Feds at Work: A pioneer on the epidemiologic study of human reproduction

Fundamentally changed the understanding of fertility and pregnancy

During his influential, nearly four-decade career at the forefront of human reproduction research, Dr. Allen Wilcox has produced groundbreaking studies fundamentally changing our understanding of fertility and pregnancy.

A senior investigator at the National Institute of Environmental Health Sciences, Wilcox has studied the critical phase from conception to birth, looking into how environmental factors might affect reproduction and development. His research spans the spectrum from fertility and miscarriages to fetal growth and birth defects.

Allen Wilcox speaks at a National Institute of Environmental Health Sciences event. (Photo by NIEHS)

“Allen is viewed as the father of the epidemiologic study of human reproduction. He has defined the field over his 37-year career,” said Dr. Darryl Zeldin, scientific director at the institute, part of the National Institutes of Health.

Wilcox joined the institute in 1979 when little attention had been paid to the epidemiology of human reproduction.

“I can’t imagine anything more exciting than finding a field that is not well-plowed, and that still has basic questions and problems to be addressed,” he said. “I wanted a workplace that would let me explore human reproduction as a research area, and the institute encouraged me to go for it. It was a real gift for a young investigator.”

Wilcox focused his first study on early pregnancy.

The four-year study looked at 221 women who were trying to become pregnant. Wilcox tested daily urine samples for the key hormone marker of pregnancy to identify pregnancy at the earliest possible time — around implantation.

He was the first to show that 25 percent of pregnancies are lost before women are even aware they’re pregnant. When recognized miscarriages are added, one-third of pregnancies fail. He also found that most women who miscarry are fertile and later able to have a healthy pregnancy.

The landmark study made the cover of Newsweek.

“If my work makes a contribution, it has probably not been a single study, so much as an approach to how all these separate pieces — fertility, conception, fetal development, infant survival — fit into an integrated picture. You can’t understand one without considering them all.” ~ Allen Wilcox, NIEHS

“It took a very creative, meticulous and methodical approach to answer the questions about when a woman can conceive and what proportion of conceptions go on to be babies,” said Dr. David Savitz, vice president for research at Brown University.

“Allen had the courage to delve into fundamental challenges around reproduction,” he said.

The study’s data provided new insights into other aspects of human reproduction, including fertility. Wilcox found women can conceive during the five days leading up to ovulation, and the day of ovulation itself — valuable information for women trying to become pregnant.

The study also uncovered an error in the information companies were providing to women about how to use over-the-counter pregnancy tests, leading to guidelines that are more accurate.

Wilcox also upended conventional thinking around birth weight, cited at the time as the major cause of perinatal death. A series of his methodological papers showed birth weight was a secondary factor, prompting researchers to focus more on the direct causes, including pre-term delivery and fetal pathology.

His “singular talent is being able to identify really important problems and find the data to answer those problems in very clear and accurate ways,” Zeldin said.

Wilcox now is conducting a major study of cerebral palsy that peers in the scientific community believe has the potential to change radically how researchers and people view the condition.

“Allen is tackling fascinating scientific questions that have profound impact for families and society,” Savitz said.

Wilcox credits the thrill of discovery for keeping him motivated to address new questions. He also credits his “brilliant” colleagues who, he said, “have been crucial to the success of these studies.”

“If my work makes a contribution, it has probably not been a single study,” he said, “so much as an approach to how all these separate pieces — fertility, conception, fetal development, infant survival — fit into an integrated picture. You can’t understand one without considering them all.”

Dr. Allen Wilcox is a finalist for a 2016 Samuel J. Heyman Service to America Medal, or Sammies. Each year, the Partnership for Public Service honors federal employees whose remarkable accomplishments make our government and our nation stronger. For the second time, we will also present the annual “People’s Choice” award. Please vote for the person or team you find most inspiring. (Voting closes at 11:59 p.m. EST on September 9, 2016.)