Impact Of Teratogens On Development: Effects Of Alcohol, Cigarette Smoking, And Antibiotics

Congenital Malformations

Discuss about the Impact of Teratogens on Development.

Teratogens refer to any given exposures which lead to harm to any foetuses and even to babies still undergoing breastfeeding. Therefore, teratogens can include alcohol, prescribed and non-prescribed medications, vaccines, different illnesses, illegal drugs, exposures from the environment, and even autoimmune disorders within the mother (Xing et al, 2015). Teratogens can cross the mother’s placenta and lead to effects on the foetus including congenital malformations, several disease conditions, cognitive malfunctions and even foetal death.  Therefore, it is very important for mothers to stay away from these teratogens so as ensure that their babies can be protected from their harmful effects. Each woman is at a 3-5% risk of bearing with any given birth defect (Hart, 2014). Studies indicate that some teratogens as those listed above increase this particular risk depending on the time of pregnancy that the woman is exposed, the dose levels of the exposure, and even the particular exposure route (Odibo & Krantz, 2016). Clinical researches on teratogens indicate that approximately 25% of all pregnancies mostly end up in miscarriage. However, the risk of having a miscarriage drops from 25% to 10% in the eighth week of pregnancy. Even so, several teratogens increase this particular risk (Xing et al, 2015). This depends only depends on the type and/or the amount of the exposure, and also the time of the pregnancy.  It is very obvious that teratogens will always be within the environment. Even so, they cannot be a threat to the unborn babies if only mothers understand what they are and gets rid of each of them (Nazeer et al, 2015). This discussion will present different effects of teratogens on unborn babies according to different researches focused on this particular area of studies.

Abnormal embryo development including congenital malformations leading to birth defects is studied under an area known as teratology. The anatomical and/or structural abnormalities present in babies at birth but can still remain undetected until later in one’s life. Malformations due to teratogens can be visible on the body surface and even on the internal viscera of affected babies (Odibo & Krantz, 2016). Congenital malformations are believed to contribute to about 20% of all deaths during the perinatal period. About 3% of all new-born infants have very major malformations while another 3% will most likely be diagnosed with malformations later in their lives. Congenital malformations can be caused by different factors and these include; genetic factors due to abnormalities in chromosomes and gene defects; factors in the environment such as drugs, infectious disease, mechanical forces and toxins; and further, multifactorial disease condition.

Alcohol Effects

These malformations can be single or multiple in a baby and therefore have a major and/or minor clinical significance. It is indicated in several studies that minor malformations present in about 14% new-borns worldwide (Odibo & Krantz, 2016). Minor malformations have little clinical consequences and include features like simian creases and ear tags. However, particular minor malformations can suggest that there is a possibility of a baby developing a major malformation. Finding a single umbilical artery for example, suggests that there is a high likelihood of congenital heart problems in the given child.  The higher the number of malformations in both born and unborn babies the higher the possibility of a major related malformation. Apparently, the higher the number of very major malformations in foetuses, the higher the possibility of a miscarriage and a shortened individual life span.

Birth defects and miscarriage risk varies among pregnant women depending on the alcohol amounts that they consume individually. It is indicated that between small and moderate alcohol amounts like say 2-4 frequent drinks result to a condition known as Fetal Alcohol Effect (Myra et al, 2016). This effect increases miscarriage risk levels among pregnant women, delays in fetal development and a hyperactive fetus. On the other hand heavy alcohol users who take between 5 and 6 frequent drinks result to Fetal Alcohol Syndrome. This syndrome according to the journal by Myra et al (2016), increases the miscarriage risk even more, leading to a micro-cephalous condition where a baby has; a head that is small in size with facial deformations, small eyes, nose, nails, abnormalities on the ears, heart defects, difficulties in learning, problems in behavior, mental retardation among others (Hart, 2014). Therefore, alcohol remains the commonest teratogen that affects fetuses.  As the mother drinks alcohol, she passes on to the unborn baby.  This is why babies that are born from such mothers present with symptoms that relate to Fetal Alcohol Syndrome (Faure et al, 2016). They are in most cases mentally challenged, impaired cognitively apart from other physical deformities. These children also find difficulty in communicating with people and usually present with a low and/or poor attention span. Such babies find it difficult functioning properly in any given society and therefore need a constant attention by their primary caregivers.

