Re: “Herbal Use During Breastfeeding” by Anderson ( Breastfeed Med 2017;12(9):507–509)

To the Editor:

We read with interest the article by Philip O. Anderson entitled “Herbal Use During Breastfeeding.” ¹ We are in agreement with the author's comments on the paucity of high-quality safety data on herbal galactogogues. To our knowledge, this is the first case of Mother's Milk Tea, a popular tea advertised to increase milk supply, reported to cause elevated liver enzymes.

A 40-year-old Lithuanian woman with no medical history presented 5 months postpartum for evaluation of elevated liver enzymes. Her pregnancy was complicated with gestational diabetes, managed with insulin detemir, which resolved after delivery. After the birth of a healthy male infant, she discontinued insulin detemir and remained on prenatal vitamins. Laboratories at the time of delivery were normal.

After delivery, she reported poor breast milk supply and started Mother's Milk Tea (by Traditional Medicinals). Three months postpartum, laboratories revealed aspartate transaminase (AST) 47 IU/L, alanine transaminase (ALT) 95 IU/L, and alkaline phosphatase 90 IU/L (Table 1). Upon presentation, she had no gastrointestinal complaints and reported an increase in her breast milk supply. She has no evidence of chronic viral hepatitis B or C, hemochromatosis, Wilson's disease, or autoimmune hepatitis (normal antinuclear antibodies [ANA], antiactin). An ultrasonography revealed normal liver.

After discontinuation of the Mother's Milk Tea, her liver enzymes normalized with AST 21 IU/L, ALT 40 IU/L, and alkaline phosphatase 104 IU/L. She was advised to abstain from Mother's Milk Tea.

Mother's Milk Tea, a popular tea sold worldwide, is commonly marketed to new mothers to increase breast milk supply. It is composed of fennel, anise, coriander, fenugreek, and blessed thistle. Fenugreek is the most widely used herbal galactogogues with limited data regarding efficacy and safety. ² Reported side effects of fenugreek include diarrhea, maple-like smell to urine, perspiration, and worsening of asthma. Similar to other herbal supplements, it is currently not understood what amount of fenugreek might be necessary to increase milk production.

To our knowledge, this is one of the few reported cases of abnormal liver enzymes occurring from herbal galactogogues and the first for Mother's Milk Tea specifically. ³ Awareness of this potential side effect is important and caution should be exercised before recommending herbal supplements or medication to increase breast milk production. ⁴