Your doctor has prescribed Utrogestan suppositories to be inserted vaginally at night. Or Duphaston tablets twice a day. Or Proluton Depot injections, weekly, at the clinic. You have the prescription in your hand and a reasonable question in your mind: what is this for, and does it matter?
Progesterone is prescribed in pregnancy for several distinct clinical reasons, and those reasons are not interchangeable. The scenario that led to your prescription shapes which formulation you need, when you start, and when you stop. This post walks through each situation clearly.
If you want to understand what a progesterone blood test result means in terms of normal ranges by trimester, that is a separate question, covered in the guide to progesterone levels in pregnancy. This post is specifically about treatment: the clinical situations in which supplementation is prescribed.
What Progesterone Does in Early Pregnancy
In the first weeks after conception, progesterone is produced by the corpus luteum, the small structure that forms in your ovary after the egg is released. The corpus luteum is a temporary gland. Its job is to keep progesterone high enough to maintain the uterine lining and support the embryo while it implants and begins to grow.
This arrangement is designed to be temporary. Around 8 to 10 weeks of pregnancy, the placenta takes over progesterone production. This transition, called the luteo-placental shift, is a normal developmental step. Once the placenta is the primary source, the corpus luteum is no longer the critical factor. In most pregnancies, this shift happens without any intervention.
But there are clinical situations where the corpus luteum has been disrupted, where its function is inadequate, or where progesterone supplementation serves a separate purpose later in pregnancy. Those situations follow.
When Progesterone Is Prescribed
1. Luteal Support After IVF or IUI
This is the most common reason for progesterone supplementation in pregnancy, and the evidence behind it is unambiguous.
During an IVF cycle, eggs are collected from the ovaries through a needle aspiration procedure. The follicle that contained each egg would normally go on to form a corpus luteum after natural ovulation. After aspiration, it does form a corpus luteum, but the procedure partially disrupts this structure. The resulting corpus luteum does not produce adequate progesterone to support a fresh embryo transfer. Without supplementation, the uterine lining does not receive the hormonal support it needs in the days after transfer.
For this reason, progesterone supplementation is a mandatory part of IVF protocol, not an optional add-on. It begins on the day of egg retrieval or embryo transfer and continues until the 10 to 12 week scan confirms a healthy, growing placenta has taken over. Most IVF centres use the same logic for IUI cycles involving ovarian stimulation, where corpus luteum function is also affected.
For women in this situation: you need this medication. The uncertainty is about which formulation (covered below), not about whether to take it.
2. Threatened Miscarriage With a History of Prior Loss
Vaginal bleeding in early pregnancy, classified as threatened miscarriage, is more common than many women realise. Around 20 to 25% of all pregnancies involve some bleeding in the first trimester, and the majority continue without complication. For women who bleed and also have a history of at least one previous miscarriage, there is a clinical rationale for progesterone supplementation.
The largest randomised trial on this specific question is the PRISM trial (Coomarasamy et al., 2019, New England Journal of Medicine, PMID 31154676). Women who were bleeding in early pregnancy and had a history of at least one previous miscarriage were given either vaginal progesterone (400 mg per day) or placebo. In the overall study group, the difference in live birth rates was not statistically significant. In the subgroup of women with three or more previous miscarriages, the picture was different: vaginal progesterone increased live births from 57.4% to 71.8%, a meaningful and statistically significant benefit.
The clinical interpretation in practice: current bleeding plus a history of recurrent loss is the combination where the PRISM data supports progesterone use. A single prior miscarriage with no current bleeding is a different clinical situation, and the evidence for supplementation there is less clear.
If you are on progesterone for this reason and your bleeding has settled, ask your doctor at the next visit when they plan to review the prescription. It is a reasonable question with a specific answer.
For more on what miscarriage involves and what the recovery looks like, see Miscarriage: Causes, Signs & What Happens Next.
