Thread by @ClementLeeMD

1/19
When is breastfeeding contraindicated? A thread 🧵 and list of contraindications

#MedTwitter #PedsTwitter 🍼

2/19
As pediatricians, we often default to recommending BFing for infants given the numerous health benefits that have been demonstrated for both the mother and child. 👩‍🦰👶

However, there are certain situations we should be mindful of.

3/19
For me, the 1st major contraindication is maternal preference.🗳️

Moms have various reasons for opting not to BF, incl. convenience, comfort, stigma, past trauma... Our jobs as pediatricians is to explore hesitations but also support whatever choice is ultimately made.

4/19

Another common reason is the maternal med list. Which of the following medications would represent a contraindication to BFing? 💊

5/19
The correct answer is MTX, but questions like these are often not straightforward.

There is often no rhyme/reason to which drugs within a class are excreted in breast milk or not. 🤔

My go to reference is the LactMed database:

ncbi.nlm.nih.gov/books/NBK50192…

6/19
Other considerations that fall into this category include active drug use such as cocaine, or radioactive medications (e.g. iodine ablation) – unless you want a radioactive baby. ☢️👶

7/19
Another major category of things passed via breastmilk are infections.

The one most people are familiar with is HIV, though recs for BFing depends on the availability of alternate nutrition e.g. part of the world the patient is in. 🌍

8/19
Now for some infections less commonly discussed. Which of the following can be spread through breastmilk? 🦠

9/19
Correct answer: CMV.

There is no evidence that plasmodia, N. meningitidis (even with bacteremia), or TB can be spread through milk. The latter two can be spread via close contact, but pumped milk can still be used.🧴

PMC7152307

10/19
Avoidance of CMV is usually not a reason to avoid breastfeeding since 1/3 of kids are infected by age 6 (PMID 17029132).

However, one exception is SCID, where some experts recommend against BFing until the child can get IVIG or a transplant. (PMID 31706499) 🫧👶

11/19
Other infections that can be spread through breastmilk include HTLV, brucellosis, and ebola.🐐

Zika virus has been isolated in breastmilk, but the CDC still recommends breastfeeding for infected mothers. 🦟

12/19
The other major contraindications relate to infant diseases that make normal components of breast milk dangerous.

The most commonly cited is galactosemia, where a baby cannot break down galactose --> extra galactitol --> cataracts & other manifestations 🕶️

13/19
Another is hereditary lactase deficiency, which is rare and not the same as the acquired lactase deficiency seen in adults. 💩

In this rare dz, usually in Finnish patients, lactose ingestion --> hypercalcemia/nephrocalcinosis, and BFing should be stopped (PMID 8523189)

14/19
A last metabolic consideration is PKU, where the phenylalanine in milk cannot be processed by the baby. 🧠

However, there are varying degrees of enzyme activity, and most babies can still receive a small amount of breastmilk. (PMID 22703678)

15/19
There are other rare inborn errors of metabolism (IEMs) that may concern the other proteins in breastmilk, and any metabolism experts should feel free to chime in here. 🤓

16/19
Finally let's dispel myths regarding some other common “contraindications.”

In lactational mastitis, BFing can actually help relieve the engorgement and inflammation. (PMID 18819238) This is true even if a breast abscess forms and requires I&D. 🔪

17/19
Herpes zoster or simplex lesions are not a contraindication to breastfeeding.🌹

The other breast can be used, or the baby fed with pumped breastmilk.

18/19
To sum it up, here’s a quick sketch of breastfeeding considerations, sorted by maternal, milk, and infant considerations:

19/19
#MedTwitter and #PedsTwitter, can you think of other contraindications?

@JPBelinkieMD @drkatielockwood @MichaelCosimini