Cannabis use on a regular basis by breastfeeding mothers concerns me. Cannabis has a long half life (25-57 hours) and it takes 5 times this to be removed from milk. THC crosses the blood brain barrier and it is known to accumulate in body fats. Although it is highly protein bound and subject to first pass metabolism, the milk plasma ratio is 8. We do not know enough about the impact on the developing brain to be sure that the amount passing through breastmilk is safe. Regular use is not recommended in the breastfeeding mother or other members of the family who may expose the baby through passive inhalation.

Breastfeeding and Cannabis factsheet

see also Cannabis and Breastfeeding: What We Know and What We Should Do – LCGB

https://www.nutritionfirstwa.org/wp-content/uploads/2017/11/Laurel-Wilson-Marijuana-and-Breastfeeding-Handout-docx.pdf

Ustekinumab is a disease modifying, biological drug used to treat psoriatic arthritis, plaque psoriasis, Crohns disease, and ulcerative colitis. It is given by sub cutaneous injection.

It has a  molecular weight 149,000, poor oral bioavailability  and milk plasma ratio 0.001 – 0.027

Ustekinumab is a recombinant human monoclonal TNF antibody that binds specifically to TNF- α.

It is likely that any small amounts in milk are destroyed in the baby’s gut. Three studies have shown very low levels in  milk but the babies showed no evidence of increased rates of infection or other effects on physical or mental health.

BNF states that “specialist sources indicate use with caution; negligible amounts present in milk which are likely to be destroyed in the infant’s gastro-intestinal tract. In newborn or premature infants there may be greater intestinal absorption. “

Ustekinumab is compatible with breastfeeding due to poor bio-availability and hence low-level absorption by the infant. It should be avoided in the first few days post partum when the gaps between the cells are wide open to facilitate transfer of immunoglobulins.

If it is used in pregnancy live vaccines should be avoided in the baby – normally rotavirus because immunity may be compromised. If not used in pregnancy when the rotavirus is given, the breastfeeding mother needs to wear gloves for 2 weeks to avoid picking up the live viral fragments shed in faeces. This alert card may be useful to have within the red book to remind professionals.

References

• Klenske E, Osaba L, Nagore D, Rath T, Neurath MF, Atreya R. Drug Levels in the Maternal Serum, Cord Blood and Breast Milk of a Ustekinumab-Treated Patient with Crohn’s Disease. J Crohns Colitis. 2019;13(2):267-269.
• Saito J, Kaneko K, Kawasaki H, et al. Ustekinumab during pregnancy and lactation: drug levels in maternal serum, cord blood, breast milk, and infant serum. J Pharm Health Care Sci. 2022;8(1):18.
• Bar-Gil Shitrit A, Ben-Horin S, Mishael T, et al. Detection of Ustekinumab in Breast Milk of Nursing Mothers With Crohn Disease. Inflamm Bowel Dis. 2021;27(5):742-745
• https://www.ncbi.nlm.nih.gov/books/NBK500594
• https://e-lactancia.org/breastfeeding/ustekinumab/product/

Adalimumab is a disease modifying, biological drug used to treat rheumatoid arthritis, psoriatic arthritis, Crohns disease, ulcerative colitis and Hidradenitis suppurativa. It is given by sub cutaneous injection.

It has a  molecular weight 148,000. Poor oral bioavailability  and relative infant dose 0.12% ( well below 10% regarded as compatible).

Adalimumab is a recombinant human monoclonal TNF antibody that binds specifically to TNF- α.

It is likely that any small amounts in milk are destroyed in the baby’s gut. Two infants of women who

took adalimumab 40 mg subcutaneously during lactation were followed until 14.5 and 15 months of

age. No adverse reactions were found in the infant to be attributed to exposure of the drug in breast

milk. Both infants were reported to have met all developmental milestones (Fritzsche 2012).

BNF however states that it should be avoided by breastfeeding mothers because the manufacturer

advises it should be avoided for at least 5 months after last dose. This is not based on evidence.

Adalimumab is compatible with breastfeeding due to poor bio-availability and hence low-level absorption by the infant. It should be avoided in the first few days post partum when the gaps between the cells are wide open to facilitate transfer of immunoglobulins.

If it is used in pregnancy live vaccines should be avoided in the baby – normally rotavirus because immunity may be compromised. If not used in pregnancy when the rotavirus is given, the breastfeeding mother needs to wear gloves for 2 weeks to avoid picking up the live viral fragments shed in faeces. This alert card may be useful to have within the red book to remind professionals.

