Final answer:
Cigarette smoking during pregnancy reduces the oxygen available to the fetus, leading to serious health consequences and development issues for the unborn child. It is highly recommended to avoid smoking during pregnancy to ensure the fetus gets adequate oxygen and nutrients.
Step-by-step explanation:
Cigarette smoking by a pregnant woman is harmful to the fetus because it decreases the amount of oxygen
available to the fetus.
When a mother smokes, harmful substances such as nicotine and carbon monoxide from the cigarette travel through the placenta to the developing fetus. This exposure can cause the blood vessels to constrict, reducing the supply of oxygen and nutrients that the fetus needs for proper development. In addition, carbon monoxide has a high affinity for hemoglobin, the molecule in red blood cells that normally carries oxygen. Therefore, it can replace the oxygen in the mother's bloodstream, leading to lower oxygen levels available to the fetus. This results in a condition known as fetal hypoxia, which can have severe consequences, including premature birth, low-birth-weight, stillbirth, and even sudden infant death syndrome (SIDS). Moreover, smoking can lead to a host of other pregnancy complications, such as placental abruption and miscarriage. Hence, health professionals strongly advise against smoking during pregnancy to protect the health and development of the unborn child.