Category Archives: Health

Rabbits, Dogs, Humans, How Can One Bacteria Spread Infections

A woman in Arizona died from an infection called rabbit fever, despite never coming into contact with any rabbits, according to a recent report of the woman’s case.

The 73-year-old woman first got sick on June 6, 2016, and died five days later from severe breathing problems, according to a report published today (Aug. 24) by the Centers for Disease Control and Prevention.

It wasn’t until June 17 of that year, however, when the results of a blood test came back, that doctors learned the woman had rabbit fever, which is also called tularemia. [10 Bizarre Diseases You Can Get Outdoors]

Rabbit fever is a bacterial infection caused by the bacterium Francisella tularensis, according to the report. Symptoms typically start three to five days after exposure to the bacteria and can include fever, skin lesions, difficulty breathing and diarrhea. Though the infection can be deadly, most infections can be treated with antibiotics, according to the CDC.

People can get rabbit fever through insect bites, coming into contact with an infected animal or inhaling the bacteria.

Though the woman lived in a semirural area, she told doctors that she didn’t participate in outdoor activities, according to the report. In addition, the woman didn’t have any insect bites, and hadn’t been exposed to any animal carcasses or untreated water, the report said.

Her dog, however, had been found that May with a dead rabbit in its mouth, and was later noted to be lethargic and eating less. After the woman died, doctors tested the dog, and found signs of the infection in its blood. In addition, investigators found a number of infected rabbits around the woman’s property.

Because the woman had respiratory symptoms, the researchers think she inhaled the bacteria, potentially from her dog, the report said. It’s possible that the dog had the bacteria in its mouth after catching the dead rabbit, or there were bacteria on its fur, the authors said.

About 125 rabbit fever cases are reported in the U.S. each year, the report said.

Four Weeks Pregnant, What to Expect

During the fourth week of your pregnancy (measured from the first day of your last period), you may begin to have positive results on a home pregnancy test. For the sake of accuracy, it’s best to wait until the end of the first week after a missed period to take the test, according to the U.S. Department of Health and Human Service’s Office on Women’s Health.

If the test comes back positive, congratulations! You should make an appointment to see your health care provider to confirm your pregnancy with a blood test and arrange a prenatal checkup. If the results are negative, take another test at five weeks because you may have taken the test too early for it to show a positive result.

Home pregnancy tests measure the amount of human chorionic gonadotropin (hCG) in your urine, a hormone that is produced by the placenta when a woman is pregnant. The hormone begins to appear shortly after the embryo attaches to the lining of the uterus, and hCG levels increase rapidly in early pregnancy.

Most practitioners don’t see pregnant women until they are eight weeks along, so you may need to wait a few weeks before actually seeing your health care provider. However, if you have had a high-risk pregnancy or a history of problems in giving birth, you should see a health care provider sooner than that.

At this early stage in the pregnancy, there typically won’t be any major outward changes in your body, though your basal body temperature — your temperature first thing in the morning — will be higher than usual. You may experience some mild uterine cramping. Some women will notice a small amount of spotting or vaginal bleeding, caused by the fertilized egg attaching to the uterine lining, according to the Mayo Clinic. This is called implantation bleeding, and light bleeding or spotting is normal.

A woman may experience some pregnancy symptoms at this point, including fatigue and exhaustion, which may be linked to rising levels of the hormone progesterone during the first trimester, according to the Mayo Clinic. Rising hormone levels can also increase the blood flow to your breasts, causing them to feel tender and sore during early pregnancy. In addition, elevated hormone levels can increase blood flow to your pelvic region, causing the need to urinate more frequently.

The rapidly rising levels of estrogen could even cause a heightened sense of smell. An increased sensitivity to smells and odor could contribute to the nausea and vomiting known as “morning sickness,” which may begin between the second and eighth weeks of pregnancy. You may start craving certain foods, and foods that you previously enjoyed might start to taste different.

By the fourth week of pregnancy, a woman may gain one pound in weight.

At four weeks, the blastocyst — a tiny group of embryonic cells — would have already made the journey from your fallopian tube into your uterus and implanted in the uterine lining. After the fertilized egg implants, some of the cells will develop into an embryo and other cells will form the placenta, which will provide nutrients and oxygen to the developing embryo. A sac filled with fluid surrounds the embryo, called the amniotic sac, to help cushion and protect it.

