Being pregnant with twins is riskier than a singleton birth, no question. There are many more complications for both mother and babies. However, many couples undergoing in vitro fertilization (IVF) want to transfer more embryos in order to ensure they have a pregnancy and birth. But if you knew you were very likely to get pregnant with twins, would you still ask your fertility doctor to transfer more than one embryo?
A paper published in Fertility and Sterility reports the results of an advanced statistical method — which takes into account such factors as total motile sperm and Day 3 FSH levels — that can reliably predict an individual IVF patient's chance of conceiving multiples before the embryo transfer. The authors applied an advanced statistical prediction analysis to 2,413 double embryo transfer cycles at Boston IVF that resulted in live births from 2000 to 2009. They found that individual IVF patients have different risks of multiple birth probabilities, ranging from 11.8 percent to 54.8 percent. In more than half the patients, the rates were significantly different from probabilities based solely on age.
"Today, IVF patients and their physicians struggle with the choice of how many embryos to transfer," says Mylene Yao, M.D., one of the article's authorsand co-founder and CEO of Los Altos, Ca.-based Univfy Inc., developers of prognostic technology for fertility patients. "There is a general concern that transferring only one embryo can compromise the chance of pregnancy, and transferring even two embryos may raise the risks of multiple birth and associated obstetrical and neonatal complications. Personalized predictions of multiple birth risks enable patients and physicians to make safer and more informed embryo transfer decisions, while aiming to reduce incidence of unplanned multiple births."
After a cancer diagnosis, treating the disease often poses a threat to a man or woman's fertility. As treatments for cancer have advanced, so have methods to preserve fertility, and now women can freeze their eggs, men can freeze their sperm, and couples can freeze their embryos prior to undergoing potentially lifesaving treatments
Polycystic ovarian syndrome (PCOS) is often treated with progestin, a synthetic progesterone in birth control pills. Progestin is often used as the first step in fertility treatment for women with PCOS in order to regulate the menstrual cycle, and it can improve other symptoms of PCOS such as acne, male-type hair growth and male pattern hair loss.
Now a new study by the National Institutes of Health (NIH) research network finds that the hormone appears to decrase the odds of conception and giving birth in women with PCOS. The researchers found that women who skipped progestin treatment before receiving fertility drugs were four times more likely to conceive than were women given progestin.
"These are interesting findings, which are counter to the general thinking that inducing a period with Progestins BEFORE starting ovulation–inducing medications is necessary," says Laurence Jacobs, M.D., a fertility doctor with Fertility Centers of Illinois. "Since progestins are not natural hormones, it is not clear if this negative effect will also apply to the use of ‘natural progesterone’ to induce a period. More studies are needed."
PCOS is a hormonal disorder in which the ovaries, and sometimes the adrenal glands, produce excess amounts of androgens such as testosterone. Women typically have irregular menstrual periods and may have trouble getting pregnant. Often, they are treated with ovulation induction with the fertility drug clomiphene (Clomid), and before they receive ovulation induction, they may be given a single course of progestin in order to stimulate the bleeding that occurs during the monthly menstrual cycle.
Men, if you're a serious cyclist, you may want to downgrade your level of participation to recreational if you and your partner are trying to get pregnant. A new study out of the UCLA School of Nursing found that serious leisure male cyclists may experience hormonal imbalances that could affect their reproductive health.
"Although preliminary, these findings warrant further investigation to determine if specific types of exercise may be associated with altered sex hormone levels in men that could affect general health and reproductive well-being," says Leah Fitzgerald, Ph.D., FNP-BC, assistant professor at the School of Nursing and senior author of the study, which was published in the European Journal of Applied Physiology.
While many have theorized that cycling can affect male fertility because increased scrotal temperature can reduce sperm production, researchers at UCLA investigated the association between exercise intensity and circulating levels of the reproductive hormones, such estrogen and testosterone, in serious leisure male athletes (triathletes and cyclists) and recreational athletes. There were 107 healthy male athletes, ages 18 to 60, who participated and filled out the International Physical Assessment Questionnaire to obtain an objective estimate of time spent participating in different levels of physical activity and inactivity during the previous seven days. The researchers divided the participants into three groups — 1) triathletes, 2) cyclists and 3) recreational athletes.
Declining fertility rates are one of the factors driving a decline in U.S. population growth, according to a Population Reference Bureau (PRB) analysis of U.S. Census Bureau data. Lower immigration levels and population aging are additional factors in declining population growth.
According to the analysis, from 2010 to 2011, the U.S. population grew 0.7 percent after averaging 0.9 percent each year from 2000 to 2010.
"There's two parts of this," says Mark Mather, PRB associate vice president for Domestic Programs. "There's the declining fertility rate, which is the number of births per woman, and there's the declining total number of births, which is a different issue and sometimes caused by other factors, including trends in immigration. If there's fewer people living in the United States who are of reproductive age, then that can also contribute to a decline in the number of births just because there's fewer potential parents."
Researchers are increasingly finding genes that are linked to fertility, such as the recent British study that identified a gene in mice that is important in sperm to egg binding. Now, scientists at the University of North Carolina at Chapel Hill Nutrition Research Institute have found a possible genetic cause for some cases of male infertility in humans and published their findings in PLoS One.
Led by Amy Johnson, Ph.D., the study found that a genetic variant, called a single nucleotide polymorphism (SNP), is more common in men with compromised sperm motility (sperm movement). Sperm have to be able to propel themselves and move forward to successfully fertilize an egg.
During the past few weeks, several studies have come out with alarming headlines about fertility treatment, with the most recent linking a type of fertility treatment to birth defect risk in the resulting children. Other recent studies have linked fertility treatment to childhood leukemia and circulatory problems in children.
If you are a fertility treatment patient, try to put the studies into perspective. There are many factors that can increase the risk of a certain condition, but the overall risk may remain relatively low.
Fertility Treatment and Birth Defects Study
Researchers have known for a while that babies born via assisted reproductive technology (ART) are more likely to have birth defects. A recent study, published in the New England Journal of Medicine, suggests that two things play a role in this: certain fertility treatments and infertility itself.
“This study confirms what has been known for quite some time: Patients who need medical assistance to conceive have a somewhat higher risk of having children with birth defects than parents able to conceive on their own," says Linda Giudice, MD, PhD, a fertility doctor with UCSF Center for Reproductive Health and president-elect of the American Society for Reproductive Medicine (ASRM). "Patients considering medically assisted conception have been, and should continue to be, counseled on those risks prior to undergoing any treatment.”
There have been several new developments in male fertility research recently.
Male Fertility Gene Discovered in Mice
British researchers have identified a gene in mice that is important for the process of sperm-to-egg binding. The gene makes a protein called PDILT, which enables sperm to bind to an egg and is essential to fertilization.
Catherine, the writer and creator of Making Babies in Brooklyn, a blog not only about her personal experience going through IVF, but one that tries to shed some light on an often opaque and confusing process.