Polycystic ovary syndrome (PCOS) is a common endocrine disorder, affecting 5–15% of reproductive-aged women (Joham et al., 2016). It is characterized by hyperandrogenism, insulin resistance, and often obesity. While much of the research on PCOS has focused on fertility and pregnancy outcomes, there is growing recognition that PCOS may also influence lactation. Some women with PCOS report low milk supply or delayed lactogenesis II, yet findings are mixed. For lactation professionals, understanding the physiological, hormonal, and metabolic mechanisms at play—and the evidence from key studies—is essential for providing effective, compassionate support. This post provides an evidence-based overview of how PCOS may affect breastfeeding outcomes, examining physiological and hormonal factors involved. I also discuss current scientific findings and offer clinical recommendations to improve breastfeeding success in women with PCOS.

Breastfeeding Outcomes in Women with PCOS

Emerging research indicates that PCOS can be associated with reduced early breastfeeding success, although findings are somewhat mixed. A case-control study by Vanky et al. (2008) found that new mothers with PCOS had lower exclusive breastfeeding rates at 1 month postpartum (75% vs 89% in controls) and higher rates of not breastfeeding at all (14% vs 2% in controls) (Joham et al., 2016) By three and six months postpartum, however, breastfeeding rates between PCOS and non-PCOS mothers became equivalent (Vanky et al., 2008). This suggests that the most significant impact of PCOS may occur in the early postpartum period, potentially manifesting as delayed lactogenesis II or initial low milk supply. Indeed, delayed secretory activation (onset of milk “coming in” >72 hours postpartum) has been observed more frequently in women with metabolic disorders, including those with insulin resistance (Nommsen-Rivers et al., 2022; Vanky et al., 2008). Many women with PCOS fall into this category due to their higher rates of obesity and gestational diabetes.

Not all studies find an independent effect of PCOS on breastfeeding when accounting for confounders. Joham et al. (2016) reported that unadjusted breastfeeding duration was slightly shorter in women with PCOS (median 6 months vs 7 months in controls), but after adjusting for body mass index (BMI) and other factors, PCOS status per se was not significantly associated with breastfeeding outcomes. High BMI was the stronger predictor, correlating with lower odds of initiating breastfeeding and breastfeeding <6 months (Joham et al., 2016). Similarly, a large U.S. survey (2016–2018 data) found that PCOS mothers were just as likely – or even slightly more likely – to initiate breastfeeding as non-PCOS mothers, once differences in BMI and other demographics were considered (Bui et al., 2025). In that study, obesity (especially class III obesity) was associated with significantly decreased breastfeeding initiation, whereas PCOS by itself did not predict lower initiation or shorter duration (Bui et al., 2025).

These findings underscore that obesity and related metabolic issues (which often accompany PCOS) are key risk factors for breastfeeding difficulties, potentially more so than the PCOS diagnosis alone (Joham et al., 2016; Bui et al., 2025). Nonetheless, other investigations and clinical reports suggest a subset of women with PCOS experience genuine lactation insufficiency unrelated to poor technique or routine factors, indicating a need to understand PCOS-specific mechanisms (Kirigin Biloš et al., 2017). For instance, if a PCOS mother exhibits minimal breast growth during pregnancy – a possible sign of insufficient glandular tissue development – studies indicate she is more likely to have low milk supply postpartum (Vanky et al., 2012). In summary, while PCOS does not guarantee breastfeeding problems, it may predispose some mothers to challenges such as delayed milk onset or low supply, especially in the presence of obesity or other metabolic risk factors.

