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preterm
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.
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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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Simple test can spot premature birth false alarms
Dec 8th
A simple test can help reliably determine whether signs of an imminent premature delivery are likely to result in a false alarm, research suggests.
Less than half of women showing these signs actually go on to give birth soon after, and they often have to undergo what turn out to be unnecessary tests.
UK researchers found a test that looks for a protein called fetal fibronectin (fFN) could solve the problem.
The study was conducted by University College London.
fFN is the protein that helps attach the foetal sac, in which the foetus develops, to the uterus.
Previous research has shown that when fFN is found to be leaking at a certain stage of pregnancy, a premature birth is more likely.
A test to detect fFN levels is relatively cheap and easy to perform - but it is not commonly used in all maternity units.
It is done at the same time as a vaginal examination, which is routinely carried out when a woman is admitted with abdominal pain in pregnancy.
If the results show low levels of fFN, then the chance of a women having a premature delivery imminently is low.
The researchers conducted an audit to determine whether use of the test made any significant difference.
Initially they analysed 22 cases of women admitted to hospital showing signs of being about to go into premature labor.
Of these, 17 did not give birth during their hospital stay, which averaged just more than eight days.
Most received steroid drugs to improve their baby's lung function, or tocolytic drugs to halt labor contractions.
The situation changed significantly after staff began to use the fFN test.
It proved to be 98.6% accurate in identifying women who, despite showing signs of premature delivery, did not go into labor for at least another two weeks.
As a result just seven women out of 78 who showed signs of being about to go into labor, but who registered low levels of fFN, required hospital treatment - for pain management.
Source
Preterm Births Higher Among Poor Mothers, Despite Equal Care
Dec 2nd
Despite improvements in obstetric care services, women from deprived areas are still more likely to give birth to a very preterm baby compared with mothers from more affluent areas, finds a study published on the British Medical Journal website.
Yet survival rates and provision of care was similar for infants from all areas, suggesting that neonatal care provision is equitable. A finding in contrast to many other areas of health care where socioeconomic inequalities in survival and access to care are common.
These findings highlight an urgent need to better understand the link between deprivation and risk of preterm birth, say the authors.
Researchers at the University of Leicester tracked 7,449 very preterm infants born 1998-2007 in the former Trent region of England from the onset of labor until discharge from neonatal care. A deprivation score was calculated for each infant using postcode data.
The authors point out that the data came only from one English region, which has about 54,000 births a year, representing one in 12 UK births, so the findings can't necessarily be extrapolated to different places. However, Trent does have a particularly good prospective dataset about births.
Their results show that mothers from the most deprived areas were nearly twice as likely to have a very preterm infant compared to those from the least deprived areas and consequently there were nearly twice as many deaths due to very preterm birth in the most deprived areas.
However, among very preterm infants, survival rates and neonatal care provision showed little variation across all deprivation measures. This suggests that, although socioeconomic inequalities in preterm birth rates persist, deprivation does not seem to be a barrier to accessing and receiving neonatal care.
This study did not look at individual factors such as smoking, ethnicity, and history of previous preterm birth. They believe that future studies should focus on the interplay between very preterm birth and the wider determinants of socioeconomic inequalities in health.
Source
Plastics Chemical Phthalate May Lead to Preterm Birth
Nov 30th
Pregnant women who are exposed to higher levels of an increasingly controversial chemical in certain plastics may deliver their babies slightly earlier than women with less exposure, results of a study suggest.
The chemical, DEHP - short for di(2-ethylhexyl)phthalate - is a "plasticizer" used widely in consumer products to help make vinyl plastic soft and flexible.
"Exposures (to DEHP) are ubiquitous," Dr. Robin M. Whyatt from Columbia Center for Children's Environmental Health in New York City told Reuters Health. DEHP breakdown products "have been detected in 95% of the general U.S. population."
In recent preliminary studies, DEHP exposure has been linked to some health risks. In animal studies, for example, exposure to this and other so-called phthalates has been linked to lower-weight babies and shorter pregnancies.
In preliminary human studies, prenatal DEHP exposure has been shown to affect the timing of labor; however, the findings have been mixed.
They gauged DEHP exposure by measuring four DEHP breakdown products in urine samples collected from the 311 African American or Dominican women aged 18 to 35. All of the women were living in New York City and were in their third trimesters.
The team found that the higher the level of DEHP breakdown products in the mothers' urine during pregnancy, the earlier the infant was born, Whyatt told Reuters Health. Babies with the highest level of exposure were born about five days earlier than those exposed to the lowest levels.
It's important to note, the researchers say, that the women in the study delivered their babies at or near term. However, if prenatal DEHP exposure were to lead to more infants being delivered prematurely, on average, this could be cause for concern.
Steve Risotto, Senior Director, Phthalate Esters, at the American Chemistry Council industry group, noted that two earlier studies contradicted the current one, showing opposite effects. "There was also no association found between phthalate exposure and prematurity, as all of the births were full term," he told Reuters Health.
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