Life all starts from the division of cells in order to produce offspring through the development of a fetus (embryo) during the reproduction process. The fetus is very delicate in the beginning stages of pregnancy. Severe morphological abnormalities can occur within the first 3-8 weeks of pregnancy from influences such as terratogens while weeks 9-38 the abnormalities which can occur are minor. With that said fetus susceptibility to injury depends on its period of development (Diversity of Life). Specific Organs have different time periods where they are most vulnerable.
During gestational period day 15 to day 60 is when a majority of organs are in there most critical state allowing (Diversity of Life). The heart is most sensitive during the third and fourth weeks of gestation, whereas the external genitalia are most sensitive during the eighth and ninth weeks. The brain and skeleton are sensitive from the beginning of the third week to the end of pregnancy and into the neonatal period.
Terratogens are toxins or infectious agents that interfere with development and causes physical defects to developing fetus. During the first trimester while major body structures are forming the fetus is extremely vulnerable to environmental factors such as terratogens that can lead to congenital malformations or birth defects. One of the most common terratogens is smoking. Carbon monoxide in smoke can overpower oxygen intake for binding sites of hemoglobin. This can cause the fetus of a smoker to receive less oxygen than a non-smoker. Levels nicotine in amniotic fluid can also be higher in a smoking mother’s blood. Effects of maternal smoking can be last long after birth of a child. One study conducted showed a followed a group of children who were born within the same week for a period of seven years. There was a higher rate of death in children of smokers dying due to post-delivery complications than that of non-smokers. Also those children of smokers who did survive were smaller than the children of non-smokers as well as had multiple heart defects. Furthermore smoking can affect the learning capacity as at the conclusion of the study children of smokers were close to half a year behind in reading for their age.
Smoking can lead to many complications during pregnancy as well as pregnancy loss. There are several factors that may result from this. One of these is still birth, which is fetus being delivered with no signs of life. It has been found to be most common African American women. Another issue caused is placenta preuia. Placenta preuia is when the placenta either completely or partially covers the cervical opening (Insel ). This prevents the mother from delivering the baby through vaginal canal. As a result a cesarion section (C-section) must be performed. C-sections are performed by a baby being removed through a surgical incision in abdominal wall in uterus.
31.1% of American babies born in 2006 were delivered by C-section (Insel ). Placental abruption can also be caused. This occurrence is when implanted placenta prematurely separates from the uterine wall. Mothers will show signs of abdominal pain, vaginal bleeding and uterine tenderness condition which leads to increase risk of fetal death. One of the most common effects of smoking is low birth weight upon delivery. Low birth weight is deemed when a bay is weighing less than 5.5lbs at birth. Babies with low birth rate are normally premature before 37th week of development.
As smoking causes a majority of defects second hand smoking is can still produce just as many complications. One study conducted was on fetal exposure to passive smoke. Twenty babies born to mothers who did not smoke but were exposed to second hand smoke from someone who did within the household were found to have twice the amount of cotinine (by product of nicotine) as 35 babies born to mothers who were not exposed to second hand smoke.