Hormonal and Metabolic Mechanisms

Breastfeeding is regulated by a complex interplay of hormones and adequate mammary gland development. PCOS can disrupt these factors in several ways:

Androgens and Prolactin

Elevated androgens are a hallmark of PCOS and are known to inhibit lactation when present in excess. Women with PCOS often have higher circulating androgens during pregnancy than non-PCOS women (Kirigin Biloš et al., 2017). Research by Carlsen et al. (2010) found that higher mid-pregnancy androgen levels (such as dehydroepiandrosterone sulfate, DHEA-S) were negatively associated with breastfeeding success postpartum (Kirigin Biloš et al., 2017). Vanky et al. (2008) similarly noted a weak inverse correlation between late-pregnancy DHEA-S levels and breastfeeding rate at 1–3 months in PCOS mothers. 

The mechanism is not fully determined, but excessive androgens might impede the lactogenic hormonal environment. PCOS can also involve dysregulation of prolactin – some patients have elevated prolactin levels outside of pregnancy, yet paradoxically, prolactin action during lactation may be suboptimal. Hyperandrogenism could reduce prolactin receptor sensitivity in the breast, as suggested by animal models. Altered prolactin feedback or lower prolactin release in response to infant suckling has been postulated in PCOS, although more studies are needed. In short, the hormonal profile in PCOS may thwart the normal endocrine changes that trigger and sustain milk synthesis.

Mammary Gland Development

Adequate breast tissue development is crucial for milk production capacity. During puberty and pregnancy, rising levels of estrogen and progesterone drive ductal and lobulo-alveolar growth in the breasts (Kirigin Biloš et al., 2017). Women with PCOS, however, often have hormonal imbalances that might impair this process. PCOS pregnancies are sometimes characterized by relative progesterone deficiency despite high circulating estrogen (Kirigin Biloš et al., 2017). Progesterone is needed for alveolar lobule maturation, so low bioavailability of progesterone (or resistance to its effects) could result in less developed glandular tissue.

Additionally, hyperandrogenism in PCOS may antagonize breast development – high levels of androgens can down-regulate estrogen and prolactin receptors in mammary tissue, potentially blunting the breasts’ response to the usual pregnancy hormones (Kirigin Biloš et al., 2017). Clinically, some women with PCOS exhibit insufficient glandular tissue (IGT) or notice little breast enlargement during pregnancy, which has been correlated with subsequent low milk output (Kirigin Biloš et al., 2017). In a follow-up analysis of a trial in PCOS mothers, those who had no breast size increase in pregnancy produced less milk and had more metabolic disturbances (higher obesity and insulin levels) than those who did experience breast growth (Kirigin Biloš et al., 2017). This highlights that the endocrine environment of PCOS (especially severe insulin resistance or androgen excess) may impair the normal breast changes required for lactation.

Insulin Resistance and Lactogenesis

Insulin is emerging as a key hormone for lactation physiology. Normally, late pregnancy and postpartum changes make the mammary gland more sensitive to insulin, which helps drive lactogenesis II (Rassie et al., 2021). Insulin and cortisol work synergistically with prolactin to activate milk secretion. In insulin-resistant states, this process can be compromised.

Women with PCOS often have insulin resistance (with compensatory hyperinsulinemia), especially if they are overweight or have gestational diabetes (Kirigin Biloš et al., 2017). Studies have shown that maternal insulin resistance is linked to delayed lactogenesis II and low milk supply (Kirigin Biloš et al., 2017). For example, in one pilot trial, mothers with signs of insulin resistance produced significantly less milk on average than metabolically healthy mothers, even with optimal breastfeeding management (Nommsen-Rivers et al., 2022).   

Researchers have pinpointed that the mammary gland must remain insulin-sensitive for proper lactation; insulin resistance can disrupt the cellular signals needed for milk synthesis. In PCOS, if the insulin signaling in breast tissue is blunted, the coordination of lactogenic hormones (prolactin, insulin, cortisol) may falter. Moreover, insulin resistance in PCOS often coexists with inflammation and hormonal aberrations that could further impede lactation. In summary, a mother with PCOS may face lactation difficulties not only because of reproductive hormone issues, but also due to metabolic factors: hyperandrogenism and insulin resistance act as physiological barriers to timely and sufficient milk production (Kirigin Biloš et al., 2017).

