Assisted reproductive technology (ART) has been a part of modern medicine now for over 30 years and in the US alone over 132,000 IVF cycles were performed in 2007. All birth outcomes are reported to the Centers for Diseases Control but there is no mechanism for long-term follow-up of IVF births.

Well over a million babies have been born world wide through IVF and new data are emerging about reproductive birth outcomes after conception. Some countries, particularly the Scandinavian countries, do an excellent job on gathering data for all births, including IVF-conceived births. One of the greatest risks of ART is prematurity from multiple gestation. From several of these databases, it has become apparent that even singleton IVF births are statistically associated with poorer birth outcomes. Lower birth weights, pre-term delivery and infants small for gestational age (i.e. lower weight than expected for number of weeks in utero) are some of the findings from follow up of IVF babies.

These findings beg the question: is it something about IVF, namely the culture of the early embryo in a lab for the first three to five days of life, that results in these poorer outcomes, or is it something about the couples that need IVF to conceive that is associated with them? This can be a difficult issue to sort out because relatively few people undergo IVF who are not infertile.

A recent study from Norway was published in the British medical journal Lancet that tried to address this question by comparing IVF babies with their spontaneously-conceived siblings. The study compared 1,200,922 spontaneously-conceived live births and compared them with 8,229 live births after ART between January 1984 and June 2006. Of those women who had given birth to a singleton infant after ART, 2,456 also delivered a singleton infant after spontaneous conception. In 56% of the cases, the ART baby was born first and in 44% the ART baby was conceived after the birth of the spontaneously-conceived infant. The researchers looked at birth weight, gestational age as well as a number of other factors.

Compared with women in the general population that delivered a spontaneously-conceived birth, the women that delivered after IVF were older, less likely to smoke and had fewer previous births. Induced labor and cesarean section were more common in the IVF moms. The difference in birth weight between ART and non-ART babies was 131 grams (4.6 ounces). That is, the ART babies weighed, on average, 4.6 ounces, or about 3/4 pound less than the spontaneously-conceived babies. After statistical adjustment for gestational age, maternal age, prior births, year of birth, the difference in birth weight between ART and non-ART babies was 25 grams (0.88 ounces). The ART babies were born, on average, 3.7 days earlier than the controls. After statistical adjustment, the number of days of total gestation was 2 fewer days. Because of the large sample size, these were statistically significant differences but realistically, they were probably not clinically significant.

In comparing the sibling relationship ART vs. non-ART births, the differences were even smaller. The difference in birth weight was only 87 grams (about 3 ounces) for the ART babies as compared to their spontaneously-conceived siblings. The gestational age differences at birth were 1.3 days less for ART. After adjustment, these differences were only 9 grams and 0.6 days. These differences were not even statistically significant.

From these data, we can see that ART births do show statistical differences in some birth outcomes as compared to spontaneously conceived births. However, none of the differences seem are to an extent that would have any real clinical meaning. These differences tend to disappear to a large extent when comparing siblings from both spontaneous and IVF conception, suggesting that it is something about the families that utilize ART, rather than the technique itself that may be associated with the outcome differences.

In the press today we see that the “world’s oldest new mom dies” at age 69 (see our earlier blog post clarifying that PFC did not treat this patient), three years after giving birth to twins conceived through IVF. Maria del Carmen Bousada apparently lied about her age to the Los Angeles Physician who helped her become pregnant, creating a firestorm of criticism in the press.

The case demonstrates one of the most basic dilemmas that we face in helping women become pregnant: at what age is a woman too old to become a mother?

