The birth defect spina bifida is a devastating condition, often leading to a life of cognitive disability and even paralysis. But for a new study in the New England Journal of Medicine, doctors have shown that fetal surgery conducted in utero, though tricky and carrying some risk, can help to fight the ravages of this affliction.
The study focused on women carrying fetuses diagnosed with myelomeningocele, the most common and most severe form of spina bifida, in which the spinal cord bulges outside the spinal column. The condition can result in lifelong cognitive disabilities, fluid on the brain, bowel problems and paralysis. Typically surgeons operate on such babies within a few days of birth. [Science News]
The option of performing surgery before birth—sealing the opening in the spinal column while the fetus is in the womb—has actually been around for more than a decade.
But no one knew if operating before birth was preferable to operating after. What they did know was that fetal surgery had a number of complications, including causing premature birth, which in some cases killed babies who would otherwise have survived. [ScienceNOW]
Talk about early intervention. One day, a fetus with a genetic disease may be able to get treatment before it even leaves the womb–and that treatment will come in the form of an extra gift from mom. While this scenario will only come to pass if new mouse research can be translated to humans, the finding are exciting.
The new work solves a medical mystery. When researchers realized they could diagnose a fetus with certain genetic illnesses as early as the first trimester, they plunged into the search for in utero treatments. Ailments like sickle cell anemia and some immune disorders might be treatable with blood stem cells taken from a donor’s bone marrow, researchers thought: the transplanted cells would multiply and populate the fetus’s bone marrow with healthy blood-forming cells, and the fetus’s immature immune system wouldn’t reject the foreign entities. But when researchers tried such transplants, they didn’t work.
“The fact that fetal stem cell transplantation has not been very successful has been puzzling, especially given the widely accepted dogma that the immature fetal immune system can adapt to tolerate foreign substances,” said co-senior author Qizhi Tang…. “The surprising finding in our study is that the mother’s immune system is to blame.” [press release]
In a remarkable medical feat, researchers used a blood sample from a pregnant woman to work out the entire genome of her unborn fetus. The technique, published in the journal Science Translational Medicine, could provide a safer and less invasive way to check a fetus for fatal genetic mutations.
Currently, determining a fetus’s genome requires either amniocentesis, in which a needle is inserted through the mother’s abdomen into the amniotic sac, or chorionic villus sampling, in which a piece of placenta is removed. But both techniques carry a small risk to the baby, and are reserved for cases when there is an increased risk of genetic defects.
“The major advantage of the technique in this paper is that there’s no risk of miscarriage,” said Dr. Diana W. Bianchi, a reproductive geneticist at Tufts University who called the work a “technological tour de force.” Amniocentesis and CVS testing carry about a 1% risk of miscarriage, she said. [LA Times]
The new technique sequences the fetal genome from fragments present in the mother’s blood. In the late 1990s researchers discovered that fragments of fetal DNA are present in maternal plasma, presumably because the DNA gets broken down and crosses over the placental barrier.
The United States is still bogged down in uncertainty over which stem cell science the government can and can’t fund, but that doesn’t mean the march of research has ground to a halt. This week brought news of two new human stem cell treatments that are going forward.
In Britain, a former truck driver in his 60s who suffered a stroke has now become the first person to receive an experimental stem cell treatment for the condition. Doctors injected two million fetal stem cells developed by British company ReNeuron into his brain with the hope of stimulating the growth of brain cells and blood vessels.
The patient received a very low dose of stem cells in an initial trial to assess the safety of the procedure. Over the next year, up to 12 more patients will be given progressively higher doses – again primarily to assess safety – but doctors will be looking closely to see if the stem cells have begun to repair their brains and if their condition has improved. [BBC News]
If those treatments go well, those higher doses could go as high as 10 to 20 million cells. ReNeuron scientist John Sinden explains that the fetal cells were taken from a 12-week-old fetus, and were already destined to become brain cells. This treatment is thought to have fewer uncertainties than those that use embryonic stem cells, which can grow into any type of cell and which can sometimes cause tumors.
“Hongerwinter,” or “hunger winter”—that’s what they called the end of 1944 in the Netherlands. As World War II lurched toward its end, Nazi Germany put up a blockade to prevent food from entering the Netherlands. According to a study by Dutch researchers, that famine is still felt all these years later in the brains of people who were born during those years.
Susanne de Rooij and colleagues looked at more than 700 people born during those years, 300 of whom experienced famine in utero, to see if that experience changed their brains.
In the study, 64 seniors who were exposed to famine in the early stages of gestation did worse on cognitive-function tests that required them to do tasks like name the color of the word “blue” when it was printed in yellow ink, than seniors who were exposed later or not at all to hunger in utero. The researchers also found that exposure to famine at any stage of the mother’s pregnancy resulted in a smaller head circumference at ages 56-59.”Head size is related to brain size and reduced size has been associated with decreased cognitive abilities in the elderly,” they wrote. [AFP]
In a development that’s certain to stir passions in the abortion debate, the Royal College of Obstetricians and Gynaecologists in the UK published a report today on “fetal awareness.” The group states, citing a review of current research, that human fetuses cannot feel pain before 24 weeks.
The group’s reasoning, as described in a press release, is based on these points:
-The fetus cannot feel pain before 24 weeks because the connections in the fetal brain are not fully formed
-The fetus, while in the chemical environment of the womb, is in a state of induced sleep and is unconscious
-Because the 24 week-old fetus has no awareness nor can it feel pain, the use of analgesia is of no benefit
-More research is needed into the short and long-term effects of the use of fetal analgesia post-24 weeks [Royal College of Obstetricians and Gynaecologists]
This is certainly not the first debate over whether a fetus can feel pain. Fetal surgeries have led doctors to ask this question, as they determined whether anesthesia was appropriate and at what stage in development. As summarized in a 2008 New York Times Magazine article, researchers have looked at fetal flinch responses, heart rate, and levels of stress hormones. But any metric has remained controversial. Take stress hormones, for example. Do you say that any fetus that can release these hormones feels pain? Or do you wait until it develops the nervous system to register those hormones? Or do you say that an undeveloped nervous system makes the fetus more susceptible to pain, since it hasn’t developed the system to suppress it?