During the first month of pregnancy, the brain and spinal cord begin to form, according to the American College of Obstetricians and Gynecologists. Arms and legs begin to form, and the heart and lungs begin to develop.

At this point and throughout the pregnancy, you should avoid alcohol, recreational drugs and smoking, substances that may affect fetal development. Certain medications should also be avoided — ask your health care provider to make sure that none of the medications you are taking may be harmful to the fetus.

Limit your consumption of caffeine to 200 milligrams a day — about one 12-ounce cup of regular coffee, recommends the March of Dimes.

At least one month before becoming pregnant, women should begin taking a daily multivitamin containing at least 400 micrograms of folic acid, a B vitamin that is important in helping to prevent certain birth defects, advises the American College of Obstetricians and Gynecologists.

When a woman knows she is pregnant, her health care provider will prescribe a daily prenatal vitamin that has 600 micrograms of folic acid in it. It is hard to get this amount of folic acid from foods alone.

Taking folic acid before becoming pregnant and during early pregnancy may help to reduce a baby’s risk for birth defects of the brain and spine, according to the March of Dimes.

Besides folic acid, a prenatal vitamin will also supply additional amounts of calcium, iron and vitamin D, three nutrients that are important for the healthy development of your baby. In addition to taking a prenatal vitamin, calcium should also be obtained from foods, such as yogurt, milk, cheese and some leafy green vegetables. Pregnant women should also include more Iron-rich foods in their diet, such as chicken, meat, fish, beans and iron-fortified cereals, as well as good sources of vitamin D, such as salmon and milk.

You can learn more about healthy eating and weight gain during pregnancy here. See the following articles for more lifestyle information on sleep needs during pregnancy and tips for exercising during pregnancy.

How Floods Can Endanger Our Health

Houston and other parts of southeast Texas are in the midst of historic flooding from Harvey, now a tropical storm, with heavy rain still expected to batter the region in the coming days. How does flooding put people’s health at risk?

The public health implications run deeper than the risk of injury and drowning during a flood, though these are a serious concern. [In Photos: Hurricane Harvey Takes Aim at Texas]

Indeed, the Centers for Disease Control and Prevention (CDC) notes a slew of risks related to floodwater and standing water, including wound infections and the spread of infectious diseases and chemicals in the water.

Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University School of Medicine in Tennessee, said that the biggest concerns during and after a flood are injuries, access to medical care and providing people with clean water to drink.

Safe water is more important than food, Schaffner told Live Science. “Lack of food for a period of time is not a crisis,” but lack of water can lead to serious dehydration in the very young and the very old, he said.

People’s health is at risk even after they’ve been evacuated from a flood zone to relief centers.

When people are congregated in relief centers for long periods of time, it’s not uncommon for illnesses to spread, Schaffner told Live Science. Respiratory viruses such as the common cold can spread through shelters, and though it’s still a bit early for flu season, Schaffner said he’d still keep an eye out for cases of influenza.

Less common in the United States, Schaffner noted, is the spread of gastrointestinal illnesses after a flood. For example, although norovirus is “very readily transmitted,” there was only one outbreak of this virus in a relief center after Hurricane Katrina. Norovirus causes symptoms such as vomiting and diarrhea.

It takes “very few of those [norovirus] viral particles to cause infection,” Schaffner said. The virus, which often spreads on cruise ships, can be transmitted through water and food, and can also spread from person to person, he said. “If it gets into a shelter, it’s likely to spread to everybody in the shelter.”

Fortunately, gastrointestinal diseases such as cholera have not played a major role in the U.S. after natural disasters, which is “a testimony to the fact that we live in an environment with good sanitation,” Schaffner said. If that good sanitation were to break down, however, you could see outbreaks of more troublesome illnesses.

And although cholera is not a concern, a type of bacteria related to cholera could pose a threat, Schaffner said. This bug, called Vibrio vulnificus, can live in the water in the Gulf of Mexico and can cause a nasty infection if it gets into an open wound, he said. Wounds exposed to seawater after a coastal flooding disaster should be washed with soap and water as soon as possible, according to the CDC.

Another public health threat from hurricanes and flooding is moving people away from their usual sources of medical care.

People with diabetes or seizures may have left their medications at home, for example, Schaffner said. And events such as giving birth or having a heart attack can be more difficult to manage, because people are removed from their medical care resources, he said.

Even after the floodwaters recede, threats to health will remain, Schaffner said.

