Preimplantation Genetic Diagnosis (PGD)

Pre-implantation genetic diagnosis (PGD) Abroad

Preimplantation genetic diagnosis (PGD) is a technique used to detect unhealthy embryos before transferring them to the patient's uterus during the IVF procedure. The main purpose of PGD is to identify genetic defects in embryos created by in vitro fertilization and prevent several disorders or diseases from being passed on the child. More specifically, the PGD test is used prior to implantation in order to help identify particular problems of the embryos' genes or chromosomes. During the early stages of development, the embryo cells are analyzed for genetic abnormalities. By detecting genetic problems before implanting the embryo, defects can be eliminated, allowing only healthy embryos to be implanted during fertilization.

PGD significantly reduces the chances that the baby will be affected by genetic or chromosomal abnormalities which can cause congenital malformations. Tay-Sachs disease, cystic fibrosis, muscular dystrophy, or spinal muscular atrophy are some of the genetic diseases that can be tested and identified by this technique. A high risk for serious diseases such as aneuploidy (chromosomal abnormalities) can also be detected by the PGS screening. There are several types of aneuploidies - the most commonly tested are the Down syndrome, trisomy 18 or 13, and the Turner syndrome.

PGD can also help select embryos of a certain sex, if the future parents have a preference or if they don't want to have a child of a particular sex, due to increased threats to pass a genetic disease which has a high risk of being developed by that certain sex.

Types of Pre-implantation genetic diagnosis (PGD) Tests

Once the genetic material has been obtained from the embryo there are several possible tests that can be performed allowing for the identification of numerous different types of problems.

• PGD for genetic mutations
• PGD for structural chromosome abnormalities
• PGD for hereditary cancer
• PGD for determination of chromosome number
• PGD for tissue typing

Infertility Causes

The causes of infertility can be varied, based on independent or associated diseases, of one or both partners.

Infertility causes in women:

• Pelvic infections that interfere with the genitals - the most common secondary consequences are damaged or blocked the fallopian tubes (constriction)
• Endometriosis, a condition represented by the presence of uterine tissue to another level (fallopian tube for example) - a situation more common in women over 30 years old who are nulliparous (who have had no pregnancy)
• Ovarian diseases (ovarian cysts, polycystic ovarian syndrome, ovarian dystrophy, ovarian cancers) leading to the impossibility of forming a normal, healthy egg that can be fertilized;
• Congenital anomalies of the sexual organs (e.g. T-shaped uterus)
• Diseases of the fallopian tube, annexitis (an infection that reaches the ovary), narrow fallopian tubes that don't let the egg reach the uterus etc.
• Disorders of the uterus: birth defects, infections, diseases of the cervix which don't allow the sperm to penetrate or migrate, uterine fibroid, etc.
• Sexual dysfunctions: dyspareunia, vaginismus, vaginal trichomoniasis etc.
• Disorders of the menstrual cycle: amenorrhea (lack of menstruation) or irregular menstruation
• Central nervous system's organic lesions
• Hormonal disorders such as hyperprolactinemia
• Body weight - obesity seems to interfere with reproductive function
• Some chronic diseases

Infertility causes in men:

• Some sexual dysfunctions (impotence, premature or delayed ejaculation)
• Dysfunctions in the sperm production (quantity, mobility, sperm structure, maturation, etc.)
• Varicose veins in the scrotum
• Reproductive organs infections
• Hormonal dysfunctions caused by mumps or drug use
• Certain chronic diseases that cause reproductive function disturbances: tuberculosis, diabetes, etc.
• Testicular pathologies, testicular inflammation (orchitis), cysts, varicocele
• Excessive smoking: smoking more than two packs a day lowers sperm counts and motility
• Toxic products: lead, boric acid, ultrasounds

Infertility causes in men and women:

• Gonorrhea, chlamydiosis and other sexually transmitted diseases (STDs)
• Any drug: methadone, heroin etc.
• Certain drugs which either interfere with the hormonal metabolism or directly harm the reproduction function

Symptoms of Infertility

The main symptom or sign of infertility is the inability to get pregnant, despite having unprotected sexual intercourse regularly (trying to conceive) for over six months. Fertility problems can occur to one of the partners or to both of them.

