Progesterone During Pregnancy: What Happens If Its Level Is High Or Too Low?

Progesterone During Pregnancy

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Mood swings, food cravings, tiredness, and morning sickness – these are the common pregnancy symptoms triggered by the hormonal changes in the body.

Progesterone is one of the major pregnancy hormones that play an essential role in the woman’s body. Through the nine months, the levels of progesterone keep fluctuating, and that results in several physical changes. Keen on knowing what happens when the progesterone levels rise or fall?

In this MomJunction post, we tell you about progesterone during pregnancy, how to control and improve its levels, the side-effects of excessively high or low progesterone levels during pregnancy, and ways to prevent that.

What Is Progesterone?

Progesterone is a hormone that controls menstruation and fertility. It is released by the corpus luteum or the temporary endocrine gland that is formed in the ovary of the female body. The hormone is produced after ovulation or after the discharge of eggs from the ovary.

If you conceive, progesterone helps the lining of the uterus to prepare for implantation and then maintains it throughout the pregnancy (1). If you don’t conceive, the gland breaks down and reduces the progesterone levels, resulting in menstruation.

How Does Progesterone Help Before And During Pregnancy?

Progesterone plays an essential role in preparing and maintaining the endometrium (membrane lining of the uterus), thereby aiding the fetus’ survival (2) (3).

  • During the luteal phase (the phase after ovulation in a menstrual cycle), the hormone promotes the growth of blood vessels and activates the secretion of the endometrial gland. This thickens the lining of the uterus to accept and nourish the fertilized egg.
  • In the gestation period, progesterone promotes relaxation of muscles to prevent contractions. During pregnancy, the hormone makes a suitable environment for the fetus to grow.
  • Even during lactation, progesterone stimulates milk-producing cells.

Progesterone plays a vital role in the functioning of the woman’s reproductive cycle. Also, progesterone influences endometrium secretory changes, maintains pregnancy, and reduces uterine contractility. Hence, it is essential to have balanced levels of progesterone in the body.

What Happens If Progesterone Levels Are High During Pregnancy?

Hormonal balance is essential for the body to function properly. When progesterone levels rise during pregnancy, you could experience certain symptoms such as tiredness, bloating, anxiety, and decreased sex drive. In rare cases, there could be adverse effects on decidualization (changes to endometrial cells) and endometrial receptivity (4).

The levels of progesterone, however, can be managed and maintained optimally.

[ Read: Ways To Increase Progesterone To Get Pregnant ]

How To Keep Progesterone In Control?

A healthy lifestyle that includes regular exercise, a well-balanced diet, less junk food, no smoking or alcohol, and proper sleep could help in balancing the progesterone levels in the body.

In some instances, progesterone levels could go low, and that is not good.

What Happens If Progesterone Levels Are Too Low?

Low progesterone levels could be a problem if you are trying to get pregnant or when you are pregnant. Irregular periods, headaches, and mood swings are the symptoms you’ll experience when the progesterone is low in your body.

When the body doesn’t release enough progesterone, there could be estrogen (another pregnancy hormone) dominance that could result in symptoms such as depression, weight concerns, breast tenderness, and even gallbladder issues. While there are certain risks of low progesterone levels, there are also ways to bring the hormone levels up to normalcy.

What Are The Different Forms Of Progesterone?

Based on the progesterone levels in your body, the doctor will prescribe the form of progesterone supplement you should take. Tell the doctor about any allergies or health conditions you have before taking a progesterone supplement.

  1. Vaginal gel: It is prescribed as a part of fertility treatment for women who are trying to get pregnant. It is also prescribed when women have irregular or no periods due to low progesterone levels (5). The gel needs to be stored at room temperature. Make sure you consult your doctor before using any over-the-counter (OTC) progesterone vaginal gel.
  1. Vaginal suppository: This medicine is compounded by the pharmacist and needs special care for using. It is prescribed to prevent preterm delivery or miscarriage in pregnant women, or for women with certain conditions such as corpus luteum insufficiency, resulting in low progesterone levels. This should be stored in a refrigerator (6).
  1. Vaginal insert: It is a tablet that contains a micronized synthetic form of progesterone hormone, which is made for vaginal administration (7).
  1. Progesterone injection: It is prescribed to treat abnormal uterine bleeding or menstrual periods due to an imbalance in progesterone. The injection is only prescribed and given by a doctor (8).

The usage, dosage, and the duration of any of these forms of progesterone are prescribed by the doctor and should be followed to the letter. Discuss with your doctor and choose an option which is safe and convenient for you.

