Smoke exposure during pregnancy damages a baby’s blood pressure control, which may explain why such babies’ risk of cot death is higher, say experts.

Maternal smoking remains one of the biggest risk factors for cot death. A team at Sweden’s Karolinksa Institute found smoke-exposed babies had abnormal surges in blood pressure, even when sleeping undisturbed in their cots.  These surges put extra demand on the heart, making it pump faster and harder, the journal Hypertension says. 

The study suggests damage to the circulation may be a factor in sudden infant death syndrome (SIDS), although it set out to look at the effects of smoking on the newborn rather than cot death per se.

Dr Gary Cohen and his team studied 36 newborn babies – 17 of whom had mothers who smoked during the pregnancy.

When they examined the babies they found the ones that had been exposed to cigarette smoke showed abnormal heart rate and blood pressure responses.

And these abnormal responses got worse throughout their first year of life.

Dramatically different

At one week of age the smoke-exposed babies showed abnormally large blood pressure rises as they were lifted up from lying down.

By the age of one, the same babies appeared to have adapted to this and now showed abnormally low blood pressure responses to the same posture change.

Usually, when a person stands the heart rate increases and the blood vessels tighten, raising blood pressure slightly, to keep up the blood flow to the heart and brain.

Dr Cohen said: “Babies of smokers have evidence of persistent problems in blood pressure regulation that start at birth and get worse over time.

“This study reveals for the first time that early life exposure to tobacco can lead to long-lasting reprogramming of the infant blood pressure control mechanism.”

He said this might explain why babies of women who smoke are at increased risk of cot death.

“We have known for some time that there is a cardiovascular element to sudden infant death.

“It’s not just breathing, but blood pressure control and heart rate control.

“This is another piece of the jigsaw.”

He plans to continue to study the babies as they grow up to see if the damage is lasting and whether it leads to problems, such as high blood pressure, in later life.

Professor George Haycock, scientific adviser for the Foundation for the Study of Infant Deaths (FSID), said: “The hypothesis presented here is highly plausible and agrees with work from other research groups.

“FSID’s top piece of advice remains, cut smoking in pregnancy – fathers too, and don’t let anyone smoke in the same room as your baby.”

Experts say a third of cot deaths could be avoided if mothers-to-be did not smoke.

Janet Fyle, Professional Policy Advisor at the Royal College of Midwives, said: “These findings support what we know; that smoking during pregnancy can harm the developing foetus.

“The RCM would urge pregnant women who smoke to seek advice and support from their midwife about stopping smoking, for the benefit of their own long-term health.

“This would also benefit the health of their child.”

The protective association was even stronger for women who had gestational diabetes during pregnancy, according to the study’s lead author, Erica Gunderson, PhD, an epidemiologist and research scientist at Kaiser Permanente’s Division of Research in Oakland, Calif.

Breastfeeding a child lowers risk by 39 to 56 percent (depending on the duration of breastfeeding) for women without gestational diabetes, and 44 to 86 percent (depending on the duration of breastfeeding) for women with gestational diabetes, researchers said. Investigators looked at durations that included 0-1 month of lactation up to greater than 9 months of lactation.

Previous research has shown that lactating women have more favorable blood levels of glucose and lipids within several weeks after delivery than women who were not lactating. Other studies have reported much weaker protective associations of breastfeeding with the presence of Metabolic Syndrome and diabetes in middle-aged and older women.

Funded by the U.S. National Institutes of Health, this 20-year prospective study is the first to measure all components of Metabolic Syndrome both before pregnancy and after weaning in women of childbearing age, enabling researchers to examine breastfeeding in relation to new onset of Metabolic Syndrome, explained Gunderson.

“The findings indicate that breastfeeding a child may have lasting favorable effects on a woman’s risk factors for later developing diabetes or heart disease,” she said, explaining that the benefits don’t appear to be due to differences in weight gain, physical activity, or other health behaviors. However, in this study, less belly fat and higher levels of good cholesterol (HDL-C) were characteristic of women who did not develop Metabolic Syndrome, Gunderson said.

Among the 704 women who were aged 18 to 30 years at enrollment, had never previously given birth and were free of Metabolic Syndrome before all their pregnancies, there were 120 new cases of Metabolic Syndrome after pregnancies during 20 years of follow-up.

