Thursday, April 17th, 2014
The protein mechanism that allows a sperm and egg to connect to each other and fertilize to become an embryo has been identified by British scientists. More from Reuters:
Fertilization takes place when an egg cell and a sperm cell recognize one another and fuse to form an embryo. But how they recognize each other in order to hook up had remained a mystery.
Researchers said on Wednesday they have identified a protein on the egg cell’s surface that interacts with another protein on the surface of a sperm cell, allowing the two cells to join.
This protein, dubbed Juno in honor of the ancient Roman goddess of fertility and marriage, and its counterpart in sperm, named Izumo after a Japanese marriage shrine, are essential for reproduction in mammals including people, they said.
This new understanding of the role of these two proteins could help improve the treatment of infertility and guide the development of new contraceptives, the researchers said.
“By identifying this interaction between Juno and Izumo, we now know the identity of the receptor proteins found on the surface of our father’s sperm and our mother’s egg that must interact at the moment at which we were conceived,” said Gavin Wright of the Welcome Trust Sanger Institute in Britain, one of the researchers in the study published in the journal Nature.
The researchers are now screening infertile women to try to determine whether problems with the Juno receptor are to blame.
“It is remarkable that about 20 percent of infertility cases have an unexplained cause,” said Enrica Bianchi of the Sanger Institute, another of the researchers.
“We are now asking whether Juno is involved in these cases of unexplained infertility,” Bianchi added.
Wright said that if defects in the Juno receptor are in fact implicated in human infertility, a simple, non-invasive genetic screening test could be developed to identify affected women.
“This then would allow us to guide the fertility treatment,” Wright said, letting affected women proceed directly to a procedure called intracytoplasmic sperm injection involving direct injection of sperm into an egg obtained from in vitro fertilization.
Image: Sperm and egg, via Shutterstock
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Monday, March 17th, 2014
A major doctor’s group is urging obstetricians to have serious, often difficult conversations with their patients, telling them that being overweight or obese can have negative impact on both their fertility and their pregnancy health. More from Time.com:
The latest news about the negative effects of our nation’s obesity epidemic on everything from fertility to pregnancy and maternal mortality recently prompted the American College of Obstetricians and Gynecologists (ACOG) to urge doctors to talk with patients about the benefits of slimming down before trying to conceive. It’s part of an ongoing push to make chats about women’s “reproductive lifespan” as routine as an annual pap smear. Just as doctors have historically shied away from telling women that their eggs are getting too old, many haven’t been eager to point out that a woman’s size might come in between her and her dream of becoming a mother.
“For a woman who’s been trying for a year, the last thing she wants to hear is to take another year off to lose weight,” explains Dr. Jeanne Conry, ACOG president and assistant physician in chief at The Permanente Medical Group in Roseville, California. “But if a woman walks into my office who’s been trying to get pregnant and she has a body mass index of 30 or over [more than 180 pounds for a 5’5” woman] and she’s having an irregular period, the first thing we’re going to do is discuss a healthy diet and exercise program.”
Of course, doctors point out that the majority of the estimated 30% of obese women in the U.S. have no problems conceiving. But there’s a growing body of evidence that’s difficult to ignore. Obesity raises a woman’s risk of gestational diabetes, hypertension, premature delivery, miscarriage, and stillbirth. A mother’s chance of having to undergo a caesarian section is 34% if her BMI is over 30, and 47% if her BMI is over 35—compared to 21% for women with a BMI under 30, according to one study. There’s even evidence that babies born to obese women have a greater chance of suffering neural defects than those whose mothers are normal weight, and will be at greater risk of being obese themselves.
In one recent survey of more than 3,300 women, one-third responded they didn’t believe or were unsure whether a woman’s weight affected her chances of conceiving. The doctors’ organization hopes that encouraging ob-gyns to broach the topic will educate women about that connection, considering that about 6% of infertility is due to obesity (another 6% is due to being too thin), according to statistics by the American Society for Reproductive Medicine. (That goes for men, too, since a recent French study showed their excess poundage contributed to low sperm production.) The good news is that 70% of these women will get pregnant naturally after they lose or gain enough weight to get closer to a healthier BMI.
