Maternal & Child Health Links:
Research, Education, Extension & Technology
  Volume IV

This newsletter is written by and transmitted electronically from Karen L. Konzelmann, National Program Leader--Maternal and Child Health, Cooperative State Research, Education and Extension Service, USDA.  It is intended for Cooperative Extension System educators in the fields of nutrition, human health and nutrition research.

TABLE OF CONTENTS

Impact of  Cigarette Smoking During Pregnancy
Mental Retardation and Maternal Smoking
Is It Too Late To Stop Smoking During Pregnancy?
Does Smoking Affect Breastfeeding?
Consequences of Secondhand Smoke on Childrens' Health
Advice on What To Do About Secondhand Smoke
Using Smokeless Tobacco Is As Hazardous As Smoking Cigarettes
Cigar Smoking and Women
Resources Available
Electronic Connections
Journal Articles Worth Noting
Subscribe Online for the electronic version of MCH LINKS
 

Impact of Cigarette Smoking During Pregnancy

Tobacco use during pregnancy has been associated with miscarriages, low birth weight, and other complications in newborns. Recently Joseph DiFranza, MD, and  Robert Lew, PhD, conducted a meta-analysis of about 100 studies in order to estimate the annual morbidity and mortality among fetuses and infants that could be attributed to the use of tobacco products by pregnant women. The researchers estimate between 18 and 27 percent of pregnant women smoke cigarettes.  Based upon their study, smoking while pregnant is tied to the following estimated outcomes annually.

• Spontaneous Abortions - 19,000 to 141,000 tobacco-induced miscarriages - as many as 7.5 percent of all miscarriages
• Low Birth Weight - 32,000 to 61,000 infants born weighing less than 2500 grams - as many as 21 percent of all low weight births
• Neonatal Intensive Care - 14,000 to 26,000 infant admissions.
• Perinatal Mortality - 1,900 to 4,800 infant deaths--as many as 8.4 percent of all deaths in the perinatal period. These deaths are caused primarily by low weight births and premature separation of the placenta.
• Sudden Infant Death Syndrome - 1,200 to 2,200 SIDS deaths from maternal smoking.  Additional deaths would be attributed to smoking by other household members. Maternal smoking is responsible for as many as 40 percent of all SIDS deaths and 66 percent of SIDS deaths among the infants of women who smoked  during their pregnancy. Smoking during pregnancy triples the risk of SIDS.

The investigators conclude since there is a well established body of scientific evidence  to document the complications of smoking during pregnancy, an emphasis should be placed on the prevention of tobacco use by teen age girls. The rate of success for smoking cessation programs during pregnancy is low. (Journal of Family Practice 40:385-394, 1995)

Mental Retardation and Maternal Smoking

Research has shown smoking to be tied to small deficits in cognition, achievement and behavior.  Few studies have looked at the possible connection between smoking and more severe mental retardation (MR).  After analyzing data from interviews of mothers of 221 children with idiopathic (unknown origin) mental retardation and the mothers of 400    normal children attending public school, investigators from Rollins School of Public Health of Emory University determined  maternal smoking during pregnancy to be associated with slightly more than a 50 % increase in the prevalence of idiopathic MR if the mothers smoked as few as 5 cigarettes per week. The increase went to 75 % if the mothers smoked a pack or more daily.  Smoking continued to be associated with a   more than 60 % increase in MR when women who continued to smoke into the second trimester were compared with those who did not smoke during the latter two thirds of pregnancy. The more cigarettes the women smoked during the latter part of their pregnancy, the more likely the children would be retarded. (Pediatrics 97:547-552, 1996)

Is It Too Late To Stop Smoking During Pregnancy?

Several studies have found women who quit smoking during pregnancy can increase their chances of having a baby born at normal birth weight. In a study done at the University of Alabama at Birmingham, researchers compared the smoking practices of three groups of women. They  found infants born to mothers who had quit smoking completely during their pregnancy had the highest mean birth weight, followed by infants born to mothers who had cut down on their smoking during pregnancy and then lastly, by infants born to mothers who did not change their smoking amounts at all during their pregnancy. Ideally, women would quit smoking Completely. However, even limiting the number of cigarettes smoked can have a positive effect on birth weight.

A similar effect has been found regarding the effect of smoking on Sudden Infant Death Syndrome (SIDS). Studies have shown the more cigarettes the mothers smoked, the higher the risk to the baby. If the Mother can decrease the number of cigarettes she smokes, the risk also can decrease.( Healthy Mothers, Healthy Babies News 12:(2) Spring, 1997)

Does Smoking Affect Breastfeeding?

Cigarette smoking can affect both the amount of breast milk produced and the fat content of the milk, according to a study conducted at the Children's Nutrition Research Center.  Judy Hopkinson, PhD, research assistant professor at Baylor College of Medicine, compared the volume and composition of milk provided for premature infants to determine whether women who smoked cigarettes produced less milk or milk of a   different composition during early lactation than women who did not Smoke.