Clinical Strategies for Supporting PCOS Mothers

Given the interplay of hormonal, metabolic, and psychosocial factors, a comprehensive and proactive approach is recommended to help women with PCOS achieve their breastfeeding goals. Below are evidence-based strategies and clinical recommendations for lactation professionals working with this population:

Prenatal Preparation and Education

Early in pregnancy (or even preconception), identify patients with PCOS and educate them about potential breastfeeding challenges without discouraging them. Emphasize that many women with PCOS do breastfeed successfully, but being alert to possible issues allows for prompt support. Monitor breast changes during pregnancy – if minimal breast enlargement or tenderness is noted by the third trimester, discuss the possibility of breast hypoplasia. Formulate a plan for enhanced lactation support postpartum. Prenatal expression of colostrum in late pregnancy (if medically approved) might be considered in some cases to build confidence and have milk available if the newborn needs early supplementation. Above all, reassure the mother that any amount of breast milk she can provide is valuable, and that formula supplementation when necessary does not mean failure but can be a temporary tool while working on increasing supply.

Optimize the Birth and Early Postpartum Practices

Whenever possible, support birth choices that facilitate breastfeeding. Strive for immediate skin-to-skin contact and early initiation of breastfeeding within the first hour of birth if possible. Early and frequent feeding is critical for mothers at risk of delayed lactogenesis. A PCOS mother should be advised to nurse on demand, at least 8–12 times in 24 hours, or use hands-on pumping if the baby is unable to latch, to stimulate milk production. Avoiding unnecessary formula supplementation in the first couple of days is important, as supplementation can further delay milk production.

Metabolic and Hormonal Management

Address underlying hormonal and metabolic imbalances that could hinder lactation. Good blood sugar control is beneficial; advise mothers with PCOS (especially those with gestational diabetes or insulin resistance) to continue a balanced, lower-glycemic diet postpartum to stabilize insulin levels. Recent research suggests low-carbohydrate or low glycemic-index diets may improve hormonal profiles in PCOS (Moran et al., 2013; Goss et al., 2020), which might in turn support better milk production.

In terms of medications, metformin – an insulin-sensitizing drug often used during PCOS pregnancies – can generally be continued during breastfeeding with physician oversight. Metformin is excreted into breast milk only in very small amounts and is considered compatible with lactation by the American Academy of Pediatrics (Hale, 2019). While earlier expectations were that metformin might boost milk supply by improving insulin action, a randomized trial did not find a significant benefit of metformin over placebo for increasing milk volume in women with low supply and insulin resistance. Likewise, a follow-up of PCOS mothers in the PregMet study found that metformin use during pregnancy had no measurable impact on subsequent breastfeeding outcomes (Vanky et al., 2012).  Metformin’s safety profile means it can be used to manage the mother’s PCOS symptoms or prediabetes postpartum without harming the infant, and there are anecdotal reports of it modestly improving milk supply in some cases.

Each patient’s situation should be individualized – if a mother had been benefiting from metformin for metabolic control, continuing it might help her overall health during lactation (and by extension support better energy and lactation capacity). Additionally, ensure other endocrine factors are addressed: check thyroid function postpartum, as thyroid disorders can mimic or exacerbate lactation failure and are more common in women with PCOS. If hyperandrogenism persists postpartum (which is less common while breastfeeding due to lactational amenorrhea, but may recur if breastfeeding is not exclusive), consultation with an endocrinologist about safe treatments may be warranted. In short, optimizing the mother’s metabolic and hormonal milieu through diet, lifestyle, and medication can remove some barriers to successful lactation.

Intensive Lactation Support and Monitoring

Women with PCOS should receive early and frequent follow-up from lactation professionals. This includes weight checks for the infant and milk transfer assessments to catch any low supply issues promptly. An IBCLC can work with the mother on ensuring an effective latch and suggest techniques to increase milk removal. The use of at-breast supplementers can allow babies to receive needed supplementation without using a bottle, which maintains stimulation at the breast. Because perceived insufficient milk supply is a common reason for early weaning, careful counseling is needed to set realistic expectations and troubleshoot effectively. Celebrating small victories helps maintain morale. It’s also wise to enlist peer support: connecting the mother with breastfeeding support groups can reduce feelings of isolation and boost confidence through shared experiences.

