Most of the exposure to lead is through contaminated drinking water and soil, occupational exposure and lead based paint. Lead can cross the human placenta and is a known teratogen. Also it can cause premature labor, spontaneous abortion, premature rupture of membrane and also low intelligence quotient in the baby born. Unnecessary exposure in pregnancy has to be avoided by having your drinking water tested or by using a filter. Also avoid construction in buildings painted prior to 1950. Let the water run for several minutes in the morning if your house has lead pipes.

Some paints use lead, though maximum has been replaced today. Exposure to lead during pregnancy can occur through contact with lead based paints or through inhalation of dust particles from torn down or sanded wall painted many years back. Prenatal exposure to lead has been reported to cause lower mental developmental scores. Also it has been considered to be a teratogen. Better to avoid any construction especially if the walls have been painted before 1950. If need be one should consider wearing a mask or even moving to a different location.

Recent reports from US FDA (food and drug administration) has some chemicals used in nail polish and in nail polish removers are potentially dangerous and can cause skin irritation and rashes. Chemicals that are potentially dangerous includes Methyl Methaacrylate, Acetonitrile and Formaldehyde, therefore it is best avoided in pregnancy though nail treatment without the nail polish is safe.

Marijuana, derived from cannabis plant is a drug of abuse and illegal. Smoking marijuana prior to pregnancy has been associated with decreased male and female fertility. Some studies have also shown low birth weight and neurological delay in fetus. It has to be avoided in pregnancy.

There is no scientific data that use of microwave ovens for cooking in pregnancy cause any harm to the fetus or mother.

Only the ingredient raw eggs in mousse can be problematic as there is a risk of bacterial infection with salmonella. One particular type of these bacteria can cross the bacteria and cause miscarriage, stillbirth and preterm labor. Meat which is undercooked can cause Listeria or Campylobacter infection. Both these diseases can cause preterm labor or miscarriage.

 It is a food additive and may cause adverse reactions to some people irrespective of pregnancy. Reaction involves headache, nausea, vomiting, and sleep disturbances as such it is safe to be used in pregnancy but one should avoid if she has an allergic tendency to this.

High heeled footwear though safe for the fetus, can cause strain and backache to the mother. Moreover losing balance and falling may be detrimental for both. You may like to feel high but try not to look too high.

Herbicides are chemicals used to kill weeds. These may penetrate the soil and cause contamination of the drinking water. Even low levels of these are known to cause congenital anomalies, and fetal death in the animals. So herbicides have to be used with extra precaution and protective gear.

The US FDA (Food and Drug Administration) recommends that until conclusive evidence is available, pregnant women should use hair dye with caution. You may consider using a hair dye which uses the shortest possible time.