“The Metabolic Syndrome is a clustering of risk factors related to obesity and metabolism that strongly predicts future diabetes and possibly, coronary heart disease during midlife and early death for women,” Gunderson said.

“Because the Metabolic Syndrome affects about 18 to 37 percent of U.S. women between ages 20-59, the childbearing years may be a vulnerable period for its development. Postpartum screening of risk factors for diabetes and heart disease may offer an important opportunity for primary prevention.”

Recent studies suggest a stronger link between Metabolic Syndrome to diabetes than coronary heart disease.

Another recent Kaiser Permanente study by Gunderson published in the American Journal of Obstetrics and Gynecology in August 2009 found that women with gestational diabetes are 2.5 times more likely to develop Metabolic Syndrome after pregnancy.

Gunderson explained that further research is needed to learn more about the mechanism(s) through which lactation may influence risk of cardiovascular disease or diabetes. Further research also is needed to learn about whether lifestyle modifications, including lactation duration, may affect development of coronary artery disease and type 2 diabetes, particularly among high-risk groups, such as women with a history of gestational diabetes.

This study was part of the Coronary Artery Risk Development in Young Adults (CARDIA) Study, a multi-center, longitudinal, population-based, observational study designed to describe the development of risk factors for coronary heart disease in young black and white adults recruited from four geographic areas in the United States: Birmingham, Ala..; Chicago; Minneapolis; and Oakland.

This study is part of Kaiser Permanente’s larger ongoing effort to research and promote the health benefits of breastfeeding. For example, Kaiser Permanente’s South Sacramento, Hayward and Fremont facilities have received the international recognition by the World Health Organization and UNICEF as Baby-Friendly™ birth facilities for offering an optimal level of care for breastfeeding mothers and their babies.

Additional investigators on the study include: David R. Jacobs, Jr., University of Minnesota Division of Epidemiology and Community Health and University of Oslo, Department of Nutrition; Vicky Chang, Kaiser Permanente Division of Research; Cora E. Lewis, University of Alabama Birmingham, Division of Preventive Medicine and the Diabetes Research and Training Center; Juanran Feng, Kaiser Permanente Division of Research; Charles P. Quesenberry, Jr., Kaiser Permanente Division of Research; and Stephen Sidney, Kaiser Permanente Division of Research.

The study was funded by U.S. National Institutes of Health (Contracts # N01-HC-48047, N01-HC-48048, N01-HC-48049, N01-HC-48050, and N01-HC-95095, from the National Heart, Lung, and Blood Institute, and Career Development Award, Grant number K01 DK059944 from the National Institute of Diabetes, Digestive and Kidney Diseases) and a Research Award from the American Diabetes Association.

Australian researchers have identified a link between allergic asthma in 3 to 5 year-old children and exposure to folic acid that their birth mothers took as supplements during late pregnancy. They said the timing of when folic acid is taken in pregnancy might be important.

The study was the work of Dr Michael Davies, associate professor with the Research Centre for the Early Origins of Health and Disease at the Robinson Institute in the University of Adelaide, and colleagues, and is published online in the 15 November issue of American Journal of Epidemiology.
The researchers said the study may have revealed why childhood asthma has been on the rise in Australia and other developed countries over recent decades.

Davies told the press that mothers are advised to take folic acid supplements during pregnancy to prevent birth defects, but research in mice and infants suggests this may also lead to “additional and unexpected” consequences.

“In our study, supplemental folic acid in late pregnancy was associated with an increased risk of asthma in children, but there was no evidence to suggest any adverse effects if supplements were taken in early pregnancy,” he added.

For the study, Davies and colleagues set out to investigate the effect of timing, dose and source of folate during pregnancy on childhood asthma.

They used data from an Australian prospective birth cohort study covering 1998 to 2005 that involved more than 500 women whose diet and supplements were assessed by food frequency questionnaire in early ( before 16 weeks) and late (between 30 to 34 weeks) pregnancy, and whose children’s asthma status was followed up at 3.5 and 5.5 years.

