Understanding IGT, Optimizing Milk Supply and Caring for your Mental Health

BREASTFEEDING
Written By Hillary M .

IGT is a condition in which the glandular (milk-producing) tissue of the breast did not develop fully, either in utero, during puberty, or during pregnancy.

The condition is rare, though it's likely under-diagnosed because many providers — including some lactation professionals — aren't well-trained to recognize it.


A few important things to know up front:

  • Breast size has nothing to do with IGT. Small breasts can have plenty of glandular tissue; large breasts can be mostly fatty tissue. Size is not a predictor.

  • Having physical markers doesn't guarantee you have IGT. Plenty of people have one or more of the classic features and produce a full supply.

  • IGT exists on a spectrum. Some parents produce no milk, others produce a partial supply, and some produce more with each subsequent pregnancy as additional glandular tissue develops.


Signs and Physical Markers

A landmark case series published in Pediatrics in 1985 by Neifert and colleagues was one of the first papers to formally describe lactation challenges caused by insufficient glandular development, identifying features like absence of breast changes during pregnancy and lack of postpartum engorgement (PubMed). Since then, six physical characteristics have become widely used as antenatal indicators (PubMed):

  • Lack of breast changes during pregnancy (often the most telling sign)

  • Tubular breast shape

  • Significant breast asymmetry

  • Stretch marks on the breasts without corresponding growth

  • A wide “intramammary space” (typically more than 4 cm between the breasts… though it sounds like a really good interstellar comin book idea…)

  • Areolar abnormalities, such as unusually large or bulbous areolae


It is important to note that some parents with several of these features still go on to produce a full milk supply, while others, even with extensive support, struggle to meet their breastfeeding goals.


Causes and Associated Conditions

The honest answer is that researchers still don't fully understand what causes IGT. Breast development is a multi-stage process that begins in utero, continues through puberty, and finishes during pregnancy and disruption at any of these stages can result in incomplete glandular development. Several factors have been associated with IGT:

  • Hormonal and endocrine factors like Polycystic Ovarian Syndrome (PCOS) / Polyendocrine Metabolic Ovarian Syndrome (PPMOS), insulin resistance, thyroid disorders, and luteal phase defects have all been linked to IGT in case reports and clinical observations. A frequently cited case study described a mother diagnosed with IGT after her first child who later breastfed her second child exclusively, with no supplementation, after being treated with progesterone for a luteal phase defect during pregnancy — the authors speculated that the progesterone treatment supported additional alveolar development (Bodley & Powers, 1999, PubMed). The evidence for progesterone treatment is still emerging.

  • Family histories of lactation failure show up repeatedly in the case literature, revealing that there may be a genetic component.

  • Some research has examined the possibility that endocrine-disrupting chemicals during fetal development or puberty may interfere with normal breast tissue development, though this remains an area in need of more study.

  • Augmentation, reduction, or other thoracic surgeries can sever ducts or nerves. Importantly, augmentation surgery itself is usually not the cause of low supply — rather, the underlying anatomy (tubular shape, asymmetry, wide spacing) that led someone to seek surgery in the first place is what's associated with IGT.


A scoping review and several clinical sources point out that IGT is rarely diagnosed prenatally, even though many of the physical signs are visible long before pregnancy (Spatz & Edwards, 2021, PMC). This is one of the most important advocacy points for anyone who suspects they may be at risk: a prenatal breast assessment by an IBCLC can change the trajectory of the postpartum experience.


What You Can Do During Pregnancy

If you've identified risk factors for IGT (either because you've had a previous low-supply experience or because you have physical markers) there are several things you can do during pregnancy to optimize your potential. None of these guarantee a full supply, but they meaningfully improve your odds and, just as importantly, prepare you emotionally and logistically for whatever your journey ends up looking like.


1. Find an IBCLC during pregnancy, not after birth.

This is the single most impactful step. An International Board Certified Lactation Consultant can do a prenatal breast assessment, identify physical markers, take a thorough hormonal and medical history, and help you build a feeding plan tailored to your specific anatomy. Crucially, you'll already have an established relationship with someone you trust by the time your baby arrives … when sleep deprivation and emotional intensity make it much harder to vet a new provider.


