It’s been more than three years since the FDA approved Gardasil, the vaccine against the sexually transmitted Human Papilloma Virus (HPV) that is responsible for most cases of cervical cancer. How is the vaccine being accepted by young college-age women?
To find out, researchers conducted a survey of 972 female college students at a large Midwestern state university. Most of the women were freshmen or sophomores. Sixty-five % of the women reported being sexually active, and by the Spring of 2009 57% had already received at least the first of the three shots required by the vaccination protocol for Gardasil. (The vaccine was available on request at the university student health center, at a cost of $360).
Vaccination coverage of 57% in this age group within three years of vaccine availability is welcome news, considering that these college-age women were already 15 or 16 years old when the vaccine first became available. Current recommendations are that girls should be vaccinated as early as 11-12 years of age. Significantly, young women who believed that their mothers would approve of their receiving the vaccine were more likely to have been vaccinated or to have an interest in being vaccinated.
More than a third of the women reported having had three or more sexual partners, and over 25% had had vaginal sex with a casual partner (not a serious or steady dating partner) without using protection against sexually transmitted diseases. All the more reason they should be vaccinated…
Tampilkan postingan dengan label reproductive system. Tampilkan semua postingan
Tampilkan postingan dengan label reproductive system. Tampilkan semua postingan
Rabu, 13 Oktober 2010
Minggu, 05 September 2010
Vaginal Gel is Effective Against HIV
Finally, there’s an HIV prevention method that’s controlled by women. This is especially important for women who are not in a mutually monogamous relationship and who cannot convince their men to use a condom. (In Africa, over 60% of HIV-infected persons are women who contracted the disease via heterosexual sex.)
In a study published last week in Science, nearly 900 sexually active women in a high-risk area in South Africa were supplied with either a vaginal gel containing the antiviral drug tenofovir, or just the gel alone as a control, over a thirty-month period. Women who received the drug were 39% less likely to become infected with HIV, compared to women in the control group.
Why wasn’t the treatment 100% effective? Part of the reason may be that some study participants may not have used the gel properly and consistently. Among women who used the gel as advised (both before and after sex) more than 80% of the time, the reduction in HIV infections was 54%. When the gel was used less than half the time the reduction in infections was only 28%. No one should be surprised; after all condoms, too, only work if you use them!
AIDS researchers are cheering. Although prevention wasn’t perfect, they’ve proved that pre-exposure prophylaxis controlled by women is at least partially effective. The next step will be to find more potent drugs or a more effective delivery method – perhaps a vaginal ring that releases the drug over longer periods of time.
By the way, would you like to know how the researchers monitored compliance to the study protocol (participant’s actual use of the gels)? They counted the used gel applicators returned by the women in the study and compared that number to the 181,340 gel applicators they gave out. Obviously the researchers suspected in advance that compliance might be a problem. You have to admire the researchers’ advance planning and their willingness to do what was necessary to improve the validity of their results.
In a study published last week in Science, nearly 900 sexually active women in a high-risk area in South Africa were supplied with either a vaginal gel containing the antiviral drug tenofovir, or just the gel alone as a control, over a thirty-month period. Women who received the drug were 39% less likely to become infected with HIV, compared to women in the control group.
Why wasn’t the treatment 100% effective? Part of the reason may be that some study participants may not have used the gel properly and consistently. Among women who used the gel as advised (both before and after sex) more than 80% of the time, the reduction in HIV infections was 54%. When the gel was used less than half the time the reduction in infections was only 28%. No one should be surprised; after all condoms, too, only work if you use them!
AIDS researchers are cheering. Although prevention wasn’t perfect, they’ve proved that pre-exposure prophylaxis controlled by women is at least partially effective. The next step will be to find more potent drugs or a more effective delivery method – perhaps a vaginal ring that releases the drug over longer periods of time.
By the way, would you like to know how the researchers monitored compliance to the study protocol (participant’s actual use of the gels)? They counted the used gel applicators returned by the women in the study and compared that number to the 181,340 gel applicators they gave out. Obviously the researchers suspected in advance that compliance might be a problem. You have to admire the researchers’ advance planning and their willingness to do what was necessary to improve the validity of their results.