The results showed that:

• Asthma was reported in 11.6 per cent of children at 3.5 years and 11.8 per cent of children at 5.5 years.
• Nearly a third of these children reported persistent asthma.
• Folic acid taken in supplement form in late pregnancy showed a statistically significant association with an increased risk of childhood asthma at 3.5 years.
• There was a similarly statistically significant link to an increased risk of persistent asthma at 3.5 years.
• The links were just as strong when the researchers accounted for potential confounders.
• There was a similar but not statistically significant link at 5.5 years.
• Nearly half of all mothers in the study took a folic acid supplement pre-pregnancy and 56 per cent met the required daily public health recommended dosage of 400 micrograms in early pregnancy.

The authors concluded that:

“These findings on childhood asthma support previous observations that supplementation with folate in pregnancy leads to an allergic asthma phenotype in mice via epigenetic mechanisms and is associated with poorer respiratory outcomes in young children.”

Public health guidelines currently recommend that women supplement their diet with 400 micrograms of folic acid per day in the month leading up to and during the first trimester of pregnancy to reduce the risk of neural tube defects in children.

Davies said this study supports this guideline, because they found no increased risk of asthma when the folic acid supplements were taken before or early in pregnancy.

“These findings show there is a potentially important critical period during which folic acid supplement dosages may be manipulated to optimise their neuro-protective effects while not increasing the risk of asthma,” he said.

“However, these guidelines may need to be expanded to include recommendations about avoiding use of high dose supplemental folic acid in late pregnancy,” added Davies.

He also emphasized that they found no evidence that asthma was linked to folate found naturally in foods like green leafy vegetables, some fruits and nuts.

Writing in the Journal of Epidemiology and Community Health, they say the problems can be evident in children as young as three years old.

They believe smoking in pregnancy may damage the developing structure of the baby’s brain.

One expert said it was another strong reason for mothers to give up smoking.

The researchers from the universities of York, Hull and Illinois looked at more than 14,000 mother and child pairs who were taking part in the Millennium Cohort Study.

This covers UK children born between 2000 and 2001.

The mothers were categorised as light or heavy smokers depending on how many cigarettes they smoked every day during pregnancy.

They were asked to score their three-year-old children’s behaviour using a questionnaire called Strengths and Difficulties, which focuses on behaviour problems and hyperactivity, or attention deficit disorders.

Findings

They took into account factors likely to influence the results, including the mother’s age at the child’s birth, her level of education and socioeconomic status, family stability and problematic parenting.

Mothers who were light smokers were 44% more likely to have boys who had problems with their conduct.

Heavy smokers were 80% more likely to have boys with these problems.

Both heavy and light smokers were also significantly more likely to have boys who were hyperactive or had attention deficit disorders.

For three-year-old girls, light and heavy smoking in pregnancy were significantly associated with conduct problems but not with hyperactivity and attention deficit behaviours.

Foetal development

Professor Kate Pickett, who lead the research, said their findings were consistent with previous research in older age groups.

She said: “Smoking in pregnancy may have direct effects on the foetal development of brain structure and functioning which has been shown in studies of rats.

“Or it may be a marker for the transmission of processes between the generations that are associated with both smoking in pregnancy and behaviour problems in children.”

Professor Alan Maryon-Davis, president of the Faculty of Public Health, said: “This is another reason why mothers should make every effort to give up smoking – ideally before they get pregnant.

“There are four thousand toxic substances in cigarette smoke and many of these will pass into the brain of the foetus and it is possible that they could have an effect on how the brain chemistry works.”

They also told men to avoid beer to maximise their chances of becoming a father.

A large-scale study of couples in their 30s found that even low levels of alcohol consumption can increase the risk of miscarriage or an embryo not implanting properly in the womb.

Sharing just one bottle of wine a week could cut a couple’s chances of having a baby by 26 per cent.

White wine had a bigger effect on women’s fertility than any other drink, while beer had the worst impact on the quality of a men’s sperm.

Last night experts said couples trying to conceive naturally should also take note.

The findings come just days after the president of the Royal College of Physicians warned of the dangers to women’s health of ‘winding down’ after work by having a glass of wine.

In the study, researchers from Harvard Medical School in Boston in the U.S. asked more than 2,500 couples – before their first IVF cycle – about the amount and type of alcohol they regularly consume.

After taking into account factors including age, weight and whether they smoke, they found that women who drank white wine more than once a week had a 24 per cent lower chance of a live birth.

There was 23 per cent reduced chance of the embryo implanting properly.
But the researchers said they did not know why white wine appeared to be more dangerous than red.

