Esther Friedman held the Book of Psalms with both hands as she peered over her glasses at the fertility lab monitor. There were eight eggs, retrieved earlier that day. “A good number,” she said.

A technician grabbed a glass tube, and within minutes the eggs were fertilized. Eight potential new lives.

Friedman — an Orthodox Jewish rabbinical observer hired by the prospective parents — took a step back and began to pray.

Forty years ago this July, the world’s first “test tube” baby was born at a British hospital, heralding a radical change in the creation of human life. As one of the doctors involved in Louise Joy Brown’s birth put it: It seemed that science — not God — was in charge.

Since then, in vitro fertilization and related technologies have produced 7 million babies — roughly the combined population of Paris, Nairobi and Kyoto — and fertility clinics have blossomed into a $17 billion business.

The procedures have amplified profound questions for the world’s theologians: When does life begin? If it begins at conception, is it a sin to destroy a fertilized egg? What defines a parent? What defines a marriage? If a man’s sperm fertilizes an egg from a woman who is not his wife, does that constitute adultery?

The moral questions are rapidly becoming more complex. Researchers are working to advance gene-editing tools that would allow parents to choose, or “correct for,” certain preferred characteristics; to create artificial wombs; and to perfect techniques to produce “three-parent” babies who share genetic material from more than two people.

The risks, both scientific and moral, are enormous — particularly with gene editing, which could be used to produce babies with superhuman eyesight, speed and intelligence. “Off target” effects could result in fundamental changes not just to human bodies but to human nature.

Some religious leaders have objected to using gene editing in ways that could affect future generations, arguing that the human genome is sacred and editing it violates God’s plan. The U.S. National Academies of Sciences, Engineering and Medicine have invited religious critiques of the technology, and the Vatican is convening meetings to discuss its moral implications.

Harvard geneticist George Church helped launch the Human Genome Project to map human DNA and is part of a team that announced plans in 2016 to use the gene-editing tool CRISPR to create synthetic human genomes to advance research. He said he believes critics will come to accept gene-editing technology, just as religious leaders adapted to the discoveries of Galileo, Copernicus, Darwin and IVF, which was originally viewed with equal alarm. “In the Bible, it says we are given dominion over the Earth,” he said. “Inventing newer and newer advanced technologies is almost a key component of human nature.”

The world’s 7.6 billion people practice an estimated 4,200 religions, each with various ideas about the soul and destiny. So when scientists Patrick Steptoe and Robert Edwards helped produce the first IVF baby on July 25, 1978, the event was viewed through heavy filters of wonder and suspicion. Some reports recognized it as a milestone akin to Neil Armstrong’s walk on the moon.

Some faith leaders expressed grave misgivings. But Brown’s parents, who had been trying to conceive for nine years, saw divine intervention. “Louise is, truly, a gift from God,” Lesley Brown said.

Edwards, who won the Nobel Prize for medicine in 2010 for the breakthrough, was more direct in challenging critics in the religious establishment. “I wanted to find out exactly who was in charge, whether it was God Himself or whether it was scientists in the laboratory,” he told the London Times in 2003. “It was us.”

Some communities were quicker to accept assisted reproduction, including within the Hindu, Buddhist and Protestant traditions. Egypt’s Gad El-Haq Ali Gad El-Haq, a grand imam, noting the prophet Mohammed spoke of the need to seek remedy for disease, concluded IVF is permissible as a cure for infertility.

But the procedure is still condemned at the highest levels of the Catholic Church. “Technology is a great thing, but technology does change us,” said the Rev. Michael J.K. Fuller, executive director of the Secretariat of Doctrine and Canonical Affairs for the U.S. Conference of Catholic Bishops. “At some point, we need to ask — how much is it changing us, and is that a good thing?”

Some of the first scholarly writings about IVF from Jewish experts were also negative. But attitudes changed with greater understanding of the procedure and many leaders began to encourage IVF, viewing it as a way to heed God’s instruction to “be fruitful and multiply.”

Working with Friedman and Rabbi Avrohom Friedlander, the Genesis Fertility and Reproductive Medicine clinic in Brooklyn was among the first U.S. American clinics to adopt the practice to meet the needs of its large population of Orthodox and Hasidic patients.

“Religious couples who go through infertility, no matter what religion, suffer because it feels like divine punishment,” said Genesis founder Richard Grazi.

Technical worries remained, however. The solution — which originated in Israel — was rabbinical observers. Monitoring IVF is similar in intensity to certifying kosher restaurants, Friedlander said. He said observers like Friedman keep the keys to cryo-tanks where eggs, sperm and embryos are stored and must be present whenever technicians handle genetic material.

Friedman, 63, a mother of six, grandmother to 29 and great-grandmother to one, said she got into the work after seeing so many in her community suffer from infertility. She said, “I believe in a higher being and that He is good and will help us.”