BACKGROUND:  The prevalence and duration of breastfeeding are reduced among women who smoke cigarettes regardless of their social group or educational level.  Early weaning of breastfed infants by mothers who smoke has been attributed to various physiologic effects of  cigarette smoke and to differences in maternal and infant behaviors which affect milk production.  Infants of mothers who smoke have been reported to have 'poor feeding behavior', reduced suckling frequency and amplitude, and more episodes of colic than infants of mothers who do not smoke. The 'poor feeding behavior' of infants whose mothers smoke may either cause or result from lower milk production and inadequate caloric intake or from differences in the composition of the breastmilk. Unlike adults, infants need to consume a high-fat diet in order to meet their caloric needs.

STUDY METHOD: Twelve mothers who smoked and 29 mothers who served as control subjects were enrolled in the study.  All subjects were healthy, planned to breastfeed when their premature infants were able to nurse, had no plans to return to work before six weeks and were able to arrange  the daily delivery of their milk to the hospital.  Mothers in the experimental group smoked at least 10 cigarettes per day and delivered newborns at 28-32 weeks gestation.  Mothers in the control group delivered newborns between 28 and 30 weeks gestation.  All were enrolled within one week postpartum and given a breast pump and instructions. Each mother recorded the beginning and ending time of every pumping until the end of the study. All expressed milk was brought to the hospital daily. Milk production rates were calculated as the average 24-hour volumes of milk collected each day.

RESULTS: At two weeks postpartum, there was little difference between the milk produced by the mothers who smoked and those who did not smoke cigarettes.  Between 2 and 4 weeks, milk fat and milk volume increased as expected only in the group who did not smoke cigarettes.  At 4 weeks, milk fat concentration was 19% lower in milk from the mothers who smoked cigarettes. Mothers who smoked produced an average of 43 % less milk at 4 weeks and 46 % less at 6 weeks postpartum. Milk protein concentrations, on the other hand, did not differ between the two groups of women.  Differences in milk production remained significant after adjusting for minor differences in pumping frequency and duration, infant gestational age and demographic difference including race, age, parity, gravidity, and maternal weight and height. Cigarette smoking did not preclude sufficient lactation after premature delivery in all cases.  However, low milk production rates and lactation failure were more common among lactating women who smoked than among those who did not smoke.  The combination of low milk volume and low milk fat concentration may explain the reported early weaning of breasted infants by mothers who smoke cigarettes.  ( Pediatrics 90:934-937, 1992)

Consequences of Secondhand Smoke on Childrens' Health

To evaluate the impact of adult tobacco use on the health of children, researchers from the Fitchburg Family Practice Residency Program, University of Massachusetts Medical Center and Brigham and Women's Hospital  conducted a literature search of reports concerning pediatric diseases associated with tobacco smoke in healthy populations.  They then conducted a  separate meta-analysis for each disease.  Results show children of smokers have a disproportionate number of medical conditions. Listed below are the estimated numbers of cases impacted by environmental tobacco smoke annually.

1. Otitis Media - 354,000 to 2.2 million episodes, from 2 % to 13 % of cases.
2. Tympanostomy Tubes (ear tube insertions) 5,200 to 165,000 insertions, from 0.84 % to 26 % of cases.
3. Tonsillectomy & Adenoidectomy 14,000 to 21,000 , from 16 % to 24 % of cases.
4. Prevalence of Asthma - 307,000 to 522,000, from 8% to 13 % of cases among children younger than 15 years of age.
5. Coughs - 1.3 million to 2 million visits to physicians, from 10 % to 16 % of all visits.
6. Bronchitis - 260,000 to 436,000 episodes, from 12 % to 20 % of  all cases among children younger than 5 years of age.

(Pediatrics 97:560-568, 1996)

Advice on What To Do About Secondhand Smoke

In the Home:

• Do not smoke in your home or permit others to do so.
• If a family member smokes indoors, increase ventilation by opening windows or using fans.
• Do not smoke if children, especially infants and toddlers are present.  They are especially susceptible to the effects of  passive smoking.
• Do not allow baby-sitters or others who work in your home to  smoke in the house or near your children.

In Other Places Where Children Spend Time:        

• Find out the smoking policies of the day-care providers,  preschools, schools, etc.
• Help other parents understand the health risks to  children from secondhand smoke.

In Automobiles:

• Do not smoke with the windows closed if passengers are present.  The high concentration of smoke in a small area substantially increases the exposure of other passengers.

Source:  U.S. Environmental Protection Agency, Secondhand Smoke. 402-F-93-004.

Using Smokeless Tobacco is as Hazardous as Smoking Cigarettes

The average smokeless tobacco user first tries it at 10 years of age and advances to regular use by 13 years of age.  As cigarette consumption decreases, the use of snuff tobacco products increases. The American Academy of Otolaryngology-Head and Neck Surgery cites five reasons why smokeless tobacco (ST) use is not a safe alternative to cigarette smoking.

