Short answer
Islam wants children to learn about puberty, purity and the body, with modesty and at the right age. Parents should teach this themselves first. Lessons that teach facts are useful; content that presents what Islam forbids as normal, or that is explicit beyond the child's age, is not. Many schools let parents see the materials and withdraw children from parts of it.
Teaching a child what they must know about puberty, ghusl, periods and the limits of halal and haram is a duty on parents, since worship depends on it. Exposing children to immodest images or to teaching that approves of zina or other sins is not permitted.
The four schools agree on this.
Explanation
The women of the Ansar asked the Prophet ﷺ openly about periods and ghusl, and Aishah praised them: modesty did not stop them from learning their religion. Islamic law books discuss wet dreams, periods and marital relations plainly, because a person cannot pray correctly without knowing them. So the question is not whether children learn, but what, when and from whom.
What parents should teach, before school does:
- Body changes at puberty, for boys and girls, before they happen. Periods can start as early as nine.
- Ghusl after a period or a wet dream. See how to do ghusl.
- Privacy, awrah and that no one may touch them inappropriately.
- That intimacy belongs within marriage, and why.
School lessons:
- Ask to see the lesson materials. Many schools share them.
- Biology of reproduction is part of science and is usually compulsory. It is fine to learn.
- Where lessons teach things Islam forbids as simply normal, or show explicit content, speak to the school calmly and in writing.
- Some countries let parents withdraw children from sex education but not from other subjects such as relationships or health education. Find out the rules where you live.
Withdrawal alone is not enough: a child who learns nothing at home will learn from friends and the internet. Teach with honesty and modesty, and keep the door open for questions. See puberty in Islam.
The evidence
Quran, Surah An-Noor 24:59
وَإِذَا بَلَغَ ٱلْأَطْفَٰلُ مِنكُمُ ٱلْحُلُمَ فَلْيَسْتَـْٔذِنُوا۟ كَمَا ٱسْتَـْٔذَنَ ٱلَّذِينَ مِن قَبْلِهِمْ ۚ كَذَٰلِكَ يُبَيِّنُ ٱللَّهُ لَكُمْ ءَايَٰتِهِۦ ۗ وَٱللَّهُ عَلِيمٌ حَكِيمٌۭ ﴿٥٩﴾
And when the children among you reach puberty, let them ask permission [at all times] as those before them have done. Thus does Allah make clear to you His verses; and Allah is Knowing and Wise.
The Quran itself addresses puberty and privacy in the home.
Sahih Muslim 332
Sahih... نعم النساء نساء الأنصار لم يكن يمنعهن الحياء أن يتفقهن في الدين ...
"How excellent were the women of the Ansar: modesty did not stop them from learning their religion."
Learning about bodily matters is part of religion.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Kitab al-Taharah, chapters on ghusl and on menstruation. The knowledge of puberty and purity every Muslim needs.
- Radd al-Muhtar (Ibn Abidin), Kitab al-Hazr wal-Ibaha, section on looking and touching. Rules of modesty and looking.
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.