Standing water in puddles, small receptacles and gutters can provide “an ideal breeding ground for mosquitoes,” Schaffner said. And when you get mosquitos, you have to worry about mosquito-borne illnesses, includingWest Nile virus and Zika virus. Fortunately, Houston and Harris County — another area affected by the storm — have excellent mosquito control under normal circumstances, Schaffner added.

Once things get back to normal, “I would think that they would start monitoring [mosquito] populations and using their mosquito abatement techniques,” he said.

Another concern after a flood is mold, but Schaffner noted that in the vast majority of cases, mold is an annoyance and a nuisance rather than a source of illness. “Mold-related illness is really quite rare,” he said.

FDA Moves Forward on Ecstasy Material Testing for PTSD

The active ingredient in the drug ecstasy passed an important hurdle on the path to becoming a prescription drug for treating post-traumatic stress disorder.

The ingredient, MDMA, was granted “Breakthrough Therapy Designation” status by the U.S. Food and Drug Administration (FDA), according to a statement released Aug. 26 by the Multidisciplinary Association for Psychedelic Studies (MAPS), a nonprofit organization that advocates for medical research on psychedelic substances.

The Breakthrough Therapy Designation term means that the FDA will “expedite the development and review” of the drug. The designation is given to those drugs that are intended to treat a serious or life-threatening disease or condition; such drugs also present preliminary clinical evidence indicating that the drug may demonstrate substantial improvement over existing therapies, according to the FDA.

“By granting Breakthrough Therapy Designation, the FDA has agreed that this treatment may have a meaningful advantage and greater compliance over available medications for PTSD,” according to the MAPS statement.

MAPS has funded clinical trials looking into the use of MDMA along with psychotherapy as a treatment for PTSD. With the new designation from the FDA, the association will move forward with Phase 3 clinical trials and plans to conduct the trials in 2018. Phase 3 clinical trials are conducted after earlier trials have established that a new treatment works and is safe. Phase 3 trials are done in larger groups of people than earlier trials, and serve to confirm how well the treatment works and compare the new treatment to existing treatments, according to the National Institutes of Health.

The Phase 3 clinical trials will focus on “MDMA-assisted psychotherapy,” MAPS said. The treatment involves three daylong sessions, during which a participant is given either MDMA or a placebo in conjunction with psychotherapy over a 12-week period. In addition to the daylong sessions, the subjects will also participate in 12 90-minute therapy sessions, according to MAPS.

AI Can Predict Alzheimer’s Disease Two Years Ahead

An artificial-intelligence-driven algorithm can recognize the early signs of dementia in brain scans, and may accurately predict who will developAlzheimer’s disease up to two years in advance, a new study finds.

The algorithm — which accurately predicted probable Alzheimer’s disease 84 percent of the time — could be particularly useful in selecting patients for clinical trials for drugs intended to delay disease onset, said lead study author Sulantha Sanjeewa, a computer scientist at McGill University in Canada.

“If you can tell from a group of of individuals who is the one that will develop the disease, one can better test new medications that could be capable of preventing the disease,” said co-lead study author Dr. Pedro Rosa-Neto, an associate professor of neurology, neurosurgery and psychiatry, also at McGill University. [6 Big Mysteries of Alzheimer’s Disease]

The technology is still in its early stages, but the findings suggest that AI analysis of brain scans could offer better results than relying on humans alone, Rosa-Neto told Live Science.

The findings are detailed in a new study, which was published online in July in the journal Neurobiology of Aging.

Developing drugs that slow the onset of Alzheimer’s disease requires that the drugs be tested in clinical trials that run between 18 and 24 months, Rosa-Neto said. But if people who are selected for the trial never develop Alzheimer’s during that time, it’s impossible to say whether a drug was effective, he said.

“You want to include people who will be progressing from mild cognitive impairment to dementia in the time of the clinical trial,” Rosa-Neto said. Alzheimer’s disease is the most common form of dementia, according to the Alzheimer’s Association.

But selecting the best patients for these trials is a challenge, because it is difficult to predict who will develop the condition, Rosa-Neto said. Scientists know that the buildup of a protein called amyloid, which accumulates in various regions of the brain, can lead to cognitive impairment. But piecing together the complex patterns of where and how much of the protein builds up, and then using that information to predict when a person will develop Alzheimer’s disease is difficult to do by reading PET scans alone. (These scans are imaging tests that use a radioactive dye to identify certain diseases in the body.)