3. Recurrent Pregnancy Loss (Three or More Losses) Without Bleeding
For women with a history of three or more unexplained consecutive miscarriages who are not currently bleeding, progesterone is sometimes prescribed as a precaution from the moment a positive test is confirmed.
The PROMISE trial (Coomarasamy et al., 2015, New England Journal of Medicine, PMID 25738455) tested vaginal progesterone against placebo in exactly this group. The live birth rate was 65.8% in the progesterone group and 63.3% in the placebo group, a difference that did not reach statistical significance.
In clinical practice, many doctors still prescribe progesterone in this setting. The rationale is that the treatment is low-risk, some women do respond, and the confidence intervals in the PROMISE trial did not rule out a modest benefit. Your doctor will weigh your individual history. What matters most, before or alongside progesterone, is understanding whether your losses had an identifiable cause. Chromosomal analysis of the pregnancy tissue, thrombophilia testing, and antiphospholipid antibody screening, among other investigations, may be more consequential than the supplement itself. For the full investigation pathway after recurrent loss, see Recurrent Miscarriage: What Tests to Get After 2 Losses.
4. Short Cervix and Preterm Birth Prevention
Vaginal progesterone has a well-established role in reducing the risk of preterm birth for women found to have a short cervix on a second-trimester ultrasound scan.
The PREGNANT trial (Hassan et al., 2011, Ultrasound in Obstetrics and Gynecology, PMID 21775849) showed that vaginal progesterone gel (90 mg daily) in women with a cervical length of 10 to 20 mm between 19 and 24 weeks of pregnancy reduced preterm birth before 33 weeks by 45%, from 16.1% to 8.9%. This finding has been replicated in multiple meta-analyses. For what a short cervix measurement means on your scan report, see Short Cervix in Pregnancy: What Cervical Length Means.
A separate indication involves weekly progesterone injections (17-alpha-hydroxyprogesterone caproate, abbreviated 17-OHPC) for women who have had a prior spontaneous preterm birth before 37 weeks. The MEIS trial (New England Journal of Medicine, 2003, PMID 12771116) showed that 250 mg weekly injections from 16 to 20 weeks reduced preterm birth before 37 weeks from 54.9% to 36.3%. In India, this is available as Proluton Depot (Bayer/Schering). A subsequent large trial, PROLONG (Blackwell et al., 2020, PMID 32032719), did not replicate these results, and the US FDA withdrew approval for this indication in 2023. Your obstetrician will weigh this evidence against your specific history when recommending whether Proluton is appropriate for your pregnancy.
WhatsApp Dr. Suganya for an online consultation, pan-India. She can review your clinical situation and explain which formulation and duration applies to your case.
Which Formulation, and Why?
The route and formulation of progesterone follow from the clinical reason for prescribing it.
Vaginal Micronized Progesterone (Utrogestan, Susten, Gestofit, Prajex)
Micronized progesterone means the hormone has been broken into very fine particles to improve absorption. When taken vaginally, it achieves high local concentrations directly in the uterus, a property called the uterine first-pass effect. The same dose produces a much larger local uterine effect when inserted vaginally than when swallowed. This is why the vaginal route is the standard of care for uterine support in IVF and for threatened miscarriage, where local uterine action is the goal.
Available brands in India:
- Utrogestan (100 mg, 200 mg capsules for vaginal use): the original micronized progesterone brand
- Susten (200 mg, 400 mg capsules; also as a 90 mg gel for the short-cervix preterm-prevention indication)
- Gestofit (200 mg, 400 mg capsules)
- Prajex (200 mg vaginal capsules)
These are inserted vaginally, typically at bedtime. A white waxy discharge from the undissolved capsule coating is expected and is not a sign of infection.
Dose depends on the clinical indication. IVF luteal support commonly uses 400 mg per day, given as 200 mg twice daily or 400 mg once at night. The short-cervix preterm-prevention indication uses the Susten gel at 90 mg daily.