For men, drinking beer every day decreased live births by 30 per cent, and led to a 38 per cent greater chance of failed implantation.

The study also found that if both parents drank six units of alcohol a week, the chances of a live birth declined by 26 per cent.

Six units is equal to two large glasses of wine, three pints of beer or six shots of spirit.

Dr Brooke Rossi, who presented their findings to the American Society for Reproductive Medicine conference in Atlanta, said: ‘In general, women are told they should stop drinking when they are trying to achieve pregnancy.’

Tony Rutherford, chairman of the British Fertility Society, said the society’s guidelines and those from the National Institute for Health and Clinical Excellence stated that women should not drink at all during pregnancy.

However, government guidelines say one or two units a week should not do any harm.
Mr Rutherford said: ‘The association [between alcohol and conception] is not entirely clear.

‘But this is further evidence to suggest that alcohol does have an impact and that those women who try for a baby should think about their lifestyle choices.

‘Eggs and sperm take at least three months to develop so women have got to stop smoking, reduce alcohol consumption or if you are overweight, correct that weight, that far ahead if you want to maximise your chances of conception.’

Professor Ian Gilmore, president of the Royal College of Physicians, said: ‘Emerging results from this large cohort of couples undergoing IVF underline the pervasive dangers of alcohol in relation to conception and pregnancy.

‘They lend weight to the importance of giving clear and unambiguous advice to women who are pregnant or hoping to become so, that they should avoid drinking alcohol.’

UK doctors say a treatment for heavy periods caused by fibroids can seriously harm a subsequent pregnancy.

An Elizabeth Garrett Anderson Hospital study looked at the outcomes of 215 pregnancies following uterine artery embolisation (UAE) treatment.

The researchers found much higher rates of miscarriage, caesareans and heavy bleeding after delivery, and call for caution in recommending the treatment.

The study appears in the journal, The Obstetrician and Gynaecologist.

UAE has been available as a treatment in the UK since 1995.

Pregnancy problems

The doctors pulled together the data from five small studies carried out in the UK, Czech Republic and Canada.

Fibroids are small, benign lumps of smooth muscle in the womb.

Sometimes, because of their number, size and location, they cause heavy period pain or difficulty in getting pregnant and treatment is needed.

Doctors at the Elizabeth Garrett Anderson Hospital say as many as 40% of women of reproductive age have fibroids.

They found that the risk of miscarriage following UAE was 35% compared with a rate in untreated women of 10 to 15%.

The incidence of caesarean sections was much higher at 67% compared with a normal rate of 20 to 25%.

And bleeding after delivery was more than twice as common at 14% compared with 5%.

The babies tended to be smaller and they were more likely to present in an awkward position.

‘Increase awareness’

Ertan Saridogan, who led the research, said although a large number of women had already undergone the procedure, there had been relatively little study of its long-term effects.

He said: “We do not offer it as a first-time treatment, but, for some women, surgery and other treatments do not work.

“We want to increase awareness of the pitfalls of this widespread procedure.

“I hope this will inform women before they make their decisions, so they can make an informed choice – they’ve been going at it blindly without realising what it might imply for their future pregnancies.”

Henry Annan, from the Royal College of Obstetricians and Gynaecologists, said he agreed that care should now be taken in recommending the treatment.

“A proper randomised controlled trial of this procedure would take many years – it’s important that patients should have some idea of the pros and cons of all the various treatments for fibroids.”

A UK survey of 12-year-olds found those whose mothers smoked were 20 per cent more likely to have psychotic-like symptoms such as hallucinations or delusions.

The researchers from four British universities found the link was 84 per cent more pronounced if mothers smoked 20 or more cigarettes a day.

Many previous studies have shown cigarettes can harm the foetuses of mothers who smoke while pregnant. The risks include causing babies to be born smaller and increasing the risk of sudden infant death syndrome or heart defects.

Despite countless studies flagging up the risks to babies, it is estimated up to one in five women in Britain smoke during pregnancy.

Being Overweight or Obese Before Pregnancy May Be Tied to Increased Risk of Congenital Heart Defects

Women who are overweight or obese before getting pregnant may be more likely than leaner women to have babies born with heart defects, a new study shows.

The study, published in the advance online edition of the American Journal of Obstetrics and Gynecology, included the mothers of 6,440 babies born with congenital heart defects between 1997 and 2004.

