Infertility

It is exceedingly difficult to predict what will be good for children who have yet to be conceived, and nigh on impossible to collect the evidence that is needed to make a balanced decision.

Many GPs quite properly refuse to co-operate, citing patient confidentiality.

The police can be consulted, but their advice can leave doctors with a judgment of Solomon.

Should a convicted thief be approved for treatment?

What about a reformed drug addict or a 40-year-old who had a Saturday night brawl in his youth?

It all comes down to a subjective hunch.

The British Fertility Society estimates that this elaborate, costly and time-consuming vetting prevents the birth of about ten children each year.

It is rather extreme to protect a child’s welfare by stopping it from being born, and also quite unnecessary.

Most rejected patients have a medical issue such as psychiatric illness or drug abuse, and would in any case be turned down for treatment in accordance with doctors’ professional ethics.

Social services can easily be alerted to the very few children that are thought to be at risk.

The 1990 legislation that imposes this well-meaning but misguided burden is under review.

The Royal College of Physicians, the Royal College of Obstetricians and Gynaecologists, and the Commons Science and Technology Committee have all called for its end.

So sensible a move, though, ...

Without it, they say, an embryo cannot survive in uterine tissue or attach to a mother's blood supply.

Other genes also play roles, but C/EBPb is critical for implantation of an embryo, said Milan K.

Bagchi.

C/EBPb is scientifically known as CCAAT/Enhancer Binding Protein beta.

It is regulated by the hormones estrogen and progesterone.

In normal conditions, the protein, driven mostly by progesterone, is expressed rapidly and in large quantities during the critical four-day implantation period in mice, Bagchi said.

During this period, an embryo attaches to the wall of the uterus, advances into it and eventually attaches to the blood supply and forms the placenta.

For a successful pregnancy to occur, stromal cells of the uterus must be transformed into decidual cells, which secrete nutrients that allow the embryo to survive until it plugs into the blood supply.

C/EBPb is necessary for decidualization, the researchers discovered.

" This protein in the mouse is also in humans," Bagchi said.

" We believe it plays a critical role in human pregnancy.

It is expressed in the human endometrium at a time that coincides ...