How Successful is IVF?
In vitro fertilization (IVF) is a form of assisted reproductive technology where the egg and sperm are brought together in a laboratory culture dish. This is done to allow the sperm to fertilize the egg. After IVF, one or more embryos are placed into the uterus.
• Ovulation and Egg Retrieval – The first step in the IVF process is ovulation and egg retrieval. The woman receives hormones (gonadotropin-releasing hormone analogue) to stimulate egg production and control ovulation. After 10 days of medication, an ovary-stimulation hormone injection is given each day for two weeks. The doctor monitors the ovaries and follicles using transvaginal ultrasound and blood tests. Mature eggs are collected by needle aspiration using ultrasound guidance.
• Sperm Collection – The sperm are collected following masturbation or by taking the sperm from the testicle using a small needle. If frozen sperm are used, they are thawed on the day the eggs are collected.
• Fertilization and Embryo Transfer – The sperm and eggs are placed in a glass dish, and incubated for 48-120 hours. After fertilization occurs, the best eggs are selected for transfer. One to three embryos are placed inside the uterus using a thin, flexible catheter.
Birth rates from IVF vary, depending on the woman’s age. From a single IVF cycle, national birth rates for women age 34 and younger are around 30-40%. After age 35, the rates steadily decline. Aging of the egg supply greatly affects the chances that in vitro fertilization will result in pregnancy.
Cause of Infertility
Infertility can be related to the woman’s reproductive system, or it can be due to a problem with the male’s reproductive system. The actual cause of the infertility affects the success of IVF.
A woman who has at least one live birth already is more likely to have a successful IVF procedure than a woman who has never given birth. This is known as the ‘previous birth advantage,’ and it gradually narrows as a woman ages from her early 30s to her 40s.
Use of own Eggs
Many women age 40 years and older choose to use donor eggs, which can greatly improve chances of giving birth to a healthy baby. Birth rates are better when a woman uses her own eggs during IVF if she is young, but for older women, chances improve with donor eggs. Using her own eggs, the chance of having a live birth decreases from 40% in the late 20s, to 30% by age 38, and then down to less than 10% by age 43 years.
Frozen Eggs vs. Fresh Embryos
Frozen (cryopreserved) eggs from a donor used for IVF are less likely to result in a live birth than fresh, newly fertilized embryos. However, frozen embryos are less expensive and less invasive, as superovulation and egg retrieval are not required.
IVF Success Rates in the U.S.
According to a National ART Outcomes Report by the Center for Disease Control and Prevention (Cd), around 175,000 IVF cycles were performed in 2013 alone. The average success rates based on live births per transfer of fresh embryos were 48% for women age 34 and younger, 39% for women aged 35-37 years, 28.5% for women aged 38-40 years, and 16% for women aged 41 and 42 years.