Within one 24-hour period last week, I read two news articles on in vitro fertilization (IVF) that had completely opposite messages. One said that IVF success rates are upwards of 90% while the other said that less than 25% of women get pregnant after IVF. So what is the truth?

The Society for Assisted Technology (SART) is the principle professional organization for fertility specialists in the United States. Each year SART collects information from the nation’s fertility clinics, compiles them, and publishes them online. This allows patients and health care providers to both understand the fertility clinic success rates in their area and determine how that stacks up against the national average. For example, I was able to find out that in 2009, the most recent year available, there were more than 140,000 IVF cycles done in the US. Of those, 47% of cycles resulted in pregnancies for women under age 35 and 41% of cycles resulted in live births. So why does the media have such conflicting reports? Here is the fine print:

Age: The statistics I mentioned above were for women age 35 and younger. As in nature, older women are less likely to get pregnant from IVF and be able to carry a baby to term than younger women. For example, birth rates from IVF drop to 31% for 35-37 year olds, 22% for 38-40 year olds, 12% for 41-42 year olds, and 4% for women older than 42. Much of this age-related decrease is due to the fact that older women are less likely to respond to the hormones that cause the release of multiple eggs retrieved from a woman’s ovaries before IVF. This is good news for many oncofertility patients since younger women tend to respond better to hormones. One caveat for cancer survivors is that some cancers and their treatments may also affect the uterus and the ability to carry a child to term.

When comparing different fertility centers it is also important to note that the demographics of patients may vary between centers. In fact, the SART statistics include the following disclaimer,  “Caution: Patient characteristics vary among programs; therefore, these data should not be used for comparing clinics.” Besides age, differences in the overall health of the patients and diagnosis that causes infertility may affect success rates.

Number of Cycles: Another factor in IVF rates is number of cycles a woman undergoes and the SART database includes statistics on the success of each IVF cycle. Some women are able to participate in multiple cycles if the first one does not result in a baby. However, young cancer patients may not have time to undergo more than one egg retrieval cycle before starting fertility-damaging treatment. In addition, as the cost of IVF can be more than $10,000 and not all insurance covers treatment, multiple cycles can be financially prohibitive.

Multiple births: Between 15 and 30% of deliveries from assisted reproductive technologies result in multiple births, such as twins, compared with 1-2% in spontaneous pregnancies.  This is a result of implanting more than one embryo in a woman’s uterus after IVF. The industry standard is to transfer up to 2 embryos into a woman at a single time, although the American Society for Reproductive Medicine does authorize the transfer of more than 2 embryos for women over 38. Interestingly, implanting more embryos does not generally seem to increase the chance of pregnancy-just the chance of a multiple pregnancy. Since multiple pregnancies also increase the risk of complications it is important to examine the average number of embryos transferred at a clinic.

For all women, especially cancer survivors, it is important to keep in mind that a lot of factors go into the IVF success rates. Thus, many media reports can include information that is not completely accurate. Read additional mythbusters in oncofertility.

In preparing for fertility preservation, cancer fighters may worry about the risks of fertility preservation on the health of their future children. Fertility techniques, such as in vitro fertilization (IVF), produced more than a million babies over the past 30 years. As such, it is important to know whether egg banking , embryo banking, or other forms of fertility preservation cause birth defects in children ranging from cleft palate to neurodevelopmental disorders.

Studies do report that congenital malformations and birth defects increase slightly in couples using infertility treatments. Two other issues may be at play in these cases. First, parental factors affect the likelihood of birth defects. A Swedish study found that babies born to infertile couples (those who failed to get pregnant within a year of trying) had higher rates of congenital malformations, whether or not they used assisted reproductive technologies. This suggests that parental background may play a greater role than infertility treatment in the risk of childhood birth defects.

In addition, couples using fertility treatments often give birth to two or more children at one time. Multiple births in one pregnancy are associated with low birth weight and increased risks for growth problems. Some studies that find a rise in birth defects after infertility treatment also determine that these risks are minimized or eliminated when only one baby is born from each pregnancy. (Interestingly, there is a correlation between mandated health insurance coverage for infertility treatment and birth number that I will discuss at a later date).

There is evidence that infertility treatment may increase the risk of specific types of genetic diseases, called imprinting disorders. Some genes are expressed in a parental-specific manner. For example, a child may express the copy of a gene that they received from their mother but not their father. If, for some reason, the paternal gene is expressed, the child may develop abnormally. Some of the most well-know imprinting disorders are Beckwith-Wiedmann and Angelman syndromes, which normally occur in one out of every 10,000-20,000 children. While some studies did not find an increased risk of imprinting disorders after assisted reproductive technologies, others estimate that the risk may be as high as 4 times the risk in the general population. Further investigation is still ongoing to determine the likelihood of these disorders after fertility preservation and to find whether some techniques have higher risks than others.

Overall, birth defects occur in just under 2% of all births conceived naturally. When using fertility treatments such as IVF, this number increases to about 3%. Cancer survivors who understand the risks can also do their part in making the healthiest baby possible after fertility preservation, such as getting appropriate prenatal care and medical advice.