2. Address underlying hormonal conditions.

If you have PCOS, insulin resistance, thyroid issues, or a history of luteal phase defects, work with your OB or endocrinologist on optimal management during pregnancy. While direct evidence that treating these conditions improves IGT outcomes is limited, well-controlled hormone levels are foundational to breast tissue development and lactogenesis (milk making). The progesterone case report mentioned above is intriguing but not yet replicated in larger studies, so any hormonal supplementation should be done in conversation with your medical team.


3. Consider antenatal colostrum expression from 36 weeks.

Antenatal colostrum expression (ACE) involves hand-expressing small amounts of colostrum starting around 36 weeks of pregnancy, then freezing it for use after birth. The landmark Diabetes and Antenatal Milk Expressing (DAME) trial (a randomized controlled trial of 635 pregnant women with low-risk diabetes published in The Lancet) found that twice-daily ACE from 36 weeks was safe, did not increase preterm birth or NICU admissions, and was associated with a higher likelihood of exclusive breastfeeding in the first 24 hours of life (Forster et al., 2017).


A 2024 narrative review in Proceedings of the Nutrition Society concluded that ACE is safe for low-risk women from around 36 weeks' gestation, and that the skill of hand expressing itself is a valuable postpartum tool regardless of how much colostrum is actually collected. For parents at risk of low supply (including those with IGT, PCOS, or a history of breast surgery) ACE provides a buffer of stored milk and helps you learn hand expression before you need it. Always discuss ACE with your care provider first: it's not appropriate for everyone, particularly those with a history of preterm labor, cervical insufficiency, or other obstetric risk factors.


4. Build your postpartum support infrastructure now.

This includes:

  • A pediatrician or family doctor who understands IGT and won't pressure you into all-or-nothing decisions

  • A backup feeding plan (donor milk, formula, or both) that you've researched and feel at peace with

  • Access to a hospital-grade pump for the early weeks. Some insurance and provincial programs cover rentals for medical indications

  • A supplemental nursing system (SNS), like the Medela SNS or Lact-Aid, or a "DIY" setup" which lets you deliver supplemental milk through a thin tube at the breast, preserving the nursing relationship even when full supply isn't possible


5. Learn what optimal early breastfeeding looks like.

Even though IGT is anatomical, postglandular factors stack on top — meaning a poor early start can compound a glandular issue. Skin-to-skin in the first hour, frequent on-demand feeding (8–12+ times in 24 hours), avoiding unnecessary supplementation, and ensuring proper latch all matter. The early day and weeks are crucial for setting your supply, so doing everything possible to optimize them gives you the best shot at maximizing whatever capacity you have.


6. Discuss galactagogues with your care team.

Herbal galactagogues like fenugreek, goat's rue, shatavari, and moringa are commonly recommended in IGT communities. Goat's rue is particularly interesting because, unlike most galactagogues that boost prolactin response, it's thought to support actual mammary tissue growth — though high-quality clinical evidence is limited. Pharmaceutical options like domperidone are used in Canada for those with suitable medical history. Any galactagogue, herbal or pharmaceutical, should be discussed with a knowledgeable provider, and none should be expected to overcome the anatomical limit set by glandular tissue.


Management After Delivery

Once your baby is here, the management of IGT becomes a balance of three things: maximizing whatever supply you have, ensuring the baby is adequately fed, and protecting the nursing relationship.

  • Maximize milk removal: Frequent, effective milk removal is the single biggest driver of supply. For parents at risk of low supply, this typically means nursing on demand plus pumping after feeds with a hospital-grade pump in the early weeks.

  • Supplement strategically: Supplementation is often necessary with IGT, and that's not a failure — it's appropriate medical care. The goal is to feed the baby adequately while continuing to stimulate the breast as much as possible. Supplemental nursing systems are particularly valuable here because they allow the baby to receive supplemental milk at the breast, maintaining the nursing relationship and the stimulation that drives whatever supply is possible.

  • Track output and growth: Wet diapers, stool patterns, and weight gain are the objective measures that matter.

  • Reassess at each stage: Some parents find their supply increases with subsequent pregnancies as additional glandular tissue develops. Others find a stable pattern. Either way, IGT management is iterative, not static.


It's worth being honest about the current state of the evidence: there is no definitive treatment for IGT, and there is no reliable way to grow new glandular tissue once breast development is complete. Management is about optimization, not cure.


