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Birth - Labour

Biology: Cambridge International GCSE Supplement, topic 16.4.8

Labour

After roughly 38-40 weeks of pregnancy, human women go through labour to give birth:

Amniotic sac breaks

Amniotic sac breaks

  • The amniotic sac surrounding the foetus breaks and the amniotic fluid in it leaves through the vagina.
  • This is often known as 'waters breaking'.
Muscle contractions start

Muscle contractions start

  • The muscular walls of the uterus contract repeatedly, preparing to push the baby out.
Cervix dilates

Cervix dilates

  • The cervix (the opening at the bottom of the uterus) gets wider so that the baby can pass through.
Birth through the vagina

Birth through the vagina

  • The baby is born.
Umbilical cord cut

Umbilical cord cut

  • The baby is still attached to the mother by the umbilical cord when it is born, so this is cut and tied.
  • The remnants of the umbilical cord will eventually fall off the baby, leaving behind a 'belly button'.
Afterbirth delivered

Afterbirth delivered

  • After the baby is born, the placenta is delivered through the vagina.

Test yourself on Birth - Labour

  • Labour

  • Which muscles contract to push the baby out during labour?

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