Infertility and its treatment can be a roller-coaster ride for patient and physician. Amid the emotional stress that arises, the goal of treatment can inadvertently shift from achievement of a successful singleton pregnancy to pregnancy at any cost—even high-order multiple gestation.
Here’s an essential question: Can the rate of multiple gestation be reduced without seriously compromising the pregnancy rate? Several developments of the past year suggest that it can be. In this article, we discuss:
- new guidelines that limit the number of embryos to be transferred at in vitro fertilization (IVF)
- strategies to reduce the risk of multiple gestation after controlled ovarian stimulation or ovulation induction
- the need to address the patient’s emotional status during treatment
- a new index that helps predict the pregnancy rate after surgical staging of endometriosis.
Multiple gestation is known to have adverse effects on infants, including a significantly elevated risk of prematurity and related physical and developmental problems. It also greatly increases the need for resources. And the high cost of caring for infants affected by prematurity further burdens an already overwhelmed health-care system.
Not only is it essential that we reduce the rate of high-order multiple gestation (i.e., more than two fetuses), but we should also attempt to lower the rate of twin pregnancy. A healthy singleton pregnancy, with its diminished risks and more reasonable health-care cost, should be our goal.
New guidelines limit the number of embryos to be transferred at IVF
Practice Committee of the American Society for Reproductive Medicine, Practice Committee of the Society for Assisted Reproductive Technology. Guidelines on number of embryos transferred. Fertil Steril. 2009;92:1518–1519.
Since the birth of Louise Brown in 1978, assisted reproductive technology (ART) has enjoyed dramatic technological advances. Intracytoplasmic sperm injection (FIGURE 1), preimplantation genetic diagnosis, and improvements in cryopreservation have broadened the application of ART and increased the live birth rate to 30% for every cycle that is initiated. The cumulative live birth rate from additional fresh and frozen-thawed cycles can reach 50% to 80%.
These gains have not come without cost, however. Multiple emotional, financial, and other variables affecting the practice of IVF have produced a higher-than-natural rate of multiple gestation.
In November 2009, the Society for Assisted Reproductive Technology (SART) and the American Society for Reproductive Medicine (ASRM) issued new guidelines limiting the number of embryos that should be transferred in one IVF cycle. IVF clinics are required to report outcomes, and approximately 93% of US cycles are reported to SART. High-order multiple-pregnancy rates are audited by SART, and outlier clinics must implement remediation programs to lower their high rate or risk expulsion from SART.
The increasing emphasis on single-embryo transfer in young women who have a good prognosis reflects the societies’ commitment to help patients achieve a healthy singleton pregnancy and good birth outcome.
FIGURE 1 A wonder of technology
Intracytoplasmic sperm injection overcomes many barriers to fertilization, such as severe malefactor infertility. At some institutions, the technique yields a fertilization rate of 70% to 80%.
What makes a “good prognosis”?
Identification of patients who have a good prognosis is an essential component of these new guidelines. The patient is more likely to have a favorable outcome if one or more of the following is true:
- She is undergoing her first cycle of IVF
- The embryos have good morphology
- Excess embryos are available for cryopreservation
- She has had earlier success with IVF.
The TABLE details the recommended number of embryos to transfer, based on the age and prognosis of the patient. In cycles that involve a donor egg, base the number of embryos to be transferred on the age of the donor. In cycles that involve a frozen embryo, base the number of good-quality, thawed embryos to be transferred on the age of the patient at the time the embryos were created. One additional embryo may be transferred if the patient has a less favorable prognosis or a history of two failed, fresh IVF cycles.
Two important requisites: Careful counseling about the risk of high-order multiple gestation, and documentation of that counseling.
SART and ASRM recommend limits on the number of embryos to be transferred at in vitro fertilization