Galactagogues

There is limited high-quality evidence for many galactagogue remedies, so use them judiciously, in conjunction with addressing the fundamentals above, and in partnership with the primary healthcare provider. That said, some options may be particularly relevant for PCOS mothers:

Herbal Galactagogues

Traditional remedies like fenugreek, goat’s rue, and moringa have been used to increase milk supply. Goat’s rue is noteworthy for PCOS because it contains galegine (a compound from which metformin was originally derived) and may help insulin sensitivity (Mortel & Mehta, 2013). Caution that herbal supplements are not well-regulated; goat’s rue in particular can cause hypoglycemia, so it should be used carefully in mothers also on anti-diabetic medications. Moringa has some small studies indicating it can elevate prolactin levels and milk volume in the early postpartum period, and it is generally regarded as safe. Fenugreek is widely used and may help some women, but others see no benefit; it also carries a risk of lowering blood glucose and causing gastrointestinal side effects. Myo-inositol, a supplement often used in PCOS to improve insulin resistance and lower androgens, is another intriguing option. While primarily studied for fertility and metabolic outcomes, myo-inositol could theoretically support lactation by improving insulin-mediated processes. It is considered safe during breastfeeding, and ongoing research is examining its role in PCOS management. Any herbal or supplement should be discussed with the healthcare provider, and mothers should be informed that “natural” does not guarantee effective or risk-free – responses vary individually.

Pharmacological Galactagogues

Domperidone is used in many countries to increase prolactin secretion and has shown efficacy in improving milk output, particularly in mothers with lactation failure related to hormonal issues. Domperidone is not FDA-approved in the U.S. (due to cardiac arrhythmia risks at high doses), but it is considered relatively safe in the postpartum period under medical supervision (Hale & Rowe, 2019). Metoclopramide is an alternative in the U.S.; it can raise prolactin as well, though side effects like depression or fatigue sometimes limit its use. These medications should be reserved for situations where first-line interventions haven’t yielded sufficient milk and the benefits outweigh risks. Before resorting to them, ensure treatable factors (like thyroid levels or suboptimal breastfeeding management) have been addressed. If used, a defined course (e.g. 2–4 weeks) can be tried while closely monitoring milk production and any adverse effects. It’s important to inform the mother about potential side effects (for instance, metoclopramide can cause mood changes, which is noteworthy given PCOS mothers’ vulnerability to depression).

Conclusion

PCOS can present unique hurdles to breastfeeding, due to its complex web of hormonal imbalances, insulin resistance, and psychological stressors. Lactation professionals should be aware that women with PCOS might experience delayed lactogenesis II, low milk supply, or other feeding difficulties at higher rates than average, particularly if obesity or metabolic complications are involved. Early postpartum support and tailored interventions can make a significant difference. 

Encouragingly, research to date also shows that PCOS is not an insurmountable barrier to breastfeeding. Many women with PCOS breastfeed exclusively and for extended durations, especially with appropriate help. Key strategies for success include proactive lactation support (preferably starting in the prenatal period), meticulous management of modifiable factors (diet, weight, blood sugar, and endocrine issues), and the judicious use of galactagogues or medical therapies when indicated. 

For now, an individualized plan that addresses both the biology and the emotions of breastfeeding in PCOS is the best approach. By staying informed on current research and maintaining a supportive, non-judgmental stance, healthcare providers can empower mothers with PCOS to achieve their personal breastfeeding goals. In doing so, we not only improve outcomes for these mothers and their infants, but also contribute to a more inclusive understanding of breastfeeding challenges across diverse maternal health conditions.

References

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