SIDS: Ireland: Smoking in pregnancy

ALMOST ONE IN five mothers in Ireland drinks or smokes at some point during her pregnancy, a new report has suggested.
‘Growing up in Ireland’ is a government-funded study that has followed the development of thousands of children all over the country. The first part of the study relates to data collected on 11,100 nine month old infants.
Smoking
Smoking during pregnancy has been linked to an increased risk of pregnancy complications such as pre-term delivery, low birth weight, placenta praevia, poorer lung functioning in infants and Sudden Infant Death Syndrome (cot death).
The study found that:

• 18 per cent of mothers said they had smoked at least at some stage during their pregnancy
• 13 per cent smoked in all three trimesters
• Mothers born in Ireland had higher rates of smoking in pregnancy (20 per cent) than those born in other countries (13 per cent)
• Mothers with the lowest levels of education were the most likely to have smoked at some stage in pregnancy (40 per cent)
• Semi-skilled/unskilled social class (33 per cent), the lowest-fifth income income group (33 per cent)

The study notes that it is “relatively common” for women to be unaware of their pregnancy until several weeks into the first trimester – particularly if they had not intended to become pregnant.
The report suggests that 70 per cent of the mothers of nine month old children are married, and 15 per cent are living with a partner.
Of those included in the study, 27 per cent of mothers and 24 per cent of fathers were not born in Ireland.

SIDS: Māori breastfeeding practices under spotlight

23 November 2010, University of Auckland

Māori breastfeeding practices under spotlight in new book
The baby formula industry has been likened to the tobacco industry, for its serious effects on Māori health in a new book co-authored by a University of Auckland academic.
Dr Marewa Glover from the University’s School of Population Health contributed a chapter on Māori breastfeeding in a new resource book for researchers and health practitioners – Infant feeding practice: A cross-cultural perspective.

Dr Glover says the practice of breastfeeding has undergone a huge ideological shift since colonisation, resulting in fewer Māori women breastfeeding.

“The actual contribution of the artificial baby milk industry to Māori babies having the lowest rates of breastfeeding in New Zealand has yet to be studied, but traditional Māori infant care practices have been lost as the ‘benefits’ of western and modern practices have been sold to Māori mothers,” said Dr Glover.
“Sudden Infant Death Syndrome (SIDS) rates are higher and have been known to be higher for some decades, bedsharing and its attendant risks are more frequently seen for Māori, yet the knowledge and practice of Māori traditions by contemporary Māori mothers is poor.”
Dr Glover’s chapter looks at the growth of the baby formula industry in New Zealand, the destruction of Māori traditions, influences which divert Māori women from breastfeeding, and smoking as a significant barrier to breastfeeding.
http://www.scoop.co.nz/stories/GE1011/S00123/maori-breastfeeding-practices-under-spotlight.htm

SIDS: The Effect of In Utero Cigarette Smoke Exposure

PEDIATRIC ALLERGY, IMMUNOLOGY, AND PULMONOLOGY

Volume 23, Number 3, 2010

Hemant Sawnani, M.D., Erik Olsen, B.E., and Narong Simakajornboon, M.D.

Maternal cigarette smoking is the most modifiable risk factor for sudden infant death syndrome. Although the

mechanism underlying the association between maternal smoking and sudden infant death syndrome is unknown,

the effect of

important causative mechanism. In human, several studies have linked maternal smoking and alterations in

breathing pattern, ventilatory, and arousal responses in infants during the early postnatal age. Cigarette contains

many compounds, but nicotine has been identified as the main culprit underlying changes in respiratory control.

Further investigations in animal models have demonstrated that perinatal nicotine exposure results in alteration

in baseline ventilation, ventilatory response to hypoxia, arousals, and autoresuscitation processes in developing

animals. The mechanisms underlying the effect of nicotine exposure on respiratory control may be related to

modulation of neurotransmitters and signal transductions mediating ventilatory control and arousal responses.