Rabu, 25 Agustus 2010
The Benefits of Human Breast Milk
Colonization of the human infants’ gastrointestinal tract by bacteria occurs only after birth. It is known that human breast milk encourages colonization of the newborn’s gut by beneficial bacteria and discourages colonization by harmful ones, but how exactly does it do that? An article in the Proceedings of the National Academy of Sciences provides a tantalizing glimpse into the likely mechanisms.
About 4-12% of the macronutrient composition of human milk consists of a structurally diverse group of complex sugars called oligosaccharides. These oligosaccharides are indigestible by the infant, and so for many years scientists thought they had no function. It turns out that they are digestible by a particular group of beneficial bacteria called bifidobacteria. The presence of these oligosaccharides in human milk gives the bifidobacteria a nutritional advantage over less desirable bacteria in the human infant’s gut. In other words, these oligosaccharides are produced in human milk specifically to provide nutrients to beneficial bacteria, rather than to nourish the infant.
Some of these oligosaccharides have another interesting property; they bind to certain harmful bacteria, thus preventing them from attaching to the epithelial cells lining the gut. Researchers think that these oligosaccharides may flush out harmful bacteria during that very vulnerable time in early life when the infant’s immune system has not yet developed fully.
About 4-12% of the macronutrient composition of human milk consists of a structurally diverse group of complex sugars called oligosaccharides. These oligosaccharides are indigestible by the infant, and so for many years scientists thought they had no function. It turns out that they are digestible by a particular group of beneficial bacteria called bifidobacteria. The presence of these oligosaccharides in human milk gives the bifidobacteria a nutritional advantage over less desirable bacteria in the human infant’s gut. In other words, these oligosaccharides are produced in human milk specifically to provide nutrients to beneficial bacteria, rather than to nourish the infant.
Some of these oligosaccharides have another interesting property; they bind to certain harmful bacteria, thus preventing them from attaching to the epithelial cells lining the gut. Researchers think that these oligosaccharides may flush out harmful bacteria during that very vulnerable time in early life when the infant’s immune system has not yet developed fully.
Rabu, 07 Juli 2010
It's Official: She Can Compete
It took more than 10 months for a committee of the IAAF, international track and field’s governing body, to decide that Caster Semenya could compete in track and field events as a woman. As you may recall, Ms. Semenya’s gender was called into question after she completely dominated the 800-meter event in the world championships last August in Berlin (see this blog, Sept. 7, 2009.) A statement released yesterday by the IAFF on their Web site (www.IAAF.org) reads in full:
Caster Semenya May Compete. “The process initiated in 2009 in the case of Caster Semenya (RSA) has been completed. The IAFF accepts the panel of medical experts that she can compete with immediate effect. Please note that the medical details of the case remain confidential and the IAAF will make no further comment on the matter.” (IAFF statement)
Remember the old “Where’s the beef?” commercials for Wendy’s chain of restaurants? One might ask, “Where’s the proof?” Out of fairness to all athletes in sports, sports governing bodies should develop understandable policies, guidelines, or criteria for gender assignment in sports. But it won’t be easy (gender IS ambiguous, sometimes), so I’m betting the IAAF won’t even attempt it.
The Wendy’s commercial ended with the remark, “(I don’t think there’s anybody back there…)” IAAF, are you listening?
Caster Semenya May Compete. “The process initiated in 2009 in the case of Caster Semenya (RSA) has been completed. The IAFF accepts the panel of medical experts that she can compete with immediate effect. Please note that the medical details of the case remain confidential and the IAAF will make no further comment on the matter.” (IAFF statement)
Remember the old “Where’s the beef?” commercials for Wendy’s chain of restaurants? One might ask, “Where’s the proof?” Out of fairness to all athletes in sports, sports governing bodies should develop understandable policies, guidelines, or criteria for gender assignment in sports. But it won’t be easy (gender IS ambiguous, sometimes), so I’m betting the IAAF won’t even attempt it.
