Life is all about tradeoffs and recently published research by Virginia J. Vitzthum, a senior scientist at Indiana University's Kinsey Institute for Research in Sex, Gender, and Reproduction, and professor in the IU College of Arts and Sciences' Department of Anthropology, has shown that during periods of intense labor and low food intake, rates of early pregnancy loss can more than double.
The findings, reported recently in the American Journal of Human Biology, are the first to show seasonality of early pregnancy loss in a non-industrialized population -- in this case rural Bolivian women -- and the first to demonstrate a relationship between economic activities and early pregnancy loss.
Vitzthum's research challenges the past belief that nearly all early pregnancy losses are caused by genetic defects in the embryo. Genetic defects wouldn't change with the seasons, so Vitzthum's findings show that environmental factors must also play a major role in early pregnancy losses.
"This finding applies to U.S. moms just as much as Bolivians, and it applies to psychosocial resources just as much as food supply," Vitzthum said. "As well as healthy food, pregnant women also need good working conditions and adequate social support from family, friends and workplace to keep their risks of early pregnancy losses low."
Men are affected, too. In a second research paper, also published in the "American Journal of Human Biology," Vitzthum reports a similar relationship between reproductive fitness and external influences.
"This paper also concerns the effects of limited resources, this time on male physiology," she said. "In the worst part of the year, late winter, testosterone levels are suppressed. This is particularly interesting because it had been thought that males were much less sensitive, if at all, to environmental conditions because they don't need a lot of energy for a pregnancy. The effects of poor resources on males appear to be more subtle but can still be important for their own health and well being."
Vitzthum's work has long been at the crossroads of biology and culture, focusing on how human reproductive functioning has evolved in response to different environmental conditions.
"Until recently, it was assumed that women everywhere had similar reproductive biology," she said. "We now know that women vary tremendously, and these differences affect women's health."
One example is how high hormone levels increase the risk of breast cancer and other diseases. By studying the international patterns of hormone levels and how they relate to different environmental conditions, Vitzthum hopes to learn more about which women are at the greatest risks for these diseases. Doctors could then recommend extra monitoring or screening tests for those women.
Coauthors for "Seasonal Modulation of Reproductive Effort During Early Pregnancy in Humans," includes Jonathan Thornburg, Indiana University; and Hilde Spielvogel, Universidad Mayor de San Andres, Bolivia. It was supported by the National Science Foundation and the University of California.
Coauthors of "Seasonal and Circadian Variation in Salivary Testosterone in Rural Bolivian Men," include Carol M. Worthman, Emory Univesity; Cynthia M. Beall, Case Western Reserve; Jonathan Thornburg, Indiana University; and Enrique Vargas, Mercedes Villena, Rudy Soria, Esperanza Caceres and Hilde Spielvogel, of the Universidad Mayor de San Andres in Bolivia. It was supported by the NSF, National Institutes of Mental Health and the University of California Regents.
To speak with Vizthum or for additional assistance, contact Steve Chaplin, University Communications, at 812-856-1896 or firstname.lastname@example.org. Top
Journal citations: "Seasonal Modulation of Reproductive Effort During Early Pregnancy in Humans," American Journal of Human Biology, 2009 Jul-Aug;21(4):548-58; "Seasonal and Circadian Variation in Salivary Testosterone in Rural Bolivian Men," American Journal of Human Biology, published online in April, 2009.
Steve Chaplin | EurekAlert!
Smart Data Transformation – Surfing the Big Wave
02.12.2016 | Fraunhofer-Institut für Angewandte Informationstechnik FIT
Climate change could outpace EPA Lake Champlain protections
18.11.2016 | University of Vermont
In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.
Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
08.12.2016 | Power and Electrical Engineering
07.12.2016 | Health and Medicine
07.12.2016 | Life Sciences