Biology Forums - Study Force

Although it is strongly suggested that a woman avoid harmful substances (like alcohol) during her entire pregnancy, why is this advice particularly important during the first trimester?

Because pregnant women deliver almost everything they ingest directly to their baby through the placenta. A baby's liver does not mature in its development until the last half of pregnancy. Because of this, the baby's liver cannot process alcohol, and other potential harmful substances, as well. the overexposure of alcohol to a baby in the first trimester can affect it's development as well as increase the risk for a miscarriage. The first 8 weeks of development following fertilization are when "the body plans are being laid out, and the precursors of what will become organ systems are determined" (O'Neil, 2011). During the first trimester, the baby's facial features and brain and spinal cord are being developed. ingestion of harmful substances during the first trimester can lead to facial abnormalities, atrial and ventricular abnormalities, microphthalmia, optic nerve hypoplasia, small brain size, altered brain circuity, learning and behavioral disorders, the loss of specific nerve cells, abnormal head size, and low birth weight. Even small amounts of alcohol during this stage can have an impact on how the baby looks and the way they function and reason as an adult.


Ref:

Alcohol abuse and pregnancy. (n.d.). Retrieved December 02, 2017, from
http://www.dualdiagnosis.org/alcohol-addiction/pregnancy/

Alcohol, drugs and medicine during pregnancy. (n.d.). Retrieved December 02, 2017, from http://pregancybirthbaby.org.au/alcohol-drugs-and-medicine-during-pregnancy.

O'Neil, Erica, "Development Timeline of Alcohol-Induced Birth Defects". Embryo Project Encyclopedia (2011-04-24). ISSN: 1940-5030 http://embryo.asu/edu/handle/10776/2011.


If you are satisfied with the answer, please mark it solved.