The Wendy’s commercial ended with the remark, “(I don’t think there’s anybody back there…)” IAAF, are you listening?
Selasa, 15 Juni 2010
Teens and the Rhythm Method of Birth Control
According to a recent government survey of teen sex entitled “Teenagers in the United States: Sexual Activity, Contraceptive Use, and Childbearing, National Survey of Family Growth, 2006-2008”, teens aged 15-19 increasingly are relying on the rhythm method for birth control. Among sexually active teens, 17% reported using the rhythm method in 2006-2008, compared to just 11% in 2002.
The rhythm method, also known as periodic abstinence, is moderately effective as a birth control method. Approximately 25% of women who rely on the rhythm method will become pregnant in a year. (Approximately 85% of women who use no birth control method at all will become pregnant in the first year.) However, the rhythm method is much less effective than birth control pills or condoms, which have failure rates of less than 5% per year if used properly.
The new findings coincide with both an increased number of teen pregnancies and an increased acceptance of unwed pregnancy by teens. In the survey, 2/3 of all teens said they agreed or strongly agreed with the statement, “It is OK for an unwed female to have a child”. Sex-education messages to teens may have to change if this trend is to be reversed.
The rhythm method, also known as periodic abstinence, is moderately effective as a birth control method. Approximately 25% of women who rely on the rhythm method will become pregnant in a year. (Approximately 85% of women who use no birth control method at all will become pregnant in the first year.) However, the rhythm method is much less effective than birth control pills or condoms, which have failure rates of less than 5% per year if used properly.
The new findings coincide with both an increased number of teen pregnancies and an increased acceptance of unwed pregnancy by teens. In the survey, 2/3 of all teens said they agreed or strongly agreed with the statement, “It is OK for an unwed female to have a child”. Sex-education messages to teens may have to change if this trend is to be reversed.
Jumat, 12 Maret 2010
Should Older Women be Vaccinated Against HPV?
The U.S. Centers for Disease Control and Prevention (CDC) recommends that all girls and women between the ages of 11 and 26 be vaccinated against the strains of human papillomaviruses (HPVs) that cause cervical cancer. But what about older women; wouldn’t they benefit as well?
The answer appears to be no, or at least not very much. A study of over 9,000 Costa Rican women conducted over a seven-year period found that older women (over 40) tend to get fewer new HPV infections. They also found that HPV infections do not progress towards cancer any faster in older women than in younger women.
Cancer develops in only a small fraction of women who have an HPV infection during their lifetimes, and most HPV infections clear up on their own within a couple of years anyway. Even among women who do develop cervical cancer as a result of an HPV infection, it takes about 25-30 years on average for the cancer to develop fully to the metastatic stage. Therefore, vaccinating older women is not of much use. The ideal time to vaccinate women and girls is before they become sexually active so that they never have an HPV infection in the first place.
The answer appears to be no, or at least not very much. A study of over 9,000 Costa Rican women conducted over a seven-year period found that older women (over 40) tend to get fewer new HPV infections. They also found that HPV infections do not progress towards cancer any faster in older women than in younger women.
Cancer develops in only a small fraction of women who have an HPV infection during their lifetimes, and most HPV infections clear up on their own within a couple of years anyway. Even among women who do develop cervical cancer as a result of an HPV infection, it takes about 25-30 years on average for the cancer to develop fully to the metastatic stage. Therefore, vaccinating older women is not of much use. The ideal time to vaccinate women and girls is before they become sexually active so that they never have an HPV infection in the first place.
Selasa, 02 Februari 2010
Smoking and Breast Sagging
A couple of years ago a plastic surgeon and his colleagues did a study in which they interviewed 132 women who had requested breast lift surgery or breast augmentation. The goal of the interviews was to try to determine whether there was any truth to the commonly held belief that breast-feeding causes breast sagging later in life.
The results showed no difference in the degree of breast ptosis (sagging) between women who had breastfed and those who had not. However, factors that did correlate with breast sagging included the woman’s age, how many pregnancies she had had, and whether she had smoked.
