Trusted Information for Healthy Pregnancies
fetal development
Very premature twins do just as well as singletons
Feb 18th
Overall, very premature twins fare just as well as single babies born very early, and they may even face a lower risk of certain complications, new research shows.
But for twin pairs of the same sex but sharply different sizes who are born before 28 weeks, the risks of death and bleeding on the brain are higher than they are for single babies born at the same time, Dr. Jennifer Zeitlin of the Hopital Saint-Vincent de Paul in Paris and her colleagues found.
Premature birth is much more common among twins than singletons, Zeitlin and her team note; while one in every 10 twin pairs is born before 32 weeks' gestation, just one in 100 singletons is born this early. There is evidence that preemie twins do better than singles of the same gestational age, they add.
A full-term pregnancy lasts for 39 weeks, while babies born between 28 and 31 weeks are considered "very preterm." Babies born between 24 and 27 weeks' gestation are "extremely preterm."
To investigate outcomes for very premature and extremely premature twins compared to those of singletons born equally early, Zeitlin and her colleagues looked at births and stillbirths in nine European countries in 2003. Their analysis included 1,254 twins and 3,586 singletons born between 24 and 31 weeks' gestation.
The women carrying twins were less likely to develop high blood pressure during pregnancy than those with singletons, the researchers found: about 8 percent of those carrying twins, compared to about 22 percent of those carrying single babies.
They also found that severe bleeding and restrictions on the growth of the fetus were also less common in twin pregnancies.
Twins' mothers were also more likely to have been given corticosteroids before delivery; these drugs are administered to speed up premature newborns' lung development.
Among the very premature babies, the likelihood of dying in the first few weeks of life was lower for twins, who were also less likely to need oxygen. But once the researchers took factors such as mother's age, pregnancy complications, and infant health problems into account, the difference disappeared.
For the extremely premature infants, however, the researchers calculated that the risk of death or serious bleeding in the brain was about 1.5 times higher for twins than it was for single babies. While about 17 percent of singletons suffered from such bleeding, roughly 24 percent of twins did.
The greater risks were only seen for same-sex twins in which one twin weighed at least 15 percent more than the other twin at birth.
"Why the effects of these twin-specific complications were so much more pronounced for extremely preterm births is an area for further study," the researchers conclude.
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Two languages in womb makes bilingual babies: study
Feb 17th
Babies who hear two languages regularly when they are in their mother's womb are more open to being bilingual, a study published this week in Psychological Science shows.
Psychological scientists from the University of British Columbia and a researcher from the Organization for Economic Cooperation and Development in France tested two groups of newborns, one of which only heard English in the womb and the others who heard English and Tagalog, which is spoken in the Philippines.
To determine the babies' preference for a language, the researchers studied the newborns sucking reflex; increased sucking by a neonate indicates interest in a stimulus.
In the first experiment, infants heard 10 minutes of speech, with every minute alternating between English and Tagalog.
The English-only infants were more interested in English than Tagalog -- in other words, they "exhibited increased sucking behavior" when they heard English than when they heard Tagalog being spoken.
The infants exposed to two languages, on the other hand, showed an equal preference for both English and Tagalog, suggesting to the researchers that prenatal bilingual exposure prepares infants to listen to and learn about both of their native languages.
The researchers also tested the newborns to see if they could tell the differences between two languages -- key to becoming bilingual.
The infants listened to sentences being spoken in one of the languages until they lost interest, and then heard sentences in the other language or heard sentences in the same language, but spoken by a different person.
The infants exhibited increased sucking when they heard the other language being spoken, but their sucking did not increase if they heard additional sentences in the same language.
"These results suggest that bilingual infants, along with monolingual infants, are able to discriminate between the two languages, providing a mechanism from the first moments of life that helps ensure bilingual infants do not confuse their two languages," the authors of the study said.
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Mom’s Lifestyle in Early Pregnancy Affects Baby’s Size
Feb 10th
The lifestyle habits you bring into pregnancy can have lasting effects on your baby's health, new research shows.
A Dutch study found that women who smoked, had high blood pressure or low folic acid levels in early pregnancy had babies that were smaller in the first trimester of pregnancy and had a higher risk of complications later.
"Our study demonstrates that several maternal physical characteristics and lifestyle habits, such as smoking and non-use of folic acid supplements, affect first-trimester fetal growth," said study senior author Dr. Vincent Jaddoe, a pediatric epidemiologist at Erasmus Medical Center in Rotterdam, the Netherlands.
"First-trimester growth restriction is associated with higher risks of adverse birth outcomes and accelerated postnatal growth rates. Thus, the first trimester of pregnancy seems to be a very critical period for fetal growth and development. This is important, since it suggests that the fetus is already affected before pregnant women visit their midwife or obstetrician," he said.
For the study, published in the Feb. 10 issue of the Journal of the American Medical Association, the researchers followed 1,631 pregnant women from their first trimester through their pregnancies. The growth of their offspring was assessed until the children were 2.
The average age of the mothers was 31, and 71 percent were white. More than half had a higher than high school education. The average body mass index was 23.5, which is normal (over 25 is considered overweight). About one-quarter smoked at the start of the study.
The researchers found that certain factors affected the likelihood that a fetus would have a small crown to rump length (a standard way to measure babies using ultrasound). Babies whose mothers smoked or had higher diastolic blood pressure readings (diastolic is the bottom number in blood pressure) were more likely to be smaller. Women who didn't use folic acid supplements and those with higher levels of red blood cells also had smaller babies, according to the study.
A small size during the first trimester translated to a higher risk of certain complications later in the pregnancy, such as preterm birth and low birth weight.
Babies that had first-trimester growth restriction had 7.2 percent odds of being born preterm compared to 4 percent for babies who weren't growth-restricted. Odds of low birth weight were 7.5 percent for growth-restricted babies compared to 3.5 percent for other babies. And, the odds of being born small-for-gestational-age were 10.6 percent for babies who were growth-restricted compared to 4 percent for babies who grew normally during early pregnancy.
Jaddoe and Dr. Gordon Smith, author of an accompanying editorial in the same issue of the journal, believe that when a woman is exposed to poor lifestyle habits in early pregnancy, it may affect development of the placenta, which then affects the fetus' ability to survive and thrive.
The bottom line for women is that it's important to go to the doctor before getting pregnant to find out what steps to take to ensure that you're in the best shape possible before you get pregnant, such as quitting smoking and taking folic acid supplements.
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Milk in pregnancy may lower MS risk
Feb 10th
Mothers-to-be can reduce their babies' risk of developing multiple sclerosis in later life by drinking milk, research suggests.
The link emerged from a study of 35,794 female nurses whose mothers provided information about their diet during pregnancy. Of the nurses taking part, 199 developed multiple sclerosis (MS) over a 16-year period.
The researchers found that the risk of MS was lower among women born to mothers who drank a lot of milk while pregnant. A similar trend was seen for vitamin D. Mothers who had a relatively high vitamin D intake during pregnancy also gave birth to daughters with a reduced risk of MS.
Dr Fariba Mirzaei, from the Harvard School of Public Health in Boston, US, who led the study, said: "The risk of MS among daughters whose mothers consumed four glasses of milk per day was 56% lower than daughters whose mothers consumed less than three glasses of milk per month.
"We also found the risk of MS among daughters whose mothers were in the top 20% of vitamin D intake during pregnancy was 45% lower than daughters whose mothers were in the bottom 20% for vitamin D intake during pregnancy."
She added: "There is growing evidence that vitamin D has an effect on MS. The results of this study suggest that this effect may begin in the womb."
Exposure to sunlight, oily fish such as salmon and mackerel and fortified milk are key sources of vitamin D.
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Childhood asthma in premature babies linked to pregnancy bug
Feb 2nd
A common complication during pregnancy may predispose children born prematurely to asthma, a large study reports today.
The condition, chorioamnionitis, is inflammation of the fetal membranes and amniotic fluid from a bacterial infection. It is thought to be linked to more than half of all preterm births, before 37 weeks' gestation, scientists write in today's Archives of Pediatric and Adolescent Medicine.
The infection may have ascended to the uterus from the mother's genital tract or traveled through her bloodstream from a more remote site, such as her gums or upper respiratory tract, says lead author Darios Getahun, a scientist at Kaiser Permanente Southern California's Department of Research and Evaluation in Pasadena.
In animals, chorioamnionitis has been shown to cause lung and brain damage in offspring, Getahun says. Scientists also have found lung scarring in infants who died after pregnancies complicated by the condition.
Getahun and his co-authors analyzed electronic health records for all singleton children born at Kaiser's Southern California hospitals in 1991 to 2007, a total of 397,852. Of those, 28,869 were preterm.
Among children born full-term, chorioamnionitis wasn't linked to an increased risk of being diagnosed with asthma by age 8. But among those born prematurely, the condition was associated with double the risk of childhood asthma in blacks, a 70% increase in Hispanics and a 66% increase in whites. The researchers observed these differences even after accounting for other possible risk factors such as whether the mother smoked or had asthma herself. Only in Asian/Pacific Islanders preemies did chorioamnionitis not seem to make a difference in childhood asthma risk.
Getahun speculates that chorioamnionitis wasn't related to asthma risk in full-term children because their mothers might not have had it as long as those born prematurely. But, he adds, his team didn't have information about how early in their pregnancy women were diagnosed.
Diagnosing the condition is tricky, Getahun says, because symptoms — fever in the mother, tenderness or pain in the uterus, foul-smelling amniotic fluid — aren't definitive, and some women never exhibit symptoms. Getahun's team is now trying to find a marker in the mother's blood that would signify her symptoms are because of chorioamnionitis.
A study of 1,096 children published in 2008 found a higher risk of wheezing by age 2 in preemies whose mothers had had chorioamnionitis.
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Omega-3 Supplements Don’t Reduce Risk of Preterm Birth
Jan 28th
Omega-3 fatty acid supplements are believed to have many health benefits, but the one thing they can't do is help women with a history of delivering their babies early carry their next child to full term, new research finds.
"The omega-3 did not add any benefit," said study author Dr. Margaret Harper, an associate professor of obstetrics and gynecology at Wake Forest University School of Medicine, Winston-Salem, NC. The study appears in the February issue of Obstetrics & Gynecology.
Harper and her colleagues randomly assigned 852 pregnant women with a history of a preterm birth either to get a daily omega-3 supplement or a placebo beginning about week 16 to 22 and continuing through week 36 of gestation.
All women also received weekly intramuscular hormone injections of hydroxyprogesterone caproate, which has been shown to improve the chances of carrying a baby to term, Harper said.
Her team followed up to see which women delivered before 37 weeks. Full-term is defined as 37 weeks of completed gestation.
Delivery before 37 weeks occurred in 37.8 percent of those taking omega-3, and 41.6 percent of those in the placebo group, a small difference.
Prematurity is the leading cause of newborn death, the authors write in the report, and it is increasing in the United States. A woman who delivers one baby before term is more likely to deliver future babies early.
Harper's team decided to study the value of the omega-3 supplements after conflicting findings about the value of the supplements for women at high risk of premature delivery. For those at low-risk, she said, the findings seem to agree that omega-3 supplements don't further reduce the risk of preterm birth.
A recent large review of published studies found only one that showed benefit of the supplements in high-risk women, she said.
According to Harper, omega-3 fatty acids, when metabolized, are converted to much less potent biochemicals called prostaglandins, which make the uterus contract, than are omega-6 fatty acids -- also essential fatty acids but typically over-eaten in Western diets. Adding omega-3s to an omega-6-heavy diet, so the thinking went, might result in better chances of carrying the baby to term.
Omega-3 supplements, in other research, have been found to help heart health, to lower blood pressure and to reduce the risk of abnormal heartbeats.
But in Harper's study, she also noted that women getting omega-3 supplements were more likely to give birth to a baby with respiratory distress syndrome (RDS). While 59 babies (13.9 percent) of those in the omega-3 group had RDS, only 35 (8.7 percent) of those in the placebo group did. In other words, the omega-3 mothers' babies were 1.6 times more likely to get RDS than infants born to mothers taking placebo. It's the first time such a finding has been reported in clinical trials, the authors wrote.
"While the study's results showed no difference, there is early evidence that omega-3 fatty acids are beneficial for fetal brain development, so women should still consider taking them, in conjunction with their doctor's advice, despite what seems to be little benefit for the reduction of spontaneous preterm birth."
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Prenatal Exposure to Flame-Retardant Compounds Affects Neurodevelopment of Young Children
Jan 27th
Prenatal exposure to ambient levels of flame retardant compounds called polybrominated diphenyl ethers (PBDEs) is associated with adverse neurodevelopmental effects in young children, according to researchers at the Columbia Center for Children's Environmental Health (CCCEH) at Columbia University's Mailman School of Public Health.
The study is online in Environmental Health Perspectives and will be released in the April 2010 print issue.
PBDEs are endocrine-disrupting chemicals and widely used flame-retardant compounds that are applied to a broad array of textiles and consumer products, including mattresses, upholstery, building materials, and electronic equipment. Because the compounds are additives rather than chemically bound to consumer products, they can be released into the environment. Human exposure may occur through dietary ingestion or through inhalation of dust containing PBDEs.
The researchers found that children with higher concentrations of PBDEs in their umbilical cord blood at birth scored lower on tests of mental and physical development between the ages of one and six. Developmental effects were particularly evident at four years of age, when verbal and full IQ scores were reduced 5.5 to 8.0 points for those with the highest prenatal exposures.
"The neurodevelopmental effects of prenatal exposure to PBDEs have not previously been studied among children in North America, where levels are typically higher than in Europe or Asia," said Julie Herbstman, PhD, first author on the paper and a research scientist in Environmental Health Sciences at the Mailman School of Public Health. "The findings are consistent with effects observed in animal studies and, if replicated in other North American populations, they could have important public health implications."
Frederica Perera, DrPh, professor of Environmental Health Sciences at the Mailman School, CCCEH Director, and coauthor added, "These findings are of potential concern, because IQ is a predictor of future educational performance; and the observed reductions in IQ scores are in the range seen with low level lead exposure." This research underscores the need for preventive policies to reduce toxic exposures occurring in utero."
The investigators controlled for factors that have previously been linked to neurodevelopment in other studies, including ethnicity, mother's IQ, child's sex, gestational age at birth, maternal age, prenatal exposure to environmental tobacco smoke, maternal education, material hardship, and breast feeding.
The study is part of a broader project examining the effects of chemicals released by the World Trade Center's destruction on pregnant women and their children. However, residential proximity to the World Trade Center site did not affect levels of PBDE exposure.
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Newborns of Smokers Have Abnormal Blood Pressure
Jan 25th
Babies of women who smoked during pregnancy have blood pressure problems at birth that persisted through the first year of life, a new study finds.
"What is of concern is that the problems are present at birth and get worse over time," said Gary Cohen, a senior research scientist in the department of women and child health at the Karolinska Institute in Stockholm, and lead author of a report in the Jan. 25 online edition of Hypertension.
The study led by Cohen compared 19 infants of nonsmoking couples with 17 infants born to women who smoked an average of 15 cigarettes a day during pregnancy. At one week of age, the infants of nonsmoking mothers experienced a 2 percent increase in blood pressure when tilted upright, with a 10 percent increase at one year. The pattern for the children of smoking mothers was reversed: a 10 percent blood pressure increase at one week, a 4 percent increase at one year.
And the heart rate response to tilting of the children of mothers who smoked was abnormal and exaggerated, the report said.
It's not possible to say whether the abnormalities seen in the babies will lead to trouble later in life, Cohen said. But, he noted, "the extent of the condition at one year suggests that it is not going to disappear quickly."
The reason why exposure to tobacco in the womb affects blood pressure is not clear, Cohen said. A leading possibility is that "smoking might damage the structure and function of blood vessels," he said, mainly by damaging the endothelium, the delicate layer of cells that line the interior of blood vessels.
Whether that damage will persist is not known. "We're only up to 12 months at the moment," he said. "We plan to follow them."
The damage seen in the Karolinska study is similar to that observed in babies born to mothers whose pregnancies were marked by such abuses as drug use, said Barry M. Lester, a professor of psychiatry and pediatrics at Brown Medical School, and director of the Brown Center for the Study of Children at Risk.
"Early kinds of natal insults can cause reprogramming of brain circuitry," Lester explained. He has led studies of the long-term effects of cocaine and amphetamine use during pregnancy. Many women who take such drugs also smoke, Lester added.
"When we isolated tobacco effects, we showed that there are inborn neural effects of tobacco exposure similar to what we see in cocaine and methamphetamine abuse," he said.
Some research has connected such problems to overproduction of cortisol, a "stress hormone" that plays an important role in regulation of blood pressure and the immune system, Lester said. "Cortisol overexposure is one hypothesis," he said. "There is a lot of evidence showing that too much cortisol is damaging."
It is a reasonable hypothesis, Cohen said. Babies born preterm have problems with blood pressure that have been linked to overproduction of cortisol by the adrenal glands, he noted, "and there are some parallels between tobacco smoke exposure and preterm babies of the same age."
Whatever the mechanism of damage, treatment to eliminate the problems after birth does not seem possible, Cohen added.
"What we know from studies in older kids is that even if you remove them from an environment of exposure to tobacco smoke, it is unlikely you will get full restoration of normal function," he said. "The best intervention to solve these problems is prevention. Women who are pregnant need to avoid exposure to tobacco smoke in the air. Passive smoke exposure can be as bad as being an active smoker."
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Pot smoking during pregnancy may stunt fetal growth
Jan 22nd
Women who smoke marijuana during pregnancy may impair their baby's growth and development in the womb, a new study suggests.
Poor fetal growth and reduced head circumference at birth are linked to an increased risk of problems with thinking, memory and behavior in childhood. Cigarette smoking during pregnancy is known to impair fetal growth, but studies on the potential effects of marijuana have been inconclusive.
For the new study, researchers in the Netherlands followed more than 7,000 pregnant women, 3 percent of whom acknowledged smoking marijuana at least during early pregnancy. They found that babies born to marijuana users tended to weigh less and have smaller heads than other infants.
What's more, the study found, the longer a woman had used marijuana during pregnancy, the stronger the impact on birth size - suggesting that the drug itself was to blame.
And while most marijuana users in the study also smoked cigarettes, the drug appeared to have effects over and above those of tobacco. In fact, marijuana showed stronger effects on birth size than tobacco, the investigators report in the Journal of the American Academy of Child and Adolescent Psychiatry.
The findings suggest that marijuana use, even restricted to early pregnancy, may have irreversible effects on fetal growth, write the researchers, led by Hannan El Marroun of Erasmus University Medical Center in Rotterdam.
The study included almost 7,500 pregnant women who were surveyed on their use of alcohol, tobacco and drugs, and had ultrasounds to chart fetal growth during the first, second and third trimesters.
Overall, 214 women said they had used marijuana before and during early pregnancy; 81 percent quit after learning they were pregnant, but 41 women continued to smoke marijuana throughout pregnancy.
The researchers found that, on average, marijuana users gave birth to smaller babies, particularly those who had used throughout pregnancy.
Women who had smoked only during early pregnancy had babies who were 156 grams -- about 5.5 ounces -- lighter than infants born to women who had not used the drug. Women who had continued to smoke past early pregnancy had babies who were 277 grams, or nearly 10 ounces, smaller.
Based on ultrasound, marijuana use only in early pregnancy impaired fetal growth by about 11 grams per week, while use throughout pregnancy slowed fetal growth by roughly 14 grams per week. That compared with a deficit of 4 grams per week with tobacco use, the researchers found.
Similar patterns were seen when the researchers looked at fetal head circumference.
According to El Marroun's team, mothers' marijuana use could stunt fetal growth for several reasons. Like tobacco smoking, it may deprive the fetus of oxygen. It is also possible that the byproducts of marijuana directly affect the developing nervous and hormonal systems of the fetus.
Finally, the researchers note, pregnant women who use marijuana may have other factors in their lives - such as a less-than-healthy diet or chronic stress -- that could contribute to poor fetal growth.
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Prenatal Learning Products Draw Expert Skepticism
Jan 12th
For those who say you're never too young to learn, try typing "smart baby" into YouTube. It may give you some doubts.
You'll find plenty of brainy babies who will dazzle you with geography and other skills, their parents pushing them every step of the way. But you might find yourself thinking there is such a thing as too young to learn.
Monique Heller, of Conn., is nine months pregnant. She's already started trying to teach her new baby before the new daughter is even born.
"I want to give her every advantage that we're able to," said Heller. "And to a certain extent, I want her to be prepared for school as early as possible." Heller uses a device called Baby Plus, marketed as a "prenatal education system." The motto: "Your womb ... the perfect classroom."
"I used it in my pregnancy with my daughter Giovanna," said Heller. "And I'm using it now with my second daughter. And the product claims to help babies self-soothe and come out of the uterus a little more calm."
Heller insists it worked for her first daughter. So why not for daughter No. 2? The device straps right onto the mother's belly, for one hour, twice a day.
Baby Plus spokeswoman Lisa Jarrett explained how the device works.
"It plays a sound that is simple and similar to the maternal placental heartbeat. And that encourages a child to discriminate. That discrimination over time strengthens learning skills for life."
Proponents of the device claim it leads to babies that nurse more readily, that soothe themselves, that are more interactive and responsive, more relaxed and more ready for school.
"Ninety-seven percent of parents who utilize this curriculum would use it again, recommend it to a friend, and feel that it has made a difference," said Jarrett.
But Janet DiPietro, a developmental psychologist at Johns Hopkins University, says there's no evidence whatsoever that products like Baby Plus actually help a developing fetus.
"Just because fetuses respond to something doesn't mean that they are learning it," said DiPietro. "Or that it's important to give that sound. So what fetuses seem to respond to most are loud sounds: the vacuum cleaner, a rock concert. And just because they might get kind of jazzed up to one of those things doesn't mean it's either good or bad for them. They just react to it."
We asked Jarrett if there were any studies to back up her product's claims.
"Yes," she said, "there's a study that was published in the Preimparnatal Psychology Journal. It was small. My experience has been with the anecdotal evidence. ... It's been studied. It's just not been studied in long-term huge clinical trials. ... There's one early study... [by] Dr. Brent Logan ... and a developmental specialist in Russia. And it was years ago."
Why didn't it get studied here?
"Well, we are trying," said Jarrett. "We are trying."
Katherine Kranenburg is a middle-class mom in Washington who, like every mom, wants to give her kids every advantage. She has a 2-year-old, Kennedy. And Kennedy's little brother -- not yet born -- already has a teddy bear that plays the sound of a mother's heartbeat.
Kranenburg said she also does prenatal yoga. And she agreed to try out another brainy baby product, made in Israel, called the Ritmo. It hooks up to your iPod, so that mom can play tunes right into her belly.
Kranenburg played Bob Marley. And sure enough, the fetus responded.
But our expert at Johns Hopkins was dubious about the Ritmo, too, because, she says, all that fluid in the mother's belly doesn't muffle the sound -- it amplifies it.
"Which is counterintuitive to most people," DiPietro said. "Because as it goes through the amniotic fluid, the sound gets more intense, not less intense. So when you take these devices and you put them on your abdomen, you're blasting sound at the ear. ... You're taping their head to the speaker. It's akin to taking your sleeping newborn -- because fetuses are mostly asleep -- and putting speakers right next to their crib and blasting Mozart while they're asleep. ... Who would do that?"
Ritmo's manufacturer says its device "works through a sophisticated controller to regulate the output of sound to a level safe for a baby in-utero."
But it may surprise expecting mothers to learn that you have to take their word for it. The government does not require them to meet any special product safety standards.
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