The presence of amyloid in the brain, however, doesn’t necessarily mean that a person will develop Alzheimer’s within a certain time; for some, it may take five to 10 years for the symptoms of dementia to appear, Rosa-Neto said. Others may never develop the disease, he said. But once a person has developed dementia, it is very difficult to return the brain to normal cognitive function, Rosa-Neto added.

The artificial intelligence program that Rosa-Neto’s team developed could help doctors identify the best participants for Alzheimer’s drug clinical trials by predicting who is likely to develop the disease within a two-year window.

Creating an effective AI algorithm involves three main steps: writing the software, training it and then testing it to see how well it works, the researchers said.

As they were writing the software, the software engineers gave the algorithm some hints to help it analyze the PET images, Rosa-Neto said. The engineers designed it to take into consideration a common problem that pops up when studying people with mild cognitive impairment: In any given population, only a small fraction of a people will develop dementia.

The programmers also designed the algorithm to consider that the buildup of amyloid protein can occur at different rates, in different concentrations and at different locations in the brain, according to the study. [10 Things You Didn’t Know About the Brain]

During the training portion of the study, the scientists used the algorithm to analyze the presence of amyloid in PET scans from nearly 200 patients who had mild cognitive impairment. The algorithm was then shown images from up to 24 months before the patients had developed the disease.

Once the program learned from this information, it was shown an entirely new set of amyloid PET brain scans from more than 270 individuals who had mild cognitive impairments. Of them, 43 were diagnosed with probable Alzheimer’s disease after the 24-month follow-up. However, the algorithm was shown only the images taken before the disease had fully developed. Using what it had learned, the AI algorithm predicted with 84 percent accuracy which individuals would develop the disease, according to the study.

In the study, the authorsnoted that no system that predicts Alzheimer’s disease based on images alone can be 100 percent accurate. In about 10 percent of diagnoses of “probable Alzheimer’s diseases,” for example, people actually have a different form of cognitive impairment.

The researchers also noted the group of people included in the study described themselves as having some loss of memory and may not represent the general public. The authors added that it would be highly desirable to replicate the findings in a general population.

Based on this study, the team also created a pilot version of a real-time prediction tool that will analyze individuals’ PET brain scans and spit out probabilities of when the individuals may develop dementia within a 24-month period. The tool is available to the public online.

How Fast Do You Go? The Answer You Can Predict The Risk Of Your Heart Disease Death

A simple question — how fast do you walk? — may help researchers determine who has a higher risk of death from heart disease, a new study from the United Kingdom suggests.

The study found that middle-age adults who said they typically walk at a slow pace were about twice as likely to die from heart disease during the study period, compared with those who said they walk at a brisk pace. The findings held even after the researchers accounted for factors that could affect the results, such as people’s exercise habits, their diets, and whether they smoked or drank alcohol.

The study suggests that “a simple, self-reported measure of slow walking pace” would help doctors determine people’s risk of death from heart disease, the researchers wrote in the Aug. 21 issue of the European Heart Journal. [Top 10 Amazing Facts About Your Heart]

For the study, the researchers analyzed information from more than 420,000 middle-age adults in the United Kingdom, who were followed for about six years. None of the participants had heart disease at the time they entered the study. Participants were asked to rate their usualwalking pace as “slow,” “steady/average” or “brisk.” The subjects also underwent an exercise test in a laboratory to determine their fitness levels.

During the study, nearly 8,600 of the participants died, and of these, about 1,650 died from heart disease.

People who said they were slow walkers were between 1.8 and 2.4 times more likely to die of heart disease during the six-year study period, compared with those who said they were brisk walkers. The risk was highest for those with a low body mass index (BMI), which could mean the individuals were malnourished or had high levels of muscle tissue loss with age (a condition known as sarcopenia), the researchers said.

The study also found that people’s self-reported walking pace was strongly linked with their levels of physical fitness on the exercise test. In other words, a low fitness level among slow walkers could explain their higher risk of death from heart disease, the researchers said.

“Self-reported walking pace could be used to identify individuals who have low physical fitness” levels and, consequently, higher risk of death from heart disease, study co-author Tom Yates, of the University of Leicester in the United Kingdom, said in a statement. These individuals might benefit from interventions to improve their physical fitness, he said. However, more research is needed to examine the extent to which people’s walking pace could be used to improve current predictors for risk of death by heart disease, the researches said.

