Can PMOS cause miscarriage​? A fertility specialist explains

Many across our community living with Polyendocrine metabolic ovarian syndrome or PMOS (formerly known as PCOS) have questions around how the condition impacts fertility. 

And if that’s you, and you’ve already experienced one (or multiple) losses, it’s so natural to want to understand whether there could be a connection, so you can move your journey forward.

Reliable information is empowerment, especially when it comes to something so many of us go through. So we picked up with Miss Shirin Khanjani, Co-Founder and Medical Director at Fitzrovia Fertility, to understand the link between PMOS and miscarriage, what bleeding in early pregnancy can mean, and which factors can be addressed before and during fertility treatment.

Located in the heart of London, Fitzrovia Fertility combines cutting-edge reproductive science with their trademark holistic and compassionate approach. Bookmark our library of resources created in partnership with their expert team, for more authoritative takes on the key fertility questions you’re asking.

Now, over to Shirin Khanjani.

Can PMOS cause miscarriage?

Large studies have consistently shown that women with PMOS may have a modestly increased risk of miscarriage.

Much of this increased risk appears to be driven by the metabolic and hormonal changes that can accompany PMOS, including insulin resistance, high levels of male hormones (aka. hyperandrogenism), thyroid dysfunction, obesity and chronic inflammation.

It is important to remember that having PMOS does not mean you will have a miscarriage. It means that some of the underlying factors associated with the condition may increase your risk.

PMOS miscarriage rates, in the spotlight

A recent study looked at women with PMOS who’ve had the transfer of a chromosomally normal embryo and compared the risk of miscarriage to women who don’t have PMOS.

After controlling the study for quality of the embryo, the findings showed that women who have PMOS had a significantly higher risk of having an early pregnancy loss compared to women who don’t have PMOS.

This study suggests that the environment that is hosting the embryo in PMOS has an impact on the outcome of the pregnancy, even when the embryo is normal.

Looking for PMOS miscarriage rates by week? Unfortunately, there isn’t a single reliable percentage we can lean on here. 

Miscarriage risk changes throughout early pregnancy and is influenced by several factors, including age, previous pregnancy history and the individual circumstances of the pregnancy.

Does metformin reduce miscarriage in PMOS?

Generally speaking, metformin may reduce the risk of early miscarriage. But more studies are needed. 

Recent research by Tommy’s National Centre for Miscarriage Research indicates that continuing metformin through the first trimester of pregnancy may reduce the risk of early miscarriage in women with PMOS.

However, this is just one treatment approach, and metformin is not appropriate for everyone with PMOS. The evidence is still developing, and decisions about whether to start or continue metformin during pregnancy should be made with your fertility or maternity team.

The research is particularly relevant because we currently use different approaches to metformin in pregnancy, depending on how the condition is impacting you.

Some patients will stop it after a positive pregnancy test, while others continue treatment into pregnancy. 

PMOS and bleeding in early pregnancy​ – what’s normal, and what’s not

Very light bleeding or spotting in early pregnancy can happen, and does not always mean that you’re having a miscarriage.

However, any bleeding during early pregnancy should always be discussed with a healthcare professional, particularly if it is accompanied by pain, heavier bleeding or other symptoms.

At Fitzrovia Fertility, we’d recommend you to have an assessment, blood tests and/or an ultrasound depending on how far along the pregnancy is and your symptoms.

But does PMOS cause random bleeding​?

Yes, PMOS can cause random, unpredictable or breakthrough bleeding between periods.

This happens because PMOS can disrupt ovulation and the normal hormonal pattern that controls the menstrual cycle. If you’re not ovulating regularly, the womb lining can build up and shed unpredictably, resulting in irregular bleeding.

During pregnancy, however, bleeding should be assessed separately – even if you have a history of irregular bleeding because of PMOS.

Preventing miscarriage with PMOS during fertility treatment 

The encouraging news is that most of these factors associated with PMOS are modifiable.

So when I have a patient with PMOS here at Fitzrovia Fertility, it is not just that diagnosis that is important, it is about the metabolic impact of that diagnosis on your health.

I’d factor in: Are we dealing with insulin resistance? Are you struggling with your weight? Are we dealing with high levels of the male hormone? Is there inflammation in the body?

Understanding these factors helps us get to the root of what may be affecting your fertility and identify where we can make meaningful changes that we can then tackle individually. Our goal isn’t just to simply get you pregnant, but it is to support you to have a healthy pregnancy and eventually take your baby home with you.

Looking for this exact kind of specialist fertility support? Fitzrovia Fertility offers dedicated fertility and hormone health care in central London. 

Under the care of Miss Shirin Khanjani and the wider team, they’ll help explore the wider hormonal and metabolic factors that may be relevant to your individual fertility journey. Book in for a consultation here.

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