Findings from these studies will help to understand how perinatal cigarette smoke exposure interferes with

respiratory control development, and may lead to more effective preventive strategies and therapeutic intervention

for this significant health problem.
http://www.liebertonline.com/doi/pdfplus/10.1089/ped.2010.0036in utero cigarette smoke exposure on respiratory control development is speculated as the

SIDS: Changing concepts of sudden infant death syndrome: implications for infant sleeping environment and sleep position. American Academy of Pediatrics. Task Force on Infant Sleep Position and Sudden Infant Death Syndrome.

Pediatrics. 2000 Mar;105(3 Pt 1):650-6.

Pediatrics. 2001 Apr;107(4):809.

Abstract

The American Academy of Pediatrics has recommended since 1992 that infants be placed to sleep on their backs to reduce the risk of sudden infant death syndrome (SIDS). Since that time, the frequency of prone sleeping has decreased from >70% to approximately 20% of US infants, and the SIDS rate has decreased by >40%. However, SIDS remains the highest cause of infant death beyond the neonatal period, and there are still several potentially modifiable risk factors. Although some of these factors have been known for many years (eg, maternal smoking), the importance of other hazards, such as soft bedding and covered airways, has been demonstrated only recently. The present statement is intended to review the evidence about prone sleeping and other risk factors and to make recommendations about strategies that may be effective for further reducing the risk of SIDS. This statement is intended to consolidate and supplant previous statements made by this Task Force.
http://www.ncbi.nlm.nih.gov/pubmed/10699127

J Paediatr Child Health. 1994 Apr;30(2):140-3.

Well health care and the sudden infant death syndrome.

Ford RP, Mitchell EA, Taylor BJ.

Community Paediatric Unit, Healthlink South, Christchurch, New Zealand.

Abstract

The aim of this study was to examine whether poor attendance at routine antenatal and postnatal 'well child' health services was associated with a higher risk of sudden infant death syndrome (SIDS, or cot death). A nationwide case-control study of SIDS in New Zealand enrolled 485 postneonatal deaths due to SIDS and 1800 control infants who were selected randomly. The risk for SIDS was found to be higher for infants whose mothers attended their first antenatal check later than 3 months into the pregnancy, made fewer antenatal visits, and did not go to antenatal education classes. However, this increased risk was largely explained by high parity, maternal smoking, the mother not being married, mother being < 20 years old at the birth of her first child, and delivery during the winter months. Infants not attending a 6 week postnatal check had an almost three-fold increased risk of SIDS compared with those who did attend (odds ratio [OR] 2.86; 95% confidence interval [CI] 1.93, 4.24). Similarly, infants not attending well child clinics were at increased risk of SIDS (OR 2.75; 95% CI 2.09, 3.62). These differences persisted when adjusted for likely confounders. This study demonstrates that infants who miss child health nurse clinics are those most at risk for SIDS and are those who warrant increased surveillance.
http://www.ncbi.nlm.nih.gov/pubmed/8198848

SIDS: Risk factors for sudden infant death syndrome following the prevention campaign in New Zealand: a prospective study.

Pediatrics. 1997 Nov;100(5):835-40.

Mitchell EA, Tuohy PG, Brunt JM, Thompson JM, Clements MS, Stewart AW, Ford RP, Taylor BJ.

Department of Paediatrics, University of Auckland, Auckland, New Zealand.

