Science in the Triangle

When you get a bunch of people over 30 to talk about sex, there’s a good chance the conversation will involve babies. Sprinkle in a healthy dose of Generation Xers and baby boomers and fertility is sure to come up.

And so it went at Durham’s Broad Street Cafe Tuesday evening, where more than 70 people came to listen and talk to Dr. Allen Wilcox, a pediatrician and epidemiologist at the National Institute of Environmental Health Sciences in Research Triangle Park. Wilcox had prepared a presentation on sex, human fertility and why the rabbit dies for the Periodic Tables, a monthly science talk organized by the North Carolina Museum of Life and Science.

It can be difficult to capture the attention of a crowd sitting in a restaurant, eating pizza and drinking beer. Wilcox managed by climbing on a chair and stretching out his arms. On each side he positioned a helper holding a ball. And for anybody who didn’t get the picture, Wilcox declared: “I’m the female reproductive system.”

The balls represented the ovaries and Wilcox’s arms were the oviducts, better known as Fallopian tubes. As he was demonstrating how the oviducts scoop up eggs released during ovulation, Wilcox pointed out that the woman holding his right ovary was his mother.

Then, he went on to the mythical, the unknown and what he called “the downright weird.”

An oviduct bending over to the opposite ovary to grab an egg was among the weird. Wilcox said that can happen in women with only one oviduct. Even without the acrobatics, a fertilized egg can slip out of the oviduct’s fingers and fall into the abdominal cavity. When he was a doctoral student at the University of North Carolina, Wilcox recalled, a woman delivered a baby she had carried to full-term outside of the uterus. The placenta had attached to the mother’s intestines. The baby was born by C-section.

On to the myths.

Studies have proven smoking reduces fertilization, but the same can’t be said for coffee, Wilcox said. There also isn’t enough evidence to prove women who live or work together develop concurrent menstrual cycles. About 50 years ago, the reputable research journal Science published a paper that suggested women who live together cycle together. But since then, the finding has failed a key scientific test, Wilcox said. Nobody has been able to replicate or confirm it.

And then there are the unknowns. Plenty of them. Among them, Wilcox counted the answer to the question when life begins. There was a theological answer, he said, but he didn’t believe there was a scientific one.

He had an easier time answering why the rabbit died.

The expression used to be code for a positive pregnancy test when the test required a live, female rabbit. The animal was injected with the urine of a woman, Wilcox said. If the woman was pregnant, the hormones in her urine were powerful enough to make the rabbit’s uterus grow.

What the code failed to acknowledge was that every rabbit used in a pregnancy test - positive or negative - died. That didn’t change until newer and more accurate pregnancy tests became available in the 1970s.

NOTE: The next Periodic Tables will convene Aug. 11. Dr. David McNelis, Director of the Center for Sustainable Energy, Environment and Economic Development, UNC Institute for the Environment, will talk about the future of nuclear energy.