Short answer
No. Breastfeeding does not break wudu, and breast milk is pure, so milk on your clothes does not stop you praying. The four schools agree. In the Hanafi school, though, a baby nursing from a woman while she is in the prayer, with milk flowing, breaks the prayer itself.
Wudu is broken by what leaves the body from the private parts, by flowing blood or pus, vomiting a mouthful, sleep lying down, loss of consciousness and laughing aloud in prayer. Breast milk is none of these and is pure (tahir). Nursing while in salah, so that milk comes out, invalidates the prayer (and, in some texts, three sucks even without milk).
The four schools agree on this.
Explanation
New mothers often worry that feeding the baby means making wudu again before every prayer. It does not. The Prophet ﷺ said there is no wudu except from sound or wind, teaching that wudu is broken by specific causes, and nursing is not one of them. The four schools agree that breastfeeding does not break wudu and that human milk is pure.
Common situations:
- Milk on clothes or skin: it is not najis (impure). You may pray in those clothes, though cleaning a wet patch is good manners.
- Uncovering the chest to feed: does not break wudu. Exposing the body only matters during the prayer itself.
- The baby's spit-up: a different question; see is baby vomit or urine najis.
- Bleeding after birth: that is nifas, and wudu and prayer rules change while it lasts.
During the prayer. In the Hanafi school, if a baby latches on and nurses while the mother is praying and milk comes out, her prayer is broken and she starts again; her wudu is still valid. Some Hanafi texts add that three sucks break the prayer even if no milk comes. If the baby is crying hard, it is better to feed first and then pray calmly, or to shorten the prayer as the Prophet ﷺ did when he heard a child crying. See praying while holding a baby.
For the full list of what breaks wudu, see how to make wudu.
The evidence
Jami' at-Tirmidhi 74
Grading to be checked... لا وضوء إلا من صوت أو ريح ...
"There is no wudu except from sound or wind."
Wudu is broken only by specific causes, and breastfeeding is not among them.
Sahih al-Bukhari 707
Sahih... فأسمع بكاء الصبي فأتجوز في صلاتي ...
"I hear a child crying, so I shorten my prayer."
Care for a crying baby is considered even in prayer.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Kitab al-Taharah, chapter on what breaks wudu. Lists the causes that break wudu.
- al-Fatawa al-Hindiyya, Kitab al-Salah, chapter on what invalidates the prayer. A baby nursing from a praying woman with milk coming out breaks her prayer.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.