Abstract

OBJECTIVES: To identify the risk factors for sudden infant death syndrome (SIDS) following a national campaign to prevent SIDS.
METHODS: For 2 years (October 1, 1991 through September 30, 1993) data were collected by community child health nurses on all infants born in New Zealand at initial contact and at 2 months.
RESULTS: There were 232 SIDS cases in the postneonatal age group (2.0/1000 live births) and these were compared with 1200 randomly selected control subjects. Information was available for 127 cases (54.7%) and 922 (76.8%) of controls. The previously identified modifiable risk factors were examined. The prevalence of prone sleeping position of the infant was very low (0.7% at initial contact and 3. 0% at 2 months), but was still associated with an increased risk of SIDS. In addition, the side sleeping position was also found to have an increased risk of SIDS compared with the supine sleeping position (at 2 months: adjusted odds ratio (OR) = 6.57; 95% confidence interval (CI) = 1.71, 25.23). Maternal smoking was found to be the major risk factor for SIDS. Bed sharing was also associated with an increased risk of SIDS. There was an interaction between maternal smoking and bed sharing on the risk of SIDS. Compared with infants not exposed to either bed sharing or maternal smoking, the adjusted OR for infants of mothers who smoked was 5.01 (95% CI = 2.01, 12.46) for bed sharing at the initial contact and 5.02 (95% CI = 1.05, 24. 05) for bed sharing at 2 months. In this study breastfeeding was not associated with a statistically significant reduction in the risk of SIDS. The other risk factors for SIDS identified were: unmarried mother, leaving school at a younger age, young mother, greater number of previous pregnancies, late attendance for antenatal care, smoking in pregnancy, male infant, Maori ethnicity, low birth weight, and shorter gestation.
CONCLUSIONS: After adjustment for potential confounders, prone and side sleeping positions, maternal smoking, and the joint exposure to bed sharing and maternal smoking were associated with statistically significant increased risk of SIDS. A change from the side to the supine sleeping position could result in a substantial reduction in SIDS. Maternal smoking is common in New Zealand and with the reduction in the prevalence of prone sleeping position is now the major risk factor in this country. However, smoking behavior has been difficult to change. Bed sharing is also a major factor but appears only to be a risk to infants of mothers who smoke. Addressing bed sharing among mothers who smoke could reduce SIDS by at least one third. Breastfeeding did not appear to offer a statistically significant reduction in SIDS risk after adjustment of potential confounders, but as breastfeeding rates are comparatively good in New Zealand, this result should be interpreted with caution as the power of this study to detect a benefit is small.
http://www.ncbi.nlm.nih.gov/pubmed/9346984

SIDS: Bedsharing and maternal smoking in a population-based survey of new mothers.

Pediatrics. 2005 Oct;116(4):e530-42.

Lahr MB, Rosenberg KD, Lapidus JA.

Disability Determination Services, Oregon Department of Human Services, Salem, OR 97305-1350, USA. lahr_mdmph@web-ster.com

