Today, in vitro fertilization (IVF) is practically a household word. But not so long ago, it was a mysterious procedure for infertility that produced what were then known as “test-tube babies.

Unlike the simpler process of artificial insemination — in which sperm is placed in the uterus and conception happens otherwise normally — IVF involves combining eggs and sperm outside the body in a laboratory. Once an embryo or embryos form, they are then placed in the uterus.

When it comes to infertility, IVF may be an option if you or your partner have been diagnosed with:

Endometriosis
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
Poor egg quality
Genetic disease of mother or father
An unexplained fertility problem

The first step in IVF involves injecting hormones so you produce multiple eggs each month instead of only one.You will then be tested to determine whether you’re ready for egg retrieval.

Prior to the retrieval procedure, you will be given injections of a medication that ripens the developing eggs and starts the process of ovulation. Timing is important; the eggs must be retrieved just before they emerge from the follicles in the ovaries. If the eggs are taken out too early or too late, they won’t develop normally. Your doctor may do blood tests or an ultrasound to be sure the eggs are at the right stage of development before retrieving them. The IVF facility will provide you with special instructions to follow the night before and the day of the procedure. Most women are given pain medication and the choice of being mildly sedated or going under full anesthesia.

During the procedure, your doctor will locate follicles in the ovary with ultrasound and remove the eggs with a hollow needle. The procedure usually takes less than 30 minutes, but may take up to an hour.

Success rates for IVF depend on a number of factors, including the reason for infertility, where you’re having the procedure done, and your age. The CDC compiles national statistics for all assisted reproductive technology (ART) procedures performed in the U.S., including IVF, GIFT, and ZIFT, although IVF is by far the most common; it accounts for 99% of the procedures.

Any embryos that you do not use in your first IVF attempt can be frozen for later use. This will save you money if you undergo IVF a second or third time. If you do not want your leftover embryos, you may donate them to another infertile couple, or you and your partner can ask the clinic to destroy the embryos. Both you and your partner must agree before the clinic will destroy or donate your embryos.

A woman’s age is a major factor in the success of IVF for any couple. For instance, a woman who is under age 35 and undergoes IVF has a 39.6% chance of having a baby, while a woman over age 40 has an 11.5% chance. However, the CDC recently found that the success rate is increasing in every age group as the techniques are refined and doctors become more experienced.