The study also looked at whether walking pace was linked with people’s risk of death from cancer, but it did not find a consistent link.

Magnetic Fields Can Remotely Control Cells in Mice

Using magnetic fields, scientists can activate specific brain cells in mice and make them run, spin and freeze, new research shows.

This could help scientists pinpoint the specific brain circuits animals use for certain behaviors, which could in turn help scientists pinpoint with greater accuracy which brain areas are involved in those same behaviors in humans, said Arnd Pralle, a biophysicist at the University at Buffalo in New York.

The main goal is to develop tools that can help scientists study the brains of laboratory animals to see how they encode emotions and behaviors, Pralle told Live Science. “We can translate a lot of that to human brains,” he added. [Top 10 Mysteries of the Mind]

Scientists have used implanted electrodes to control the movement and thoughts of monkeys, while others have genetically engineered brain circuits that turn on with a beam of laser light. Brain implants have even allowed one monkey to control the movements of another, a 2014 experiment found. However, those methods involve either implanting electrodes into the brain or hard-wiring a bulky cable into the brain. But those procedures can do damage to the animals, and essentially keeps them tethered to a cable all the time, Pralle said.

Transcranial magnetic stimulation, meanwhile, is FDA-approved to treat depression that does not respond to medication, but it acts on a wide area of the brain and is not targeted to specific networks. Scientists, however, still don’t fully understand why it works, Pralle said.

In the current study, Pralle and his colleagues used magnetic fields to turn on individual brain cells. Ordinarily, magnetic fields pass through biological tissue without affecting it, so the team needed a way to translate the magnetic stimulation into heat energy. To accomplish this task, they injected tiny magnetic nanoparticles that translated oscillating magnetic fields into heat energy. These nanoparticles then latch onto the surface of brain cells. When the cells heat up, temperature-sensitive channels on the neurons opened, flooding the channels with positive ions (charged particles) and causing the neurons to fire. (Normally, mice have very few heat-sensitive channels in their brains, so the team genetically engineered the mice to carry these channels.)

Using this technique, the team manipulated the mice’s specific movements, causing them to spin around, run, and even freeze and lose control of their extremities.

The new technique has advantages over other methods for manipulating brain function in animals, Pralle said. For instance, the magnetic field they use operates over a larger region of the brain, meaning they could target separate brain regions at the same time, he said. In primates, multiple brain regions must often be activated to perform specific tasks, he added.

The technique, with its use of genetic engineering and nanoparticles, is not intended to be used in human brains, and certainly not to manipulate or conduct mind-control on humans, Pralle said. Instead, inducing certain behaviors in animals is a way to pinpoint the brain regions responsible for these tasks, he said.

One day, the understanding of brain function gleaned from these animals could pinpoint the brain circuits needed to treat conditions such as Parkinson’s in humans, Pralle said.

“We might use different methods to stimulate the brain,” Pralle said. “But knowing which circuit does what, you don’t have to go dig around.”

Lead Poisoning Caused by ‘Homeopathic Magnetic’ Bracelet

An infant girl in Connecticut developed lead poisoning after wearing — and chewing on — a bracelet made with lead beads, according to a new report of the child’s case.

Doctors discovered that the 9-month-old had abnormally high bloodlead levels during a routine checkup. Her blood lead level was 41 micrograms per deciliter (ug/dL); anything over 5 ug/dL is considered abnormal, according to the report, published today (Aug. 31) by the Centers for Disease Control and Prevention (CDC).

Health investigators visited the infant’s home, and found two windows with peeling lead-based paint. However, the infant wouldn’t have been able to reach these areas, according to the report. In addition, the girl’s three siblings, who were between ages 3 and 5, had blood lead levels of less than 3 ug/dL, suggesting that the peeling paint wasn’t the source of the lead poisoning. [9 Weird Ways Kids Can Get Hurt]

Instead, investigators focused on a handmade bracelet the parents had given the infant. The bracelet was a “homeopathic magnetic hematite healing bracelet” that the parents purchased from an artisan at a local fair. The parents had given the infant the bracelet for “teething-related discomfort,” the report said. Sometimes the infant chewed on the bracelet, the report added. (Despite a lack of scientific evidence, some people purport that magnets have healing properties if placed close to the body.)