Abstract

OBJECTIVE: Sudden infant death syndrome (SIDS) remains the number 1 cause of postneonatal infant death. Prone infant sleep position and maternal smoking have been established as risk factors for SIDS mortality. Some studies have found that bedsharing is associated with SIDS, but, to date, there is only strong evidence for a risk among infants of smoking mothers and some evidence of a risk among young infants of nonsmoking mothers. Despite the lack of convincing scientific evidence, bedsharing with nonsmoking mothers remains controversial. In some states, nonsmoking mothers are currently being told that they should not bedshare with their infants, and mothers of infants who died of SIDS are told that they caused the death of their infant because they bedshared. The objective of this study was to explore the relationship between maternal smoking and bedsharing among Oregon mothers to explore whether smoking mothers, in contrast to nonsmoking mothers, are getting the message that they should not bedshare.
METHODS: Oregon Pregnancy Risk Assessment Monitoring System surveys a stratified random sample, drawn from birth certificates, of women after a live birth. Hispanic and non-Hispanic black, non-Hispanic Asian/Pacific Islander and non-Hispanic American Indian/Alaskan Native women, and non-Hispanic white women with low birth weight infants are oversampled to ensure sufficient numbers for stratified analysis. The sample then was weighted to reflect Oregon's population. In 1998-1999, 1867 women completed the survey (73.5% weighted response). The median time from birth to completion of the survey was 4 months. Women were asked whether they shared a bed with their infant "always," "almost always," "sometimes," or "never." Frequent bedsharing was defined as "always" or "almost always"; infrequent was defined as "sometimes" or "never."
RESULTS: Of all new mothers, 35.2% reported bedsharing frequently (always: 20.5%; almost always: 14.7%) and 64.8% infrequently (sometimes: 41.4%; never: 23.4%). Bedsharing among postpartum smoking mothers was 18.8% always, 12.6% almost always, 45.1% sometimes, and 23.6% never; this was not statistically different from among nonsmoking mothers. Results for prenatal smokers were similar. When stratified by race/ethnicity, there was no association between smoking and bedsharing in any racial or ethnic group. In univariable and multivariable logistic regression, there were no statistical differences in frequent or any bedsharing among either prenatal or postpartum smoking mothers compared with nonsmokers; the adjusted odds ratio for postpartum smokers who frequently bedshared was 0.73 (95% confidence interval [CI]: 0.42-1.25) and for any bedsharing was 1.05 (95% CI: 0.57-1.94). Results for prenatal smoking were similar. This is the first US population-based study to look at the prevalence of bedsharing among smoking and nonsmoking mothers. Bedsharing is common in Oregon, with 35.2% of mothers in Oregon reporting frequently bedsharing and an additional 41.4% sometimes bedsharing. There was no significant association between smoking and bedsharing for either prenatal or postpartum smokers among any racial or ethnic group. Smoking mothers were as likely to bedshare as nonsmoking mothers. The frequency of bedsharing in Oregon was similar to estimates from other sources. Our study has the advantage of being a population-based sample drawn from birth certificates, weighted for nonresponse.
CONCLUSIONS: Although a number of case series have raised concerns about the safety of mother-infant bedsharing, even among nonsmoking mothers, this has not yet been confirmed by careful, controlled studies. There have been 9 large-scale case-control studies of the relationship between bedsharing and SIDS. Three case-control studies did not stratify by maternal smoking status, but found no increased risk for SIDS. Six case control studies reported results stratified by maternal smoking status: 1 study, while asserting an association, provided an unexplained range of univariable odds ratios without CIs; 3 found no increased risk for older infants of nonsmoking mothers; and 2 found a risk only for infants <8-11 weeks of age. Despite the preponderance of evidence that bedsharing by nonsmoking mothers does not increase the risk for SIDS among older infants, the recent specter of bedsharing as a cause of SIDS, based on uncontrolled case series and medical examiners' anecdotal experience, has led some medical examiners to label a death "suffocation" or "overlay asphyxiation" simply because the infant was bedsharing at the time of death. This "diagnostic drift" may greatly complicate future studies of the relationship between bedsharing and SIDS. Epidemiologic evidence shows that there is little or no increased risk for SIDS among infants of nonsmoking mothers but increased risk among infants of smoking mothers and younger infants of nonsmoking mothers. It seems prudent to discourage bedsharing among all infants <3 months old. Young infants brought to bed to be breastfed should be returned to a crib when finished. It would be worthwhile for other researchers to reanalyze their previous data to evaluate the consistency of the interaction of young infant age and bedsharing. Large controlled studies that include infants who are identified as dying from SIDS, asphyxia, suffocation, and sudden unexplained infant death, analyzed separately and in combination, are needed to resolve this and other issues involving bedsharing, including the problem of diagnostic drift. Recommendations must be based on solid scientific evidence, which, to date, does not support the rejection of all bedsharing between nonsmoking mothers and their infants. Cribs should be available for those who want to use them. Nonsmoking mothers should not be pressured to abstain from bedsharing with their older infants; they should be provided with accurate, up-to-date scientific information. Infants also should not co-sleep with nonparents. In Oregon, if not elsewhere, the message that smoking mothers should not bedshare is not being disseminated effectively. Because it is not known whether the risk caused by smoking is associated with prenatal smoking, postpartum smoking, or both, bedsharing among either prenatal or postpartum smokers should be strongly discouraged. Much more public and private effort must be made to inform smoking mothers, in culturally competent ways, of the very significant risks of mixing bedsharing and smoking. Public health practitioners need to find new ways to inform mothers and providers that smoking mothers should not bedshare and that putting an infant of a nonsmoking mother to sleep in an adult bed should be delayed until 3 months of age.
http://www.ncbi.nlm.nih.gov/pubmed/16199682