Hi everyone. I'm wondering if I'm over-reacting or not, hoping for some feedback. A friend of mine is pregnant, about 25 weeks, planning hbac, and she recently confessed that she's been smoking off and on through the pregnancy. I didn't say much, didn't want to scare her unnecessarily without knowing what I was talking about, but...yikes! I'm worried about the effect it would have on her c-section scar. Wouldn't that possibly compromise it a bit? Her midwife doesn't know, but I'm wondering if she is still a good hbac candidate. Does anyone have any info on this? Thanks!
Smoking and vbac?
This article states that smoking, using alcohol and being overweight are factors (that a woman has control of) that could seriously decrease the chance of VBAC period, but doesn't mention the HBAC factor. It also doesn't touch on any effect it may have on the scar, but the fact that it could decrease her chances seems reason enough not to do it. Let alone the effects smoking can have on her unborn child, have you ever smelled the placenta of a woman who smokes? It's revolting.
(Sorry for the bold font, it won't turn off!)
I have not found an article that specifically states that complete or catastrophic rupture is more likely in smokers although aneurysm and dehiscence have been noted as slightly increased in smokers. Dehiscence in several articles was noted as having a link to smoking especially in women whose pregnancies were close together (less than 2 years from most of what I've read). I haven't read anything that mentions impeding the ability of the scar to stretch. I know you're looking specifically for info on increased rupture but there are many other concerns as well that could be as life-threatening if they were to occur, especially if your friend is not within a very close distance to emergency medical treatment. Also, if her midwife for the homebirth knew she was smoking she would probably consider her high risk and may decline to allow the birth to take place at home for safety reasons (in interviewing home birth midwives this was one of the first questions they asked to help them make the decision whether a mother is a good candidate). This article lists the other risks:
Cigarette smoking is the most common addiction among pregnant women. Also, percentages of women who smoke and of those who smoke heavily appear to be increasing. Only 20% of smokers quit during pregnancy. Carbon monoxide and nicotine in cigarettes cause hypoxia and vasoconstriction, increasing risk ofspontaneous abortion(fetal loss or delivery < 20 wk), fetal growth restriction (birth weight averaging 170 g less than that of neonates whose mothers do not smoke), abruptio placentae, placenta previa, premature rupture of the membranes, preterm birth, chorioamnionitis, and stillbirth. Neonates whose mothers smoke are also more likely to have anencephaly, congenital heart defects, orofacial clefts, sudden infant death syndrome, deficiencies in physical growth and intelligence, and behavioral problems. Smoking cessation or limitation reduces risks.
Rupture is still unlikely based on what I've read (it seems the only things that make the statistic really increase drastically is type of incision or method of induction, or maybe those are the just the only studies that have been performed). I don't know how often your friend smokes but even limiting cigarettes appears to have a major effect on complications. If it were me and it presented a potentially serious risk to my baby, I'd definitely ask my midwife is she's still comfortable with birthing at home, since no mother wants her child at risk based on her own decisions.