This is unlikely because progesterone is destroyed by the liver after oral administration due to what is known as the first pass effect. What little is taken up by the GI tract is likely to help preserve pregnancy rather than precipitate an abortion. This is my opinion.

Neither synthetic nor physical can do this always depending on the time and dose

No

She took a high dose of natural progesterone 300mg t.d.s, then after 3days she saw bloody discharge

She took the tablets in her 5th week pregnancy

Taking progesterone during pregnancy does not cause abortion. The causes of miscarriage are many and varied, not progesterone.

Thank you very much doctors

Our pregnant patients after frozen embryo transfer with substituted cycles (E+P) use Progesterone until pregnancy week 10 and that is not the cause of the miscarriages…

It is unlikely to cause abortion and also not help in continuation of pregnancy. Micronised natural progesterone do not have any role in pregnancy excepting having a placebo effect.

Very unlikely that progesterone would cause miscarriage

There is no evidence that progesterone as oral or vaginal medication causes miscarriage & much evidence that it is supportive for early pregnancy & reduces preterm birth in at risk patients .

Bruce K Young, New York University School of Medicine, USA

It is possible that progesterone prevents miscarriage - see the attached. The ongoing PROMISE trial hopes to answer this question in women who have had recurrent miscarriage.

http://www.bmj.com/content/342/bmj.d1914?view=long&pmid=21502263 http://www.controlled-trials.com/ISRCTN92644181/promise+miscarriage

Prevents but need more studies for side effects on fetus

It is not probable, just attend to complications

We use to give progesterone to support pregnancy even we can not confirm the real effect of it

Progesterone should help support pregnancy in cases of luteal insufficiency. It may help to prevent miscarriages either by its effects on the myometrium or by its effects on the inflammatory process. Concerns that need to be addressed are the chioce of progestin used [some have androgenic effects] and the use of the hormone in large doses during the second trimester.

Expensive and not usefull

Currently available evidence substantiates the long-held assumption that orally and vaginally administered progesterone is safe and supports early pregnancy. Moreover, it can reduce the risk of preterm birth in women at jeopardy. However, the results of the ongoing PROMISE trial are eagerly awaited to help answer this pivotal question.

Ahmed Nasr, Professor of OB/GYN, Assiut University School of Medicine, Egypt.

More studies are needed in early pregnancy to support its use. No more than placebo effect later on in pregnancy.

To my understanding and in my experience, there is no good evidence that progesterone prevents miscarriages. There is good evidence that progestogens prolong the gestational age in premature labour and that they prolong gestation when the cervical length is short, shortening or fibronecting is present with short cervix.

Progesterone is pregnancy maintenance hormone therefore taking it orally or parenteral can not cause abortion because so far i did not come across any information about the over dose of this hormone. but i strongly believe that it can not cause abortion.

Progesterone effect is relaxation of the smooth muscle...

Progesterone in pregnancy has been used since 1970s; not only it prevents miscarriages but also prevents preterm delivery in women with short cervical lenght.

Progesterone - through it's effects of PIBF inducer (LTH2) and cortizol-like antiinflamatory pattern - rises the rates of maintainig the high risk pregnancies and improves the delivery gestational age (of course also the live birth outcome). I'm managing around 12-15 cases by week - of high risk pregnancies (of all gestational ages) using micronised Progestogen with excelent results.

I don't know which studies found Mrs. Jane Daniels in her excelent documented answer, but I use in my presentations the arguments of: R. Romero, Mazor, Fonseca, Elovitz&Wang, P. Devroey, Cicinelli&Ziegler, Tavaniotou, etc.

Adding a joke - I hope that I don't have success using Progesterone inside placebo effect !

Progestogens are actually given routinely in our environment following successful clinical pregnancies after IVF + ET. Currently, luteal phase defect, an established cause of recurrent first trimester spontanous abortions is prevented by administering progestogens in pregnancy. Progestogens derived from testosterone were suspected to occasionally cause ambigous genitalia particularly if used or taken during the first trimester but even this has not been scientifically proven.

for luteal phase supports natural progrsterons should be choice.Other progesterons with androgenic effects should not be used as it may affect pregnancy in cas eof female fetus.....unexplianed RPL progestins give benefit.....I agree with Marius Mogas view..........

Based on my personal forthy years experience, progesterone administration has little, if any, effect on pregnancy. Over thirty years ago I decided against its use in cases of recurrent miscarriage in which it had already been used without success.

What I found greatly effective, as well as harmless, in preventing pregnancy loss is continuous administration of low doses of betamethasone throughout pregnancy. This is because the main cause of pregnancy loss is represented by inflammation. Both the pathophysiological and clinical evidence have become gradually clear over the years, while the statistical evidence requires adequate multicentre trials and meta-analysis. Complete explanation of the basis of this therapy is reported in the paper entitled "The role of glucocorticoids in pregnancy: four decades experience with use of betamethasone in the prevention of pregnancy loss", recently published by INTECH, and freely available on my Research Gate profile.

thanks dr.Fortunato , i didn't hear about this before , very interesting

There has been some report about possible side effects of progesterone in early pregnancy, such as fetal malformation. However, to my knowledge, the hormone does not precipitate abortion. As far as a protective action against pregnancy loss is concerned, it is still questioned. Large trials are needed. Nevetheless, I believe that, when a truth needs a too large trial to be ascertained, it means that it is a week truth.

Natural progesterone will not precipitate miscarriage, as such there is no evidence as of now to use any progesterone in pregnancy to prevent miscarriage. There is evidence to give progesterone for prevention of preterm labour in singleton pregnancy with risk factors for preterm labour.Better to avoid any kind of progesterone unless there is clear indication. Androgenic progesterone like norethisterone can cause androgenisation according to literature, but there is no evidence to describe the actual dose and duration which can cause androgenisation. In other words if a patient is on progesterone with out realizing that she is pregnant there is no data to say that she needs different care than usual.

Natural progesterone such as Utrogestan is considered a safe medication. It may prevent miscarriage in IVF pregnancies. It has no effect in pregnacies conceived sponataneously. However there is a small increase in epispadias it administered during the first trimester. It is often used to prevent preterm labour in high risk pregnancies (eg when the cervix is short).

Savvas could you provide the reference regarding the increase in risk for epispadias?

Adolfo Etchegaray noticed a mistake in my answer. I wrote that progesterone increases the risk of epispadias at the offspring. This is not correct. Progesterone may increase the risk of hypospadias and not epispadias. Searching Medline for relevant reference I found a paper that is attached. Maternal Progestin Intake and Risk of Hypospadias ARCH PEDIATR ADOLESC MED/VOL 159, OCT 2005

I believe their major effect is as a placebo. What is being practiced at private sector is really worrying, they are giving progesterone by all routes oral, vaginal, and injectable at the same time !!

Progesterone and its derivatives has been found to be beneficial in reducing the risk of spontaneous abortion in early pregnancy which might be due to corpus luteum insufficiency, implentation defect.

Progestagens unlikely to cause any adverse effect to pregnancy. Progesterone is a hormone that will make the endometrial to arrange into glandular form and also prevents shedding, thereby gives a safe environment for the fertilized ovum to ultimately get implanted.