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Why do the effects of alcohol on unborn babies vary?


When a woman drinks, her unborn child does too. This is because alcohol passes across the placenta into the fetus’s bloodstream.

After about 14 weeks the fetus swallows amniotic fluid in the womb. Amniotic fluid can also contain alcohol if a mother drinks. The baby’s liver eliminates alcohol very poorly. The fetus relies on the mother to remove the alcohol.

Some women break down alcohol faster than others. This is genetic. The longer it takes to break down the alcohol and remove it from the body, the longer the fetus is exposed to its harmful effects.

Other factors that affect how quickly alcohol is metabolised (broken down)
  • How quickly one drinks
  • Whether one drinks on an empty stomach or after food
  • The mother’s body type – The concentration of alcohol in the blood of people who have more fatty tissue tends to be higher than people of the same weight who are lean and muscular
  • How often a woman drinks alcohol
  • How much alcohol is consumed at a sitting
  • Whether the person is in a state of good health.

With so many different factors that can influence how alcohol will affect a fetus, it’s impossible to predict what will happen if a woman drinks during her pregnancy. The only way to be safe is to avoid alcohol altogether.


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