Smoking

If you went for that pre-baby chat with your doctor, you may already have heard that your smoking can impair your baby's development and result in poor birth weight. Now, the news gets tougher. Human Experimental Toxicology reports that either parent's smoking can put your little one at higher risk of childhood cancer.

Could you possibly have a better reason to pressurise your husband to quit ? Yes, here's one more: Since smoking is related to sperm quality  (hence infertility) in men, non-smokers are less likely to have trouble conceiving in the first place! Plus, smoking - even passively - quickly depletes your stores of antioxidants (such as vitamins C and E), which could guard your DNA against damage that affects your child's future health.

Alcohol

Put it this way, unlike with smoking, says Swinney, there simply hasn't been enough research for us to know what even small amounts of alcohol may do to your growing baby. On the other hand, alcohol decreases fertility in both sexes. So do all three of you a favour, and turn it down.

Overall balanced diet

Researcher Michael Crawford of the Institute of Brain Chemistry and Human Nutrition in London puts it bluntly - 'The individual responsibility for the development of the brain rests with the mother.' His work points to poor maternal nutrition before and during the first trimester being implicated in developmental disorders (from cerebral palsy to blindness) in babies with a low birth weight.

Coffee

One large multinational study found that women who drank the equivalent of about 4 cups of coffee took 11 per cent longer to fall pregnant, and the delay was longer still when the women also smoked! Since this study, published in the Human Reproduction journal, actually looked at caffeine consumption rather than coffee per se, you also need to push away the colas and too many cups of tea. Meanwhile, colas can also make you lose calcium, crucial for your bones as well as your baby's!

Vegetarian?

A meat-free diet has several health advantages, but if you are having trouble conceiving, see your doctor. An abrupt switch to a vegetarian diet may result in you missing certain nutrients, critically vitamin B12, which is found in very few plant foods (and even those aren't ones we commonly eat in our culture). Also, getting complete protein can be a problem unless you are an avid eater of all things soya and buckwheat (kootu to North Indians), which are among the rare plant foods that offer all essential amino acids.

Medicines and Other Drugs

Take nothing, not even aspirin and other 'mild' over-the-counter medication, without checking with the doctor, warns Dua. If you take medication for chronic problems, mention them to your doctor and have her check they are okay to take.

Food Preparation Safety

It's not just nutrient imbalance that endangers your dietary quality, but the toxins and microbes you may end up ingesting as well! For example, a form of Listeria basterium can cause miscarriage or stillbirth; toxoplasmosis, a parasite caught from cats sometimes, but also found in undercooked meats and unwashed produce, can cause mental retardation and blindness.

Salmonella from eggs can give you severe food poisoning, which will quickly dehydrate you and deplete nutrient stores, which can precipitate deficiencies at a time when morning sickness may already be making eating normally difficult.

To stay safe, wash hands scrupulously before and after handling food and pets both; also avoid uncooked/semicooked eggs, unpasteurised milk products, rare or raw flesh (from sushi to medium-rare steak, even hamburgers).

'Avoid even raw salads and unpasteurised cheeses, especially soft and blue-veined ones. Also avoid offal (organ meats). You won't be sure you are pregnant until you are at least two weeks into the pregnancy, so you might want to avoid these foods even as you start trying to conceive,' suggests Dua.