When Should You Discontinue Taking Progesterone During Pregnancy?

The course of progesterone as injections, inserts, suppositories, or other means should be as prescribed by the doctor. As the reason for progesterone supplementation is different for every woman, the duration of treatment would also be different. Some doctors suggest discontinuing the progesterone supplementation between 9 and 12 weeks of pregnancy (9).

Continue reading to know if progesterone supplements could have any side-effects.

Are There Any Side Effects Of Synthesized Forms Of Progesterone?

Yes, even though progesterone supplements are considered safe, there could be specific side effects such as (5) (6) (7) (8).

  • Change in urine and stool color
  • Nausea, mood swings, and loss or increase in appetite
  • Abnormal vaginal bleeding
  • Stomach cramps, back pain, or chest pain
  • Swelling or pain in the arms or legs
  • Changes in eyesight
  • Yellowing of skin or eyes
  • Tiredness, confusion, dizziness, and trouble speaking or understanding
  • Allergic reactions such as itching, rashes, and swelling of tongue, lips, or even face

It is better to consult your doctor, understand the side-effects, and then decide whether or not to take the progesterone supplements.

[ Read: Progesterone For Preterm Labor ]

What Are The Safety And Precautionary Measures To Be Taken?

Ideally, the progesterone supplements are safe when taken as per the doctor’s prescription. However, if you have certain health conditions or allergies, you should avoid them.

  1. Let your doctor know if the symptoms are severe and bothering you.
  1. Don’t use the supplements for a prolonged period as that may cause health complications.
  1. Let your doctor know if you have any health condition such as heart disease, liver disease, vaginal bleeding, depression, or any allergies that progesterone may worsen.
  1.  When progesterone is used to prevent premature delivery or as a part of fertility treatment, it is considered safe. Otherwise, it should not be used during pregnancy or to reduce premenstrual syndrome or irritation or pain.

Keep reading to know the answers to some commonly asked questions about progesterone levels during pregnancy.

Frequently Answered Questions

1. Does progesterone intake increase the chance of miscarriage?

No, progesterone is taken to support a healthy pregnancy. However, its use should be according to the doctor’s prescription. Never take any progesterone supplements without consulting the doctor first. The doctor can recommend the best variant and the dosage of progesterone that you should take depending on your condition.

2. Does taking progesterone cause birth defects?

No, evidence doesn’t suggest any relation between progesterone and birth defects. Some studies have shown that taking progesterone causes no harmful effects or congenital disabilities in children (10) (11).

3. Could there be any pregnancy complications with progesterone use?

Ideally, there should be no complications with the use of progesterone supplements. However, in the case of allergies or certain health conditions, it is suggested that you avoid its use.

4. Can I take progesterone when breastfeeding?

Yes, progesterone may enter breast milk in small quantities, but there is no harm to your baby in any way. If you are still in doubt about progesterone and nursing, talk to your doctor.

[ Read: Pregnancy Hormones ]

Progesterone plays an important role in supporting pregnancy. To maintain this hormone’s levels in the body, it is necessary to be healthy and fit. But if for some reason the hormone levels get tilted, consult your doctor and get treated in time.

Did your doctor prescribe any progesterone supplement to you? Do share your experiences in the comment section below.


MomJunction's articles are written after analyzing the research works of expert authors and institutions. Our references consist of resources established by authorities in their respective fields. You can learn more about the authenticity of the information we present in our editorial policy.
1. What is Progesterone; Hormone Health Network; Endocrine Society
2. P. Kumar and N. Magon; Hormones in Pregnancy; Nigerian Medical Journal (2012)
3. R. D. Beesley and J. V. Johnson; The Breast During Pregnancy and Lactation; The Global Library of Women’s Medicine (2008) 
4. Y. Liang et al.; The high concentration of progesterone is harmful for endometrial receptivity and decidualization; Scientific Reports (2018)
5. Progesterone vaginal gel; University of Chicago Medicine
6. Progesterone vaginal suppositories; UC San Diego Health
7. Progesterone vaginal insert; National Cancer Institute
8. Progesterone injection; Cleveland clinic
9. B. R. Kaplan; Progesterone Supplementation in Early Pregnancy; Fertility Centers of Illinois
10. J. H. Check, A. Rankin, and M. Teichman; The risk of fetal anomalies as a result of a progesterone therapy during pregnancy; Fertility and sterility (1986)
11. C. Vedel at a.; Long‐term effects of prenatal progesterone exposure: neurophysiological development and hospital admissions in twins up to 8 years of age; Obstetrics & Gynaecology (2016)


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