Effects of Smoking in the First Weeks of Pregnancy

Smoking cigarettes during the first few weeks of pregnancy and throughout the first trimester can lead to an array of complications. Not only can smoking affect the mother, it can also affect the unborn baby. Because the first trimester is important for the baby's growth and development, smoking can easily lead to irreversible complications that pose a serious risk to the fetus. It is important to stop smoking, avoid second-hand smoke and attend routine pre-natal checkups throughout the entire course of the pregnancy for a safe delivery and a healthy baby.

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Pregnancy Complications

When the mother smokes early on in the pregnancy, she could develop complications throughout the latter terms of the pregnancy; mainly placental problems. Placenta previa is where the placenta that surrounds the baby is lower than usual and covers up the uterus. A placental abruption is where the placenta dissipates and is destroyed before the birthing process. Both of these conditions are very serious and can cause internal bleeding resulting in a miscarriage and possibly the death of the mother during childbirth.

Early Labor

One of the most profound effects of smoking during the first weeks of pregnancy is to have the baby too early. Because the baby may not develop fully after conception, the body may reject the fetus and go into labor during the first few weeks—the result could be a stillborn baby. The baby could also die within the womb and be considered a miscarriage. At this point, prompt medical care is required and the deceased fetus has to be removed. If the baby continues to develop week-by-week, she can still be affected from the mother smoking early on. The mother could go into labor much earlier than expected. If bed rest and drugs cannot stop the labor, it could cause an emergency delivery at only 7 or 8 months (or earlier) into the pregnancy.

Premature Birth

One effect of smoking during the first few weeks of pregnancy is a premature birth. This is generally caused by a premature rupture of the membranes or the sac that is surrounding the baby. When the mother's water breaks, there is no longer fluid inside to protect the baby so delivery must occur promptly—generally with a few hours. After an ultrasound and fetal heart monitor is used to determine the health of the baby—labor is induced or a Cesarean section is performed to deliver the baby quickly and safely to prevent further trauma.

Low Birth Weight

If a baby is born prematurely there is a great risk it will have a low birth weight. The low birth weight is likely caused from the lack of oxygen to the baby throughout the first weeks and thereafter during the pregnancy. According to kidshealth.org, a healthy weight for a newborn 19 and 21 inches long is 6 to 9 pounds. Many babies born to mothers who smoke or are exposed to excessive second-hand smoke can have babies that are much smaller—some weighing only a few pounds. These babies are considered high risk for developmental delays, failure to thrive, infection, illness and poor growth. Many will need to be transported to a neo-natal intensive care unit for around the clock care and supervision until they are able to function without medical assistance.


SIDS stands for sudden infant death syndrome. A child born to a mother who smoked during her first few weeks of pregnancy is considered at high risk for sudden death under the age of one year. SIDS often occurs when the baby is asleep at night or during the day. There often times is no indication that the baby is sick or feeling unwell. According to the American SIDS Institute, there is often times no medical explanation for SIDS; only that women who smoke have babies who are at the highest risk.

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