In telephone interviews, the mothers reported their pre-pregnancy height, weight, and various lifestyle and medical factors.

For comparison, the researchers asked the same questions of 5,673 women who had babies during the same time period without heart defects.

Compared to women with a normal BMI (body mass index), women who were overweight but not obese before pregnancy were 16% more likely to have a baby born with a heart defect.

By the same comparison, women who were moderately obese before pregnancy (BMI of 30-34.9) were 15% more likely to have a baby born with heart defects.

Women who were severely obese before pregnancy (BMI greater than 35) were 31% more likely to have a baby born with a heart defect.

“Congenital heart defects are the most common types of birth defect, and among all birth defects, they are a leading cause of illness, death, and medical expenditures,” Edwin Trevathan, MD, MPH, director of the CDC’s National Center on Birth Defects and Disabilities, says in a news release.

“Women who are obese and who are planning a pregnancy could benefit by working with their physicians to achieve a healthy weight before pregnancy,” Trevathan says.

The study doesn’t prove that the women’s extra weight caused birth defects in their babies. Observational studies like this one can show associations, but they don’t prove cause and effect.

Also, the women reported their height and weight; they weren’t measured. Self reports of weight aren’t always accurate, and that could have affected the results.

However, the researchers considered factors including maternal age, and they excluded mothers with type 1 or type 2 diabetes, because diabetes is a strong risk factor for heart defects.

“These results support previous studies, as well as provide additional evidence, that there is an association between a woman being overweight or obese before pregnancy and certain types of heart defects,” Suzanne Gilboa, PhD, an epidemiologist at CDC’s National Center on Birth Defects and Developmental Disabilities, says in a news release.

“This provides another reason for women to maintain a healthy weight. In addition to the impact on a woman’s own health and known pregnancy complications associated with maternal obesity, the baby’s health could be at risk,” says Gilboa, who worked on the new study.

Gilboa’s study only compares the odds of having a baby with a heart defect; it doesn’t show the odds that any given woman, of any size, would have a baby with a heart defect.

The incidence of pregnancy-associated breast cancer rose from 16 in every 100,000 deliveries to 37.4 per 100,000 deliveries between 1963 and 2002, a study has found.

Breast cancer was underdiagnosed in pregnant and breastfeeding women because they and their doctors assumed breast firmness or lumps were a normal part of childbearing, said the chief executive of the National Breast and Ovarian Cancer Centre, Helen Zorbas.

She urged health professionals to assess all women the same way, regardless of pregnancy. ”While most breast changes won’t be cancer, early detection is vital for improving survival.”

Although pregnancy does not cause breast cancer, hormonal changes can accelerate its growth and tumours in pregnant women are often larger and more advanced by the time they are detected than those in women who are not pregnant.

The disease poses a dilemma for patients and their doctors. Pregnant women can have surgery but not radiotherapy. And chemotherapy is allowed only after the first trimester.

In 2004 Colleen Thompson was having chemotherapy for breast cancer when she discovered she was seven weeks pregnant with her third daughter, Polly.

A lump in her breast had been discovered when she was breastfeeding her second daughter, Demi, then nine months, and after a mastectomy she took a course of anti-cancer drugs. ”It was a big shock. I didn’t think I could fall pregnant while I was having chemo,” Mrs Thompson, now 38, said yesterday.

”My doctor told me that continuing the pregnancy was risking my life as well as the baby’s but I couldn’t come to terms with a termination, so I went ahead with the baby.” She stopped all treatment and, despite being exposed to the toxic drugs as a foetus, Polly, was born healthy.

Mrs Thompson’s mother died of breast cancer at 44 and she and her three sisters and one brother have tested positive to the hereditary BRCA1 gene, which greatly increases the risk. Her sister Julie Knights was diagnosed with breast cancer in 1999 when she was five months pregnant, aged 37. She, too, had a mastectomy and chemotherapy and gave birth to Jed, now nine.

The study, published in the journal Obstetrics & Gynecology, reviewed more than 4.1 million deliveries in Sweden between 1963 and 2002. The Karolinska Institute in Stockholm found the largest proportion of pregnancy-related breast cancers was among 25 to 29-year-olds. But because the breast cancer risk rose with age and the average age of mothers had increased to about 30, its incidence during pregnancy was likely to increase, the institute said.