Science Current Events | Science News | Brightsurf.com
 

Researchers pinpoint possible new cause for unexplained miscarriages

November 01, 2011
Researchers at St. Michael's Hospital have identified a potential new cause for unexplained miscarriages in mice.

They also identified two possible treatments to prevent these miscarriages and their work has broader implications for the development of new drugs to treat heart attacks and strokes.

The researchers, led by Dr. Heyu Ni, found that the same kind of blood-clotting in coronary arteries or blood vessels in the brain that causes heart attacks and strokes also happens in the placenta. The massive clotting can destroy the placenta, block blood flow to the fetus and cause miscarriages.

This condition is known as fetal and neonatal immune thrombocytopenia (FNIT), a bleeding disorder in which mothers generate antibodies that attack and destroy platelets in their fetuses and newborns. Platelets are the small cells in the blood that play a key role in clotting. In severe cases, FNIT may lead to bleeding in the brains of the fetuses and newborns and cause neurological impairment or even death.

The condition affects between one in 800 and one in 1,500 live births and is more commonly reported among Caucasians.

Maternal antibodies to one specific platelet antigen, HPA-1 (human platelet antigen) cause 75-95 per cent of FNIT cases. Antigens are the proteins that antibodies attack because they think they are a foreign substance such as bacteria or a virus.

Dr. Ni and his team discovered a novel mechanism that might partially explain this problem. They found that another antigen, HPA-2, causes a type of FNIT never described before that can lead to miscarriages in more than 83 per cent of mice. There have been only six to eight reported live births in the world of humans with FNIT caused by HPA-2. The new research suggests the reason these cases appear to be so rare is that most of the affected fetuses died through miscarriages, before doctors examined them.

Dr. Conglei Li and other researchers in Dr. Ni's laboratory found that sometimes these antibodies not only destroy platelets, but activate them and cause massive clotting in the placentas.

Dr. Ni, an immunologist, is also a scientist with Canadian Blood Services (CBS), one of the funders of this research. His findings appear in the November issue of the prestigious Journal of Clinical Investigation.

Dr. Ni's group demonstrated that, in mice, these miscarriages can be prevented using at least two therapies. One is the transfusion of IgG (IVIG), a CBS product made from plasma from donated blood, which has been widely used to treat several autoimmune diseases. The other is the transfusion of an antibody known as anti-FcRn, which blocks the attacking maternal antibodies from crossing the placenta. This second method was developed by Dr. Ni's group.

"Fifty per cent of pregnancies do not end in a live birth. Our findings may help explain why some women are having miscarriages," said Dr. Ni. "Furthermore, our treatments could be the answer to carrying a healthy child to term."

The observations by Dr. Ni's team of platelet activation and enhancement of clotting may be important in the development of safer anti-thrombotic drugs. These drugs are under development by several companies.

Dr. Ni's group is now collaborating with clinicians to address how relevant these discoveries in mice are in humans.

St. Michael's Hospital


Related Miscarriages Current Events and Miscarriages News Articles


Body clock genes could hold key to recurrent miscarriages
Researchers at the University of Warwick and UHCW have discovered how body clock genes could affect women's ability to have children.

Blood test trumps accuracy of standard screening in detecting Down syndrome in early pregnancy
A blood test undertaken between 10 to 14 weeks of pregnancy may be more effective in diagnosing Down syndrome and two other less common chromosomal abnormalities than standard non-invasive screening techniques, according to a multicenter study led by a UCSF researcher.

Failed synchronization of the womb's clock with mother's body clock critical in miscarriages
If you are trying to have a baby, a good night's sleep is more important than ever. A new research report appearing in The FASEB Journal shows that the womb has its own "body clock" that needs to synchronize with the mother's body clock to ensure optimal conditions for fetal growth and development.

Research on medical abortion and miscarriage may change international routines
Two scientific studies led by researchers at Sweden's Karolinska Institutet are expected to form the basis of new international recommendations for the treatment of medical abortions and miscarriages.

Chromosome shattering may be a hidden cause of birth defects
The human genome can be very forgiving. When children inherit chromosomes from their parents, some minor genetic changes frequently occur with few, if any, consequences.

Women diagnosed with PCOS twice as likely to be hospitalized
Washington, DC--Women diagnosed with polycystic ovary syndrome - the most common hormone disorder in women of reproductive age - face a heightened risk of developing heart disease, diabetes, mental health conditions, reproductive disorders and cancer of the lining of the uterus than healthy women.

New review looks at the effect of thyroid disorders on reproductive health
Thyroid disease can have significant effects on a woman's reproductive health and screening for women presenting with fertility problems and recurrent early pregnancy loss should be considered, suggests a new review published today (23 January) in The Obstetrician & Gynaecologist (TOG).

Link between stress and infertility can be broken
Scientists from the University of California Berkeley have discovered that by knocking down a single gene, they can stop stress from causing female infertility and miscarriage - in rats.

Chemicals Released During Natural Gas Extraction May Harm Human Reproduction and Development
Unconventional oil and gas (UOG) operations combine directional drilling and hydraulic fracturing, or "fracking," to release natural gas from underground rock.

Vitamin E deficiency linked to greater risk of miscarriage among poor women
Pregnant women in Bangladesh with low levels of the most common form of vitamin E are nearly twice as likely to have a miscarriage than those with adequate levels of the vitamin in their blood, according to new research led by the Johns Hopkins Bloomberg School of Public Health.
More Miscarriages Current Events and Miscarriages News Articles

© 2015 BrightSurf.com