The other goal is to help patients set and achieve weight-loss goals, or even consider weight loss surgery if they’re severely obese. But adding those expectations on top of conceiving can feel daunting to many women, says Julie Friedman, PhD, a psychologist who directs a weight management program comprised of counseling, workshops, and support groups, at Insight Behavioral Health Centers, a chain of outpatient mental health treatment centers based in Chicago. “They’ve struggled with their weight their whole lives and now they’re going through something so stressful, saying ‘Now you’re telling me to lose weight when I’m this stressed out and trying for a baby?’”
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Image: Overweight woman, via Shutterstock
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Tuesday, March 4th, 2014
Many parents breathed a sigh of relief when the FDA banned the chemical bisphenol-A (BPA) from plastics that are used in infant feeding vessels including bottles and sippy cups in 2012. Studies have linked the chemical, which is known to disrupt the endocrine system by mimicking the hormone estrogen, to health problems including miscarriage risk, and childhood obesity, asthma, and behavioral issues. Many parents were disappointed, though, when the FDA, shortly before making its BPA ban in infant materials, stopped short of banning it from all food containers, especially canned foods and even infant formula packages.
But the debate over the safety of plastics is far from over–and it is larger than the BPA question–according to a new report from Mother Jones magazine that chronicles the work of research organizations that claims that even “safe” plastics leach estrogenic, hormone-disrupting compounds. More from the Mother Jones article:
Each night at dinnertime, a familiar ritual played out in Michael Green’s home: He’d slide a stainless steel sippy cup across the table to his two-year-old daughter, Juliette, and she’d howl for the pink plastic one. Often, Green gave in. But he had a nagging feeling. As an environmental-health advocate, he had fought to rid sippy cups and baby bottles of the common plastic additive bisphenol A (BPA), which mimics the hormone estrogen and has been linked to a long list of serious health problems. Juliette’s sippy cup was made from a new generation of BPA-free plastics, but Green, who runs the Oakland, California-based Center for Environmental Health, had come across research suggesting some of these contained synthetic estrogens, too.
He pondered these findings as the center prepared for its anniversary celebration in October 2011. That evening, Green, a slight man with scruffy blond hair and pale-blue eyes, took the stage and set Juliette’s sippy cups on the podium. He recounted their nightly standoffs. “When she wins…every time I worry about what are the health impacts of the chemicals leaching out of that sippy cup,” he said, before listing some of the problems linked to those chemicals—cancer, diabetes, obesity. To help solve the riddle, he said, his organization planned to test BPA-free sippy cups for estrogenlike chemicals.
The center shipped Juliette’s plastic cup, along with 17 others purchased from Target, Walmart, and Babies R Us, to CertiChem, a lab in Austin, Texas. More than a quarter—including Juliette’s—came back positive for estrogenic activity. These results mirrored the lab’s findings in its broader National Institutes of Health-funded research on BPA-free plastics. CertiChem and its founder, George Bittner, who is also a professor of neurobiology at the University of Texas-Austin, had recently coauthored a paper in the NIH journal Environmental Health Perspectives. It reported that “almost all” commercially available plastics that were tested leached synthetic estrogens—even when they weren’t exposed to conditions known to unlock potentially harmful chemicals, such as the heat of a microwave, the steam of a dishwasher, or the sun’s ultraviolet rays. According to Bittner’s research, some BPA-free products actually released synthetic estrogens that were more potent than BPA.
Estrogen plays a key role in everything from bone growth to ovulation to heart function. Too much or too little, particularly in utero or during early childhood, can alter brain and organ development, leading to disease later in life. Elevated estrogen levels generally increase a woman’s risk of breast cancer….
Today many plastic products, from sippy cups and blenders to Tupperware containers, are marketed as BPA-free. But Bittner’s findings—some of which have been confirmed by other scientists—suggest that many of these alternatives share the qualities that make BPA so potentially harmful.
Those startling results set off a bitter fight with the $375-billion-a-year plastics industry. The American Chemistry Council, which lobbies for plastics makers and has sought to refute the science linking BPA to health problems, has teamed up with Tennessee-based Eastman Chemical—the maker of Tritan, a widely used plastic marketed as being free of estrogenic activity—in a campaign to discredit Bittner and his research. The company has gone so far as to tell corporate customers that the Environmental Protection Agency (EPA) rejected Bittner’s testing methods. (It hasn’t.) Eastman also sued CertiChem and its sister company, PlastiPure, to prevent them from publicizing their findings that Tritan is estrogenic, convincing a jury that its product displayed no estrogenic activity. And it launched a PR blitz touting Tritan’s safety, targeting the group most vulnerable to synthetic estrogens: families with young children. “It can be difficult for consumers to tell what is really safe,” the vice president of Eastman’s specialty plastics division, Lucian Boldea, said in one web video, before an image of a pregnant woman flickered across the screen. With Tritan, he added, “consumers can feel confident that the material used in their products is free of estrogenic activity.”