1. The average 'quid' of smokeless tobacco contains nicotine equivalent to 2 cigarettes, so it can be more addictive than smoking cigarettes.
2. Smokeless tobacco users have a 50-fold increase in the risk of  oral cancer.
3. Smokeless tobacco causes gingivitis and gum recession, stains teeth and promotes tooth decay. Dental problems often bring ST use to the attention of parents.
4. Nicotine raises blood pressure, constricts vessels and raises heart rates.
5. Lastly, ST causes bad breath and is viewed by many as socially unacceptable.

(THROUGH WITH CHEW, Public Education Campaign, American Academy of    Otolaryngology)

Cigar Smoking and Women

Cigars are enjoying a resurgence in popularity, especially among women. Some women think cigar smoking carries fewer risks than cigarette smoking.  Both cigars and cigarettes contain nicotine which speeds heart rates, raises blood pressure and constricts blood vessels. Due to the higher levels of carbon monoxide in cigar smoke, these risks are greater for cigar smokers than for cigarette smokers.  Compared to nonsmokers both cigar and cigarette smokers have higher death rates from chronic   obstructive pulmonary disease. (Womens' Health Source 1 (2), p 8, 1997)   

Resources Available

The following organizations have additional reference materials.   

1. Centers for Disease Control, Office of Smoking & Health, 3005 Chamblee Tucker Road, Chamblee, GA 30341; Telephone 770-488-5703, FAX 770-488-5939.
2. National Institutes of Health, Dental Research, Building 31, Room 5B49, 31 Center Drive, Bethesda, MD 20892-2190; Telephone 301-496-4261, FAX 301-496-9988.
3. National Institutes of Health, National Cancer Institute EPN, Room 232, 6130 Executive Boulevard, Bethesda, MD 20892; Telephone 301-496-8520, FAX 301-496-8675.
4. Office for Non-Smoking and Health, 294 Washington Street, Room 851, Boston, MA 02108; Telephone 617-542-7709, FAX 617-542-2748.
5. Summer Course Offered: Maternal Nutrition Intensive Course, July 9-12, 1997, University of Minnesota at Minneapolis. The course is designed for dietitians, nutritionists, nurses and others who work with pregnant and breastfeeding women. For information visit their web page www.cee.umn.edu/pdcs/MatNut.html or call 612-625-3451.

Electronic Connections

Journal Articles Worth Noting:

1. Glantz S, Fox B, Lightwood J. Commentary:  Tobacco Litigation - Issues for Public Health and Public Policy.  JAMA, March 5, 1997 Vol  277 No. 9:751. Comments provide an historical look at litigation and  outlines issues for discussion.
2. Pamuk E, Byers T, Coates R, Vann J, Sowell A, Gunter E, Glass D.  Effect of smoking on serum nutrient concentrations in African-American women.  Am J Clin Nutr 1994; 59:891-895.  Article reports results of studying the relationship between smoking and serum concentrations of vitamins C, E & A plus 5 carotenoids.
3. Mueller M.  Smoking any substance raises risk of lung infections. National Institute on Drug Abuse Notes,  Vol 12 No 1, Jan/Feb 1997. Report outlines the results of smoking to the lungs, especially in persons with compromised immune systems.
4. Blair P, Fleming P, Bensley D, Smith I, Bacon C, Taylor E, Berry J,  Golding J, Tripp J.  Smoking and the sudden infant death syndrome: results from 1993-5 case-control study for confidential inquiry into  stillbirths and deaths in infancy.  BMJ 1996, 313:195-198. This study confirms the increased risk of SIDS associated with maternal smoking  and shows evidence that household exposure to tobacco smoke has an independent additive effect.
5. Seddon J, Willett W, Speizer F, Hankinson S.  A prospective study of  cigarette smoking and age-related macular degeneration in women. JAMA, October 9, 1996, Vol 276, No 14:1131-1145. Results of this  study provide evidence that smoking increases the risk of developing this severe visual impairment.
6. Committee on Environmental Health, American Academy of Pediatrics,       Environmental tobacco smoke: a hazard to children.  Pediatrics April 1997, Vol 99 No 4: 639-642. This is a 'must read' summary of the effects of tobacco on children and a list of strategies for a smoke-free environment.

The purpose of this communication is to provide updates on relevant research and resources for education programming.  Please let me know if this meets your needs or if you have ideas for topics to include.  In order to facilitate sharing materials across the states, information about new materials will be included if details are forwarded to me.  A specific electronic mail address has been established by Baylor College of Medicine
for responses.  It is MCHLINKS@bcm.tmc.edu

The Cooperative State Research, Education, and Extension Service, USDA, is the Federal partner of the state and territory land grant universities in their research, education, and extension missions.  The USDA prohibits discrimination in its programs on the basis of race, color, national origin, sex, religion, age, disability, political beliefs, marital or family status.  Mention of a  product, service, or curriculum does not constitute endorsement by USDA or CES unless the curriculum citation specifically says "recommended for use in all States and Territories".