Two Reasons You Need Progesterone During Pregnancy

Progesterone is a natural female hormone. It’s called “the pregnancy hormone,” and is essential before and during pregnancy.

Progesterone supplementation is often necessary during Assisted Reproductive Technology (ART) procedures, such as in-vitro fertilization (IVF) because the medications you may use during these procedures can suppress your body’s ability to produce progesterone. Certain procedures can even remove progesterone-producing cells from your ovaries.

Sometimes, there are other reasons to use progesterone supplementation, such as little or no progesterone production from the ovaries or poorly developed follicles that do not secrete enough progesterone to develop the uterine lining.

The bottom line is this — all women who wish to become pregnant need progesterone to help the uterus prepare for and maintain a fertilized egg.

Two Reasons You Need Progesterone Before and During Pregnancy

  1. Progesterone prepares the uterus for pregnancy. After ovulation occurs, the ovaries start to produce progesterone needed by the uterus.
  2. Progesterone causes the uterine lining to thicken, helping to prepare a supportive environment in your uterus for a fertilized egg. After 8 to 10 weeks of pregnancy, the placenta takes over progesterone production from the ovaries and substantially increases progesterone production.

Several types of progesterone are available, including vaginal products that deliver progesterone directly to the uterus. Here are different forms:

Vaginal gel:

  • Used once a day for progesterone supplementation
  • Unique — the only once-daily FDA-approved progesterone for ART for up to 12 weeks of pregnancy
  • The only FDA-approved progesterone for replacement for donor egg recipients and frozen embryo transfers
  • Over a decade of experience and over 40 million doses prescribed
  • In studies where patient preference was measured, a majority of women preferred the gel for comfort and convenience over other progesterone formulations
  • Some discharge reported during use

Vaginal suppositories:

  • Compounded at specialty pharmacists
  • Wax-based
  • Widely used but not FDA-approved
  • Used 2 to 3 times a day
  • Leakage can be messy

Vaginal inserts:

  • Designed for vaginal use
  • FDA-approved for progesterone supplementation but not for progesterone replacement
  • Effective in women under 35 years; no established results in women over 35 years
  • Used 2 to 3 times a day

Progesterone oral capsules, used vaginally:

  • Not formulated or FDA-approved for vaginal use
  • Fewer side effects when capsules are used vaginally instead of orally
  • Used up to 3 times a day


  • An oil-based solution (sometimes called progesterone in oil)
  • Widely used; the oldest, most established method of progesterone delivery
  • Injected into the buttocks once a day
  • Require long, thick needle to penetrate layers of skin and fat
  • Difficult to administer by yourself
  • Injections may be painful
  • Skin reactions are common

Source: Columbia Laboratories

About lesley

Lesley Vance is the author of Infertility Journeys, Finding Your Happy Ending.
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  • Linnea
    June 28, 2011

    Do both ovaries release progesterone while pregnant? Or is the hormone coming only from the corpus luteum? I am over 9week pregnant, seen the baby several times, heard the heartbeat all 3 times. Both ovaries are sore. The doctor said the corpus luteum is sending progesterone to the baby and says this is why my right ovary feels this way. But what about the left one?

    • lesley
      June 29, 2011

      Hi Linnea,
      I’m asking 2 of my doctor friends today to get an answer for you. But in the meantime, I did find that progesterone is first produced by the corpus luteum of the ovary for the first 8 weeks of pregnancy. From implantation of the embryo onwards for 40 weeks the placenta takes over the production of progesterone….I’ll get more info and let you know. Thanks for asking! Great question.

  • lesley
    June 29, 2011

    Hi Linnea,

    I talked to Dr. Margot Aiken who is a fertility specialist and endocrinologist in Encinitas, Calif. She said that the corpus luteum is involved in the production of progesterone. The corpus luteum develops from the ovarian follicle during the menstrual cycle. While the oocyte (later the zygote if fertilization happens) goes down the fallopian tube into the uterus, the corpus luteum stays in the ovary where the follicle initially released its egg. Hence, the corpus luteum comes from the ovary that produced your egg.

    You asked if both ovaries release progesterone while pregnant. Dr. Aiken said that the ovary that produced the egg is the one that releases progesterone via the corpus luteum.

    I’m wondering if both your ovaries released eggs? Do you know? If so, maybe the one got fertilized, and the other egg didn’t but maybe the corpus luteum from that other egg is still present? Did you ask your doctor about that?

    But, Dr. Aiken said that if an egg is not fertilized, the corpus luteum stops secreting progesterone and dies off after 2 weeks. So, that negates the idea that corpus luteum is still hanging out in your other ovary.

    Dr. Aiken said, that both ovaries can produce an egg each month (for example, twins would be the result), but both ovaries don’t always produce eggs with each cycle. And as you probably already know you can’t predict when your ovary will release an egg. Not all women produce follicles each month. Of course, if you’re doing IVF they check for all that to see how the follicles are developing up to the time of egg retrieval, but that’s another story.

    Have you asked your doctor if it’s possible that because your egg was fertilized, then could it be that your other egg’s corpus luteum is still there even though it didn’t get fertilized?

    I hope this information helps you as you continue to talk with your doctor about your particular situation. I’m not a doctor and always encourage women to seek the professional advice of a medical professional.

    Let me know what you find out, and if there’s any other questions you have. If I get more info I will let you know.

    I hope you feel better soon!


  • lesley
    June 30, 2011

    Hi Linnea,

    I heard back from Dr. Diane Hoppe, M.D., F.A.C.O.G., who is a highly respected, board-certified obstetrician/gynecologist in private practice in San Diego, California.

    Dr. Hoppe said, “Usually just one ovary ovulates the dominant follicle which releases the egg to be fertilized. If the egg is fertilized, a signal is sent back to the ovary to continue producing progesterone. Therefore, there might be a small cyst/corpus luteum cyst on one ovary. The other ovary should be normal size without evidence of corpus luteum.”

    “Did thhis patient receive infertility drugs, injections? If so , then, yes there may have been superovulation and both ovaries produced follicles, with one or more follicles releasing eggs, and potentially more cysts may be on both ovaries. This is why there may be twins or triplets with Clomid, or other injectables to induce ovulation.”

    “Hope this makes sense…If she wants to make sure that no problem with the ovary (ies.) she could always check with pelvic ultrasound and measure ovaries.”

    Hope this helps. Let me know what findings you get from your doctor.

    Warm Regards,

  • Ashley
    July 29, 2012

    Is it common to take progesterone to avoid other misscarriage?

    • lesley
      November 19, 2012

      That’s a good question for your doctor. When my progesterone was low during my pregnancy, I was given supplements. The idea was to create a balance in my hormones and to provide the right levels for a developing embryo. Please talk with your doctor or a fertility specialist.
      I’m not sure if this relates specifically to your situation, but you may want to read up on LPD…Luteal Phase Defect (LPD) occurs when the endometrium is inadequately prepared for an embryo. If there is an insufficient level of progesterone or non-responsiveness to the hormone, implantation may not happen or may result in a miscarriage.
      You can read more on Dr. Acacio’s blog:

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