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One more step in assisted chlidbirth

May 12, 2004

The Assisted Childbirth Units at Quir'³n San Sebasti'¡n and Quir'³n Bilbao have achieved the first pregnancy in the Basque Autonomous Community and Navarre by means of the technique known as Preimplantational Genetic Diagnostic (PGD), the novelty of which lies in optimum selection of embryons by means of their genetic study prior to their implantation in the uterus.

This technique provides the possibility of selecting optimum embryons and thus prevent genetically-transmitted illnesses such as those related to the X-chromosome. It is also suitable for couples with a history of miscarriages (more than 3) or repeated failures in Assisted Birth Techniques.

The Assisted Childbirth Units at Quir'³n San Sebasti'¡n and Quir'³n Bilbao have succeeded in that a patient with a history of miscarriage has had a successful pregnancy by means of a novel technique known as Genetic Preimplantational Diagnosis (GPD). With this new achievement Quir'³n has advanced one step further in Assisted Childbirth, the treatment for which the Bilbao and San Sebastian centres are pioneers. This is the very first time that a pregnancy has been achieved using this technique in the Basque Country/Navarre.

According to the Quir'³n authorities, the GPD means a "'qualitative leap" for Assisted Childbirth laboratories and their patients. "The joint use of Assisted Childbirth and Genetics above all enables the selection of embryons free of determined illnesses (hereditary and/or congenital) before their transfer. This is possible thanks to genetic data analysis of one of their cells (known as blastomeres)".


Along these lines, it has been pointed out that "to date Assisted Childbirth techniques have not involved the manipulation of the embryon, with the application of Genetics to these techniques, a highly significant change is about to take place, because it is now possible to operate on an embryon before its implantation in the uterus of the mother".

The Technique

According to the medical researchers, the new technique (GPD) involves the prior formation of the embryon at the Assisted Chldbirth Laboratory. In order to achieve this, the couple has to undergo an Intracitoplasmatic Sperm Injection (ICSI) involving the introduction of a previously-selected single spermatozoid into each ovum by means of a high-resolution microscope and micromanipulators.

Subsequently, when the embryon is found in the cellular stage of 6-8 cells, a cell or blastomere is extracted from each embryon for its corresponding genetic study, the embryon being kept in the laboratory. Once checked for genetic normality in function of the illness in question, the embryon(s) is/are transferred to the patient "in order to achieve the gestation of a baby free from this ailment".

Indications

Application of Genetic Preimplantational Diagnosis is advised in those cases where certain specific conditions are indicated: selection of sex for ailments linked to the X chromosome (such as haemophilia, Duchene....); alterations of the sex chromosomes (such as Turner's or Klinefelter syndromes); or certain monogenic mutations that give rise to relatively frequent and serious family-transmitted , such as Huntington's Corea.

Apart from these indications, the application of GPD is expanding, being also used in those cases of repeated miscarriage (3 or more), in repeated failure of Assisted Childbirth Techniques and in elderly women undergoing Assisted Childbirth treatment in which the number of genetically normal embryons are usually less.

The percentage success rate for the technique is 25% of the total number of cases, a high number taking into account the concrete nature of the situations that it is applied and the complexity of the whole laboratory process. Likewise, using this technique, it is possible to know the sex of the foetus, although current legislation does not allow selection according to sex of the baby but in function of specific illnesses.

The Assisted Childbirth Units at Quir'³n San Sebasti'¡n and Bilbao have a great variety of patients from the Basque Country Autonomous Community and Navarre and from the south of France, which have found a reference for Assisted Childbirth at these Units. Moreover, the Assisted Childbirth Unit at San Sebasti'¡n has a joint agreement with the Navarre Health Service (Osasunbidea), providing cover to the population of Navarre in this ambit to the great satisfaction of both parties for some years now.

Elhuyar Fundazioa