Yes, you read that right - smoking. It is well known that smoking damages elastin, the protein fibers in skin responsible for skin’s youthful appearance and elasticity. That’s why chronic smokers are much more likely to have wrinkled skin than non-smokers. It would not be much of a stretch (no pun intended) to hypothesize that healthy elastin supports breast tissue and helps maintain breast shape.
One more reason not to smoke?
Reference: Rinker, Brian et al. The effect of breastfeeding on breast aesthetics. Aesthet. Surg. J. 28:534-537, 2008.
The results showed no difference in the degree of breast ptosis (sagging) between women who had breastfed and those who had not. However, factors that did correlate with breast sagging included the woman’s age, how many pregnancies she had had, and whether she had smoked.
Yes, you read that right - smoking. It is well known that smoking damages elastin, the protein fibers in skin responsible for skin’s youthful appearance and elasticity. That’s why chronic smokers are much more likely to have wrinkled skin than non-smokers. It would not be much of a stretch (no pun intended) to hypothesize that healthy elastin supports breast tissue and helps maintain breast shape.
One more reason not to smoke?
Reference: Rinker, Brian et al. The effect of breastfeeding on breast aesthetics. Aesthet. Surg. J. 28:534-537, 2008.
Rabu, 13 Januari 2010
Depo-Provera and Bone Loss
Around two million women use Depo-Provera as their contraceptive of choice. About 400,000 of them are teenagers. Depo-Provera is popular with teenagers because of its ease of use – just a single injection is required every three months.
However, Depo-Provera has one side effect not shared by oral contraceptives; it causes a slight but statistically significant bone loss. Researchers compared bone mineral density in young women aged 12-18 who used either Depo-Provera, oral contraceptives, or no birth control at all (the control group) for two years. Bone mineral density increased over the two-year period in the control group, as expected in young women still in their teens. It also increased in the oral contraceptives group by the same amount. However, bone mineral density decreased slightly but significantly in the Depo-Provera group.
The decrease in bone mineral density among Depo-Provera users was not sufficient to pose an immediate health risk, and any long-term risks are still unknown. Nevertheless, women’s health experts suggest that teenagers who are taking Depo-Provera should be sure to get enough calcium in their diet.
Reference: Cromer, Barbara A., et al. Bone mineral density in adolescent females using injectable or oral contraceptives; a 24-month prospective study. Fertility and Sterility 90: 2060-2067, 2008.
However, Depo-Provera has one side effect not shared by oral contraceptives; it causes a slight but statistically significant bone loss. Researchers compared bone mineral density in young women aged 12-18 who used either Depo-Provera, oral contraceptives, or no birth control at all (the control group) for two years. Bone mineral density increased over the two-year period in the control group, as expected in young women still in their teens. It also increased in the oral contraceptives group by the same amount. However, bone mineral density decreased slightly but significantly in the Depo-Provera group.
The decrease in bone mineral density among Depo-Provera users was not sufficient to pose an immediate health risk, and any long-term risks are still unknown. Nevertheless, women’s health experts suggest that teenagers who are taking Depo-Provera should be sure to get enough calcium in their diet.
Reference: Cromer, Barbara A., et al. Bone mineral density in adolescent females using injectable or oral contraceptives; a 24-month prospective study. Fertility and Sterility 90: 2060-2067, 2008.
Sabtu, 24 Oktober 2009
Infertility Patients Favor Stem Cell Research
Most couples that have had to resort to in vitro fertilization (IVF) techniques in order to have a child are in favor of stem cell research. When asked in a national survey what they might choose to do with their frozen embryos left over after they have successfully had a child, 60% reported that they were “somewhat likely” or “very likely” to donate them for stem cell research. In contrast, less than a quarter of the respondents planned to discard their frozen embryos, or expressed a desire to donate them to another couple.
Infertility patients are especially aware of the advances in science that have made it possible for them to have children. Perhaps they are just more grateful than most, but apparently most of them have resolved any internal moral dilemma over what to do with their leftover embryos. It is interesting, however, that most of them would rather donate their embryos to research than to know that their biological child was being raised by another couple.
