George Lucas, 69, creator of Star Wars, and his wife, Mellody Hobson, 44, president of Ariel Investments, announced the birth of a baby girl, Everest Hobson Lucas, born via gestational surrogacy on Friday, according to the Huffington Post.

This is the first biological child for both parents. Lucas has three children: Amanda, 32, adopted during his first marriage to Marcia Griffin, and Katie, 25, and Jett, 20, adopted by Lucas on his own. Hobson and Lucas met at a business conference in 2006 and were married at Skywalker Ranch in northern California earlier this year. Last year, Lucas sold his famed movie studio, which is responsible for both the Star Wars and Indiana Jones franchises, for more than $4 billion to the Walt Disney Company. Hobson, in addition to her work at Ariel, is a regular contributor and analyst on finance, the markets, and economic trends for CBS News.

Lucas and Hobson join the ranks of a growing number of couples who have employed the services of a surrogate. Nicole Kidman and Keith Urban used a gestational surrogate for their second child. Sarah Jessica Parker and Matthew Broderick became the parents of twins via a gestational surrogate. Neil Patrick Harris and David Burtka had twins born through a surrogate. Just last month, Jimmy Fallon and Nancy Juvonen welcomed a daughter born of surrogacy, and Robert DeNiro, at age 68, became the father of a child with Grace Hightower through a surrogate.

What is a surrogate?

The American Society for Reproductive Medicine describes surrogacy as “an arrangement in which a woman is inseminated with the sperm of a man who is not her partner in order to conceive and carry a child to be reared by the biologic (genetic) father and his partner.” This is sometimes called “traditional surrogacy,” and in such cases, the surrogate remains the genetic mother, though she gives up her legal rights to the child. This procedure has been utilized by women with no eggs, unhealthy eggs, no uterus, or a serious health problem.

In cases of gestational surrogacy, the intended mother (partner of the genetic father) uses her own egg, which is fertilized in vitro by the father’s sperm, and then the embryo is placed inside a surrogate’s uterus. In this case, the child is biologically related to the intended mother and father. This procedure has been utilized by women who have healthy eggs but may have difficulty carrying a child.

In some cases of gestational surrogacy, a third woman’s egg — not that of the intended mother but also not that of the surrogate carrier — may be fertilized before implantation in the surrogate’s womb.

To achieve surrogacy, in vitro fertilization (IVF) — which involves surgically removing eggs from a woman’s ovaries, combining them with sperm, and then returning them to the woman’s body or donating them to another woman — is used.

Risks

Surrogacy is sometimes considered a controversial procedure. Some have argued it represents a commodification of the body. Others argue that it may be a form of genetic selection as there appears to be a greater likelihood of an IVF birth resulting in a boy, according to some studies.

The health consequences of a gestational surrogate, though they have not been studied extensively, appear to be minimal. Medications called gonadotropins are typically prescribed to stimulate the ovaries to produce multiple follicles. According to the Mayo Clinic, some early studies suggested a possible link between the medications involved in IVF and the development of a type of ovarian tumor, but “more recent studies do not support these findings.” The American Society for Reproductive Medicine states that “serious complications from the medications and procedures required … are rare. However, as with all medical treatments, there are some risks.”

There may be psychological consequences for surrogates, in that a woman may not be able to anticipate her feelings subsequent to giving birth and find she regrets the decision to give away her child.

Surrogacy takes place on a global level today; according to South China Morning Post, surrogacy represents a $2.3 billion unregulated business in India, where many women have provided a low-cost service to childless couples in other parts of the world.

Numbers

IVF is also used in cases of assisted reproductive technology (ART), which covers any procedure, the most common of which is IVF, that may assist a woman in achieving conception and birth. Often ART is used by a woman who has trouble conceiving, and the embryo resulting from an IVF cycle is simply implanted in her own womb. The Centers for Disease Control and Prevention (CDC) collects data from fertility clinics in order to monitor the safety and effectiveness of ART procedures, which “present significant public health challenges due to the substantial risk for multiple birth delivery, which is associated with poor maternal and infant health outcomes,” according to the CDC. The risk of birth defects, though, is very small; in children conceived naturally, the risk is two to three percent whereas in children conceived by IVF, the risk is estimated to be only slightly higher at 2.6 to 3.9 percent.

According to a report from the CDC, 163,038 ART cycles were performed at 451 reporting clinics in the U.S. during 2011, resulting in 47,849 live births (deliveries of one or more living infants) and 61,610 live born infants. The use of ART, estimates the CDC, has doubled over the past decade with slightly over one percent of all infants born in the U.S. conceived through this method each year; gestational surrogates were involved in 915 cycles, or one percent, of ART cycles performed in the U.S. during 2008.

Louise Joy Brown, born in 1978 and dubbed “test tube baby,” was the first child born through IVF. After trying for nine years to have a child, her parents consented to the experimental process that had been developed by Patrick Steptoe and Robert Edwards. In 2010, after the death of Steptoe, Edwards alone was awarded the 2010 Nobel Prize in Medicine for this work (the Nobel Prize is not awarded posthumously). In 2006, Louise Brown gave birth, conceiving naturally, to her first child.