The Mental Health Dimension


This is the part of IGT that gets the least attention in clinical settings and matters the most. Research consistently shows a strong link between challenges breastfeeding and perinatal anxiety and depression — and parents with IGT often describe a specific kind of grief that survey research has begun to call "breastfeeding grief": a prolonged sense of loss, failure, and disconnection from an experience they had imagined would be foundational to early parenthood (The Conversation).


A 2024 survey of women with low milk supply found that 72% had breasts that did not change appearance during pregnancy and around 70% reported at least one irregular-shaped breast — and the emotional experiences reported ranged from frustration and confusion to profound feelings of failure, guilt, and despair. The research is clear that this grief is not a personal weakness; it's a recognized psychological response to a real loss, often compounded by a healthcare system that frequently fails to recognize the underlying condition.

Several things make the mental health impact of IGT particularly hard:

  • Most parents don't know they have IGT until they've already spent weeks or months feeling like they're failing. By the time the diagnosis comes, significant emotional damage has often been done.

  • Our culture repeats "breast is best" with insufficient acknowledgment of physical limits. The original Pediatrics paper put this bluntly: "Preserving the 'every woman can nurse' myth contributes to perpetuating a simplistic view of lactation" (Neifert et al., 1985).

  • Many parents with IGT describe being made to feel they have to justify supplementation or formula use, even when it's medically necessary for their baby.

  • Parents often have to educate their own care providers about the condition as their primary care team is not knowledgeable about this condition.


What helps

  • Name it: Many parents describe a turning point when an experienced IBCLC finally identifies IGT not because the diagnosis changes the physical reality, but because it reframes the experience. It wasn't a failure of effort or motivation. It was anatomy. Naming it allows grief to start moving.

  • Allow yourself to grieve: Grief over a feeding journey not going how you expected is legitimate. It’s valid. And that’s all there is to say about that!

  • Find peer community: IGT-specific support groups (in person and online) are some of the most valuable resources available, because they connect you with people who deeply understand the specific shape of this experience.

  • Screen for perinatal mood disorders, and get help: The link between feeding difficulties and postpartum depression/anxiety is well-established. If you find yourself struggling beyond what feels like normal adjustment (low mood that lasts for ages, intrusive thoughts, anxiety that doesn't let up, or feelings of disconnection from your baby) please reach out to a perinatal mental health specialist. Organizations like Postpartum Support International (postpartum.net) maintain provider directories, or e-mail me and I can let you know who I can find in your area.

  • Redefine the nursing relationship: Breastfeeding is not a “success” or “fail” setup. Some parents with IGT continue to nurse for comfort even when most of their baby's nutrition comes from supplements or formula. Others use a supplemental nursing system to combine the experience of breastfeeding with the nutrition the baby needs. Others choose to move entirely to bottle feeding and find that responsive, present, loving feeding is what their baby actually needed all along. Any of these is a valid path. The relationship you build with your baby is the point! The point of all of it!


A Final Note

If you're reading this in pregnancy because you suspect you may be at risk for IGT, the most important thing I want to leave you with is this: knowledge changes outcomes. Knowing now means you can build the team, build the plan, and build the emotional preparation that parents who don't get diagnosed until weeks postpartum don't have access to. That's a big deal!!

If you're reading this postpartum, or further into your parenting journey, and you're recognizing yourself for the first time — please know that what happened to you was not a failure of effort, knowledge, or love. It was anatomy. And the grief you may be carrying is real, valid, and worth tending to. Give yourself a big hug, from me :)

You are not alone in this. The condition is rare, but a growing community of parents, IBCLCs, and researchers is working to bring IGT out of the shadows and into the standard of care it deserves.


Sources


Written by Hillary Maguire, IBCLC

Hillary Maguire is an IBCLC practicing in private clinic, community healthcare and volunteer settings in and around Waterloo Region, Ontario Canada. Hillary practices with an evidence-based approach that centres the client’s infant feeding goals and prioritizes the overall wellbeing of the family unit. Hillary is known for her candour, sense of humour and ability to translate medical information to understandable tidbits. Hillary has a particular interest in helping first-time parents navigate the establishment of their milk supply and “get to the good part” of infant feeding and parenting. Hillary has worked in multiple settings where tongue-tie releases are performed and has helped hundreds of families navigate the process of diagnosing, preparing to release, treating, and rehabilitating tongue tie with their infants and small humans. Hillary can help with issues like low milk supply, nursing pain, recurrent mastitis, infant oral skills assessment, infant weight concerns, allergy concerns, and breastmilk pumping.


Hillary M .
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