Cigarette smoking is another type of common teratogens. Women who smoke more than others have a higher risk of miscarriages. Cigarette smoking contributes to stillbirth where babies are born when they are already dead (Szatkowski, &  McNeill, 2014). Others are born with below average weight while others are born prematurely. Research indicates that due to delicate handling in incubators for babies born prematurely, there is a high mortality possibility especially in developing countries where there is poor medical infrastructure. Sudden Infant Death Syndrome (SIDS) also results from cigarette smoking among pregnant mothers(Nevenka & Nikola, 2014). It is a condition where the effects of the teratogen lead to a sudden death of infants born to smoker mothers.  Just like other teratogens, cigarette smoking also leads to; delays in the development of the fetus, a 1% risk of cleft palate where a baby is born with a hole at the roof of its mouth, and further a failure to thrive for among infants (Szatkowski, &  McNeill, 2014).  It is estimated that smoking above ½ cigarette packs each day among pregnant mothers puts them in a group of those with increased risk of its effects. It is even advised that no one should be allowed to smoke in areas where there are newborns and/or young infants. Direct contact with tobacco smoke and second-hand smoke contact affects a mother’s placenta and with extension, the embryo. This thus leads to developmental issues to the placenta resulting in foetal problems.

Cigarette Smoking

Accutane refers to a retinoic acid which is administered as pill for the treatment of severe acne. This particular medication is very dangerous to pregnant mothers because between 25 and 38% infants exposed to it during the first trimester eventually exhibit a number of abnormalities(Mburia-Mwalili & Yang, 2015). These include; developing hydrocephalus condition where the fetus has excess fluid in its brain, defects in the brain, retarded brain development, abnormalities on the ears and face (Hart, 2014). Other effects of Accutane use among pregnant mothers include abnormalities on the heart and the limbs; and chronic lesions on the skin.  Even further, there is an increase in the risk of miscarriages, cleft lip and/or palate in babies.

Pregnant mothers are often exposed to different antibiotics which are mostly safe in nature. However, there are documented exceptions.  For example, antibiotics such as aminoglycosides which are used in the treatment of severe infections pose a 2% increase in the risk of hearing impairment among babies born to these mothers (Bastow & Holmes, 2016). Other antibiotics such as Tetracycline and Doxycycline are capable of causing yellow-brown stains on the teeth of the unborn babies when taken up between the 4th an 9th pregnancy month. The latter two antibiotics if used during the 3rd trimester of pregnancy can result to a decreased growth rate of bones of the fetus (Mburia-Mwalili & Yang, 2015). They should also not be used especially when mothers are breastfeeding.  The Varicella Virus which causes chicken pox is also among the most dreaded teratogen. It is a common air borne disease which can spread very easily from an infected person to a healthy person (Bastow & Holmes, 2016). Despite the short term effect of the Virus on adults, it is very dangerous to unborn babies. This is because it leads to mental retardation, small-head head condition and a low birth weight.

Antidepressants have been associated with causing approximately 1% increase in the risk of learning difficulties. They also result into mild and moderate withdrawal symptoms after birth. This effect is however temporary and usually the baby tends to be unexpectedly irritable, present with problems when feeding, and proves difficult to sooth (Faure et al, 2016). Antidepressants also lead to premature delivery despite the fact that their benefits to a pregnant mother outweigh the different risks posed to the fetus. This is because research in maternal and child healthcare show that stress among pregnant mothers pose many problems to the unborn baby. There is further documentation that post-partum depression among mothers can even be worse and therefore the need to prescribe some anti-depressants.

