Volume 1

~ News From Your Birthing Family ~

Issue 12

 

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Smoking Cigarettes and the Unborn Baby

Question: I attended the birth of a baby to a mother who smoked the entire pregnancy. During her labor and delivery, she was administered oxygen, her placenta was in pieces, and her baby was having breathing difficulties and transferred to the NICU. While there were other factors such as the use of drugs in her labor and meconium staining, would the smoking have contributed greatly to these complications? What other complications in labor and delivery and in the baby can a smoking mother anticipate?  ~anonymous doula~

Dr. Osborne
Susan P. Osborne, DO

In residency, I had the same experience. We saw a large volume of deliveries, many from the public health clinic, some with little prenatal care. We encountered friable, calcified, old-looking placentas in mothers who were not post term, often they were preterm. In my home-birth practice, smoking was a relative contraindicated to home delivery.

The March of Dimes maintains an excellent accessible website at www.marchofdimes.com. They cite that 20% of women in the US smoke, and not all quit during pregnancy. This results in an excess of 11% still births, and 5% more newborn deaths. In the Reuter’s news article “Prenatal Smoke Exposure Linked with Apnea in Preterm Infants” from Am J. Respir. Care Med (2004; 169; 733-738) sleep studies were done on 30 infants – 16 were exposed to prenatal smoke, 14 were not. The smoke exposed infants showed 28.6 apneic events/hour, compared to 13.2 in the controls. The subjects in the maternal smoking group had 34.5 arousals per hour, compared to 46.3/hour in the controls. After a respiratory event, 10.7% of the smoke exposed infants aroused, compared to 29.4% for controls. In an American Journal of Public Health Article, March 1995 (vol.85, no.3, pp395-398) patients reporting bias was eliminated in studies by measuring serum cotinine. In this study, confounding variables of infant sex, maternal race, parity, age education, weight gain, maternal alcohol and caffeine consumption showed no correlation to preterm birth and infant weight – but – serum cotinine was related on a dose response basis. 0-1.9mg/ml of cotinine were classified as nonsmokers, 2.0-10.0mg/ml were passive smoke exposed, 0-78mg/ml were light smokers, 79-165mg/ml were moderate smokers, and >166mg/ml were heavy smokers. Skeptical moms may see having a smaller baby as easier to birth not realizing these are not small, healthy babies, many are preterm due to the placenta wearing out early.

March of Dimes also stated, 12.2% of babies born to smokers were less than 5˝lbs, compared to 7.5% of nonsmokers. Specific to your question – twice as many placenta previas and abruptions are seen in smokers vs. nonsmokers. The studies on this mechanism go back to the early 1980s – specific histologic studies on the “morphologic change in the placental villi” in relation to quantity of tobacco exposure were published by Asmussrin 1980 and VanderVeen, and Fox in 1982. These were referenced in the paper, “The Effects of Passive Smoking on the terminal Villi of Human Placenta”, published in the Journal of the Anatomical Society of India 50(1) 19-23(2001) by Ruth, G, Jinn, A.K, Bastia, B. Sood, M., and Makherjee, A. One hundred placentas were studied, all from nonsmokers, but 50% had passive exposures though husbands chain smoking Beedis. Now, keep in mind the complex mechanism by which the placenta allows transfer of nutrients without blood mixing. A thin syncytiotrophoblastic membrane lies over a cytotrophoblast layer of cells, all on a thin basement membrane. The endothelial cells of the capillary beds lie on one side of this structure, and this is repeated in villi over a vast surface area, projecting into in the myometruim of the uterus.

In 36% of the smoke-exposed placentas, the syncytiotrophoblastic membrane was bunched up in knots, compared to 24% of the controls. The number of cells in the trophoblastic layer was 4.27/field in the controls, but were 70.25 field in the passive smokers. Endothelial cells intruded into the vascular layer 5.35 times/hpf vs 0.66 times in the controls. 75% of the passive smoker had irregularly irregular basement membranes in a zigzag pattern. Absorption of nutrients is impaired by this irregularity, and you can imagine why the blood vessels grow in to get more absorption, which increases the potential for blood mixing and vessel rupture. This is a scary situation.

In the family practice setting, I have OB doctors taking my prenatal patients off of nicotine patches because they are note approved by the ACOG, so the mom often relapses. Doctors who are willing to do a c-section against a mother’s will are afraid to upset a mother by telling her to quit smoking. In a 1985 New York Times article, William G. Cahon, MD published an opinion “abusing children by smoking”. In a 1975 article “smoking mothers are more likely to have hyperkinetic (ADHD) children” was published in the Canadian Psychiatric Association Journal. (vol 20: 183-187, 1975). Children who met the criteria for ADHD – were born to mothers who average 14 cigarettes/day, children evaluated as “normal” were born to mothers who averaged 6 cigarettes /day (which would include the nonsmokers). Carboxyhemoglobin was found in 2x the levels in the fetus as the mother. (R. Denson, MD, J.L. Nansom, MA, MA, McWalters, RN, University of Saskatchewan, CA)

So how does this affect our practice? We have to start very early. The first pap smear is a chance to screen. I hear “I’ll quit when I have a baby”, and grandmothers say “I smoked when I had you, and you turned out okay”. I went to a presentation of a paper at the American Society of Addiction Medicine on neonatal tobacco addiction. It was an elegant study. It explained why I see children who smoke their first cigarette and get high – no nausea, no choking – they are relapsing after being addicted in the womb. Even care providers are not immune to this addiction. I am very worried about this pervasive legal toxin we expose our babies to. Is it all about freedom? As mothers, we lose some of our freedom when we accept the responsibility of a child.

Sincerely,

Susan P. Osborne, DO

Dr. Osborne has a Family Practice in Floyd, VA.
She provides prenatal care and midwifery support.  She attended home births in the Richmond area until the Virginia Board of Medicine placed her license on probation for four years for "aiding and abetting the practice of midwifery".  She is very  homebirth, breastfeeding and mommy/baby friendly and has a tremendous wealth of experience along with her knowledge.  Her heart exceeds the size of this world! She, along with being a Family Practice Doc, is the only Medical Examiner for Floyd County, so her time is preciously filled. We thank her for sharing her time and knowledge on this important topic. She has indeed helped many folks take that step to quit smoking.  I have very personally witnessed her educational abilities, in this, and in other areas as well.  ~Susan Oshel~




 

 'Behold, I will bring them from the north country, And gather them from the ends of the earth,
 Among  them the blind and the lame, The woman with child and The one who labors with child,  together,
 A great throng shall return there...And My people shall be satisfied with My goodness, says the LORD.'
 Jeremiah 31:8, 14
~~~
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December  2006