Infertility patients are especially aware of the advances in science that have made it possible for them to have children. Perhaps they are just more grateful than most, but apparently most of them have resolved any internal moral dilemma over what to do with their leftover embryos. It is interesting, however, that most of them would rather donate their embryos to research than to know that their biological child was being raised by another couple.
Senin, 07 September 2009
Is She a Woman?
After 18-yr-old South African Caster Semenya turned in the fastest time of the year in a women’s 800-meter event in 2009, track and track and field’s governing body ordered an investigation into her gender. They're demanding “proof” that she’s actually a female, so they’ve assembled a committee tell them. Let's see, now, a geneticist, an endocrinologist, a gynecologist, and a psychologist are getting together to determine the sex of…
It sounds like the beginning of a bad joke, but it’s not. Legitimate physiological and anatomical “gender confusion” can be caused by sex hormone imbalances, tissue unresponsiveness to sex hormones, genes that don’t turn on properly during fetal development, or even sex-determining genes located on the wrong chromosome (in rare cases, an XY male can develop the characteristics of a female).
Sports federations should develop rules that allow gender determination (for the purposes of sports competition) before an athletic event, not afterwards, in the public eye. One can only wonder about the emotional damage about to be done to young Caster Semenya.
It sounds like the beginning of a bad joke, but it’s not. Legitimate physiological and anatomical “gender confusion” can be caused by sex hormone imbalances, tissue unresponsiveness to sex hormones, genes that don’t turn on properly during fetal development, or even sex-determining genes located on the wrong chromosome (in rare cases, an XY male can develop the characteristics of a female).
Sports federations should develop rules that allow gender determination (for the purposes of sports competition) before an athletic event, not afterwards, in the public eye. One can only wonder about the emotional damage about to be done to young Caster Semenya.
Sabtu, 15 Agustus 2009
Breast-Feeding and Breast Cancer
A recent study in the Archives of Internal Medicine raises the possibility (but does not entirely prove) that breast-feeding may lower the risk of breast cancer among women at high risk for the disease. The study gathered data from over 60,000 women who had reported at least one pregnancy by 1997. Among women with close relatives who developed breast cancer, those who breast-fed for a period of time had only 41% as many breast cancers by 2005 as women who had never breast-fed. The lowered cancer incidence was only seen among women at high risk for breast cancer; women with no family history of breast cancer did not benefit from breast-feeding.
Why doesn’t this study prove once and for all that “breast-feeding prevents cancer”? Because it only shows an association between breast-feeding and lowered cancer risk - cause-and-effect has not been proved. Perhaps women who choose to breast-feed are more health-conscious overall. Perhaps they exercise more or have a better diet, and that’s actually what lowered the cancer risk. Further research will be needed to tease out the details.
Why doesn’t this study prove once and for all that “breast-feeding prevents cancer”? Because it only shows an association between breast-feeding and lowered cancer risk - cause-and-effect has not been proved. Perhaps women who choose to breast-feed are more health-conscious overall. Perhaps they exercise more or have a better diet, and that’s actually what lowered the cancer risk. Further research will be needed to tease out the details.
Sabtu, 25 Juli 2009
Birth Control Method Failures
In Human Biology 5th ed. (p. 387) there’s a table of data provided by the U.S. Food and Drug Administration on the failure rates of various contraceptive methods. I’ve always felt that the reported failure rate for condoms of 10-20% seemed awfully high. Condoms are supposed to work, right?
Now there’s an explanation. Recent evidence shows that for both condoms and withdrawal, there’s a big difference between “perfect use” and “typical use”. If a couple actually uses a condom every time (no exceptions, folks), the annual failure rate is only about 2%. For withdrawal every time, the failure rate is about 4%. The problem is that in the heat of passion some couples “forget”, or convince themselves that not using a birth control method just this once won’t be a big deal. Under these more typical use conditions, the failure rates of condoms and of withdrawal are indeed closer to 20% per year.
If you’re going to rely on these contraceptive methods, don’t cheat!