Most of us might agree that a 25 year old woman is young enough to receive help, but that a 70 year old is too old. However, drawing the cut-off line at some point between these extremes is not easy. With the help of in vitro fertilization and donated oocytes, women like Maria can become pregnant at an age where nature would naturally prevent the possibility of conceiving. Typically, women run out of oocytes in their early 50’s and without oocytes and the granulosa cells that surround them, they lose their ability to make estrogen. This natural process, called menopause, can happen earlier or later for a given individual, but the ability to get pregnant and deliver a healthy baby declines rapidly for women in their late 30’s and on into their 40’s. The age of the woman is a determining factor of her since a 40 year old woman is trying to get pregnant with a 40 year old oocyte, and these older oocytes don’t perform well. For example, the older oocyte is not good at keeping track of its own DNA, as evidenced by the increasing incidence of genetic defects such as Down syndrome in older mothers. And as if this wasn’t bad enough, the rate at which oocytes are lost from the ovaries (also know as a woman’s biological clock) doubles at about age 38. If this doubling didn’t happen, we think that women wouldn’t reach menopause until their early 70’s. It is thought that the speeding up of the biological clock in the late 30’s is nature’s way of clearing out the remaining oocytes, so that women lose their ability to become pregnant but are then around to raise the children that they already have.

Based on nature’s model, we might consider limiting IVF treatment to women that are in their early forties or younger. But with donated oocytes, this limit can be pushed and there are no legal age limits for pregnancy. So, who gets to decide when it’s too late to become pregnant? As far as following “nature’s model”, is age different than other factors that lead to infertility? Do we make rules? And do the rules apply to men too, where nature doesn’t have limits?

Note: Pacific Fertility Center does have both lower and upper age limits in place.

News broke earlier today about the death of a 69 year old mother who had undergone fertility treatment at age 66. She gave birth to twins in December 2006.

This is a very unfortunate incident and we express condolences to the loved ones, especially the children who are left behind. However, it is necessary to clarify that Pacific Fertility Center was not involved in the treatment of this patient. The AP article printed the name of the clinic as “Pacific Fertility Center”, which is an error of ambiguity since there are two fertility clinics with similar names. The fertility clinic where this woman received services was Pacific Fertility Center-Los Angeles. Our center, which is located in San Francisco, has no affiliation with the clinic in Los Angeles. While our names are similar, our standards of practicing medicine are much different. To begin, here at Pacific Fertility Center in San Francisco, it is standard procedure to verify the identity and age of the persons being treated at every visit.  Our physicians would not have treated a woman at the age of 66, since we believe this to be unethical. At Pacific Fertility Center in San Francisco, we believe it is our foremost and ethical responsibility to assure the children that are a result of our services are provided loving and caring families.

It is always frustrating, both for patient and physician, when we perform a full fertility evaluation and conclude that that patient’s diagnosis is “unexplained infertility.” But unexplained infertility does not mean “no” infertility. It means that we recognize there is some abnormality or inefficiency in the process of getting pregnant, but that we do not have a good test to assess what is the actual problem.

There are many critical steps in the process of getting pregnant which we can not directly assess; such as how efficiently the eggs are captured by the fallopian tubes, how efficiently the tubes push the eggs along to the uterus, how well the sperm are fertilizing the eggs, how well the fertilized eggs are developing to embryos, and how efficiently the embryos find their way to the uterus. All these steps are critical—yet we have no direct test. If one were to proceed to an IVF cycle, we can then make some assessment of these steps, but not prior.

So, if the evaluation shows normal egg quality (FSH, Estradiol, ultrasound), dye study (HSG) shows open tubes, sperm test shows normal count and motility, and there is no evidence of endometriosis—this typically defines unexplained infertility.

One of the first studies addressing the efficacy of treatment for unexplained infertility was published in 1998 (1), and indicated that patients who underwent no treatment had a 1-4% pregnancy rate per month; insemination alone, 3.8% pregnancy rate/cycle; clomid alone, 5.6% pregnancy rate/cycle; Clomid plus insemination, 8.3% pregnancy rate/cycle; gonadotropins alone, 7.7% pregnancy rate/cycle; and gonadotropins plus insemination 17.1% pregnancy rate/cycle. This study was retrospective, and did include patients with mild endometriosis, so while providing good insight, more studies were needed to better define treatment efficiency for these patients. However, it was important to see that insemination alone did not provide an improvement, and best improvement was noted with combination therapy.

