IVF: What Are The Risks?
I am undergoing in vitro fertilization. What are the major risks of this procedure?Question:
In vitro fertilization (IVF) involves the stimulation of multiple ovarian follicles in the woman, retrieval of oocytes via transvaginal aspiration, fertilization of oocytes in the laboratory and the transfer of embryos into the uterus.
There are a number of recognized risks associated with in vitro fertilization. These risks include -- but are not limited to -- the possibility for failure, multiple pregnancies, cancellation, ovarian hyperstimulation syndrome and ectopic pregnancy.
The risk of failure from IVF is dependent upon a couple's particular diagnostic category. It may range from 25 percent to 90 percent. Women with a previous tubal ligation may have "take home" baby rates of 70 to 75 percent, while couples with severe male factor associated with advanced maternal age may have less than a 10 percent chance per cycle.
Multiple pregnancies occur in approximately 10 to over 30 percent of cycles. The number of embryos transferred is the critical determinant of the risk. Your physician will determine with you the number of embryos to be transferred. Reproductive endocrinologists, who are trained in obstetrics, gynecology and infertility, are clearly aware of the complications for both the mother and babies of high order multiple pregnancies. They utilize techniques which are designed to avoid multiple pregnancies.
In GIFT and IVF, standards regarding the number of eggs and sperm or embryos transferred, respectively, have been established by the American Society of Reproductive Medicine. Adherence to these guidelines helps to reduce the incidence of high order multiple pregnancies.
Cancellation occurs because a woman either over responds or under responds to her ovulation induction regimen. The rates of cancellation range from approximately 5 to 25 percent. There is an overall tendency for a higher cancellation rate in women older than 39 years of age. This is usually due to an inadequate response to stimulation.
Ovarian Hyperstimulation Syndrome (OHSS) occurs when too many ovarian follicles have developed. It consists of a marked ovarian enlargement, high estradiol levels and the accumulation of fluid in the pelvic/abdominal cavity. This accumulation of fluid is the result of increased vascular permeability and a shift of fluids and protein from the vascular system into the abdominal cavity. The decrease in intravascular fluid volume results in thickened blood, diminished perfusion of organs and an increased risk of blood clot development. When it appears that OHSS is developing, the patient may: be canceled; continue with the known risks of this disorder; "coast" in her stimulation regimen in order to reduce the risks; or, cryopreserve all embryos for a delayed primary transfer.
Ectopic pregnancies after IVF occur in approximately two to five percent of couples. It appears that tubal factor infertility is the most prominent risk factor for an ectopic pregnancy after IVF. Other risk factors that may increase the incidence of ectopic pregnancy with IVF are previous abdominal surgeries, previous ectopic pregnancy or pelvic infection, presence of a hydrosalpinx or fibroid and the type of transferred catheter used.
An epidemiological study in 1992 by Whittemore and colleagues suggested a strong association between the use of infertility drugs and ovarian cancer. Unfortunately, there were significant methodological errors in the study. Prospective studies have not demonstrated a clear risk between gonadotropins use and ovarian cancer. Obtaining a pregnancy significantly reduces the risk of ovarian cancer. Thus, the potential risk of ovarian cancer caused by the use of gonadotropins may be completely offset by a pregnancy. Women who may be at a greater risk of ovarian cancer (family history, polycystic ovary syndrome, family history of colon cancer) should be notified of their own inherent increased risk.
Additional risks of IVF include: injury to the bowel, bladder, blood vessels or ureter during the transvaginal retrieval; the need for further surgical interventions; bruising pain and infections around injection sites; allergic reactions to medications.
Your reproductive endocrinologist will be able to detail for you your inherent risks and assist you in weighing them against the benefits of treatment.Answer: