Trusted Information for Healthy Pregnancies
preterm labor
High-dose vitamin D safe during pregnancy
May 3rd
Taking high doses of vitamin D during pregnancy is safe and appears to reduce the risk of preterm birth and infections, say the authors of a study that compared different amounts of supplementation in expectant mothers.
But their recommendation that pregnant women should take 4,000 international units of vitamin D daily -- at least 10 times the standard recommended amount -- is sure to generate controversy.
"When we first proposed the study in 2002, it was heresy to even think about giving more than 400 international units a day of vitamin D," co-principal investigator Dr. Carol Wagner said from Vancouver, where the two-part study is being presented at an international pediatrics meeting.
"Diet doesn't provide enough vitamin D, and we don't go in the sun as much as we need (to)," said Wagner, adding that her research team set out to determine the optimal dose of vitamin D supplements for pregnant women that would promote health without doing harm.
The researchers enrolled 494 pregnant women at 12 to 16 weeks' gestation in the study and assigned them to three groups: one group received 400 IUs of vitamin D a day until delivery; the second got 2,000 IUs; and the third 4,000 IUs. The women were tested monthly to ensure they were not suffering any negative effects.
Neither the women nor the researchers knew what dose of vitamin D they were receiving in the study, a "blinded," randomized controlled trial whose methodology is considered the gold standard of medical science.
"What we found was that 2,000 was better than 400, and 4,000 was the best, without any adverse events that were associated with vitamin D," said Wagner. "And then ... we found fewer infections in the 4,000 group and fewer preterm labors and-or preterm birth deliveries in the 4,000 group compared to the 400 group."
Analysis of the data also showed that the women taking 4,000 units of vitamin D had half the rate of pregnancy-related disorders, such as gestational diabetes and preeclampsia, compared to expectant mothers taking 400 units.
However, Wagner conceded that the notion of pregnant women taking a daily dose of 4,000 IUs of vitamin D will likely stir some debate, especially within the medical community. The current recommended daily dose is 200 to 400 IUs daily.
Dr. Gideon Koren, head of the Motherisk Program at Toronto's Hospital for Sick Children, said the study is too small to provide such a definitive recommendation and to "declare therapeutic superiority" of 4,000 units of vitamin D.
"I think for now women should be sure that they get the recommended dose. I don't know that this study by itself should send women to buy 4,000. No, no way. I don't think this is sufficient."
"The study's important to show that it doesn't cause side-effects, but I think to tell women that they need 4,000 - to go from 400 to 4,000 - is huge."
However, Dr. Reinhold Vieth, head of the Bone and Mineral Laboratory at Mount Sinai Hospital in Toronto, has long argued that recommended daily amounts (RDAs) for vitamin D are outdated and woefully inadequate.
Vieth, who has conducted numerous studies on vitamin D in different patient populations, said the Canadian Pediatric Society has been advocating 2,000 units during pregnancy since 2007.
"The next step, 4,000, well, I bet you they'll come up with that in a couple of years, because this (the Wagner-group study) has to get published first," he said, adding that he agrees that pregnant women should be taking that level of vitamin D daily.
Dr. Robert Gagnon, a spokesman for the Society of Obstetricians and Gynecologists of Canada (SOGC), said the study was well-designed and its findings are important.
The Montreal specialist said SOGC is in the process of reviewing the medical literature before deciding on its official recommendation for expectant mothers.
"We need to see all the details of the study before we come to the recommendation," he said. "To say (pregnant women) should take 4,000, I think it's a little premature for that."
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Excess weight raises pregnancy risks: study
Feb 12th
Being overweight or obese increases a woman's chances of having an extra-big baby, even after the effects of pregnancy-related, or "gestational," diabetes are taken into account, new research shows.
Excess weight in and of itself also sharply increased a woman's risk of pre-eclampsia, a potentially deadly pregnancy complication, Dr. Boyd E. Metzger of Northwestern University Feinberg School of Medicine in Chicago and his colleagues found.
Women have more difficulty delivering very large babies, while these newborns are also at risk of suffering injury during birth, including shoulder dislocation. While women who are overweight or obese are known to run a greater risk of having very large babies and experiencing other pregnancy complications, it has been difficult to separate out the effects of a mother's weight from those of gestational diabetes, Metzger and his colleagues note in the British Journal of Obstetrics and Gynecology.
This led them to investigate whether body mass index (BMI) -- a standard measure of weight in relation to height used to gauge how fat or thin a person is -- might influence pregnancy risks and fetal and newborn health, independently of a woman's blood sugar levels.
The study involved 23,316 women from 15 different medical centers in nine different countries. All had undergone an oral glucose tolerance test, which is used to identify women with, or at risk for, pregnancy-related diabetes; at that time, their height and weight were measured, too.
The researchers then used statistical techniques to control for women's oral glucose tolerance test results. Even after this adjustment, they found that the women with BMIs of 42 or greater, denoting severe obesity (for example, a 5-foot-5-inch tall woman weighing at least 250 pounds), were at more than triple the risk of having an excessively large baby, compared to the thinnest women in the study, who had BMIs of 22.6 or less (a 5'5" woman weighing less than 138 pounds).
The heaviest women's risks of having a C-section were more than doubled, while their likelihood of pre-eclampsia was 14-fold greater than for the leanest women. However, the heaviest women's risk for delivering a preterm baby was actually cut in half.
These findings help sort out the role BMI and gestational diabetes each play in the risk of complications of pregnancy and delivery, Metzger told Reuters Health in an interview.
He noted that recent studies have shown that dietary changes can effectively treat gestational diabetes for more than 90 percent of women with the condition.
"We're pretty confident that treating gestational diabetes going forward is going to continue to be beneficial," the researcher said. "We have much less evidence at this point as to how to neutralize or reduce the impact of overweight on pregnancy outcome."
What is becoming clear, he added, is that it's probably a woman's weight before she gets pregnant, rather than how much she gains during pregnancy, that's important in determining risk.
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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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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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Mothers with Celiac Disease Face a Higher Risk of Underweight and Early-term Births
Jan 25th
Women with celiac disease face greater risks for adverse pregnancy outcomes. A team of researchers recently set out to examine the effects of treated and untreated maternal celiac disease on infant birthweight and preterm birth. Among their findings are that expectant mothers with celiac disease face a higher risk of underweight and early-term birth than those without celiac disease.
For their data, researchers used a population-based cohort study of all live births in Denmark between 1 January 1979 and 31 December 2004. During that period, 836,241 mothers gave birth to a total of 1,504,342 babies. Mothers with diagnosed celiac disease gave birth to 1105 of those babies, while 346 were born to women with undiagnosed celiac disease.
The team considered mothers with diagnosed celiac disease to be following a gluten free diet, and those with undiagnosed celiac disease to be on a gluten-inclusive diet. The team measured outcomes based on birthweight, small for gestational age, very small for gestational age and preterm birth. They then compared the results for the treated and untreated celiac disease mothers with those of a celiac-free reference group.
The research team found that mothers with untreated celiac disease gave birth to smaller babies [difference = –98 g (95% CI: –130, –67)], with a higher risk of SGA [OR = 1.31 (95% CI: 1.06, 1.63)], VSGA [OR = 1.54 (95% CI: 1.17, 2.03)] and early birth [OR = 1.33 (95% CI: 1.02, 1.72)] compared with women with no celiac disease.
The good news is that mothers with treated celiac disease showed no increased risk of reduced mean birthweight, or of delivering SGA and VSGA infants or preterm birth compared with mothers with no celiac disease.
From the results, the research team concluded that untreated maternal celiac disease increases the risk of low birthweight, SGA and VSGA, and preterm birth.
Diagnosis and treatment of maternal celiac disease with a gluten-free diet seems to return the birthweight and preterm birth rate to one comparable to women without celiac disease.
Source
Stress, Anxiety Can Up Risk of Depression in Pregnancy
Jan 22nd
Stress, history of depression, lack of social support and unintended pregnancy are among the major factors that contribute to increased risk of depression in pregnant women, a new study shows.
Other important factors are maternal anxiety, domestic violence and having public insurance coverage, said the University of Michigan researchers, who reviewed 159 studies conducted between 1980 and 2008.
The study appears in the January issue of the American Journal of Obstetrics & Gynecology.
Depression, which occurs in about 12.7 percent of pregnant women, can cause problems for mothers and babies, including pre-term delivery, preeclampsia, sleep disturbances and disrupted mother-infant bonding.
It's important for physicians to know how to identify depression in pregnant women, said the study authors, who noted that not all women who test positive on depression screening tests have or will develop clinical depression.
"We are hoping that [health-care] providers can use the presence or absence of risk factors such as those identified in our study to enhance their assessments for depression in addition to the information they obtain from the screening test," study author Dr. Christie A. Lancaster, a clinical lecturer in the obstetrics and gynecology department at U-M, said in a news release.
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Birth Weights Are Falling in U.S.
Jan 21st
Mothers are giving birth to lighter babies in the U.S., and no one is quite sure why.
This finding, published Thursday in the Journal of Obstetrics and Gynecology, has potentially troubling public-health implications, if the trend continues. Low-birth-weight babies are at higher risk for a host of health problems.
Between 1990 and 2005, the birth weight of full-term babies in the U.S. declined nearly two ounces to an average of seven pounds and 7.54 ounces, a reversal of a trend that had seen birth weights climb steadily since the 1950s, according to the study. They were also born 2.5 days earlier on average in 2005 than in 1990, the study said.
The decrease in weight—based on an analysis of nearly 37 million non-multiple births from a national database—isn't likely to affect the health of the average baby in the study, according to researchers. But the data showed a 1% increase in the number of the lowest-weight babies and suggested the birth-weight decline didn't stop in 2005.
These data suggest that it may be important for medical professionals to pay attention to the weight of babies born around 37 weeks and 38 weeks, as well as those considered pre-term, or less than 37 weeks, according to Joann Petrini, senior adviser at the March of Dimes and assistant research director at Danbury Hospital in Connecticut, who wasn't involved in the study.
Researchers also found a 2% decrease in the number of babies considered large—those over the 90th percentile of weight for gestational age—which is a positive, according to Dr. Oken. Large babies can experience more birth trauma and cause more birth injury to the mother.
The lower-birth-weight trend could not be explained by common factors like how much weight mothers gained during pregnancy, whether the delivery was induced or by cesarean section, prenatal care, or common maternal-health issues such as smoking and hypertension, researchers said.
Researchers also repeated their analysis in a sample of low-risk women—healthy, educated Caucasians in their mid-to-late 20s—and found that the decrease in birth weight was even more pronounced, suggesting that the trend isn't the result of changes in the population of mothers.
Other investigators also have begun to note the same trend. "There's no question" about the change in birth-weight pattern, said Michael Kramer, scientific director of the Institute for Human Development and Child and Youth Health at the Canadian Institutes of Health Research, who wasn't involved in the study.
"It is a new trend," he said. "We really don't know why the birth weight has decreased." A similar pattern has been observed in Canada, he said.
Some potential factors that weren't examined in this study include better control of gestational diabetes—when a mother develops diabetes during pregnancy—and more physical activity during pregnancy, said Dr. Kramer.
Babies considered too large, as well as too small, tend to have more health problems in the long run. The optimal size for a newborn is around 4,000 grams, or roughly 8.8 pounds, according to Dr. Kramer. The average baby in the study was found to be smaller than optimal. In 1990, the average birth weight was 3,441 grams, and in 2005 it fell to 3,389 grams, according to the study.
Babies born too small tend to have higher blood pressure and a greater risk of diabetes in the long run, said Dr. Oken.
From the 1950s until the 1980s, birth weights had increased as a result of increases in mothers' weight and how many pounds they gained during the pregnancy, as well as reduced smoking and older maternal age, according to Dr. Kramer.
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Drugs for depression, anxiety tied to preterm birth
Jan 21st
Pregnant women who take certain drugs for depression or anxiety may have heightened risks of preterm delivery or other birth complications, according to a new study.
Researchers found that among nearly 3,000 women who gave birth in Washington State, those who started taking antidepressants known as selective serotonin reuptake inhibitors (SSRIs) in the second or third trimester had a higher risk of preterm birth.
Compared with their counterparts not on the medications, these women were nearly five times more likely to deliver prematurely.
The same risk was not seen, however, among women who started on an SSRI before pregnancy or during the first trimester. SSRIs include drugs like sertraline (Zoloft), paroxetine (Paxil) and fluoxetine (Prozac).
The researchers also found a higher risk of preterm delivery among women who took anti-anxiety drugs known as benzodiazepines, regardless of when they began treatment.
Those drugs, which include medications like lorazepam (Ativan) and alprazolam (Xanax), were linked to higher risks of other complications as well - including low birth weight, newborn respiratory distress and a low Apgar score, a standard measure of newborn health.
The findings of the study are published in the American Journal of Obstetrics & Gynecology.
Exactly what the study means for women on SSRIs or benzodiazepines is not entirely clear. A major limitation is that it could not estimate the benefits of treatment, lead researcher Dr. Ronit Calderon-Margalit, of the Hebrew University-Hadassah School of Public Health in Jerusalem, noted in an email to Reuters Health.
Any risks of using the medications during pregnancy need to be balanced against the risks of leaving depression and anxiety disorders untreated.
"It is very important to have other studies of the risks associated with (these) drugs, but also of benefits associated with treating mothers," said Calderon-Margalit, who was at the University of Washington in Seattle at the time of the study.
In addition, SSRIs did not appear to present equal risks for all women. Calderon-Margalit described the antidepressant findings as "mostly reassuring" for women who start the drugs before pregnancy or in the first trimester -- as most SSRI users in the study had.
The study included 2,793 pregnant women, 11 percent of whom used a psychiatric medication during pregnancy. Of these, 138 were on an SSRI, while 85 used a benzodiazepine.
Among women who were not on any medication, 9 percent gave birth prematurely, versus nearly half of women on benzodiazepines.
Meanwhile, 14 percent of women on SSRIs had a preterm birth, but the elevated risk turned out to be concentrated among those who started an antidepressant after the first trimester. Of those 21 women, 16 delivered prematurely.
Several other birth complications, often related to preterm birth, were also higher-than-average among women on benzodiazepines.
Seventeen percent of their newborns suffered respiratory distress syndrome and one-third ended up in the neonatal intensive care unit. Those figures were 3 percent and 6 percent, respectively, among newborns whose mothers had not used psychiatric medications during pregnancy.
Calderon-Margalit pointed out that most women on benzodiazepines used lorazepam (Ativan), so it is possible that the risks are associated mainly with that drug. However, further research is needed to determine whether any particular medications carry particular risks.
Source
Mothers’ Genes Important in Preterm Birth Risk
Dec 9th
A mother's genes may be an important factor in the risk of preterm birth, two new studies suggest.
Past research has shown that genes likely play a role in a pregnant woman's odds of delivering prematurely - before the 37th week of pregnancy.
The risk is increased, for example, among women who were themselves born prematurely or have a sister who ever gave birth preterm, And findings from twin studies suggest that up to 40 percent of preterm deliveries involve some genetic susceptibility.
But little is known about the specifics of how genes influence preterm labor.
The two new studies, reported in the American Journal of Epidemiology, suggest that the mother's genes - rather than genes affecting fetal development that are inherited from both parents - are key.
In one study, Danish researchers analyzed national database information on more than 1 million singleton births in Denmark between 1978 and 2004. They found that, not surprisingly, women with a history of preterm delivery were at increased risk of having a subsequent early birth.
But the risk was also elevated among women with a mother, sister or half-sister (born to the same mother) who had delivered prematurely. Compared with women without such a family history, these women were 60 percent more likely to have a preterm birth.
In contrast, preterm births among female members of the father's side of the family, or among the female partners of a woman's male relatives, had no bearing on a woman's own risk of premature delivery.
The findings were similar in the second study - this one of more than 989,000 births in Sweden between 1992 and 2004. Researchers found that sisters of women who had delivered preterm had an 80 percent higher risk of early delivery, versus women without that family history.
There was no evidence of an increased risk, however, when a brother's partner had delivered prematurely. Nor was there evidence that the increased risk shared by sisters was explained by non-genetic factors that could influence the chances of preterm delivery, like smoking or lower education levels.
Overall, the researchers estimate that mothers' genes account for one-quarter of the variation in preterm delivery risk across the population. In contrast, fetal genes - which are inherited from both parents - showed little influence.
The vast majority of women in the studies did not deliver early, regardless of family history. In the Danish study, for example, about 7 percent of women with a sister who had delivered prematurely had a preterm birth themselves; that compared with 4.5 percent of women whose sisters had no history of preterm delivery.
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