PCOS in Pregnancy: Preventing Miscarriage
PCOS in Pregnancy: What Happens When You Finally Get Pregnant
Written by Dr. Fiona Callender, ND and Pelvic Therapist
For many people with PCOS, the journey to pregnancy can feel long, medicalized, and emotionally exhausting. Much of the focus, especially when trying to conceive, is on ovulation. This is for good reason: ovulatory dysfunction is one of the most visible features of PCOS, and it’s something we are often very effective at supporting! Whether through lifestyle interventions and naturopathic support, or medications prescribed by a family doctor or fertility clinic - those with PCOS can often get pregnant.
But ovulation is not the whole story.
PCOS is not only an ovulatory disorder. It is also a metabolic, hormonal, inflammatory, and cardiovascular condition. This distinction matters deeply once pregnancy occurs. Even when pregnancy happens through IVF, where ovulation is medically supported, the underlying physiology of PCOS is still present. The metabolic environment continues to influence how pregnancy is established and maintained.
A brief refresher: what is PCOS?
Polycystic ovary syndrome (PCOS) is one of the most common endocrine and metabolic conditions worldwide, affecting upwards 1 in 10 women. PCOS can look very different from person to person, influenced by genetics, environment, stress, nutrition, and more. It’s not always an obvious diagnosis.
Diagnosis is typically based on the Rotterdam Criteria, which require two of the following three:
Irregular or absent menstrual cycles
Clinical or biochemical signs of elevated androgens (such as facial hair growth, scalp hair thinning, or acne)
Polycystic-appearing ovaries on ultrasound
There are also several features that commonly accompany PCOS but are not required for diagnosis, including:
Insulin resistance
Elevated anti-müllerian hormone (AMH)
Cardiometabolic changes (blood pressure, cholesterol, inflammation)
These metabolic and inflammatory features are not just relevant for ovulation, they play a central role in pregnancy, particularly in placental development.
Pregnancy and PCOS: why the placenta matters
Many of the pregnancy-related risks associated with PCOS trace back to the placenta.
The placenta begins forming very early during the first trimester - around 5–6 days post-conception. This is a critical window in early pregnancy. The placenta is responsible for delivering oxygen and nutrients to the developing fetus, removing waste, and producing hormones that support pregnancy. To do this effectively, it requires healthy blood vessel development and strong maternal cardiovascular adaptation.
In PCOS, several underlying factors can interfere with this process.
What we see in placentas from women with PCOS
Research has consistently shown that placental structure and function can be altered in pregnancies affected by PCOS:
Impaired placental development: Placentas tend to be smaller, with fewer and less well-developed blood vessels. These changes correlate with markers such as insulin resistance, elevated testosterone, and low sex hormone–binding globulin (SHBG).
Reduced blood flow: Changes to how the placenta develops leads to impaired connection between the circulation of the uterus and the placenta, limiting oxygen and nutrient delivery.
Increased inflammation: Chronic low-grade inflammation is often present in those with PCOS. Placental blood vessels often show higher levels of inflammation, which can further impair function.
These changes do not always cause problems immediately - but they can set the stage for complications later in pregnancy. It’s also important to note that this does not impact every pregnancy in PCOS to the same degree.
How this translates clinically
Because placental development underpins so much of pregnancy health, impaired placental function in PCOS is associated with higher rates of:
Miscarriage
Hypertensive disorders of pregnancy (including preeclampsia)
Gestational diabetes
Preterm birth
Importantly, the metabolic changes/environment in PCOS are not related to higher rates of chromosomal abnormalities in embryos. PCOS affects the environment supporting the pregnancy, not the genetic integrity of the embryo itself. Women with PCOS often actually make great egg donors!
Those with PCOS also tend to have higher blood pressure throughout pregnancy, which can hinder the normal cardiovascular adaptations required to support increased blood volume and placental perfusion. Rather than a single mechanism, it appears that vascular, metabolic, inflammatory, hormonal factors all interact to influence placental health.
So, what can we do?
The goal in pregnancy is not to “cure” PCOS, but rather to support overall health and metabolism to prevent symptoms/pregnancy-related side effects down the road.
Key areas of support
Early lifestyle intervention
Women with PCOS benefit from early, proactive support around nutrition, movement, sleep, and stress management.
Blood pressure monitoring
Regular blood pressure checks are essential, ideally starting preconception or early in fertility treatment.
Glucose screening
An oral glucose tolerance test (OGTT) should be offered when planning pregnancy or early in pregnancy, as hyperglycemia often develops earlier in PCOS. This may be offered to you earlier than the typical pregnancy timeline.
Nutritional strategies
Dietary approaches that support insulin sensitivity - often with a focus on protein, lower in refined carbohydrates, and filled with lots of fruits and vegetables - to support metabolic and cardiovascular health.
Addressing insulin resistance and androgen excess
Supporting insulin sensitivity (through diet, exercise, supplements) and reducing androgens may positively influence placental development and vascular health. High testosterone impacts insulin, but insulin resistance also increases androgens - it can become a cycle! Addressing one often supports the other.
Medication considerations
In some contexts, medications that improves vascular function or ovarian blood flow may be used during fertility treatment. Medication can be a supportive option alongside lifestyle, nutrition and exercise changes.
Close monitoring throughout pregnancy and postpartum
Close monitoring and consistent support includes screening for hypertensive disorders, gestational diabetes, and postpartum mood concerns, which are also more common in women with PCOS. Getting support if there are a number of lifestyle changes to be made is also helpful. You don’t have to do this alone or rely on ChatGPT!
A gentle but important reMINDER
Getting pregnant with PCOS is wonderful and to be celebrated - but it’s not the finish line.
Your deserve informed, compassionate, and proactive care that acknowledges your whole health and how PCOS impacts your pregnancy - without fear-mongering or shame. With appropriate monitoring and support, many people with PCOS go on to have healthy pregnancies and babies. The key is understanding why the risks exist and address them early.
If you have questions about PCOS, pregnancy planning, or how to support a healthy pregnancy after a long fertility journey, you’re not alone.
You are welcome to book a complimentary meet and greet appointment to see if I’m the right fit to support you on this journey.