In Vitro Fertilisation

Introduction

The term Assisted Reproduction includes a wide range of methods that aim to help subfertile couples to have their own child. From the birth of Louise Brown – the first child conceived with Assisted Reproduction in Bourn Hall of England – up to this moment thousands of couples have succeeded. This method gives solution to subfertility issues both for women (e.g. blocked tubes) and for men (e.g. oligospermia). Success rates per effort cycle depend on many factors such as woman’s age and the cause of subfertility. Usually the accumulative success rate may reach 60-65% after 34 efforts.

Preparation

During this course of the treatment medications are administered aiming at the collection of more oocytes than the one produced by the woman in her regular cycle. Following up is performed with ultrasonography and blood test usually every 2-3 days; the doses of the medication are customised according to individual needs. With transvaginal ultrasound we can observe the size increase of the ovarian follicles that contain oocytes. Our goal is to achieve the development of many ovarian follicles of a size greater than 18 mm; in that case we consider that oocytes are mature and ready for collection. In parallel we measure the increase in the endometrium thickness. Endometrium covers the endometrial cavity where embryos will be transferred at a later stage. Blood test helps us control estradiol produced by the ovarian follicles and it is also an index of the oocytes maturation. When we achieve the satisfactory number of ovarian follicles greater than 18mm, satisfactory thickness of endometrium and good level of estradiol, we achieve the final maturation of the oocytes by administering β – chorionic gonadotropin and thirty four to thirty eight hours later, oocytes are collected.

Oocytes collection

Oocytes collection takes about 15 minutes and it is realised under light sedation. With the use of a needle the gynaecologist transvaginally takes the ovarian follicular fluid from the ovaries under ultrasound monitoring. The ovarian follicular fluid is handed to the embryologist to find the oocytes with the use of the microscope.

Fertilisation

After being collected the oocytes are placed into a nutritious environment. Subsequently fertilisation is performed with the spouse sperm that has been already processed with special methods. Next morning, embryologist checks the fertilisation of the oocytes and during the following days their progress is monitored.

Transfer of the embryos

The transfer of the embryo is a simple process that does not require narcosis. It is carried out 2-3 days after the collection of oocytes. In some cases, this can happen at a stage of blastocyst, i.e. 6-7 days after the collection of oocytes. Embryos are placed in the endometrial cavity with the help of a thin plastic catheter passing through the cervix. The number of the embryos that shall be transferred is decided with the couple and the doctor. If there are big numbers of embryos, they may be frozen and used in a future effort.

Pregnancy Test

The pregnancy test is done 12 days after the transfer of the embryos. It includes blood test for the definition of chorionic gonadotropin <HCG>. If the test is positive, two weeks later, the first ultrasound check-up takes place; during this check-up, the intrauterine sac of the embryos within the uterine starts to appear. If the test result is negative, pharmaceutical treatment is stopped and an effort is made to analyse the possible reasons of the failure and to take further decision.

SUBFERTILITY THERAPIES – LABORATORY METHODS

Ovulation induction

It is recommended to women with ovulation induction disorders, i.e. those woman with irregular or no menstruation. Our goal is to correct this ovulation disorder by administering medications either orally (clomiphene) or by injections (FSH). We watch the augmentation of ovarian follicles with ultrasound and when one of them becomes greater than 17mm we can schedule contact with the spouse. Success rates are 6 – 10% per observation cycle. Multiple pregnancy rates: 10-20%.

Ovulation Induction and Intrauterine Insemination (IUI)

  • It is recommended to women whose previous therapy has failed and also in cases of unexplained subfertility, cervical factor and mild problems of male factor (mild spermogram disorders).
  • Pharmaceutical treatment and observation are the same as in the previous method, only instead of contact, the husband gives his sperm to the laboratory, where after processing it with special method, it is placed transvaginally in the uterus. Success rate is 8-18%. Multiple pregnancy rate: 10-25%.