REFERENCE: R.K. Jones. Better than nothing or savvy risk-reduction practice? The importance of withdrawal. Contraception 79:407-410, June, 2009.
Now there’s an explanation. Recent evidence shows that for both condoms and withdrawal, there’s a big difference between “perfect use” and “typical use”. If a couple actually uses a condom every time (no exceptions, folks), the annual failure rate is only about 2%. For withdrawal every time, the failure rate is about 4%. The problem is that in the heat of passion some couples “forget”, or convince themselves that not using a birth control method just this once won’t be a big deal. Under these more typical use conditions, the failure rates of condoms and of withdrawal are indeed closer to 20% per year.
If you’re going to rely on these contraceptive methods, don’t cheat!
REFERENCE: R.K. Jones. Better than nothing or savvy risk-reduction practice? The importance of withdrawal. Contraception 79:407-410, June, 2009.
Selasa, 23 Juni 2009
Freeze Your Eggs
Okay, so you’re a woman in her thirties who wants to have children some day but has not yet met “Mr. Right”. What to do? Well, some women have made the decision to freeze some of their eggs before their reproductive clock stops ticking, just in case. The basic techniques are readily available at any fertility clinic; stimulate egg maturation hormonally, harvest some eggs, and then (instead of fertilizing and implanting them) just freeze them.
Worldwide, only about a thousand children have been born from previously frozen eggs. In contrast, over 50,000 babies are born each year in the U.S as a consequence of in vitro fertilization and implantation (Human Biology 5th ed., p. 394). Obviously, the idea of older single women freezing their eggs has not yet caught on. But it just might!
See “Why I Froze My Eggs”, by Rachel Lehmann-Haupt. Newsweek May 11, 2009, pp. 50-52.
Worldwide, only about a thousand children have been born from previously frozen eggs. In contrast, over 50,000 babies are born each year in the U.S as a consequence of in vitro fertilization and implantation (Human Biology 5th ed., p. 394). Obviously, the idea of older single women freezing their eggs has not yet caught on. But it just might!
See “Why I Froze My Eggs”, by Rachel Lehmann-Haupt. Newsweek May 11, 2009, pp. 50-52.
Kamis, 23 April 2009
Access to the "Morning-After" Pill
The F.D.A. is lowering the age limit for obtaining Plan B, the “morning-after” contraceptive pill. Soon anyone over the age of 17 will be able to purchase Plan B over the counter at pharmacies and health clinics, simply by providing proof of age.
News articles on the upcoming change appeared in most major papers yesterday, including the Los Angeles Times.
News articles on the upcoming change appeared in most major papers yesterday, including the Los Angeles Times.
Kamis, 09 April 2009
A DNA test for Cervical Cancer
It was bound to happen eventually. The annual Pap smear, the gold standard for over 40 years for detecting cervical cancer, may soon be replaced by a modern, much more specific DNA test for the human papillomavirus that is responsible for most cervical cancers. The cost of the test is currently around $20-30, but the test is so accurate and specific that women may only need the test once every 5-10 years.
A comparative study of the effectiveness of the new DNA test (HPV test) versus the Pap smear (cytologic test) in preventing cervical cancer deaths was conducted in India with funds provided by the Bill and Belinda Gates Foundation. After just eight years, the study showed that the DNA test reduced cervical cancer deaths by nearly 50% compared to the Pap test. Significantly, not one woman whose DNA test for HPV was negative died of cervical cancer during the study period.
A comparative study of the effectiveness of the new DNA test (HPV test) versus the Pap smear (cytologic test) in preventing cervical cancer deaths was conducted in India with funds provided by the Bill and Belinda Gates Foundation. After just eight years, the study showed that the DNA test reduced cervical cancer deaths by nearly 50% compared to the Pap test. Significantly, not one woman whose DNA test for HPV was negative died of cervical cancer during the study period.
Rabu, 04 Maret 2009
Designer Babies? - Not Yet!
