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Is there any evolutionary advantage for pregnant women suffering morning sickness

01:00 Mon 17th Dec 2001 |

A.� Although any pregnant woman suffering from morning sickness might not thank you for telling her, morning sickness, on the whole, is thought to be advantageous. It plays an important role in preventing miscarriage, pre-term birth, low birth weight and perinatal death.

Q.� How can being unable to eat properly for at least 3 months help the developing foetus

A.� Traditionally scientists have suggested that morning sickness helps women avoid toxins in foodstuffs that would harm the developing foetus during the critical first months of life when the organs are forming.

Q.� Is there any evidence to back this up

A.� Well many women totally go off alcohol, coffee and anything generally strong smelling during this time. Also many women report an aversion to meat, fish and eggs, which helps them avoid food poisoning, such as salmonella, which can have a fatal affect on the foetus.

Statistically speaking women that suffer morning sickness are less likely to miscarry than those that don't.

Q.� Why are women more susceptible to food poisoning when pregnant

A.� It's possible that as the woman's efforts are concentrated on the new task of building up a placenta, which will, nourish the baby for the last 6 months of pregnancy, her immune system is temporarily compromised.

Q.� If morning sickness is so advantageous why do most women stop suffering it after 12 weeks of pregnancy

A.� Well obviously suffering morning sickness for the entire 9 months would eventually lead to a nutritionally poor diet that would affect the mother's, as well as the baby's chance of survival.

After 12 weeks, when the placenta begins supporting the growing baby, it is less at risk from toxins and this is the point at which most women start to feel positive about most foods again.

Want to know how an apparently disadvantageous body function works Click here to ask The AnswerBank.

by Lisa Cardy

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