1. Smoking habit during pregnancy cause hearing abnormalities in child

The exposure to nicotine during pregnancy has always been seen to harm the brain development of a fetus. Mothers who smoke do so at an increased risk of premature delivery, decreased child birth weight, and an increased rate of sudden infant death. 

This latest research study has now added another to the long list of risks associated with pregnancy smoking: hearing abnormalities in the child.

The result published in the The Journal of Physiology, based on a mouse model study, reports that nicotine exposure before and after birth can lead to abnormal development in the auditory brainstem.

The auditory brainstem, an area of the brain which plays a role in analyzing sound patterns, may develop abnormally in offspring when pregnant mothers have a habit of smoking. Children with impaired auditory brainstem function not only show hearing abnormalities but are likely to have learning difficulties and problems with language development.

This causes the inputs from the sensory area in the ear to be less effective at transmitting signals to other auditory brainstem neurons, the research on mouse showed. 

Thus children showing learning difficulties at school should now be tested for auditory processing deficits as well if the mothers had a habit of smoking during pregnancy.

2. Smoking in pregnant women keep children’s kidney function at risk

Known to cause various health hazards, kidney failure is a well-known consequence of smoking in adults. Thus an obvious question coming with it is if a smoking pregnant women pass it on to her baby.

The American Society of Nephrology has found an answer to this, which unfortunately is establishing a link between maternal smoking and flawed kidney condition in the baby.

The research undertook, checked the presence of proteinuria – a condition of elevated protein in the urine and a sign of reduced kidney function in children. Data from more than 50,000 children found that maternal smoking during pregnancy was found to be associated with a 1.24-times increased risk of child proteinuria compared with babies who had zero exposure to maternal smoking during development.

maternal smoking during pregnancy, apart from preterm birth, low birth weight, and neonatal asphyxia, is now also known to be associated with kidney risks as well. 

The prevention of child proteinuria is of prime importance since child proteinuria can lead to the development of chronic kidney disease in adulthood and ultimately to end-stage renal disease.

3. Child's genetic make-up stand to change due to Maternal smoking during pregnancy

This latest research by Helmholtz Centre for Environmental Research – UFZ propounds that maternal smoking during pregnancy, apart from all other commonly heard consequences, also causes long-lasting changes in the genetic make-up of the baby.

Exposure to tobacco smoke causes epigenetic changes in enhancers of gene expression, it was found.

Epigenetic changes are a common part of countless processes that occur during human development. But this development that happens through epigenetic changes always stands a chance to be disrupted by various environmental factors. 

The current research undertook a study on two groups of mother-child pairs: mothers who smoked during pregnancy and mothers who were not exposed to tobacco smoke. 

The team was able to find evidence of epigenetic changes occurring in the smoking mothers and particularly affecting the enhancer regions in the genome. If an enhancer region (regions that regulate the expression of one or more genes ) is affected by the effects of smoking, this may lead to deregulation of several genes in the fetus, all at the same time.

Epigenetic changes related to tobacco smoke increase the risk of children developing lung diseases.

The researchers also found epigenetic changes to occur in the umbilical cord blood of the baby at birth - an effect the researchers found still to be seen in the child several years after he was born.