Oral Dydrogesterone (Duphaston)
Dydrogesterone is a synthetic progestogen that binds the same receptors as natural progesterone. It is not identical to progesterone, but it has a well-documented safety profile and clear clinical trial evidence. Duphaston (Abbott) 10 mg tablets, taken two or three times daily, is one of the most widely prescribed medications in early pregnancy across India.
For IVF luteal support, the LOTUS I and LOTUS II trials (Tournaye et al., 2017, PMID 28847565; Griesinger et al., 2018, PMID 29175080) compared oral dydrogesterone 30 mg daily against vaginal micronized progesterone and found noninferior ongoing pregnancy and live birth rates. This means either formulation is a valid choice for IVF luteal support.
For threatened miscarriage, earlier randomised trials including Kumar et al. (2014, BJOG, PMID 23855972) showed benefit from dydrogesterone in women with threatened miscarriage and a prior pregnancy loss, with a reduced rate of subsequent miscarriage compared to placebo.
The practical advantage of dydrogesterone: it is an oral tablet, not a vaginal suppository. For women who find vaginal insertion difficult, uncomfortable, or culturally distressing, Duphaston provides an equally effective alternative backed by solid evidence.
Progesterone Injections (Proluton Depot / 17-OHPC)
Weekly intramuscular injections of 17-alpha-hydroxyprogesterone caproate are used specifically for the prevention of recurrent preterm birth in women with a prior preterm birth. This formulation is not used for early pregnancy loss prevention or IVF luteal support.
The injections begin between 16 and 20 weeks of pregnancy and continue weekly until 36 to 37 weeks. Proluton Depot (250 mg per mL) is the available brand in India. The injection site can be tender, and some women develop localised skin reactions. As noted above, the evidence for this formulation is contested after the PROLONG trial, and the discussion with your obstetrician should include a clear account of what is known and what is uncertain.
How Long Do You Take Progesterone?
Duration depends on the indication.
| Indication | Typical Duration |
|---|---|
| IVF / IUI luteal support | Day of retrieval or transfer until 10-12 weeks |
| Threatened miscarriage with prior loss | Until bleeding settles, typically to 12-16 weeks |
| Recurrent pregnancy loss (preventive) | From positive test until 12-16 weeks |
| Short cervix, preterm prevention | From diagnosis (around 19-24 weeks) until 36-37 weeks |
| 17-OHPC for prior preterm birth | From 16-20 weeks until 36-37 weeks |
The most common question is whether stopping at 12 weeks risks a drop in progesterone. For early-pregnancy indications, stopping around 10 to 12 weeks is standard because by that point the placenta has taken over as the primary source. Stopping does not cause a sudden fall in progesterone levels. The placenta compensates. Your doctor will set the stopping date. Do not adjust the schedule without that guidance.
Is Progesterone Safe for the Baby?
This is the question most women want answered before they feel comfortable taking the medication.
For micronized progesterone (the natural hormone in Utrogestan, Susten, Gestofit): no credible study has found an increased risk of congenital anomalies. Progesterone is a hormone the pregnant body produces in large amounts, rising through pregnancy to levels far above what supplementation adds. Using natural progesterone does not introduce a molecule the uterine environment is not already exposed to.
For dydrogesterone (Duphaston): the molecule is structurally close to natural progesterone and does not carry the androgenic or glucocorticoid activity found in some older synthetic progestogens. Duphaston has been in clinical use for more than 50 years. The available evidence does not show a teratogenic signal. It should not be confused with older progestogens, such as norethisterone, which had a different receptor profile and are not used in pregnancy.
For 17-OHPC injections (Proluton Depot): the available data do not indicate fetal harm. The uncertainty around this formulation relates to its efficacy, not its safety.
A note on what to avoid: some older injectable progestogens and high-dose synthetic progestins are not recommended in pregnancy. If you have been given a prescription for a progesterone-related medication and the brand name is unfamiliar, check with your prescribing doctor what category it falls into.
