Why is it so dangerous to smoke during pregnancy?
Cigarette smoke contains more than 4,000 chemicals, including truly nasty things like cyanide, lead, and at least 60 cancer-causing compounds. When you smoke during pregnancy, that toxic brew gets into your bloodstream, your baby’s only source of oxygen and nutrients.

While none of those 4,000-plus chemicals is good for your baby (you would never add a dollop of lead and cyanide to a bowl of strained peaches), two compounds are especially harmful: nicotine and carbon monoxide. These two toxins account for almost every smoking-related complication in pregnancy, says ob-gyn James Christmas, director of Maternal Fetal Medicine for Commonwealth Perinatal Associates at Henrico Doctors’ Hospital in Richmond, Virginia.

The most serious complications – including stillbirth, premature delivery, and low birth weight – can be chalked up to the fact that nicotine and carbon monoxide work together to reduce your baby’s supply of oxygen. Nicotine chokes off oxygen by narrowing blood vessels throughout your body, including the ones in the umbilical cord. It’s a little like forcing your baby to breathe through a narrow straw. To make matters worse, the red blood cells that carry oxygen start to pick up molecules of carbon monoxide instead. Suddenly, that narrow straw doesn’t even hold as much oxygen as it should.

How will smoking affect my baby?
A shortage of oxygen can have devastating effects on your baby’s growth and development. On average, smoking during pregnancy doubles the chances that a baby will be born too early or weigh less than 5 1/2 pounds at birth. Smoking also more than doubles the risk of stillbirth.

Every cigarette you smoke increases the risks to your pregnancy. A few cigarettes a day are safer than a whole pack, but the difference isn’t as great as you might think. A smoker’s body is especially sensitive to the first doses of nicotine each day, and even just one or two cigarettes will significantly tighten blood vessels. That’s why even a “light” habit can have an outsize effect on your baby’s health.

How smoking affects your baby:

– Weight and size: On average, a pack-a-day habit during pregnancy will shave about a half-pound from a baby’s birth weight. Smoking two packs a day throughout your pregnancy could make your baby a full pound or more lighter. While some women may welcome the prospect of delivering a smaller baby, stunting a baby’s growth in the womb can have negative consequences that last a lifetime.

– Body and lungs: Undersize babies tend to have underdeveloped bodies. Their lungs may not be ready to work on their own, which means they may spend their first days or weeks attached to a respirator. After they’re breathing on their own (or even if they did from the start), these babies may have continuing breathing problems – because of delayed lung development or other adverse effects of nicotine. Children whose mothers smoked during pregnancy are especially vulnerable to asthma, and have double or even triple the risk of sudden infant death syndrome (SIDS).

– Heart: A baby whose mother smoked in the first trimester of pregnancy is more likely to have a heart defect at birth. In a U.S. Centers for Disease Control and Prevention (CDC) study published in February 2011, these babies’ risk of having certain types of congenital heart defects was 20 to 70 percent higher than it was for babies whose moms didn’t smoke. The defects included those that obstruct the flow of blood from the right side of the heart into the lungs (right ventricular outflow tract obstructions) and openings between the upper chambers of the heart (atrial septal defects). Researchers analyzed data on 2,525 babies who had heart defects at birth and 3,435 healthy babies born in Baltimore and Washington, D.C., between 1981 and 1989.

– Brain function: Smoking during pregnancy can have lifelong effects on your baby’s brain. Children of pregnant smokers are especially likely to have learning disorders, behavioral problems, and relatively low IQs.

What can I do?
Behind all these grim statistics lies an incredible opportunity: You can give your baby a huge gift by giving up your habit – the sooner the better. Ideally, you should give up smoking before you conceive. For one thing, you’ll have an easier time getting pregnant. (Smoking lowers the chance of conceiving during any particular cycle by about 40 percent.) You also won’t have to struggle with quitting at a time when you should be thinking about other things, like eating well, exercising, and preparing for your baby’s birth.

Of course, not everybody manages to plan that far ahead. But if you’re still smoking when you discover you’re pregnant, it’s not too late. Immediately taking steps toward quitting can hugely benefit your baby.

A study published in the August 2009 journal Obstetrics and Gynecology found that expecting moms who quit in the first trimester actually raise their odds of delivering a healthy full-term, full-size baby to about the same as that of a nonsmoker. Moms who quit in the second trimester improved their odds, too, but not as much.

After weeks 14 to 16, fetuses should be greedily putting on weight. If you’re still smoking at that stage, your baby’s growth will start to lag. But as soon as you quit, your baby will start getting the oxygen he needs to grow. By the time you have your next ultrasound, your doctor should be able to see a significant change in your baby’s growth rate. Even if you’re smoking at 30 weeks or beyond, you can still give your baby several weeks to put on weight as quickly as possible. It’s as easy – and as difficult – as throwing away your cigarettes and never lighting up again.

Even though you’re aware of the dangers of smoking, it’s not always easy to give up the habit. The pull of nicotine can overwhelm your good intentions and even override your devotion to your child. That’s why you shouldn’t try to quit on your own. Talk to your doctor about different ways to quit. Ask your partner and other people around you for support. It won’t be easy, but don’t give up. There’s somebody counting on you.

Source: www.babycenter.com