In Vitro Fertilization and Prenatal Diagnosis DENIZ ESER MERVE GÜLMEZ SELEN İREM GORALI

Outline In Vitro Fertilization Definition Procedure Complications Various Applications Prenatal Diagnosis Techniques Invasive Fetal Screening Fetoscopy Embryoscopy Chromosomal and Molecular Analysis Using Fetal Tissue Samples Amniocentesis Chorionic Villus Sampling Cordocentesis Organ Biopsy Non-invasive Fetal Screening Fetal Ultrasonography Fetal Echocardiography Magnetic Resonance Imaging (MRI) Biochemical Screening Tests Double Screening Triple Screening Quadruple Screening Analysis of Fetal Cells in Maternal Blood Sample

What is In Vitro Fertilization (IVF)? Type of assisted reproductive technology. A procedure which involves the fertilization of egg and sperm in the laboratory. Mainly used to treat infertility and for gestational surrogacy. First successful IVF was performed in 1978 by Robert G. Edwards and his team.

Applications of IVF Treatment for infertility Embryonic stem cell collection Cryopreservation Prenatal diagnosis techniques

Treatment for Infertility Help people with infertility deficiencies such as Endometriosis Damaged or blocked fallopian tube Immobile or fragile sperms Ovulation disorders People who had cancer treatments in the past The most powerful and successful technique for having a baby. Babies born in this way are referred as “test tube babies”.

Step 1 – Stimulation of Ovaries Also referred as “super ovulation”. Drugs including hormones like follicle-stimulating hormone (FSH) are given to the egg donor to make the ovaries produce more eggs than usual. The egg production in the ovaries is monitored using a vaginal ultrasound scan.

Step 2 – Egg Retrieval Performed under general anesthesia. An ultrasound probe is used to detect the eggs in the ovaries. A thin needle connected to a suction pump is inserted into the ovaries using the ultrasound as a guide. The eggs are sucked out with the needle from the ovaries and put in a collection tube.

Step 3 – Sperm Retrieval and Fertilization Sperm is taken from the male or a sperm bank. The best ones are chosen for fertilization. There are two ways for fertilization to occur: The egg and sperm is put in a culture dish and wait for the fertilization to occur by itself, called as Natural IVF. Only one sperm is injected inside the egg by a process called intracytoplasmic sperm injection (ICSI).

Step 4 – Embryo Development The fertilized egg is provided with amino acids to support the embryo growth and put in an incubator. The growing embryo Is observed carefully for 5 to 6 days after fertilization. The embryo should reach two- to four-cell stage on day 2 and six- to eight-cell stage on day 3. When the embryo is at blastocyst stage, it is ready for transfer into the uterus. Not all fertilized eggs can form embryos.

Step 5 – Embryo Transfer Before the transfer, genetic tests can be performed. More than one embryo is transferred if the ideal one can not be chosen. The embryo is placed into the womb using a thin tube. Two weeks after the transfer, the mother is asked to give a blood test to check if the transfer was successful. Miscarriages may occur if the womb is not suitable for the baby.

Possible Complications Multiple pregnancy Risk of ectopic pregnancy Side effects of ovary stimulating drugs Risk of developing ovarian cancer Premature delivery Birth defects

Human Embryonic Stem Cell Collection Collected from the inner cell mass of the blastocysts. Leftover embryos are used for collection. ESCs can differentiate into all cell types. A hope to treat many diseases which their treatments are not available. Controversial because once the cells are collected, the fertilized egg can not become an embryo. Banned in many countries.

Cryopreservation Preserving biological structures in very low temperature, usually at -196°C in liquid nitrogen. At low temperature, all biological activity stops including reactions that lead to cell death. Oocytes, sperms and embryos can be preserved for several years. Advantage for women who want to delay childbearing. Future application: Freezing whole organisms

What is Prenatal Diagnosis? Diagnosis of birth defects and genetic diseases in fetus by using different techniques prenatally Observation can be made by some techniques like ultrasounds, blood or tissue sample examination Includes screening testing and diagnosting testing

Which Diseases Can Be Detected? Cystic Fibrosis Duchenne Muscular Dystrophy Hemophilia A Polycystic Kidmey Disease Sickle Cell Disease Thalasemia Trisomy 21 Trisomy 18 Trisomy 13 Fragile X Syndrome Tay-Sachs Disease

PRENATAL DIAGNOSIS TECHNIQUES INVASIVE TESTS NON-INVASIVE TESTS Fetal screening Fetal Ultrasonography Fetal Echocardiography Magnetic Resonance Imaging (MRI) Biochemical screening tests Double screening Triple screening Quadruple screening Analysis of fetal cells in maternal blood sample Fetal screening Fetoscopy Embryoscopy Chromosomal and molecular analysis using fetal tissue samples Amniocentesis Chorionic villus sampling Cordocentesis Organ biopsy

INVASIVE TESTS Defined as a technique that involves the physically insertion of probes or needles into the fetal space Prefomed at different gestational weeks Provide precise results of diseases Increase the risk of pregnancy loss performed at specific times throughout the gestational period

References Yüreğir, Ö. et al Prenatal (Doğum Öncesi) Tanı