It’s well known that preeclampsia, a condition characterized by a progressive rise in a pregnant woman’s blood pressure and appearance of protein in the urine, can have negative, even life-threatening impacts on the health of both mother and baby. Now, NIH-funded researchers have documented that preeclampsia is also taking a very high toll on our nation’s economic well-being. In fact, their calculations show that, in 2012 alone, preeclampsia-related care cost the U.S. health care system more than $2 billion.
These findings are especially noteworthy because preeclampsia rates in the United States have been steadily rising over the past 30 years, fueled in part by increases in average maternal age and weight. This highlights the urgent need for more research to develop new and more effective strategies to protect the health of all mothers and their babies.
Caption: Immunofluorescence staining showing that the testes of Zika-free mice (left) are full of developing sperm (pink), while the testes of Zika-infected mice (right) contain very few sperm. Credit: Prabagaran Esakky, Washington University School of Medicine, St. Louis
Recent research has shown that the mosquito-borne Zika virus has the potential to cause serious health problems, including severe birth defects in humans. But the damaging effects of Zika might not end there: results of a new mouse study show that the virus may also have an unexpected negative—and possibly long-lasting—impact on male fertility.
In work published in the journal Nature, an NIH-funded research team found that Zika infections can persist for many weeks in the reproductive systems of male mice . As a result of this infection, levels of testosterone and other sex hormones drop, sperm counts fall, and, in some animals, the testicles shrink to 1/10th of their normal size, possibly irreversibly. All of this adds up to Zika-infected male mice that are significantly less fertile than their healthy counterparts—producing about a quarter as many viable offspring as normal when mated with female mice. While mice are certainly not humans, the results underscore the urgent need for additional research to examine the full spectrum of Zika’s health effects in men, women, and children of both sexes.
During the first trimester of pregnancy, many women experience what’s commonly known as “morning sickness.” As distressing as this nausea and vomiting can be, a team of NIH researchers has gathered some of the most convincing evidence to date that such symptoms may actually be a sign of something very positive: a lower risk of miscarriage.
In fact, when the researchers studied a group of women who had suffered one or two previous miscarriages, they found that the women who felt nauseous during their subsequent pregnancies were 50 to 75 percent less likely to miscarry than those without nausea. While it’s not yet exactly clear what’s going on, the findings lend support to the notion that morning sickness may arise from key biological factors that reflect an increased likelihood of a successful pregnancy.
Despite years of public health campaigns warning of the dangers of smoking when pregnant, many women are unaware of the risk or find themselves unable to quit. As a result, far too many babies are still being exposed in the womb to toxins that enter their mothers’ bloodstreams when they inhale cigarette smoke. Among the many infant and child health problems that have been linked to maternal smoking are premature birth, low birth weight, asthma, reduced lung function, sudden infant death syndrome (SIDS), and cleft lip and/or palate.
Now, a large international study involving NIH-supported researchers provides a biological mechanism that may explain how exposure to cigarette toxins during fetal development can produce these health problems . That evidence centers on the impact of the toxins on the epigenome of the infant’s body tissues. The epigenome refers to chemical modifications of DNA (particularly methylation of cytosines), as well as proteins that bind to DNA and affect its function. The genome of an individual is the same in all cells of their body, but the epigenome determines whether genes are turned on or off in particular cells. The study found significant differences between the epigenetic patterns of babies born to women who smoked during pregnancy and those born to non-smokers, with many of the differences affecting genes known to play key roles in the development of the lungs, face, and nervous system.
Caption: Human neural progenitor cells (gray) infected with Zika virus (green) increased the enzyme caspase-3 (red), suggesting increased cell death. Credit: Sarah C. Ogden, Florida State University, Tallahassee
Recently, public health officials have raised major concerns over the disturbing spread of the mosquito-borne Zika virus among people living in and traveling to many parts of Central and South America . While the symptoms of Zika infection are typically mild, grave concerns have arisen about its potential impact during pregnancy. The concerns stem from the unusual number of births of children with microcephaly, a very serious condition characterized by a small head and damaged brain, coinciding with the spread of Zika virus. Now, two new studies strengthen the connection between Zika and an array of birth defects, including, but not limited to, microcephaly.
In the first study, NIH-funded laboratory researchers show that Zika virus can infect and kill human neural progenitor cells . Those progenitor cells give rise to the cerebral cortex, a portion of the brain often affected in children with microcephaly. The second study, involving a small cohort of women diagnosed with Zika virus during their pregnancies in Rio de Janeiro, Brazil, suggests that the attack rate is disturbingly high, and microcephaly is just one of many risks to the developing fetus.