The 'entrance exam' that is key to a successful pregnancy

This is an expression of trypsinogen activating enterokinase (green) in an implantation competent hatching human blastocyst on day six of development. Credit: Scarlet Salter & Anatoly Shmygol

Researchers have discovered how an 'entrance exam' set by the womb determines if the implantation of an embryo is successful; potentially a milestone for advances in pregnancy treatments.

The new study, led by Warwick Medical School and University Hospitals Coventry and Warwickshire NHS Trust, sheds light on how the lining of the womb analyses individual embryos and thus decides whether or not to support further development.

Before implantation, human embryos are genetically very diverse. Some embryos will contain no normal cells at all while others contain a mixture of normal and . Hence, no two human embryos are the same at this early stage of development.

The article, published today in Scientific Reports, shows that high quality secrete a chemical, trypsin, which renders the lining of the womb supportive of implantation. This chemical signal is deregulated in low quality embryos and causes an alarm response in the womb, which leads to either rescue or elimination of the embryo.

Professor Jan Brosens explained, "This is important, because if the lining of the womb is not well prepared for pregnancy you may find that abnormal embryos will implant or high quality will not be supported. Both scenarios can lead to pregnancy loss or even late , such as foetal growth restriction or preterm birth."

"Speaking in terms of an entrance exam; a poorly prepared womb will either make the test too rigorous or too lax – decreasing the chances of a successful pregnancy."

Approximately 15% of clinically recognised pregnancies miscarry, attributed to the invasive nature of the human embryo and prevalence of chromosomal errors.

Professor Siobhan Quenby said, "This work adds to a growing body of evidence that assessment and optimisation of the lining of the womb may be the only effective way in preventing infertility and complications."

The team, who were supported by researchers at the Universities of Southampton and Utrecht, believe that the news could prove vital to improving the options available to couples going through IVF, as implant failure remains the primary cause of unsuccessful treatment.

Professor Brosens added, "What we're looking at now is how to alter the lining of the so it can set this entrance exam at the right level and prevent implantation failure and miscarriages."

More information: Paper: DOI: 10.1038/srep03894

Related Stories

New tool for selecting embryos in fertility treatments

date Jan 21, 2013

A team of researchers from the Universitat Politècnica de València and specialists from the Hospital Universitari i Politècnic La Fe have developed a new tool, a mathematical model to be exact, to help ...

Recommended for you

Researchers find key mechanism that causes neuropathic pain

date 31 minutes ago

Scientists at the University of California, Davis, have identified a key mechanism in neuropathic pain. The discovery could eventually benefit millions of patients with chronic pain from trauma, diabetes, shingles, multiple ...

Deep sea light shines on drug delivery potential

date 42 minutes ago

A naturally occurring bioluminescent protein found in deep sea shrimp—which helps the crustacean spit a glowing cloud at predators—has been touted as a game-changer in terms of monitoring the way drugs ...

Researchers learn to measure aging process in young adults

date 18 hours ago

Looking around at a 20th high school reunion, you might notice something puzzling about your classmates. Although they were all born within months of each other, these 38-year-olds appear to be aging at different ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.