For guidance on what to expect across the first trimester alongside any progesterone supplementation, the first trimester guide covers the full picture of symptoms, tests, and development week by week.
WhatsApp Dr. Suganya: she consults online across India and can review your prescription, clarify which formulation applies to your situation, and explain when it is appropriate to stop.
Frequently Asked Questions
Can I take Utrogestan orally instead of inserting it vaginally?
Utrogestan is licensed for both oral and vaginal use, but the oral route is far less effective for uterine support. When swallowed, micronized progesterone is largely metabolised on the first pass through the liver, producing much lower uterine concentrations than vaginal insertion of the same dose. If you find vaginal insertion difficult, speak to your doctor about switching to oral dydrogesterone (Duphaston), which is a different molecule with its own clinical trial evidence and is taken as a tablet.
My doctor prescribed Duphaston, but I keep reading about Utrogestan. Are they equivalent?
They are not the same molecule, but they act through the same hormone receptors and have comparable clinical trial evidence for IVF luteal support (the LOTUS trials) and for threatened miscarriage. Your doctor’s choice will reflect their clinical experience and your specific situation. Both are valid options supported by published research. The main practical difference is the route: Duphaston is oral, Utrogestan is vaginal.
I am 11 weeks pregnant and my doctor says I can stop Utrogestan this week. Is it safe to stop now?
Stopping at 10 to 12 weeks is standard practice and is safe, because by this point the placenta is producing enough progesterone to maintain the pregnancy without the corpus luteum. Stopping does not cause your progesterone levels to fall. Follow your doctor’s specific guidance on the stopping date. If you feel concerned, you can ask for a progesterone blood test around the time of stopping for reassurance, though this is not routinely necessary.
I am on Proluton injections weekly. They are uncomfortable and I am not sure they are helping. Should I stop?
Do not stop without consulting your obstetrician. The reason for prescribing 17-OHPC (Proluton) in your specific case should be documented and discussed with you. Given the PROLONG trial result, some centres have moved away from routine 17-OHPC injections for prior preterm birth in favour of vaginal progesterone when a short cervix is found on scan. Your doctor may have a specific clinical reason for continuing, or they may be open to reviewing the decision. Ask for the conversation.
Pregnancy mein progesterone injection kab lena chahiye? (When should a progesterone injection be given in pregnancy?)
Progesterone injections (Proluton Depot) are typically started between 16 and 20 weeks of pregnancy, specifically for women who have had a previous spontaneous preterm birth before 37 weeks. They are given weekly until 36 to 37 weeks. They are not used for early pregnancy support or IVF luteal supplementation, where vaginal or oral progesterone is preferred. If your doctor has recommended Proluton, the reason will be a prior preterm birth in your history.
Can progesterone injections or suppositories prevent a miscarriage from happening?
Progesterone supplementation cannot prevent a miscarriage caused by a chromosomal abnormality in the embryo, which accounts for the majority of early pregnancy losses. What it can do, in specific subgroups (particularly women with three or more prior losses who are bleeding in early pregnancy), is improve the chance of a live birth, as the PRISM trial demonstrated. The supplement supports the uterine environment. It does not override other biological factors. If you have had repeated losses, a thorough investigation of possible causes is as important as any medication.
What is the difference between Susten gel and Susten capsules?
Susten gel (90 mg vaginal bioadhesive gel) is specifically formulated for the preterm prevention indication in women with a short cervix. Susten capsules (200 mg or 400 mg) are used for IVF luteal support and early pregnancy support. The doses and delivery systems are different. Make sure you are using the version your doctor prescribed for your specific indication, and confirm the dose with the prescription.
For the complete investigation pathway if you have had two or more miscarriages, see Recurrent Miscarriage: What Tests to Get After 2 Losses. To understand the luteal phase more broadly and its role in early pregnancy, the luteal phase defect guide covers what a short or inadequate luteal phase means and how it relates to progesterone support. For the full pregnancy resource guide, visit our pregnancy guide.