IN VITRO FERTILISATION (IVF) - METHODS

A. Classic In Vitro Fertilisation (IVF)

Oocytes and sperms are placed together in special nutritional environment and left in the steriliser for the fertilisation be carried out. Only one sperm will achieve to infiltrate to the oocyte and start the process of the embryo growth.

B. Microfertilisation (ICSI)

According to this method only one sperm is introduced in the oocyte using a special needle. It is recommended in cases of serious spermogram disorders or in cases of azoospermia (in these cases we collect the sperm directly from the testicular tissue). Moreover, it is suggested in cases when the previous efforts of oocytes fertilisation with classic method have failed.

C. Assisted Hatching

The given procedure is advised after the classic IVF or the microfertilisation before the transfer of the embryos. With this process the zone that surrounds the embryo is lightened to make its implantation easier. It is recommended in cases that the embryologist detects that the embryo zone is strong or thick. Moreover, it may be recommended to older women or after repetitive failure of in vitro fertilisation efforts.

D. Blastocyst Culture

Blastocyst is the stage which the embryo achieves 5-6 days after oocytes collection. In classic IVF and microfertilisation, embryos are transferred to the endometrial cavity 2-3 days after oocytes collection. The advantage of the embryo transfer at the stage of blastocyst, i.e. 5-6 days after oocytes collection is that it allows the selection of the highest quality embryos. Its disadvantage is that there is a possibility that none of the embryos will survive up to this stage and afterwards the transfer of the embryos is impossible.

E. Embryo and testicular tissue cryopreservation.

Cryopreservation is performed in special liquid nitrogen vessels at a temperature of 196oC. When there is great number of fertilised embryos or the conditions for the implantation are not advisable. Embryos can be preserved in the freezer and transferred to the uterus in a proper time in the future. There is also the possibility to apply cryopreservation to sperm and testicular tissue. The cryopreservation of ovarian tissue and oocytes is still at an experimental stage.

F. Preimplanation Genetic Diagnosis (PGD)

With this term we refer to the genetic diseases detection procedure in the genetic material of embryos and then the selection and the transfer of healthy embryos acquired by IVF among other methods. At this time in Greece there is the possibility to diagnose cystic fibrosis and B-Thalassaemia. You can find more information at that page.

G. Testicle biopsy (TESE)

It is recommended to patients with serious oligospermia or azoospermia. If viable sperms are detected in the biopsy material, their use for microfertilisation (ICSI) may follow.

PREIMPLANTATION GENETIC DIAGNOSIS (PGD)

With the term Preimplantation Genetic Diagnosis (PGD) we refer to the genetic diseases detection procedure in the subsequent selection and transfer of healthy embryos acquired by IVF.

The goal of the PGD is to minimise the risk for those couples who are at risk to transfer to their children hereditary diseases.

This technique is not relatively new. The first children that were subjected to biopsy at their foetal life to determine their sex and to avoid therefore the transmission of sex-linked genetic diseases were born in Hammersmith in 1989. Since then up to nowadays, scientists and clinical doctors have expanded the number of the diseases that can be diagnosed with this method and more than 200 children have been born healthy and free from some genetic disease.
Our team in collaboration with the Paediatrics Clinic of the Agia Sofia Children University Hospital offers an innovative program of preimplantation genetic diagnosis for Cystic Fibrosis and type B Thalassaemia.

Already in 1998, the first child subjected to preimplantation genetic diagnosis at an embryonic stage for type B thalassaemia was born in Greece.

  • It is recommended in cases in which the previous therapies have failed, or directly to women with blocked tubes or in cases with serious male factor problem (severe spermogram disorders).
  • Success rate in IVF depends on the woman’s age, the ability to produce oocytes in the ovaries, sperm's quality, the subfertility aetiology, the duration of subfertility, previous pregnancies and the consequence of toxic factors (e.g. smoking, alcohol).
  • The success is the interrelation of all the aforementioned factors and it has a great degree of probability that after 3-4 efforts it may reach 60-65%.
  • Multiple pregnancy rate is 25%.