Scientists report preliminary success in growing fetus eggs in lab

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Scientists Report Trying to Grow Fetus Eggs in Lab

http://ap.tbo.com/ap/breaking/MGAYATCTKHD.html

By Emma Ross The Associated Press

Published: Jun 30, 2003

 

MADRID, Spain (AP) - Israeli scientists reported Monday that they have had

some preliminary success in growing egg-producing follicles taken from

aborted human fetuses.

Dr. Tal Biron-Shental, who presented the research at the annual conference

of the European Society of Human Reproduction and Embryology, said the

technique could one day be used to provide eggs for fertility treatment.

 

However, some experts were skeptical that aborted fetuses could ever be a

practical source of human eggs, and others said they believed that even if

it were technically possible, ethical concerns make it a bad idea.

 

The signals that trigger the growth of follicles in which eggs mature are

unknown. The experiment, performed by Biron-Shental's group at Rabin Medical

Center near Tel Aviv in Israel and scientists at Utrecht University in the

Netherlands, was designed to study the development and survival of fetal

ovarian tissue.

 

Seven fetuses were used in the study, aged between 22 and 33 weeks of

gestation when they were aborted.

 

The researchers removed ovary samples and froze them immediately. They later

thawed them and cut them into thin slices before placing them in a dish of

growth-enhancing chemicals and calf blood for four weeks.

 

The scientists concluded, based on an elevation of estradiol - a form of

estrogen - in the fourth week, that some of the follicles had progressed

from the resting state to the growing stage.

 

" It's a technique that is far from being ready for use. You have still to go

many months of culture from that point, " said Dr. Johan Smitz, a professor

of endocrine physiology at the Free University of Brussels in Belgium who

was not connected with the research.

 

Smitz said he sees the technique solely as a tool for studying how to get

the growth chemical concoction correct for fertility treatments,

particularly in cases where doctors want to freeze the ovarian tissue of a

woman before cancer treatment and later restore her fertility.

 

Experts believe the reason fertility treatment is not more successful is

because the chemicals eggs and embryos are cultured in before being

implanted in the womb are not optimum.

 

Fetuses provide enough follicles to allow scientists to test various

different combinations of chemicals in order to discover the best ones,

Smitz said.

 

The main problem with using the technique as a source of eggs for fertility

treatments is that the fetus cannot consent to the use of her eggs, Smitz

said.

 

Roger Gosden, an expert on ovarian tissue and scientific director of the

Jones Institute for Reproductive Medicine in Norfolk, Va., said aborted

fetuses would be an impractical source of eggs for fertility treatment.

 

The fetuses in the study were aborted in the second and third trimester,

which is rare. Ovarian tissue taken from fetuses aborted in the first

trimester would be too primitive and immature, he said.

 

" I don't think we need it because we can obtain biopsies of ovaries from

women. From that material, you can get the proper consent, you can get

material which perhaps does not have as many eggs as fetal tissue, but it

has much more potential, " said Gosden, who was not connected with the

research.

 

" The other question is that of those eggs, very few of them make it to

puberty, " he said. " We don't know whether they disappear by a selective

process of elimination of ones that are abnormal. We might be increasing the

risk of abnormalities by using eggs that were destined to be eliminated. "

 

In any case, the prospect of mining aborted fetuses for eggs should be put

to wide public debate before it becomes a reality, said Francoise Shenfield,

coordinator for the ethics task force of the European Society of Human

Reproduction and Embryology.

 

" It cannot be the scientists saying, 'You are going to waste a fantastic

source.' If the public shares this unease, I don't think we can let it

happen, or maybe we can only let it happen in many years after we have all

dissected the issue, " said Shenfield, a lecturer in fertility at University

College in London.

 

AP-ES-06-30-03 1433EDT

 

 

 

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