Progesterone in early pregnancy

What is it?

Progesterone is a hormone which is naturally produced in pregnancy and is essential for keeping the lining of the uterus thickened and healthy, to help support the baby to implant and continue growing. Low levels of progesterone have been linked to impending miscarriage and the presence of associated early pregnancy bleeding. Recent research indicates that progesterone supplementation may reduce the risk of miscarriage in women with a history of previous miscarriage.

Progesterone is also used in other areas of gynaecology in different formats including hormone replacement therapy (HRT) and as part of assistive reproductive technology (ART) treatments like IVF.

It is important for you to continue taking folic acid if you take progesterone in pregnancy.

Why am I having this treatment?

Recent studies from the National Institute of Health and Care Excellence (NICE) updated their Miscarriage guidance in 2021. This included new recommendations on the use of progesterone for women who have vaginal bleeding in early pregnancy (under 12 weeks) and have had one or more previous miscarriage.

The recommendations are very specific:

• It is for women who have vaginal bleeding and have previously had at least one miscarriage.
• They need to have had a scan that shows that there is a pregnancy in the uterus (womb)
• If a fetal (baby’s) heartbeat is seen on scan, treatment is continued until 16 completed weeks of pregnancy.

What is the treatment?

Micronised progesterone which is identical in structure to naturally produced progesterone is taken its in the form of progesterone pessaries which are inserted into the vagina twice a day. This is the most effective route of administration as supported by research.

What are the benefits and risks to me?

Progesterone is recommended to lower the risk of miscarriage in women who experience bleeding in early pregnancy and those who have experienced at least one miscarriage. However Progesterone will not prevent every miscarriage. Sadly, miscarriages will still occur despite progesterone use.

The is no evidence of harm for women or babies following the use of vaginal micronised progesterone, with no increase in risk of stillbirth, congenital abnormalities or adverse drug reactions.

How effective is progesterone treatment?

If you have had one or two miscarriages, taking progesterone in early pregnancy may increase your chances of having a successful pregnancy by 5%.

If you have had three or more miscarriages taking progesterone in early pregnancy may increase your chances of having a successful pregnancy by 15%.

Common side effects (may affect up to 1 in 10 people):

• Abdominal distension (swelling in the abdomen), abdominal pain, constipation
• Sleepiness
• Tiredness
• Hot flush
• Breast pain

Please inform the doctor or nurse if you have a history of any of the following:

• Have or have had blood clots in the legs, lungs, eyes or elsewhere in the body,
• Currently have or have had severe liver problems
• Have epilepsy (as certain medication can decrease the effectiveness of the pessaries).

What you need to know before starting progesterone pessaries

This is an off-label use of vaginal micronised progesterone. This means its use for women who experience bleeding in early pregnancy with previous miscarriage is not within the medicine’s marketing authorisation. However, it is recommended by NICE as there is clear and strong evidence of its benefits.

Is there anything else I should know?

If your pregnancy is very early and too small to be able to see a fetus (baby) and heartbeat, you can still commence progesterone and a further scan will be arranged to confirm this.

What happens when I go home?

If you have not already done so, please book your pregnancy with your community midwife.

You should commence the pessaries as directed and continue until you reach 16 completed weeks of pregnancy.

If you are worried about anything including bleeding or pain during this time, please contact your gynaecology ward or Early Pregnancy Unit on the telephone numbers below.

Contact details

Diana Princess of Wales Hospital, Grimsby
Gynae Assessment Unit: 03033 303770

Scunthorpe General Hospital – Early Pregnancy Assessment Unit: 03033 302052/Gynae SDEC: 03033 303018

Reference section

National Institute of Health & Care Excellence (NICE). Ectopic pregnancy and miscarriage: diagnosis and initial management (accessed 18/3/26)

Tommy’s Pregnancy and Baby Charity Taking progesterone to help prevent pregnancy loss (accessed 20/5/26)

Any comments, compliments, concerns or complaints

If you have any other concerns please talk to your nurse, therapist or doctor. Our Patient Advice and Liaison Service (PALS) is available on 03033 306518 (Grimsby, Scunthorpe and Goole). You can also contact [email protected]

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