Ionizing radiations are capable of injuring the developing embryo as it causes cell death and/or injury to chromosomes.  However, the severity of the damage to foetus/embryo is determined by the amount of the dose absorbed. The stage of foetal development at when the exposure to radiations occurs is also important (Faure et al, 2016). A study done among the survivors of the atomic bomb in Japan indicated that an exposure of between 10 and 18 weeks of a pregnancy associated with the greatest sensitivity particularly for a developing brain (Nazeer et al, 2015). Today, there is still no proof that congenital malformations in humans are caused by the normal diagnostic radiation levels (Backes et al, 2013). Even so, efforts are continually made to reduce scattered radiation from the different clinical diagnostic procedures including x-rays which are not near a woman’s. It is indicated that the standard radiation dose used in diagnostic x-ray gives out a very minimal risk to a developing foetus. Despite that, all women within the childbearing age must be asked to indicate whether they are carrying a pregnancy before being exposed to radiation.

Teratogen heavy metals include Lead and Mercury, which are both also carcinogenic in nature. Exposing mothers to lead to pregnant mothers bring about babies being born with disorders which are mental and cognitive in nature (Nazeer et al, 2015).  Lead exposure can be acquired from Lead based paints, jewellery cleaning solutions, metals, Lead toys and batteries.  Mercury on the other hand comprises of the most dreaded substance with proven drastic impact on the fetus (Nevenka & Nikola, 2014). Those mothers exposed to the harmful substance usually have babies that are born presenting with serious anomalies including; physical abnormalities, mental malfunctions and fetal death. Sources of Mercury exposure include touching broken thermometers and fluorescent lamps (Linnard-Palmer, 2016). Foods such like the Tuna and swordfishes also contain minimal levels of Mercury and should not be consumed by pregnant mothers.

Thalidomide, a common but yet effective tranquilizer, still remains one of the common teratogens. Thalidomide agent as a tranquilizer was used widely in 1959 particularly in Europe and resulted to about 7000 babies being born with condition referred to as thalidomide syndrome/meromelia (Nevenka & Nikola, 2014). The syndrome presented with characteristic features such as limb abnormalities which ranged from the absence of limbs to development of rudimentary limbs to limbs that were abnormally shortened. Further, thalidomide as described by Hart (2014), leads to malformations of more other body organs such as; internal/external ear absence and congenital heart disease.

In conclusion therefore, the discussion above highlights the different effects of identified teratogens in the environment to the unborn baby.  The discussion defines each teratogen and generally shows that all of them can easily be found in a lot of things that pregnant mothers interact with every day. They are thus drugs, chemicals or infections that may lead abnormalities on the embryo. Each teratogen including alcohol, tobacco, ironizing radiations, chicken pox among others discussed has its own effect on a pregnant mother and the baby during and after pregnancy. Even so it is clear that a number of the teratogens discussed effect the unborn embryo during particular times of a woman’s pregnancy. There is thus a need to prevent teratogens as they have been proven to be difficult to predict and even manage those that could the largest damage to the embryo.

References

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Backes, CH; Nelin, T; Gorr, MW; Wold, LE (Jan 10, 2013). “Early life exposure to air pollution: how bad is it?”. Toxicology letters. 216 (1): 47–53. doi:10.1016/j.toxlet.2012.11.007.

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Faure, C., Thapar, N., & Di Lorenzo, C. (2016). Pediatric Neurogastroenterology (1st ed.). Cham: Springer International Publishing.

Hart, J. (2014). The American Medical Association. Catholic Social Science Review, 19, 287-294.

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Myra, S., Ravndal, E., Torsteinsson, V., & Wiig, E. (2016). Pregnant substance-abusing women in involuntary treatment: Attachment experiences with the unborn child. Nordic Studies On Alcohol And Drugs, 33(3).

Nevenka, V., & Nikola, K. (2014). Genotoxicological Effects of Heavy Metals on Humans Cells. American Journal Of Environmental Protection, 2(4), 71-73.

Odibo, A., & Krantz, D. (2016). Prenatal Screening and Diagnosis, An Issue of the Clinics in Laboratory Medicine. Philadelphia: Elsevier Health Sciences.

Xing, J., Toh, Y., Xu, S., & Yu, H. (2015). Erratum: Corrigendum: A method for human teratogen detection by geometrically confined cell differentiation and migration. Scientific Reports, 5(1).

Szatkowski, L., & McNeill, A. (2014). Diverging Trends in Smoking Behaviors According to Mental Health Status. Nicotine & Tobacco Research, 17(3), 356-360.