Assisted Reproductive Technologies - IVF, ICSI, Gift, Zift, IUI, PGD

More than two decades ago, in an experimental procedure called in vitro fertilization (IVF), doctors joined a woman's egg and a man's sperm in a glass dish in a laboratory. For the first time, conception happened outside a woman's body. Nine months later, the first test-tube baby was born.

Today, assisted reproductive technology (ART) refers not only to IVF but also to several variations tailored to patients' unique conditions. These procedures are usually paired with more conventional therapies, such as fertility drugs, to increase success rates. Almost one out of every three cycles of ART results in the birth of a baby.

But ART procedures are invasive and expensive. Though no long-term health effects have been linked to children born using ART procedures, most doctors recommend reserving ART as a last resort for having a baby.

Here's a rundown of the main ART techniques:

• In vitro fertilization (IVF): This is one of the most commonly used procedures. Your eggs are combined with your partner's sperm in a dish in a laboratory. Once fertilization has occurred, the resulting embryos develop for 3 to 5 days before being placed in your uterus.

• Intracytoplasmic sperm injection (ICSI): One of your partner's sperm is placed inside your egg with a microscopic needle, rather than many sperm positioned close to the outside of the egg, as in IVF, in a dish in a lab. Once fertilization occurs, the resulting embryo is placed in your uterus.

• Gamete intrafallopian transfer (GIFT): Your eggs are combined with your partner's sperm in a dish in a lab, then surgically injected into your fallopian tubes using a laparoscope or fiber-thin tube. Fertilization happens inside your body, and the embryo implants naturally. Although this procedure was once commonly practiced, it's rarely used today because the success with IVF is far greater on average.

• Zygote intrafallopian transfer (ZIFT): As with GIFT, your eggs are mixed with your partner's sperm in a dish in a lab, then surgically placed in your fallopian tubes. But, as with IVF, your doctor will wait until fertilization occurs to place your embryos inside of you. This procedure is no longer commonly performed because it has a lower success rate than IVF.

• Donor egg or embryo: If you're unable to conceive using your own eggs, an egg donated by another woman is mixed with your partner's sperm and the resulting embryo is implanted in your uterus. This procedure also can be done with a donated embryo or sperm.

• Surrogacy, or use of a gestational carrier: Another woman carries your embryo, or a donor embryo, to term and gives the baby to you after birth.