Is vaginal progesterone (a steroid hormone) effective for preventing recurrent miscarriages in women with a history of spontaneous abortions?

From the Guidelines

Vaginal progesterone should not be considered a substitute for 17OHP-C in women with a history of prior spontaneous preterm birth, but it may be beneficial for women with a history of recurrent miscarriages due to luteal phase defects or low progesterone levels. When considering the use of vaginal progesterone for women with a history of miscarriages, it's essential to evaluate the underlying cause of pregnancy loss and individual patient factors. The typical regimen for vaginal progesterone involves using micronized progesterone vaginal suppositories at doses of 100-200 mg once or twice daily, starting either after ovulation or immediately after a positive pregnancy test, and continuing through the first trimester [(1] does not directly support this, but it is a common practice). Some key points to consider when using vaginal progesterone include:

• The potential benefits of progesterone supplementation in supporting early pregnancy and preventing miscarriage
• The importance of checking hormone levels and discussing individual miscarriage history with a healthcare provider before starting treatment
• The potential side effects of vaginal progesterone, such as vaginal irritation, discharge, or mild systemic effects like fatigue or mood changes. It's crucial to weigh these factors and consider the most recent and highest-quality evidence when making treatment decisions, as the effectiveness of progesterone supplementation can vary depending on the underlying cause of pregnancy loss [(1] provides guidance on the use of 17OHP-C in women with a history of prior spontaneous preterm birth, but does not directly address the use of vaginal progesterone for recurrent miscarriages).

From the Research

Vaginal Progesterone for History of Miscarriages

• Vaginal progesterone has been studied as a potential treatment to prevent miscarriage in women with a history of recurrent or threatened miscarriage 2.
• The PROMISE and PRISM trials found that vaginal micronized progesterone 400 mg twice daily was associated with increasing live birth rates according to the number of previous miscarriages 2.
• A subgroup analysis of the PRISM trial found that women with a history of 1 or more miscarriage(s) and current pregnancy bleeding had a 5% greater live birth rate with progesterone compared to placebo 2.
• The benefit of vaginal progesterone was greater for women with 3 or more previous miscarriages and current pregnancy bleeding, with a 15% greater live birth rate compared to placebo 2.
• Other studies have found that recurrent miscarriage can be related to various factors, including anatomic, genetic, infectious, immunologic, endocrine, environmental, or psychologic problems 3, 4.
• The management of recurrent miscarriage may involve a thorough evaluation of the possible etiologies, as well as psychosocial support 3, 4.
• Treatment options for early miscarriage include expectant, medical, and surgical management, and the choice of treatment depends on various factors, including the patient's preferences and medical history 5.
• There is no direct evidence from the other studies 6, 4, 5 to suggest the use of vaginal progesterone for the prevention of miscarriage in women with a history of miscarriages.