When investigators tested the beads on the bracelet, they found that some of the beads had extremely high levels of lead: 17,000 parts per million (ppm). The amount of lead that’s considered safe for children’s products is 90 ppm or 100 ppm, depending on the type of product, according to the U.S. Consumer Product Safety Commission (CPSC).

In general, the most common way children get lead poisoning is by ingesting something that contains lead. In 2003 and 2006, for example, there were several cases of severe lead poisoning and death linked to lead-containing jewelry and charms marketed to children, the report said. After these instances, the CPSC set limits on the amount of lead allowed in products marketed to kids, and each year, there are recalls of children’s jewelry that exceed those limits. However, the limits do not apply to products that aren’t intended for use by children, the report noted.

Investigators were unable to track down the manufacturer of the beads or the bracelet maker, according to the report.

There’s no safe amount of lead exposure for children, according to theCDC, and the toxic heavy metal can affect nearly every part of the body. In many cases, lead exposure can occur with no obvious symptoms. Symptoms of severe lead poisoning can include confusion, seizures, coma and death.

This is not the first time that homeopathic teething products have been found to put children at risk. In October 2016, the U.S. Food and Drug Administration announced an investigation into homeopathic teething products that were linked to reports of seizures in infants and children. The products in that instance weren’t being investigated for lead levels, however; instead, the FDA was concerned that the products contained purportedly “natural” substances that weren’t regulated by the agency.

Homeopathy is an alternative medicine practice based on the idea that “like cures like.” In homeopathy, extremely minute concentrations of toxic substances are used in the idea that they could cure the symptoms that they would cause at higher doses.

Stages of Pregnancy

For a pregnant woman, feeling a new life developing inside her body is an amazing experience, even though she may not always feel her best at some points along the way.

Pregnancy can be different from woman to woman, and even for the same mother from one pregnancy to the next. Some symptoms of pregnancy last for several weeks or months, while other discomforts are temporary or don’t affect all women.

“Pregnancy is a long, 10-month journey,” said Dr. Draion Burch, an obstetrician and gynecologist at Magee-Womens Hospital at the University of Pittsburgh Medical Center.

A normal pregnancy usually lasts about 40 weeks, counting from the first day of a woman’s last menstrual period, which is about two weeks before conception actually occurs.

Pregnancy is divided into three trimesters. Each of these periods lasts between 12 and 13 weeks.

During each trimester, changes take place in a pregnant woman’s body as well as in the developing fetus, and a summary of these changes will be described below.

About two weeks after a woman has her period, she ovulates and her ovaries release one mature egg. The egg can be fertilized for 12 to 24 hours after it’s released as it travels down the fallopian tube toward the uterus.

If an egg meets up with a sperm cell that has made its way into the fallopian tube, it combines into one cell, a process that’s known as fertilization or conception.

At fertilization, the sex of the fetus is already determined, depending on whether the egg receives an X or Y chromosome from a sperm cell. If the egg receives an X chromosome, the baby will be a girl; a Y chromosome means the baby will be a boy.

According to the Cleveland Clinic, it takes about three to four days for the fertilized egg (or embryo) to move to the lining of the uterus, where it attaches or implants to the uterine wall. Once the embryo is implanted, the cells start to grow, eventually becoming the fetus and the placenta, which is tissue that can transport oxygen, nutrients and hormones from the mother’s blood to the developing fetus throughout pregnancy.

A woman will experience a lot of symptoms during her first trimester as she adjusts to the hormonal changes of pregnancy. In the early weeks, the pregnancy may not be showing much on the outside of her body, but inside many changes are taking place.

For example, human chorionic gonadotrophin (hCG) is a hormone that will be present in a woman’s blood from the time conception occurs. Levels of hCG can be detected in a woman’s urine about a week after she has a missed period, and it is why a woman will have a positive result ona home pregnancy test.

Other hormonal changes can contribute to pregnancy symptoms: Rising levels of estrogen and hCG may be responsible for the waves of nausea and vomiting known as morning sickness that a woman typically feels during her first few months of pregnancy. Despite its name, morning sickness can occur any time of day.

A woman will also feel more tired than usual during the first trimester, a symptom that’s linked with rising levels of the hormone progesterone, which increases sleepiness. She may also need to urinate more frequently as her uterus grows and presses on her bladder.

Early in pregnancy, a woman’s breasts will feel more tender and swollen, another side effect of rising levels of pregnancy hormones. Her areolas, the skin around each nipple, will darken and enlarge.

