Louise Brown, the 1st 'test-tube baby,' is 46. Here's how IVF has changed since then.

On July 25, 1978, the world's first "test-tube baby" was born. Louise Brown was the first person conceived through in vitro fertilization (IVF), and her birth eventually led to one of her doctors receiving a Nobel Prize.

Brown's birth got a lot of attention from around the world. Her mother's medical team filmed her caesarean birth to prove that she was, in fact, born from her mom, and photos of Brown were later released to help show the world that it was possible to have a healthy, normal baby through this new procedure. But her birth also raised a lot of questions about ethics and what IVF would mean for the future of humanity and procreation.

Brown's birthday — she's turning 46 — is now known as World IVF Day. “Not long before mum passed away, she said that without IVF she wouldn’t have anybody left in the world,” Brown previously told Time. “Even up to her last days, she was proud of who she was and what she did.”

A lot has changed with IVF since its inception. Here's where things stand right now — and how far they've come.

The term "test-tube baby" isn't used anymore.

Louise Brown was often referred to as a "test-tube baby" because her conception started in a lab. "But there were no test tubes used — it was a petri dish," Dr. Jane Frederick, a board-certified reproductive endocrinologist at HRC Fertility, tells Yahoo Life.

As IVF has evolved and become more common, so has the language used to describe it, Dr. Thomas L. Toth, a reproductive endocrinologist with Boston IVF, says. "The terminology has changed as more sophisticated and more efficient techniques have developed in the lab to replace the early use of 'test-tube baby,'" he says.

The term is also "outdated" and "could be considered offensive," Dr. Asima Ahmad, chief medical officer and co-founder of Carrot Fertility, tells Yahoo Life. "I do not recommend using this term," she says. "All pregnancies, whether as a result of fertility treatment or not, should be referred to with respect, regardless of how fertilization took place."

IVF success rates have improved.

Experts say that it's difficult to pin down exact numbers of IVF success rates, given that factors like the age of the parents and whether the mother has any underling health conditions can play a role. However, data from the Centers for Disease Control and Prevention (CDC) now shows that IVF in the U.S. has a success rate of about 38% overall.

"I remember when a 10% success rate was respectable," Dr. James Grifo, a reproductive endocrinologist and director of the NYU Langone Fertility Center, tells Yahoo Life.

Overall, success rates really depend on the person, he says. "Now, we have implantation rates as high as 70% in certain populations and, with cumulative attempts, you can get most people pregnant," Grifo notes.

IVF has become much more common.

About 4 million births a year in the U.S. — or up to 2% of annual births — are due to IVF, the CDC reports. The Society for Assisted Reproductive Technology notes that less than 5% of assisted reproductive treatments are due to IVF.

"In the beginning, IVF was very controversial and misunderstood," Grifo says. "It wasn't very successful, and it was a lot more invasive and complicated."

But Grifo says that things have "dramatically changed" since 1978. "The technology has improved dramatically and we're now better at finding the one good embryo that can make a baby," he says.

Some insurance companies and employers now cover IVF costs.

This has been huge for many families, Toth says. "Historically IVF was self-pay for those few who could afford such care," he says. "However, over time a growing number of states and companies recognized infertility as a disease and provided coverage for treatment for family-building as a needed medical treatment."

By insurance companies and employers covering IVF "it validates that infertility is a valid reason to seek a specialist. It's not just, 'You're infertile. We can't help you,'" Frederick says.

Genetic testing has been a game changer for some families.

Preconception genetic screening and genetic testing for embryos has "revolutionized" the ability for parents to conceive a healthy baby, Toth says.

"Some couples have a gene that they carry, like for cystic fibrosis or Fragile X syndrome, and they want to avoid passing it on to their children," Frederick says. "It's now something we can test for to ensure a family has an unaffected embryo so their baby won't be born with certain conditions."

Grifo says genetic testing can also help doctors and families select the best embryos. "The thing that will get us the most success is to find the healthiest embryo," he says. "It's important to find those embryos."

Reasons families use IVF have expanded.

IVF used to meet a very specific need: It helped women suffering from infertility due to issues with their fallopian tubes, Dr. Zev Williams, a reproductive endocrinologist at Columbia University Fertility Center, tells Yahoo Life. By using IVF, doctors could bypass the fallopian tubes by retrieving the egg and fertilizing it in the lab, and then placing the fertilized egg into the uterus via the vagina and cervix.

"IVF has evolved tremendously in the past four decades," Williams says. "In addition to helping in cases of tubal factor, we can now help those suffering from male-factor infertility, uterine factor, unexplained infertility and those in the LGBTQ+ community." Egg and embryo freezing can also help people undergoing chemotherapy, as well as those who want to delay having kids or haven't yet found the right partner, he says.

"The use of donor egg, donor sperm and gestational carriers has further expanded the patients who can be helped," Williams says. "And now, with the advent of preimplantation genetic testing, we can help those who are carriers of some of the most devastating hereditary diseases go on to have children who are healthy and free of those diseases."

Experts say IVF has come so far since Brown's birth — and allowed for the creation of a range of families. "Sex ed makes it sound like it's so easy to get pregnant. It usually isn't," Grifo says.

What else to know about IVF today

• An Alabama ruling on frozen embryos has put IVF under threat. In February, the Alabama Supreme Court ruled that frozen embryos — which differs from egg freezing — can be considered "children." The ruling temporarily put IVF procedures on hold and has raised questions about the legal implications of discarding an embryo.

• Frozen embryos can also get caught up in divorce proceedings. When a couple who has been trying to conceive splits up, deciding what to do with their embryos can be complicated.

• Some women donate their leftover embryos. "I want them to be a person and be on this earth and live their life," says one mother who donated her extra 12 embryos rather than have them destroyed.

• At-home insemination kits are now on the market. People trying to conceive may be able to bypass the fertility clinic as new DIY options become available.

• Donor sperm can make fatherhood a reality for men who struggle to conceive. Some men have low sperm counts or other infertility issues. These dads turned to donor sperm.

• There's a lot people still get wrong about assisted conception. Fertility doctors encounter a lot of misconceptions about their work — like the idea that turkey basters are involved.

• And terms like "blastocyst" can also cause confusion. We put together a glossary that breaks down the words commonly used during the assisted conception process.

• It can offer hope to widows who are able to conceive after their partner's death. From posthumous sperm retrieval to fertility preservation, assisted reproductive technology can give grieving spouses a shot at parenthood.

• It can also help grandmothers step in as surrogates. "The main benefit is comfort with intimately knowing the person who is carrying your child," says ob-gyn Dr. Alex Robles. "Similarly, the grandmother may feel a deep emotional connection to the baby and feel more invested in having the healthiest pregnancy possible."

• Uterus transplants could be the next wave of fertility breakthroughs. Last year the first baby born from a transplanted uterus outside of a clinical trial was successfully delivered, giving couples with infertility issues another option beyond IVF.

This article was originally published on July 25, 2023, and has been updated.