Poor cell phones. Having been blamed for everything from plane crashes to malfunctioning hospital equipment and exploding gas stations, it is a surprise that people still use them. Of special interest to the Oncofertility Consortium, cell phones have also been held responsible for causing cancer and infertility in men! So we are here to separate fact from fiction about your mobile device.

Cancer. Mobile phones give off electromagnetic radiation in the same range as microwaves. While some people believe that such low-intensity waves induce DNA mutations, there is no consistent evidence that cell phones cause cancer. Because most people hold their cell phones to their heads (I can’t with my new iPhone but that is a different story) special interest is given to the relationship between cancer and mobile devices. A recent study from the National Cancer Institute looked at brain cancer rates from 1977, before widespread cell phone use, to 2006. In addition to not seeing an increase in brain cancers as cell use became popular in the mid-1990s, the group actually noticed that brain cancers were either unchanged or decreased between 1992 and 2006!

The information about male infertility and cell phones is a little more complicated than the cancer myth.  Some studies do find differences in sperm movement and speed between cell phone users and non-users. However, the most significant findings in these studies compared people who don’t use cell phones to those who use cell phones for more than 4 hours per day. In addition, some studies suggest that carrying cell phones in a hip pocket or on a belt while using a hands-free headset may have a greater effect on sperm quality. It is important to note that most studies looking at this relationship examined relatively few people and further investigation is needed. In the meantime, it is probably wise to restrict your cell phone use to a reasonable amount of time. Who talks for 4 hours a day anyway?

Now before you start imagining Grandma with a bump, let me explain. Originally the term “geriatric pregnancy” was meant to describe the pregnancy of a woman who was 35 years or older. At some point (probably after being verbally and physically assaulted by hormonal mommies-to-be) the medical community decided to change that term to “advanced maternal age.” Now on to the mythbusting!

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In recent years, women have started childrearing later in their lives due to multiple reasons. From increased birth control and higher career goals to longer life expectancy, women are choosing to have children later. In the ten years prior to 2000, the average age a woman gave birth to her first child increased from 25 to 27 years old. As pregnancies in older women become more common, so do the myths about these pregnancies.

Women have to deal with common misconceptions including infertility. Media reports often suggest that decreased fertility is a severe problem as early as the late 20s. In reality, the risk of sterility is present at low rates even in the early 20s and increases slowly over time. At age 34 only 10% of women are sterile and that increases to 85% by age 44. In contrast to female infertility, it is rarely mentioned that male age also has an effect on infertility. It may be of interest to cougars everywhere that younger men have lower rates of infertility than older ones.

Once a woman over age 35 gets pregnant, she must often deal with assumptions about the health of her pregnancy and child. Maternal or fetal health complications can lead to early labor. Some studies have found that older mothers are at higher risk for preterm labor but these reports are conflicting. Generally, older women are not at increased risk for early labor before 32 weeks (37 weeks is considered normal for delivery). However, very preterm birth (before 28 weeks) is increased in older women. Interestingly, low-birth-weight babies have increased survival rates when they are born to older women-possibly due to better emotional, financial, and medical support.

Another common myth is that mothers with advanced maternal age are at very high risk for birth defects, such as Down syndrome. While this risk does increase over time, only 0.8% of babies born to 40-year-old mothers have Down syndrome. By age 45, this risk increases to 3.5%. It is also important to note that 80% of children with Down syndrome are born to women under age 35, since that is when most women have children.

As usual, the myths tossed around about older women and pregnancy are never as simple as they seem. However, women of any age that have been trying to get pregnant for a year should see a fertility specialist. By age 35, it is suggested that women see a health care practitioner about their fertility if not pregnant after 6 months of trying.

This week we will explore some common and not-so-common misconceptions in fertility, cancer, and oncofertility.

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Mythbuster: The Day “The Rabbit Died”

Nope, this is not a new rendition of “Bye-bye, miss American pie” by Don McLean. “The Rabbit Died” used to be a common phrase referring to a positive pregnancy test and originates from the first tests that were developed in the 1920s. The initial pregnancy tests involved injecting a woman’s urine into a female rabbit-strange but true!

If the woman were pregnant, her urine would contain trace amounts of the hormone, human chorionic gonadotropin (but most people call it hCG). Interestingly, hCG in the urine of a woman can also affect female rabbits. In response to hCG, the ovaries of a rabbit respond by swelling in size and turning a bright yellow color, essentially what happens to the woman’s own ovaries. To investigate the rabbit’s ovaries, scientists originally had to kill all of rabbits that were injected with urine. As such, the rabbit died whether or not a woman was pregnant. So, literally, the day the rabbit died, would have had absolutely no relevance to pregnancy.

Rabbits were not the only animals sacrificed during these early tests. Mice and frogs were also used. During later renditions of the test, clinicians learned how to investigate ovaries without killing the animals at all. While we no longer have to rely on animals to determine pregnancy, modern day tests still measure the hCG in urine.

It is not understood how this fallacy became part of the American lexicon but a large number of television shows and movies make allusions to rabbits and pregnancy. In 1978, a young Billy Crystal even played a pregnant man in the movie “Rabbit Test.” More recently, an episode of House also made an obscure reference to the rabbit test in pregnancy. Tell us if you see other allusions to the rabbit test in movies and television!