On Tuesday, a fertility doctor with clinics in New York and Los Angeles said that within six months he would offer couples the chance to choose some of their baby’s physical traits. Dr. Jeff Steinberg said that his company, Fertility Institutes, would use in vitro fertilization (IVF) techniques combined with pre-implantation genetic diagnosis (PGD) to help couples select from among their IVF embryos for the one with the best chance of having their preferred hair and eye color and even skin tone. Fertility experts scoffed that it could be done with any reliability. And when right-to-life advocates objected strenuously and his clinic received hundreds of calls, Dr. Steinberg backed down – at least for now. According to an article in the Daily News later the same day, he said he’ll stick to helping couples concerned about known genetic disorders.
The unresolved issue of whether would-be parents should be allowed to create designer babies is a train wreck waiting to happen. New York, for example, does not have laws against using PGD strictly for cosmetic purposes, so clinics such as Dr. Steinberg’s are free to promise what they will. Nevertheless, it’s a slippery ethical slope they’re on. The issue is discussed in Human Biology 5th ed., pp. 396-397.
The unresolved issue of whether would-be parents should be allowed to create designer babies is a train wreck waiting to happen. New York, for example, does not have laws against using PGD strictly for cosmetic purposes, so clinics such as Dr. Steinberg’s are free to promise what they will. Nevertheless, it’s a slippery ethical slope they’re on. The issue is discussed in Human Biology 5th ed., pp. 396-397.
Jumat, 27 Februari 2009
The Dark Side of Gender Preference
In China, 120 boys are born for every 100 girls. Experts think that the recent trend (since 1980) is the result of China’s “one-child” population-control policy, combined with a traditional society in which the eldest boy inherits the family land and is responsible for taking care of aging parents. So if a couple is planning on having just one child, usually they will decide it should be a boy. The boy/girl sex ratio is highest in rural areas; in cities, the earning power of women tends to be accompanied by a more normal sex ratio.
What can be done about it? One approach is educational programs to encourage couples to value daughters equally with sons; another is to allow families whose first child is a girl to have a second child; still another is to encourage young couples to live with her parents rather than his. The government is even offering cash payments for girls in some regions.
What can be done about it? One approach is educational programs to encourage couples to value daughters equally with sons; another is to allow families whose first child is a girl to have a second child; still another is to encourage young couples to live with her parents rather than his. The government is even offering cash payments for girls in some regions.
Kamis, 05 Februari 2009
8 Babies - How Did It Happen?
Last week a 33-year-old unwed California women gave birth to octuplets. Experts say that there are only two plausible explanations; they could have been conceived naturally if the woman had taken heavy-duty fertility drugs and had ovulated eight eggs at once, or an IVF clinic deliberately implanted eight embryos, against all current IVF treatment guidelines.
The woman’s mother has said that the woman had frozen embryos left over from previous IVF cycles, and that she had embryos implanted last year. But who would implant eight embryos?! It’s no surprise that the woman’s doctor has not yet come forward to take “credit” for this feat. Ethicists and fertility specialists are in agreement that implanting eight embryos during one IVF cycle would be unethical and irresponsible. Doctors apparently offered the woman the opportunity to reduce the number of embryos early in the pregnancy, but she refused.
This one is likely to be debated for awhile by ethicists and fertility experts. It might even be discussed on Oprah's show some day soon, if the woman can get enough money to appear! Reports are that she is holding out for several million dollars. Good luck.
Note added April 20, 2009: Apparently six embryos were implanted, but two split into twins. The maximum number of embryos which should be implanted is two, according to voluntary guidelines established by the American Society for Reproductive Medicine.
The woman’s mother has said that the woman had frozen embryos left over from previous IVF cycles, and that she had embryos implanted last year. But who would implant eight embryos?! It’s no surprise that the woman’s doctor has not yet come forward to take “credit” for this feat. Ethicists and fertility specialists are in agreement that implanting eight embryos during one IVF cycle would be unethical and irresponsible. Doctors apparently offered the woman the opportunity to reduce the number of embryos early in the pregnancy, but she refused.
This one is likely to be debated for awhile by ethicists and fertility experts. It might even be discussed on Oprah's show some day soon, if the woman can get enough money to appear! Reports are that she is holding out for several million dollars. Good luck.
