What is IVF?
Infertility is when a couple cannot conceive (get pregnant) despite having regular unprotected sex.
Normally, an egg and sperm are fertilized inside a woman’s body. If the fertilized egg attaches to the lining of the womb and continues to grow, a baby is born about 9 months later. This process is called natural or unassisted conception.
IVF is a form of assisted reproductive technology (ART). This means special medical techniques are used to help a woman become pregnant. IVF has been successfully used since 1978. It is most often tried when other, less expensive fertility techniques have failed.
What Causes of Infertility Can IVF Treat?
When it comes to infertility, IVF may be an option if you or your partner has been diagnosed with:
- Low sperm counts
- Problems with the uterus or fallopian tubes
- Problems with ovulation
- Antibody problems that harm sperm or eggs
- The inability of sperm to penetrate or survive in the cervical mucus
- An unexplained fertility problem
IVF is never the first step in the treatment of infertility. Instead, it’s reserved for cases in which other methods such as fertility drugs, surgery, and artificial insemination haven’t worked
There are five basic steps to IVF:
Step 1: Stimulation, also called super ovulation
Medicines, commonly called fertility drugs, are given to the woman to boost her egg production. Normally, a woman produces one egg per month. Fertility drugs tell the ovaries to produce several eggs. During this step, the woman will have regular trans-vaginal ultrasounds to examine the ovaries and blood tests to check hormone levels.
Step 2: Egg retrieval
A minor surgery, called follicular aspiration, is done to remove the eggs from the woman’s body. The surgery is normally done as an outpatient procedure in the doctor’s office. The woman will be given medicines so she does not feel pain during the procedure. Using ultrasound images as a guide, the health care provider inserts a thin needle through the vagina and into the ovary and sacs (follicles) containing the eggs. The needle is connected to a suction device, which pulls the eggs and fluid out of each follicle, one at a time.
Step 3: Insemination and Fertilization
The man’s sperm is placed together with the best quality eggs and stored in an environmentally controlled chamber. The mixing of the sperm and egg is called insemination. The sperm usually enters (fertilizes) an egg a few hours after insemination. If the doctor thinks the chance of fertilization is low, the laboratory staff may directly inject the sperm into the egg. This is called intracytoplasmic sperm injection (ICSI). Many fertility programs routinely do ICSI on some of the eggs even if everything is normal. This process is also called microinjection.
Embryo culture When the fertilized egg divides, it becomes an embryo. Laboratory staff will regularly check the embryo to make sure it is growing properly. Within about 5 days, a normal embryo has several cells that are actively dividing.
Couples who have a high risk of passing a genetic (hereditary) disorder to a child may consider pre-implantation genetic diagnosis (PGD). The procedure is done about 3 -4 days after fertilization. Laboratory scientists remove a single cell from each embryo and screen the material for specific genetic disorders. PGD can help parents decide which embryos to implant, which decreases the chance of passing a disorder onto a child. The technique is controversial and not offered at all centers.
Step 5: Embryo transfer
Embryos are placed into the woman’s womb 3 – 5 days after egg retrieval and fertilization. The procedure is done in the doctor’s office while the woman is awake. The doctor inserts a thin tube (catheter) containing the embryos into the woman’s vagina, through the cervix, and up into the womb. If an embryo sticks to (implants) in the lining of the womb and grows, pregnancy results. More than one embryo may be placed into the womb at the same time, which can lead to twins, triplets, or more.
After the Procedure
Statistics vary from one clinic to another and must be carefully interpreted.
- Pregnancy rates reflect the number of women who became pregnant after IVF. But not all pregnancies result in a live birth.
- Live birth rates reflect the number of women who give birth to a living child.
According to the Society of Assisted Reproductive Technologies (SART), the approximate chance of giving birth to a live baby after IVF is as follows:
- 41-43% for women under age 35
- 33-36% for women age 35 – 37
- 23-27% for women ages 38 – 40
- 13-18% for women over age 41