A pregnant woman’s digestive system may slow down to increase the absorption of beneficial nutrients. But reduced mobility of the digestive system might also trigger such common complaints as heartburn, constipation, bloating and gas, according to the Office on Women’s Health (OWH).

Many parts of the body will work harder during pregnancy, including a woman’s heart. Her heartbeat will increase to pump more blood to the uterus, which will supply it to the fetus.

As more blood circulates to a woman’s face, it will give her skin a rosier complexion, described as a “pregnancy glow.”

Besides the physical changes in a woman’s body, she may also experience emotional highs and lows in the early months of her pregnancy and throughout it. These emotions may range from weepiness, mood swings and forgetfulness to fear, anxiety and excitement.

A developing baby is called an embryo from the moment conception takes place until the eighth week of pregnancy.

During the first month of pregnancy the heart and lungs begin to develop, and the arms, legs, brain, spinal cord and nerves begin to form, according to the American College of Obstetricians and Gynecologists (ACOG).

The embryo will be about the size of a pea around one month into a pregnancy, Burch said. Around the second month of pregnancy, the embryo has grown to the size of a kidney bean, he explained. In addition, the ankles, wrists, fingers and eyelids form, bones appear, and the genitals and inner ear begin to develop.

After the eighth week of pregnancy and until birth occurs, a developing baby is called a fetus.

By the end of the second month, eight to 10 of the fetus’ main organs will have formed, Burch said. At this stage of pregnancy, he stressed, it’s extremely important that pregnant women do not take harmful medications, such as illegal drugs. The first trimester is also the period when most miscarriages and birth defects occur.

During the third month of pregnancy, bones and muscles begin to grow, buds for future teeth appear, and fingers and toes grow. The intestines begin to form and the skin is almost transparent.

By the second trimester, some of the unpleasant effects of early pregnancy may lessen or disappear as a woman’s body adjusts to its changing hormone levels. Sleeping may get easier and energy levels may increase.

Nausea and vomiting usually get better and go away, Burch told Live Science. But other symptoms may crop up as the fetus continues its growth and development.

Women feel more pelvic pressure, Burch said, adding that the pelvis feels heavy like something is weighing it down.

A more visible baby bump appears as the uterus grows beyond a woman’s pelvis, and the skin on her expanding belly may itch as its stretches, according to the OWH.

As the fetus is getting bigger and a woman is gaining more pregnancy weight in the front of her body, she may also experience more back pain, Burch said.

Sometime between the 16th and 18th weeks of pregnancy, a first-time mother may feel the first fluttering movements of the fetus, known as quickening, Burch said. If a woman has had a baby before, she is likely to feel the fetus kicking, squirming or turning even sooner because she knows what to expect, he explained.

The 20th week usually marks the halfway point of a woman’s pregnancy.

Burch encourages his patients to take a “baby-moon” — a mini-vacation or weekend getaway — during the second trimester, and he said the best time to get away is around the 28th week of pregnancy. A woman is generally feeling pretty good at this point, there’s a lower risk of miscarriage and premature labor, and some health professionals may discourage airplane travel after the 36th week.

In the second trimester, the fetus is growing a lot and will be between 3 and 5 inches long, Burch said. Sometime between 18 and 22 weeks, anultrasound may reveal the sex of the baby, if parents want to know this information in advance.

By the fourth month of pregnancy, eyebrows, eyelashes, fingernails and the neck all form, and the skin has a wrinkled appearance. In addition, during the fourth month the arms and legs can bend, the kidneys start working and can produce urine, and the fetus can swallow and hear, according to ACOG.

In the fifth month of pregnancy, the fetus is more active and a woman may be able to feel its movements. The fetus also sleeps and wakes on regular cycles. A fine hair (called lanugo) and a waxy coating (called vernix) cover and protect the thin fetal skin.

By the sixth month of pregnancy, hair begins to grow, the eyes begin to open and the brain is rapidly developing. Although the lungs are completely formed, they don’t yet function.

During the third trimester, as a woman’s enlarged uterus pushes against her diaphragm, a major muscle involved in breathing, she may feel short of breath because the lungs have less room to expand, according to Johns Hopkins Medicine. Her ankles, hands, feet and face may swell as she retains more fluids and her blood circulation slows.

A mother-to-be will need to pee more frequently because more pressure will be placed on her bladder. She may also have more backaches and more pain in the hips and pelvis, as these joints relax in preparation for delivery.

