Prenatal Tobacco Exposure Neurodevelopmental

We have known for some time that tobacco use during pregnancy is not a good idea. One of the consistent findings has been the association with tobacco use and low birth weights. Low birth weights are a nonspecific factor that correlates with fetal growth retardation which can occur from a variety of different factors. Tobacco use is one of those. Three studies recently presented at the 56th annual meeting of the American Academy of Child and Adolescent Psychiatry suggest longer term neurodevelopmental problems.

These three studies are all prospective studies. These were not chart reviews looking for correlating factors but involved looking directly at children and their behavior. The first study enrolled 304 women before their fourth month of pregnancy. Self reports were used to assess smoking during pregnancy. The investigators examined the newborn children 1-3 days after birth and at weeks 2 and 4 looking at reflex assessments, orientation to audio and visual stimuli and response to stressors. The infants of mother's who smoked were less attentive and exhibited consistently more irritability. This is consistent with previous findings that suggest some tobacco withdrawal symptoms do occur.

The second study involved 207 infants from the first study evaluated at 6 months of age. The infants exposed to tobacco prenatally showed lower attention spans than non exposed infants.

A third study evaluated self regulation and executive control in a different population of 237 otherwise normally developing three year olds. Those exposed to tobacco prenatally showed poorer ability to wait for a reward and to regulate motor behavior. While Attention Deficit Hyperactivity Disorder (ADHD) is not diagnosed in preschoolers these findings are similar to the problems that do show up in children with ADHD. The study is ongoing and will follow these children on an ongoing basis.

These three studies suggest that smoking during pregnancy is related to attention and self regulatory problems at multiple points of development. Given that about 20% of expectant mothers smoke a large number of children are affected. Tobacco cessation is difficult but perhaps these findings may increase the motivation to quit in women who smoke during pregnancy.

Thought for the day

Tobacco use during pregnancy is simply not a good idea.

Pregnancy Anxiety Depression SSRI's

There has been a great deal of uncertainty in the last several years about the risks of the selective serotonin reuptake inhibitors (SSRI's) in pregnancy. These medications which include Prozac, Zoloft, Paxil, Celexa, Luvox, and Lexapro are used to treat both depression and anxiety disorders. All of them are considered Category C medications which mean there are not adequate well controlled studies in women to answer the question of safety to the developing child, that caution is advised, and that the benefits of the medication may outweigh the potential risks of not using the medication. As you can see this guideline is extremely vague and doesn't really help the clinician in knowing what to do with a pregnant woman with depression or an anxiety disorder.

There are several areas of concerns for a pregnant woman. First, does the medication cause any congenital malformations? Secondly does the medication increase the risks of low birth weight or preterm delivery? Are there ill effects on the newborn such as lower Apgar scores, withdrawal symptoms, or increased need for Neonatal Intensive Care (NICU) services and finally what is the effect on the developing brain of the fetus when medications are used during pregnancy and how might that affect the cognitive and emotional development of the child? These are a lot of questions and we don't have clear answers. I will leave aide the issue of nursing for now.

What is known at this time is that SSRI's put infants at risk of low preterm birth, lower 5 minute Apgar scores and increased risk of admission to the NICU. Paxil has been associated with a slightly higher risk of congenital abnormalities than in the general population. A number of infants will develop some withdrawal symptoms of increased irritability and poor muscle tone, seizures and respiratory problems. On the other hand untreated depression is linked to preterm birth, lower birth weights, and lower Apgar scores indicating that untreated depression has an adverse effect on the developing fetus as well. Pregnant women with untreated depression ate also at significantly higher risk of alcohol use and abuse (which clearly causes fetal problems) and failure to receive adequate prenatal care. In all the studies it has also been unclear whether the adverse effects are due to the SSRI's themselves or that the SSRI use is not simply linked to women who experience significant depression who develop more problems.

A recent study published in the November issue of Paeditaric and Perinatal Epidemiology does give us some new information about untreated anxiety in pregnancy. 763 women were assessed and followed during the course of pregnancy which indicated that mild or moderate anxiety is not associated with any adverse fetal effects but that high levels of anxiety were associated with smaller birth weights and risk of preterm delivery. This does not necessarily help us with the medication issue though. It does tell us that anxiety needs to be assessed and addressed in pregnancy but there are non medication means of reducing anxiety.

So, little by little we are gaining more knowledge but for now the clinician and soon to be mother have to decide in each individual case whether it is better to continue ore use antidepressant medication during pregnancy.

Thought for the day

There are not always easy answers in medicine.