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Merie asked in 科學及數學生物學 · 1 decade ago

effect of progesterone

wt is the effect of progesterone on oxytocin dutring pregnancy?

1 Answer

  • ?
    Lv 7
    1 decade ago
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    The Role Of Progesterone

    The placenta continues to produce both progesterone and estrogen for the duration of the pregnancy and the levels get higher and higher right up to just before the birth.

    The following chart shows the average growth in the level of progesterone within the body during a pregnancy. The dotted line shows what would happen if no fertilization happened during normal menstrual cycles.


    During the pregnancy, the progesterone is needed in the following ways, (mostly in conjunction with estrogen):

    Makes the endometrium develop and secrete fluids after being primed by estrogen

    Maintains the functions of the placenta and fights off unwanted cells near the womb that could cause damage to the placenta or foetus.

    Keeps the endometrium in a thickened condition

    Stops the uterus making spontaneous movements

    Stimulates the growth of breast tissue

    Prevents lactation until after the birth (with estrogen)

    Strengthens the mucus plug covering the cervix to prevent infection.

    Strengthens the pelvic walls in preparation for labour.

    Stops the uterus from contracting (thus keeping the baby where it is)

    At the end of the pregnancy, the levels of progesterone secreted by the placenta drop off. It is this action that stimulates the beginning of the contractions that will lead to birth.

    Oxytocin - This hormone is released as a response to stretching the cervix or stimulation of the nipples. It has the effect of making the uterus contract so that birth happens rapidly. It also stimulates the mammary glands to produce milk. High levels of progesterone will prevent oxytocin from having an effect. Only when progesterone levels drop close to the birth will the effects of this hormone be felt.

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