Next, Guzick and colleagues published a large randomized study addressing superovulation with gonadotropins and insemination, for patients with unexplained infertility (though again mild endometriosis was included) (2). The control group was patients who had intracervical inseminations (to assure sperm exposure). Pregnancy rates for this group were 10% per cycle. Those who underwent intrauterine insemination had an 18% pregnancy rate. Those who underwent gonadotropin stimulation plus intracervical insemination have a 19% pregnancy rate, verses 33% for those with gonadotropin plus intrauterine insemination. Therefore, couples who undergo superovulation and intrauterine insemination have a 3 times higher chance of achieving a pregnancy, than the control group.

The question of which type of ovulation induction agent to use, oral verses injectable, has been addressed in a meta-analysis published in 2002 (3). This review of 5 randomized controlled trials shows that pregnancy rates were higher in injectable cycles (gonadotropins), though live-birth rates were not different between oral and injectable cycles. Their conclusion was that oral agents may therefore be more suitable for ovulation induction, since the multiple rates were lower, and cost of the cycle less.

Last year, a prospective trial looking at using oral Clomid verses Letrozole with inseminations in patients with unexplained infertility was published (4). This study showed that the total number of follicles was greater for the Clomid users (3.1 vs 1.6), but the pregnancy rates were the same for each group (Letrozole 19%/cycle verses Clomid 18.3%/cycle). Therefore, both agents are equally effective, and the multiple rate may be less with Letrozole.

Last year, another randomized control trial evaluated expectant management (no treatment), verses Clomid alone or intrauterine insemination alone in patients with unexplained infertility ( though included mild endometriosis patients) (5). This study again confirmed that Clomid alone (14% live-birth rate) or insemination alone (23% live-birth rate) was not statistically different than expectant management (17% live-birth rate). They evaluated patient satisfaction with the treatment process, and patients who were randomized to the “expectant management” arm were much less satisfied than those who were doing Clomid or insemination therapy, despite no improvement for those patients’ live-birth rates.

So, some take home points are as follows:

• Unexplained infertility does not mean “no” infertility
• Empirical clomiphene and/or unstimulated intrauterine inseminations are unlikely to offer an improvement over expectant management (no treatment)
• Best options are to consider Clomid or gonadotropins with intrauterine inseminations (depending on patient age, etc..)
• If this fails, then IVF is best option
• Depending on age and other evaluation, IVF may be best first option

Footnotes:

1. Guzick DS, et al. Efficacy of treatment for unexplained infertility. Fert Ster 1998; 70:2, 207-213.
2. Guzick DS, et al. Efficacy of superovulation and intrauterine insemination in the treatment of infertility. N Engl J Med 1999;340;177-83.
3. Athaullah N, et al. Oral vs injectable ovulation induction agents for unexplained subfertility. Cochrane Database Syst Rev 2002;3:CD00352
4. Badawy A, et al. Clomiphene citrate or aromatase inhibitors for superovulation in women with unexplained infertility undergoing intrauterine insemination: a prospective randomized trial. Fert Ster Aug 2008
5. Bhattacharya S, et al. Clomiphene Citrate or unstimulated intrauterine insemination compared with expectant management fro unexplained infertility: pragmatic randomized controlled trial. BMJ 2008;337:a716

At Pacific Fertility Center, we consider very carefully the number of embryos we transfer to each patient. Our goal is to create a healthy singleton pregnancy. We do our best to avoid multiple gestations. Consequently, in many cycles where we think that the chance of pregnancy is extremely high, we transfer only a single embryo. Our outstanding and robust embryo cryopreservation program preserves all embryos that were not transferred in the fresh cycle. Patients who transfer only a single embryo can feel secure in knowing that there are frozen embryo(s) available should they be needed.

Recently, we completed our analysis of the cumulative pregnancy rates per cycle for 2007. This type of report represents the overall pregnancy chance from a single IVF treatment cycle. This data was not available previously as many patients delay their use of frozen embryos. This cumulative analysis looks at the chance of pregnancy from a single IVF cycle when using both fresh embryos and subsequent frozen embryos, if needed.

Table 1 shows the rates for patients that used their own eggs (oocytes).
Table 2 shows pregnancy rates for patients that were the recipients of donor oocytes.

Please note that these are not delivered pregnancy rates. Many of these pregnancies are ongoing. There are also some patients that have not yet achieved pregnancy, but have frozen embryos remaining.