The findings, reported in the journal Fertility and Sterility, may offer some guidance on a question under debate in the infertility treatment field: How many treatment cycles should a couple undergo before proceeding to another -- often more intensive and expensive -- form of treatment?
There are a number of options for treating fertility problems, depending on what the cause is, if that can be determined at all.
For women who have problems with ovulation, fertility drugs may be used to stimulate the ovaries to produce and release eggs. Another option is intrauterine insemination (IUI), where sperm are placed directly into the woman's uterus via a catheter; the treatment, often used in conjunction with fertility drugs, may be used in cases where the man has certain fertility problems (like a low sperm count) or the cause of a couple's infertility is unknown.
In-vitro fertilization, or IVF, is a higher-tech procedure where a woman's eggs are fertilized in a lab dish, and the resulting embryos are implanted in her uterus several days later.
In the new study, researchers at the University of California-San Francisco (UCSF) looked at the rates of success with these three treatments among 408 couples seen at one of eight infertility centers.
Of the couples, 21 percent did not undergo any of the three treatments, though some had other procedures that are not considered cycle-based, such as surgery to remove uterine fibroids (benign growths in and around the walls of the uterus). The group's rate of pregnancy over 18 months was 28 percent.
In comparison, couples who had one to two cycles of treatment with fertility drugs alone had a pregnancy rate of 85 percent. Those who underwent IUI had a pregnancy rate of 71 percent after one round of treatment, and 59 percent of those undergoing IVF became pregnant after one cycle.
However, the advantage of each of the three treatments declined after a certain number of attempts.
The six couples who had three or more rounds of fertility drugs alone had a pregnancy rate of 29 percent. Similarly, the advantage of IUI over no cycle-based treatment disappeared after the third attempt.
The advantage of IVF was no longer seen after the second try. Of the 52 couples who made three or more attempts, 35 percent became pregnant.
Based on these findings, and those from past studies, it seems clear that individual treatments have diminishing success over time, lead researcher Dr. James F. Smith, an assistant professor of urology at UCSF, told Reuters Health in an email.
Medications only, IUI and IVF are all effective treatment choices, but their benefits don't continue indefinitely, he explained. If couples are not getting pregnant after several cycles of each, a change to a different strategy is probably warranted.
There are a number of factors to consider in choosing a fertility treatment, including the intensity and cost. Smith pointed out that IVF is much more involved than either drugs or IUI, and includes many more clinic visits, daily medication injections and more discomfort.
Accordingly, the costs are far greater. In this study group, for example, the average cost of medication-only cycles over 18 months was about $1,200. That, Smith said, compared with $3,600 to $8,600 for 18 months of IUI, and $24,000 total for IVF.
In the U.S., the average cost for one cycle of IVF is $12,400, according to the American Society for Reproductive Medicine. Insurance coverage varies, depending on the plan and where one lives, as states have different laws regarding coverage of infertility treatment.
But for couples, the greater intensity and cost of treatment has to be balanced against the decreasing likelihood of success, and the emotional toll, of continuing with a less-intensive tactic that has so far not worked.
Smith said that in general, the per-cycle success rate is higher with IVF than with IUI.
Couples who do not become pregnant after a couple cycles of IVF still have some options. Smith said they might consider using donor eggs or sperm (the IVF group in this study did not use donors). Changes to a couple's particular IVF protocol might also be an option.