Medical views: When does human life begin?

Mississippi residents vote Tuesday on a controversial ballot initiative that seeks to define a fertilized human egg as a person with full legal rights.

Anti-abortion advocates crafted Initiative 26, which defines personhood as "every human being from the moment of fertilization, cloning or the functional equivalent thereof."

Amendment would declare fertilized egg a person

If passed, the law could affect a woman's ability to get the morning-after pill or birth control pills that destroy fertilized eggs, and it could make in vitro fertilization treatments more difficult because it could become illegal to dispose of unused fertilized eggs.

Opponents of the measure have said they are concerned that people may not be able to understand the complexity and the consequences of the amendment.

The central question in this Mississippi controversy is when does human life begin?

The American Society for Reproductive Medicine represents fertility specialists in the United States and more than 100 other countries. The group's spokesman, Sean Tipton, tells CNN that his organization opposes the Mississippi initiative "because it interferes with the physicians' ability to provide needed care for their patients, whether that's helping someone have a child or keeping them from having children."

Tipton says while a fertilized egg  is necessary to make a person,  fertilization alone is not enough to create a new human being.  "A fertilized egg has to continue to grow, attach itself to a woman's uterine wall and gestate for nine months before it is born, and there are many potential missteps (that can happen) along the way."

Dr. Joseph DeCook, executive director of the American Association of Pro-life Obstetricians and Gynecologists, a group of about 2,500 members, said an embryo is a living human being at the moment of fertilization.

“There’s no question at all when human life begins,” said DeCook, a retired obstetrician-gynecologist.  “When the two sets of chromosomes get together, you have a complete individual. It’s the same as you and I but less developed.”

Pregnancy begins when the embryo is implanted on the uterine wall, he said.

“But we’re not talking about pregnancy,” he said.  “The question you have to focus on, is when does meaningful, valuable human life begin?  That’s with the union of the two sets of chromosome. You have a complete human being that begins developing.”

The American Society for Reproductive Medicine's Tipton points out that sometimes fertilized eggs split and create two babies.  "Unfortunately nature and science are messy and defy attempts to create human categories."

He adds that while saying personhood begins at conception is a nice ideological statement, it can create some real life problems.  For example, unless an egg is fertilized in an IVF petri dish, it can be difficult to determine when exactly a baby was conceived because sperm can survive inside a woman's body for days and it can take several more days for a fertilized egg to implant in the uterus, thus leading to a pregnancy and the potential birth of a baby.

"There are lots of fertilized eggs that never become human beings,"  Tipton says. "Humans are notoriously inefficient producers, and we believe most (fertilized eggs) actually go out with a woman's menstrual flow."

Mississippi is the only state voting on a "personhood" initiative this year, but the issue could reach far beyond that state’s borders.  Efforts to bring the personhood issue to a vote are in the works in at least five other states including Florida, Montana, and Ohio, according to supporters.

The American Congress of Obstetricians and Gynecologists, which represents 55,000 doctors providing health care for women, says Initiative 26 must be defeated in the best interest of women's health.

In a statement Monday, the group said the Mississippi referendum has "wide-reaching implications that will impact access to women's health, including treatment for cancer, infertility treatment, birth control options, and pregnancy termination. This proposal unnecessarily exposes women to serious health risks and significantly undermines the relationship between physicians and our patients. The vague and overly broad terms in Proposition 26 will prevent physicians from providing the care vital to women's health."

In vitro fertilization treatments could become more difficult because of the legal question of what to do with the unused eggs.

An unused fertilized egg is a human life, said DeCook, because “it has the mom’s DNA and the father’s DNA,” The unused fertilized eggs should be adopted through an embryo adoption program, he suggested.

“We determine a human being by chromosome, so although they (abortion rights supporters) have all sorts of word games. They’re only word games,” he said.

After fertilization, “it’s a complete human being in the process of development. It deserves protection of the law.”