Note added April 20, 2009: Apparently six embryos were implanted, but two split into twins. The maximum number of embryos which should be implanted is two, according to voluntary guidelines established by the American Society for Reproductive Medicine.
Rabu, 17 Desember 2008
Frozen Embryo Dilemma
Fertility treatments and IVF procedures generally produce more viable embryos than are needed in order to achieve a successful pregnancy. So after a couple has a child by IVF, they must decide what to do with the “leftover” embryos. There are at least five choices: 1) freeze and save them for several years in case they choose to have more children, 2) discard them, 3) donate them for research, 4) donate them to another couple, and 5) leave them frozen until some other decision is made.
A recent survey published in the journal Fertility and Sterility (online Dec. 5) indicates that the decision is a difficult one, even for couples that do not want any more children. Over 40% would not feel comfortable discarding the embryos. And even though they no longer needed them for themselves, over 50% would not consider donating their embryos to another couple. Common reasons given were because they wouldn’t want their child brought up by another couple or because of the fear that their child might meet an unknown sibling someday. Forty percent would consider donating their unused embryos for research, but that option is not available at all IVF clinics. Faced with what they view as unacceptable options, twenty percent say they will keep the embryos frozen indefinitely. However, frozen embryos may not be viable after several decades, so this may ultimately be a decision to let the embryos die.
There are now more than 400,000 frozen embryos at IVF clinics. The authors of the survey suggest that potential parents need to be counseled thoroughly about the choices ahead of them before they choose IVF, not after.
What would your students choose to do if they had leftover embryos?
A recent survey published in the journal Fertility and Sterility (online Dec. 5) indicates that the decision is a difficult one, even for couples that do not want any more children. Over 40% would not feel comfortable discarding the embryos. And even though they no longer needed them for themselves, over 50% would not consider donating their embryos to another couple. Common reasons given were because they wouldn’t want their child brought up by another couple or because of the fear that their child might meet an unknown sibling someday. Forty percent would consider donating their unused embryos for research, but that option is not available at all IVF clinics. Faced with what they view as unacceptable options, twenty percent say they will keep the embryos frozen indefinitely. However, frozen embryos may not be viable after several decades, so this may ultimately be a decision to let the embryos die.
There are now more than 400,000 frozen embryos at IVF clinics. The authors of the survey suggest that potential parents need to be counseled thoroughly about the choices ahead of them before they choose IVF, not after.
What would your students choose to do if they had leftover embryos?
Kamis, 13 November 2008
Surrogate Grandmother
According to an Associated Press article that appeared in many major newspapers and news services yesterday, a 56-year-old woman gave birth last month to triplets. The event was noteworthy because the three baby girls were actually her biological granddaughters.
Apparently a young couple could not conceive because the woman had had a hysterectomy. So they used in vitro fertilization (IVF) to produce their embryos, which were then implanted into the young woman’s 56-year-old mother.
My class took quite an interest in the many and varied reproductive possibilities raised by modern IVF techniques. They understood the obvious benefit, which is to enable some infertile couples to have children of their own. They also quickly grasped that it could also be used (in combination with preimplantation genetic diagnosis) to choose a child’s sex, to avoid having a child with certain genetic disorders, or even to cure an older sibling of a genetic disorder (See the Current Issue in Human Biology 5th ed., pp. 396-397). But they didn’t come up with this scenario!
Apparently a young couple could not conceive because the woman had had a hysterectomy. So they used in vitro fertilization (IVF) to produce their embryos, which were then implanted into the young woman’s 56-year-old mother.
My class took quite an interest in the many and varied reproductive possibilities raised by modern IVF techniques. They understood the obvious benefit, which is to enable some infertile couples to have children of their own. They also quickly grasped that it could also be used (in combination with preimplantation genetic diagnosis) to choose a child’s sex, to avoid having a child with certain genetic disorders, or even to cure an older sibling of a genetic disorder (See the Current Issue in Human Biology 5th ed., pp. 396-397). But they didn’t come up with this scenario!
Langganan:
Postingan (Atom)