.

Methods with a Weak Scientific Basis

Methods other than genetic testing of the embryo have low reliability:

• Sperm sorting (MicroSort, Ericsson albumin method): Attempts to separate sperm carrying X and Y chromosomes. The margin of error is high and the methods are not sufficiently proven scientifically.
• Shettles (timing) method: Based on timing intercourse relative to ovulation; its underlying assumptions have not been proven.
• Chinese calendar: Claims a relationship between the mother's age and the month of conception. It has no scientific basis and does not change the 50% chance.

Diagnosis After Pregnancy Begins: CVS

CVS (chorionic villus sampling) involves taking a small piece of the tissue that will later form the placenta, at weeks 9-11 of pregnancy. It was developed for the early diagnosis of Down syndrome and some hereditary diseases.

Factors Affecting Success in the PGT Process

• Ovarian reserve and age: Antral follicle count is an important method for assessing ovarian reserve. A healthy result usually requires 8-10 or more mature eggs.
• Advanced age: For women aged 40 and over with only 1-2 eggs, achieving pregnancy is quite difficult, because a significant proportion of embryos at this age may be genetically abnormal.
• Very low AMH: In women with an AMH below 0.5, the chance of pregnancy with their own eggs is low; egg donation may be considered.
• Tubes and endometrium: Fluid in the tubes (hydrosalpinx), or polyps, fibroids or adhesions in the uterus should be assessed before treatment.

Risks

The risk of PGT for the woman is similar to that of standard IVF treatment. The most important risk is OHSS (ovarian hyperstimulation syndrome), caused by an excessive ovarian response to medication. The risk of OHSS should be identified in advance and precautions taken; when many follicles develop, ovulation can be triggered with a special method and embryos can be frozen and transferred in a later cycle. There are also risks related to anaesthesia and egg collection. Chronic diseases and excess weight can also increase the risks.

Legal Framework in the TRNC

In the TRNC, determining the sex of an embryo is considered, in line with the legislation, where there is a medical need. Talking to a specialist doctor is the best step to find out which options are right for you.

Frequently Asked Questions About Gender Selection

What is gender selection?

It is the identification of the sex of embryos created during IVF treatment, before transfer, using preimplantation genetic testing (PGT).

In which cases is sex determination performed in the TRNC?

It is considered where there is a medical need, for example a risk of sex-linked hereditary disease.

What determines a baby's sex?

The chromosome carried by the sperm. The egg always carries an X chromosome; if the sperm carries a Y, the baby is a boy (XY), and if it carries an X, the baby is a girl (XX).

How accurately can PGT determine sex?

Genetic testing of the embryo can determine sex with over 99% accuracy.

In which medical situations is sex determination relevant?

It may be relevant for families at risk of sex-linked hereditary diseases passed on via the X chromosome, such as haemophilia.

What is family balancing?

It is a term describing the wish to have a child of the other sex when a family has children of only one sex.

Do the Shettles method or the Chinese calendar work?

No. These methods have no scientific basis and do not change the 50% chance.

Are sperm sorting methods reliable?

Sperm sorting techniques such as MicroSort and the albumin method have a high margin of error and are not sufficiently proven scientifically.

How many eggs are needed for PGT?

A healthy result usually requires 8-10 or more mature eggs, because some embryos may be genetically abnormal, immature or poorly fertilised.

Does embryo biopsy harm the baby?

In a day 5 biopsy, cells are taken from the outer layer (trophectoderm) that will form the placenta; the inner cell mass that will form the baby is not harmed.