References

• Wasan SK, Kane SV. Adalimumab for the treatment of inflammatory bowel disease. Expert
• Rev Gastroenterol Hepatol. 2011 Dec;5(6):679-84.
• Fritzsche J, Pilch A, Mury D, Schaefer C, Weber-Schoendorfer C. Infliximab and adalimumab
• use during breastfeeding. J Clin Gastroenterol 2012;46(8):718-19.
• https://www.ncbi.nlm.nih.gov/books/NBK501392/
• https://e-lactancia.org/breastfeeding/adalimumab/product/

I’m seeing increasing numbers of questions form mums in the perimenopause who are still breastfeeding. Maybe they delivered later or maybe they have been feeding to term or maybe lots of other reasons. I remember asking for blood tests to check my hormone levels because I just couldn;t think clearly anymore and my memory was poor which wasn;t ideal as I was just becoming an independent pharmacist prescriber! My levels had indeed dropped and I went on to HRT. This may not be everyone’s choice or be suitable for them

I have spent many hours this year looking for guidance on HRT and breastfeeding and failed to find any studies or conclusive data. Everything is anecdotal at the moment but I hope this information helps.

One vital piece of information – please keep checking your breasts for lumps . HRT can slightly increase the risk of breast cancer. If you’ve had breast cancer you’ll usually be advised not to take HRT. The increased risk is low: there are around 5 extra cases of breast cancer in every 1,000 women who take combined HRT for 5 years. The risk increases the longer you take it, and the older you are.

Risk of breast cancer BNF June 2024 https://bnf.nice.org.uk/treatment-summaries/sex-hormones/

All types of systemic (oral or transdermal) HRT treatment increase the risk of breast cancer after 1 year of use. This risk is higher for combined oestrogen-progestogen HRT (particularly for continuous HRT preparations where both oestrogen and progestogen are taken throughout each month) than for oestrogen-only HRT, but is irrespective of the type of oestrogen or progestogen. Longer duration of HRT use (but not the age at which HRT is started) further increases risk.

Although the risk of breast cancer is lower after stopping HRT than it is during current use, the excess risk persists for more than 10 years after stopping compared with women who have never used HRT. Vaginal preparations containing low doses of oestrogen to treat local symptoms are not thought to be associated with an effect on breast cancer risk.

The MHRA advises discussing the updated information on the risk of breast cancer with women who use or are considering starting HRT, at their next routine appointment. 

There are also risks of endometrial cancer, ovarian cancer, thromboembolism, stroke and coronary vascular disease. Please do not use higher than recommended/licensed doses of HRT.

As usual please message me on wendy@breastfeeding-and-medication.co.uk if you have a question

The Menopause And Breastfeeding

There remains no conclusive research on the passage of HRT medication into breastmilk. It appears anecdotally that there is less impact on milk supply from using transdermal preparations than oral medication. There remains the possibility of reduction in lactation due to the oestrogen contact inhibiting prolactin. Anecdotally HRT at standard dose has been used by breastfeeding women without impact on the nursling or supply. There is no research on higher doses or use outside of licence application.

For use of vaginal oestrogen see https://breastfeeding-and-medication.co.uk/fact-sheet/breastfeeding-and-oestrogen-cream-or-pessary

I typed “menopause and breastfeeding” into a well-known search engine and what came up first was “It is most likely that you are suffering from menopausal-like symptoms due to breastfeeding. After childbirth and during breastfeeding, women’s oestrogen levels can drop to lower levels than usual. These low levels of oestrogen can cause symptoms that mimic menopause.”

Whilst in a paper published in 2020 Langton et al found that after studying 100,000 women ages 25 to 42 years in the Nurses’ Health Study II (an analysis funded by the National Institutes of Health) “Women who breastfed their infants exclusively for seven to 12 months may have a significantly lower risk of early menopause than their peers who breastfed their infants for less than a month”.  The study also suggests that pregnancy can reduce the risk of early menopause.”

As many women now give birth later than in the past, due to changes in work and finance, and feed until they and their nursling choose to stop, questions that I have received from mothers exhibiting signs of early menopause have increased substantially. Most women begin the menopause between 45 and 55 years of age.

There is also a group who have experienced premature ovarian failure which may be hereditary. There is a further group who have had their uterus and ovaries removed surgically for a variety of reasons.

