IVF success rates vary greatly by age. In vitro fertilization, known as , is a common procedure for people hoping to start a family. Many factors can influence whether IVF works, and that's important for prospective parents to understand, says , fertility doctor and co-founder of Fora Fertility in Austin, Texas.

She explains how IVF works. "During this process, we stimulate multiple eggs to grow in the body with hormone shots," she says. "Once the eggs reach the mature size, a procedure is performed under anesthesia in which the eggs are extracted from the body in a needle aspiration procedure.

" The first step takes around two weeks and includes frequent visits for ultrasound monitoring and blood work. The eggs are then combined with sperm in the lab, a process known as fertilization. "The eggs that are fertilized become embryos and these embryos then grow in culture in the lab for the next 5-6 days to reach the normal implantation stage of the embryo, called a blastocyst," Crawford says.

"At the blastocyst stage, embryos can be transferred into the body, frozen or biopsied for genetic testing." People use IVF for many different reasons "Some include age-related infertility, carrying a genetic disease, need for egg donation or a gestational carrier, severe male factor infertility, tubal factor infertility, ovulatory disorders and fertility preservation or saving embryos for the future," Crawford tsays. The success rate for IVF is measured by live births.

Crawford says the gen.