Eastman’s offensive is just the latest in a wide-ranging industry campaign to cast doubt on the potential dangers of plastics in food containers, packaging, and toys—a campaign that closely resembles the methods Big Tobacco used to stifle scientific evidence about the dangers of smoking.
The article goes on to report that CertiChem and PlastiPure are appealing the 2013 court ruling that alleged the companies were trying to discredit Eastman in order to market their own “safe” plastics, and the groups are working on new research.
Mother Jones also published a timeline that shows the history of the fight against BPA, and how the industry and even government regulators have apparently ignored concerning research about the safety of BPA-free plastics.
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Image: Child with plastic sippy cup, via Shutterstock
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BPA, childhood asthma, childhood obesity, endocrine disruptors, estrogen, fertility, hormones, miscarriage, Mother Jones, plastics | Categories:
Child Health, Must Read, New Research, Parenting News, Safety
Thursday, February 27th, 2014
A fertility treatment in which the genetic material of three different people are combined to create an embryo that is free of certain genetic defects is under scrutiny by the Food and Drug Administration amid claims that the therapy could amount to creating “designer babies.” More on the ethically complex method from The New York Times:
The agency has asked a panel of experts to summarize current science to determine whether the approach — which has been performed successfully in monkeys by researchers in Oregon and in people more than a decade ago — is safe enough to be used again in people.
The F.D.A. meeting, on Tuesday and Wednesday, is meant to address the scientific issues around the procedure, not the ethics. Regulators are asking scientists to discuss the risks to the mother and the potential child and how future studies should be structured, among other issues. The meeting is being closely watched. The science of such therapies has advanced significantly in recent years, and many scientists are urging federal regulators to ease requirements for study in humans.
The procedure in question involves mitochondria, the power producers in cells that convert energy into a form that cells can use. Mitochondria with defects that could be passed to a fetus are replaced with healthy mitochondria from another woman. This is done either before or after an egg is fertilized.
Scientists have already experimented with combining genetic material from cells of three people. In 2001, researchers in New Jersey did so using material from the cytoplasm, the material that surrounds the nucleus of the egg and directs its development after fertilization, from fertile women into the eggs of infertile women. More than 17 babies have been born this way in the United States.
The practice raised questions and eventually led the F.D.A. to tell researchers that they could not perform such procedures in humans without getting special permission from the agency. Since then, studies have been confined to animals.
But a researcher in Oregon, Shoukhrat Mitalipov, has performed the mitochondrial procedure in monkeys and has said that it is ready to be tried in people.
Such genetic methods have been controversial in the United States, where critics and some elected officials wonder how far scientists plan to go in their efforts to engineer humans, and question whether these methods might create other problems.
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Tuesday, January 28th, 2014
About half of American women who are of reproductive age don’t discuss reproductive issues with their doctors, compounding some misinformation and confusion around fertility and pregnancy, according to new research published in the journal Fertility and Sterility. More from Time.com:
As a result, the researchers, from the Yale School of Medicine, found that women between ages 18 and 40 weren’t aware of some the important factors that influence fertility and their ability to get pregnant, as well as about basic prenatal practices once they were expecting.
Among the most notable findings, which were published in the journal, Fertility & Sterility :
- 30% of the women reported that they only visited a reproductive health provider less than once a year or not at all.
- 50% of the women did not know that taking multivitamins and folic acid are recommended to avoid birth defects.
- A little over 25% of women did not know that things like STDs, smoking and obesity impact fertility.
- 20% did not know that aging can impact fertility and increase rates of miscarriage
- 50% of the women thought that having sex multiple times in a day increased their likelihood of getting pregnant
- Over 33% of women thought that different sex positions can increase their odds of getting pregnant
- 10% did not know that they should have sex before ovulation to increase the chances of getting pregnant instead of after ovulation
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Image: Pregnant woman, via Shutterstock
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