Premature ovarian insufficiency (POI)

This affects about one in a hundred women under 40 in the UK. It occurs when the ovaries no longer produce normal amounts of estrogen and therefore may not produce eggs. This means that periods will become irregular or stop altogether, with symptoms of the menopause. Many women have POI without actually realising it. Any mother under the age of 40 and having irregular periods (or if they have even stopped completely) should be talk to their doctor about having further tests. Unlike the normal menopause when the ovaries stop working completely, in POI ovarian function can be intermittent, occasionally resulting in a period, ovulation or even pregnancy. This intermittent return of ovarian function means that 5–10% of women with POI will conceive spontaneously.

Perimenopause

The period leading up to the menopause, when hormone production decreases symptoms may start to be experienced is defined as the perimenopause. The period is rather ill defined and may vary dramatically between women. It usually suggested as beginning with irregular menstruation. There may be changes to flow with periods becoming heavier or lighter. For others it may be defined by mood swings or changes in mental function. Each person has a different awareness of their own bodies. This is the period in which most calls about breastfeeding appear to originate with a request to begin hormone replacement therapy.

Menopause

The menopause is defined as an absence of menstruation for over a year. Not all symptoms will be experienced by all women, we are all different.

Typical menopausal symptoms, include:

• hot flushes
• night sweats
• vaginal dryness and discomfort during sex
• difficulty sleeping
• low mood or anxiety
• reduced sex drive (libido)
• problems with memory and concentration

Post menopause

This is defined as the remainder of a women’s life which can present with an increased risk of osteoporosis although the risk is lowered in women who have breastfed (https://www.unicef.org.uk/babyfriendly/news-and-research/baby-friendly-research/maternal-health-research/maternal-health-research-bone-density/).

HRT and Breastfeeding

HRT contains oestrogen and sometimes a progesterone e.g., norethisterone, not that dissimilar to that in the combined oral contraceptive which can be used in breastfeeding. The ethinylestradiol content of COCs range from 20–40 micrograms whilst that in HRT products contain 1 – 2 milligrams of estradiol (there are 1000 micrograms in a milligram).

However, Hale says “Although small amounts of Conjugated estrogens may pass into breastmilk, the effects of estrogens on the infant appear minimal. Early postpartum use of estrogens may reduce volume of milk produced and the protein content, but it is variable and depends on dose and the individual.”

“Conjugated estrogens comprise more than 90% of the total estrogen content of human milk and plasma (McGarrigle) Estriol glucosiduronates were the predominant oestrogen metabolites (63%) in plasma”

His conclusion is that low levels pass into milk confirmed in a query to the InfantRisk forum (https://www.infantrisk.com/forum/forum/medications-and-breastfeeding-mothers/medications-and-mothers-milk/339-hormone-replacement-therapy )

Martindale (39^th Ed) states that estradiol has been detected in breastmilk after the use of pessaries containing estradiol 50 or 100mg (Nilsson 1978) and that the American Academy of Pediatrics (2001) considers that it is compatible with breastfeeding

Pharmacokinetics of HRT (Taken from Hale)

Conjugated estrogens:  Milk plasma ratio 0.08, Plasma Protein Binding 98%

References

• American Academy of Pediatrics Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics. 2001 Sep;108(3):776-89.
• Chollet, J. A., G. Carter, et al. (2009). “Efficacy and safety of vaginal estriol and progesterone in postmenopausal women with atrophic vaginitis.” Menopause 16(5): 978-983.
• Hale TW Medications and Mothers Milk online access
• Langton CR, Whitcomb BW, Purdue-Smithe AC, et al. Association of Parity and Breastfeeding With Risk of Early Natural Menopause. JAMA Netw Open. 2020;3(1): e1919615)
• Martindale The Complete Drug Reference 39 Ed. Pharmaceutical Press
• McGarrigle HH, Lachelin GC. Oestrone, oestradiol and oestriol glucosiduronates and sulphates in human puerperal plasma and milk. J Steroid Biochem. 1983May;18(5):607-11.
• Nilsson S, Nygren KG, Johansson ED. Transfer of estradiol to human milk. Am J Obstet Gynecol. 1978 Nov 15;132(6):653-7

I am often asked about products, usually herbal, to detox and about breastfeeding afterwards. In general these products contain a combination of herbal laxatives and at least one diuretic . Basically the result is to make you pass more urine and develop diarrhoea to “cleanse” the system and usually to lose weight. There is a large risk that in doing so your milk supply will diminish too.

The data on the safety of the herbs in breastfeeding is often poor. I cannot provide data that these products are either safe to use and feed as normal or that they are unsafe – there is just is not enough data that I would be confident in using. Therefore I cannot help with information. The decision has to be your own or on the recommendation of a qualified herbalist who is willing to take professional responsibility.