Seven SINS of Pregnancy (part 1)

There is tons of information on what to avoid during pregnancy, not to mention conflicting advice

So what are the real risks? Here you will read about the most common temptations.
Smoking

Smoking does awful damage to your unborn baby

Why is it bad?
Cigarette smoke contains over 4000 chemicals most of them leading to cancer and increases the risk to develop heart disease, lung problems and cancer.

TOP 10 Myths about Pregnancy
Why are they harmful to my baby?
During pregnancy, smoking constricts blood vessels, reducing the amount of oxygen passing through the placenta, which increases the risk of having a baby with low birth weight or pregnancy is fatal to the unborn child.
What is the official position?
This point is not negotiable. Stop smoking as soon as possible.
What exactly is the risk?
Study of Activity on Smoking and Health (Action on Smoking and Health, ASH) is conclusively proven that babies born to mothers who smoke have an average weight of 200 grams less than babies born to non-smoking mothers. Premature and low birth weight babies are more susceptible to diseases and infections.

Smokers Sleep Less and Rest Badly 
What else is there such a risk?
Passive smoking. For non-smoking mothers exposed to tobacco smoke from other people during pregnancy are more likely to give birth to babies with low birth weight (Central European Journal of Public Health 2000).
TWO Alcohol
Why is it bad for me?
The good news is that a pregnant or not, a cup from time to time probably will not hurt you.
Why is it harmful to my baby?
Remember, however, that alcohol is consumed at any time during the pregnancy crosses the placenta and can potentially affect the development of your baby. Excessive alcohol consumption can lead to low birth weight and embryonic alcohol syndrome (fetal alcohol syndrome, FAS) – a disease in which babies can have problems with vision, hearing and learning delays.
What is the official position?
Currently, the council is that moderation is the key.

PROVEN! Smoking during Pregnancy Threatens Your Children’s Health!
What exactly is the risk?
It’s a minefield. Royal College of Obstetricians and Gynecologists recommends that the only way to be completely sure that alcohol will not harm your baby is not to drink at all during pregnancy or while trying for a baby. Meanwhile, the UK government advised to drink no more than one or two units of alcohol once or twice a week. A most recent studies suggest that even one alcoholic unit per day will not harm you or your baby. However, these tips are currently being reviewed and pregnant women may be advised not to consume alcohol at all.
What else is there such a risk?
As with alcohol, other drugs (prescription, free sale or dietary supplements) can pass through the placenta and enter the baby’s blood, causing birth defects. Always consult your doctor before taking any medicine during pregnancy.

Source : dailyhealtharticles[dot]com