Infertility Symptoms in Women

• Changes in the menstrual cycle and ovulation: abnormal, irregular, absent, or very painful periods
• Skin changes (more acne, etc.)
• Sex drive changes
• Dark hair growth on the chest, lips, and chin
• Thinning hair
• Hair loss
• Weight gain
• Milky white discharge from nipples (unrelated to breastfeeding)
• Pain during sexual intercourse

Infertility Symptoms in Men

• Changes in hair growth
• Sexual drive changes
• Small, firm testicles
• Pain, lump, or swelling in the testicles
• Erections and ejaculation issues

How Pre-implantation genetic diagnosis (PGD) Works

PGD tests can be done only when the patients choose to undergo the IVF procedure. The testing is performed before the implantation of the embryo in the uterus, during the in vitro fertilization process.

The PGD screening involves the following steps:

• The patient will take the fertility medication recommended by the doctor in order to induce ovulation.
• Once the patient has ovulated, a part of the eggs will be retrieved for fertilization.
• The eggs will be fertilized with the sperm in a special laboratory.
• After about 3 days, or once the embryos have developed to the 6-12 cells stage, the doctor can begin performing the pre-implantation genetic diagnosis.
• The doctor will make a small hole in the outer membrane of the embryo and a cell will be extracted - this will not affect the embryo development.
• The DNA will be extracted from the cell's nucleus; it will then be analyzed using a procedure called polymerase chain reaction (PCR) to detect any genetic abnormalities.
• Any unhealthy embryos will be removed, while the remaining healthy embryos will be implanted in the patient's uterus.

Benefits of Pre-implantation genetic diagnosis (PGD)

There are several advantages of the pre-implantation genetic diagnosis (PGD).

• PGD tests can help future parents determine the health status of the embryo before being implanted during the fertility treatment (IVF).
• PGD prevents unhealthy embryos from being transferred to the patient's uterus.
• Pre-implantation genetic diagnosis can help identify numerous genetic diseases and chromosomal abnormalities.
• PGD can help patients increase their chances of carrying to term a healthy pregnancy.
• If patients already have a child diagnosed with a genetic disease, PGD screening can prevent passing on the genetic defect to other children.
• Thanks to its ability to identify unhealthy embryos, the procedure can help to limit the number of failed implantations (IVF) or miscarriages.
• PGS can decrease the patients' chances of having twins and multiples.
• Pre-implantation genetic diagnosis can usually be performed relatively quickly in order to ensure the timely implantation of a healthy embryo.

Cost of Pre-implantation genetic diagnosis (PGD)

An IVF with Pre-implantation genetic diagnosis (PGD) procedure in the U.S. can cost an average of $15,000 per attempt. This price usually doesn't include the fertility medications. Also, most of the times, these treatments are not covered by health insurances. The prices for an IVF with Pre-implantation genetic diagnosis (PGD) package in countries such as Turkey, Mexico, or Thailand, often costs approximately 50 percent less than in the U.S., even when adding the fertility medications’ price.

Finding Doctors for Pre-implantation genetic diagnosis (PGD)

The pre-implantation genetic diagnosis (PGD) technique is a fairly complex procedure that requires a highly skilled, board-certified reproductive endocrinology specialist. The doctors specialized in performing this technique have completed medical studies, followed by four years of residency training in obstetrics and gynecology, and two to three years of training in fertility within an approved program that results in board certification. Also, patients should look for a doctor who is a member of a fertility and/or endocrinology association.

If you want to find out more about the Pre-implantation genetic diagnosis (PGD) procedure, please contact us!