The ABCs of infertility: Here's how people are getting pregnant in 2019

Nearly one out of every eight couples in the U.S. are affected by infertility. For National Infertility Awareness Week, “GMA” is spotlighting infertility stories to help demystify and destigmatize all paths to parenthood.

In the 40 years since the world's first "test tube baby" was born, in vitro fertilization, or IVF, has become a household word.

But IVF is now also no longer the only option for people who want to bring a baby into the world.

From gestational surrogacy to embryo adoption, the number of ways a person can become a parent are both exciting and overwhelming.

"Good Morning America" tapped ABC News chief medical correspondent Dr. Jennifer Ashton, a board-certified OBGYN, to explain what to know about today's most common infertility treatment options.

But first, here are a few basics about infertility.

Infertility is defined as the inability to become pregnant after one year of having regular sexual intercourse without the use of birth control, according to the American College of Obstetricians and Gynecologists. The time span is shortened to six months without becoming pregnant for women age 35 and older.

The leading cause of infertility in women is the lack of or irregular ovulation, when an egg is released from the ovary and able to be fertilized. Other causes include scarring or blockage of the fallopian tubes (possibly from endometriosis or STIs), problems with the reproductive organs or hormones and problems with the thyroid gland or pituitary gland, according to ACOG.

A woman's fertility also decreases with age, most rapidly starting at age 37.

For men, the most common causes of infertility are problems in the testicles that affect how sperm are made and function, according to ACOG.

Obstetrician–gynecologists (OBGYNs) and reproductive endocrinologists are doctors who can help diagnose and treat infertility.

Now to the treatment options for infertility.

In vitro fertilization (IVF)

IVF is the most well-known treatment for infertility.

In this process, a woman's eggs and a man's sperm are combined in a laboratory to create an embryo, or embryos. The sperm may come from the woman's partner or a donor.

Five to 10 days after the embryo is created, it is examined by an embryologist to determine its viability, according to Ashton. If the embryo is viable, it is transferred into the woman's uterus through her cervix.

"The good news is most of the time IVF can be successful, it’s just a matter of when, how long, how much," said Ashton, who noted that IVF can cost anywhere from $12,000 to $17,000 per cycle.

Donor egg IVF

Women who do not have viable eggs can opt to use a donor egg.

Donors are typically age 30 and under and undergo both medical and psychological testing.

The recipient must take estrogen and progesterone until the pregnancy is underway and the placenta is self-sufficient.

Low Stim IVF

Also known as minimal stimulation IVF, Low Stim IVF stimulates the ovaries through low dosage medications.

Low Stim IVF is often safer and less expensive but it also brings a lower likelihood of success because a smaller number of eggs are retrieved.

Gestational surrogacy

With a gestational surrogate, an embryo is created through IVF and placed into the uterus of a surrogate to carry.

The embryo can be created with eggs from the mother and sperm from the father or with either donor eggs or donor sperm.

Gestational surrogacy can be expensive and is not legal in every state, according to Ashton. There are also important legal hurdles to cross, including making sure that the agreement between the surrogate and the parent(s) is legally documented.

The positive of a gestational surrogate is that the parent(s) not carrying the baby can still be involved with the pregnancy and be present at the birth.

Elective egg freezing

Elective egg freezing is something that women in their 20s should have a conversation about with their doctor, according to Ashton.

"This is not just for famous people. This is not just for rich celebrities," she said. "This is something that should be on the radar of every woman in her 20s. This is an insurance policy for your reproductive health."

Elective egg freezing can still cost as much as $15,000 for the whole process, but the cost is going down across the country as the process becomes more mainstream, Ashton noted.

A woman who chooses to freeze her eggs would first undergo a series of standard tests through a reproductive endocrinologist. If approved for the process, once the woman has her period, she would take stimulatory hormones in the first two weeks of her cycle.

At the two-week mark, the woman would have her eggs harvested while under general sedation. Then the eggs are frozen until the woman is ready to use them.

"For a young, healthy woman we could get 20, 30 eggs in one setting," Ashton said, noting the entire process takes only about two months.

Embryo adoption

Embryo adoption is an "emerging trend," according to Ashton, because so many couples have frozen embryos.

If a couple, or a woman, has more embryos than they plan to use, they can opt to donate their frozen embryos to infertility centers to be adopted by someone else.

"It’s just another example of the plethora of options available now to couples who want to become parents," Ashton said.

Foster care and adoption

Ashton stresses that every conversation about infertility should also include the options of adopting a child or caring for a child in the foster care system.

"I think it’s very important whenever we talk about fertility and infertility to include foster parenting and adoption as well because biology is oftentimes the least of what makes someone a parent," Ashton said.