Her face may develop dark patches of skin, and stretch marks may appear on her belly, thighs, breasts and backside. She may also notice varicose veins on her legs.

In the third trimester, a woman’s breasts may experience some leakage of colostrum, a yellow liquid, as they get ready for breastfeeding, according to the OWH. The baby will drop lower in her abdomen.

False labor, known as Braxton-Hicks contractions, may begin to occur as a woman gets closer to her due date. A “nesting instinct” may kick in as a mother-to-be and her partner baby-proof their home, shop for baby items, prepare the nursery and await their new arrival.

During the final weeks of pregnancy, it will become harder to find a comfortable sleeping position, so women may be extremely tired, Burch said.

As delivery approaches, some women love the experience of being pregnant, while others may feel like they can’t wait for it to end, Burch said.

By the seventh month of pregnancy, the fetus kicks and stretches, and can even respond to light and sound, like music, Burch said. Eyes can open and close.

During the eighth month of pregnancy, the fetus gains weight very quickly. Bones harden, but the skull remains soft and flexible to make delivery easier. Different regions of the brain are forming, and the fetus is able to hiccup, according to ACOG.

The ninth month is the home stretch of pregnancy, and the fetus is getting ready for birth by turning into a head-down position in a woman’s pelvis. The lungs are now fully mature to prepare for functioning on their own. The fetus continues to gain weight rapidly.

The new definition of a full-term pregnancy is when a baby is born after 39 to 40 weeks (it used to be 37 weeks), Burch said.

How Zika Virus Can Help Combat Brain Cancer

The Zika virus can be a serious health threat, especially to unborn children, but now researchers say the virus itself could help treat another devastating illness — brain cancer.

A new study suggests that the same properties that make Zika a dangerous virus for unborn children could be useful in treating brain cancer in adults. The study was done in lab dishes and animals, and much more research is needed before it could be tested in humans.

It’s thought that the Zika virus naturally targets and kills brain stem cells, which are abundant in fetal brains during development. As a consequence, women infected with Zika virus during pregnancy are at increased risk of giving birth to children with neurological problems. But adults have fewer active stem cells in their brains, and as a result, the effect of Zika on adult brains is usually much less severe, the researchers said.

What’s more, the growth of certain brain cancers — including often-lethal glioblastomas — may be driven by cancer stem cells that divide and give rise to other tumor cells. These glioblastoma stem cells are typically resistant to therapies such as chemotherapy and radiation, and may fuel the return of the cancer after treatment. The researchers hypothesized that the Zika virus could target these cancer stem cells. [5 Facts About Brain Cancer]

“We wondered whether nature could provide a weapon to target the cells most likely responsible” for the return of glioblastoma after treatment, study co-author Milan Chheda of Washington University School of Medicine in St. Louis, said in a statement.

The researchers found that the Zika virus preferentially targeted and killed human glioblastoma stem cells in a lab dish, without having much of an effect on normal adult brain cells.

Next, the researchers tested the Zika therapy on mice with glioblastomas. To do this, they injected a mouse-adapted strain of Zika virus into the glioblastoma tumors. (The strain of Zika virus that infects humans does not infect mice.)

They found that mice treated with Zika showed slower tumor growth and lived longer than those that didn’t get the Zika treatment. All of the untreated mice died after about a month, but close to half of the treated mice were still alive after two months, the researchers said.

Still, much more research is needed to show that the therapy is safe and effective in humans. The researchers plan to genetically modify the Zika virus so that it is weaker and would not be expected to cause disease. A preliminary test of such an “attenuated” Zika strain showed that this virus was still capable of targeting and killing glioblastoma stem cells in a lab dish.

“Our study is a first step towards the development of safe and effective strains of Zika virus that could become important tools in neuro-oncology and the treatment of glioblastoma,” said study co-author Michael Diamond, also of Washington University.

But concerns over the safety of a Zika-based therapy will need to be addressed with further studies in animals before the therapy is tested in humans, Diamond said. Ultimately, the Zika therapy might be used along with other traditional brain cancer therapies to treat glioblastomas, the researchers said.

The new study is published today (Sept. 5) in The Journal of Experimental Medicine.

Zika is not the only virus being considered as a potential treatment for glioblastomas. Other research groups are testing measles, polio and herpes viruses as possible ways to target glioblastomas.