Seven pregnancy sins

Why are they bad for my baby?
During pregnancy, smoking constricts blood vessels, decreasing the amount of oxygen crossing the placenta, which increases your chances of having a low-birthweight or stillborn baby.

What is the official line?
This one is non-negotiable. Quit smoking as soon as you can.

Just how risky is it?
Research by Action on Smoking and Health (ASH) has shown conclusively that babies born to women who smoke are on average 200g/8oz lighter than babies born to comparable non-smoking mothers. Premature and low-birthweight babies are more prone to illness and infections.

What else carries a similar risk?
Passive smoking. Non-smoking women exposed to other people's tobacco smoke during pregnancy are more likely to have lower-birthweight babies (Central European Journal of Public Health 2000).

Pregnancy sin rating 4-5

Why is it bad for my baby?
Remember, though, that alcohol consumed at any stage during pregnancy crosses the placenta and can potentially affect your baby's development. Excessive drinking can lead to low weight at birth and fetal alcohol syndrome (FAS) - a condition where babies may have problems with sight, hearing and later learning.

What is the official line?
At the moment, the advice is that moderation is key.

Just how risky is it?
This one's a minefield. The Royal College of Obstetricians and Gynaecologists recommends that the only way to be completely sure that your baby is not harmed by alcohol is not to drink at all during pregnancy or while you are trying for a baby. Meanwhile, the UK Government's advice is to drink no more than one or two units, just once or twice a week. And more recent reports have suggested that even one unit a day won't do you or your baby any harm. However, the advice is currently under review and pregnant women may be advised not to drink at all.

What else carries a similar risk?
Like alcohol, various medicines (prescribed, over-the-counter and complementary) can cross the placenta and enter the baby's bloodstream, causing birth defects. Always consult your doctor or pharmacist before taking any medication during pregnancy.

Pregnancy sin rating 1-2 units a day = 1-2; heavy consumption = 5

Why is it bad for my baby?
Although caffeine is known to cross the placenta and is passed to the fetus, moderate amounts do not appear to be harmful.

What is the official line?
Again, moderation is the key. Current Food Standards Agency (FSA) guidelines recommend that pregnant women should consume no more than 300mg of caffeine a day.

Just how risky is it?
According to Dr Maggie Blott, there are reports of an increased miscarriage rate with excessive consumption, although she stresses there is no hard evidence for this.

What else carries a similar risk?
Apart from coffee and tea, caffeine is also found in colas, various energy drinks and even green tea.

Pregnancy sin rating moderate consumption = 1

Why are they bad for my baby?
Listeriosis (being infected with listeria) can cause stillbirth, miscarriage or severe illness in newborn babies, although fortunately it is extremely rare.

What is the official line?
If you really can't hold out, thorough cooking should kill any listeria, so it should be safe to eat food containing soft mould-ripened or blue-veined cheeses, provided the food has been properly cooked and is piping hot all the way through.

Just how risky is it?
According to Dr Maggie Blott, there is established research on the effects of listeria on the fetus.

What else carries a similar risk?
Listeria can also be found in soft unpasteurised goat's and sheep's cheeses, as well as pâté (any type, including vegetable), certain prepared salads, such as potato salad and coleslaw, soft-whip ice cream and ready-prepared meals, unless they are piping hot all the way through.

Pregnancy sin rating 4

Why is it bad for my baby?
Toxoplasmosis infection may lead to miscarriage, stillbirth, or survival with growth problems, blindness, water on the brain (hydrocephalus), brain damage, epilepsy or deafness.

What is the official line?
Make sure ALL fruit and vegetables are washed thoroughly.

Just how risky is it?
While the effects of toxoplasmosis in pregnancy are well documented, Dr Maggie Blott emphasises that it is very rare in the UK, with around 50 babies a year being born with it.

What else carries a similar risk?
Handling cat litter and doing the gardening without gloves. It's best to get someone else to change the litter for you, but if you can't, at least wear gloves and wash your hands thoroughly afterwards. Toxoplasmosis can also be present in raw or undercooked meat, and in unpasteurised goat's milk or goat's cheese, so avoid these.

Pregnancy sin rating 3

Why is it bad for my baby?
Oily fish contains mercury and, at high levels, this can harm your baby's developing nervous system.

What is the official line?
The FSA advises pregnant women to limit their intake of tuna to no more than two steaks a week or four medium cans of tuna a week. They should not exceed two portions of oily fish per week; this includes fresh tuna (not canned), mackerel, sardines and trout. However, they should aim to eat at least two portions of fish per week, one of which should be oily.

Just how risky is it?
A survey by the FSA has found high levels of mercury in some fish so, as a precaution, advises women to cut down during pregnancy.

What else carries a similar risk?
Larger fish that have a longer life cycle, such as shark, swordfish and marlin, should be avoided altogether as there is a greater risk that the fish has been exposed to contaminants.

Pregnancy sin rating 2

Why is it bad for my baby?
Salmonella is very unlikely to harm your baby.

What is the official line?
Eggs are an excellent source of protein and amino acids, but enjoy them well-cooked - the yolks and the whites should be solid. According to the FSA, even organic eggs aren't entirely risk-free and it advises cooking them thoroughly for peace of mind.

Just how risky is it?
About 12,375 reported cases of salmonella in England and Wales in 2006. Pregnant women have an increased risk of contracting it due to hormonal changes that suppress the immune system.

What else carries a similar risk?
Seafood (raw or cooked) also carries the risk of food poisoning. Meat and poultry should be cooked thoroughly and products made from minced meat, such as sausages and burgers, should be cooked until they are piping hot all the way through and no pink meat is left.

Pregnancy sin rating 1-2