Caution: Translations of Quran and Ḥadīth may lead to possible misapplications and misinterpretations. This site is intended for students of sacred knowledge that are proficient in comprehending classical Arabic and have a strong foundation in Islamic sciences. Also note that religious injunctions rely on several aspects beyond what one may glean through reading individual aḥādīth.
Qurʾān Bukhārī Muslim Nasāʾī Abū Dāwūd Tirmidhī Ibn Mājah Mālik Aḥmad Dārimī Ḥākim Ibn Ḥibbān Ṭabarānī Nasāʾī's Kubrá Bayhaqī al-Luʾluʾ wa-al-Marjān Ibn Rajab's Fifty Riyāḍ al-Ṣāliḥīn Aḥmad's Zuhd Suyūṭī
quran:13:8 –

Allah knows what every female carries and what the wombs lose ˹prematurely˺ or exceed. And everything with Him is by due measure.  

God knows what every female bears, of male or female, one or more, and otherwise, and what the wombs reduce, of the time of gestation, and what they increase, of it. And everything with Him is according to a ˹precise˺ measure, a ˹precise˺ amount and limit which it does not exceed;
القرآن:١٣:٨ –

اللَّهُ يَعْلَمُ مَا تَحْمِلُ كُلُّ أُنْثَىٰ وَمَا تَغِيضُ الْأَرْحَامُ وَمَا تَزْدَادُ ۖ وَكُلُّ شَيْءٍ عِنْدَهُ بِمِقْدَارٍ  

{الله يعلم ما تحمل كل أنثى} من ذكر وأنثى وواحد ومتعدد وغير ذلك {وما تغيض} تنقص {الأرحام} من مدة الحمل {وما تزداد} منه {وكل شيء عنده بمقدار} بقدر وحدٍّ لا يتجاوزه.

See similar narrations below:

Collected by Dārimī
darimi:963 – Ḥajjāj > Ḥammād b. Salamah > ʿĀṣim al-Aḥwal

[Machine] Regarding this verse {Allah knows what every female carries and what the wombs lose] (Al-Ra'd 8), Ikrimah said, "This refers to the menstrual blood on the umbilical cord. It does not menstruate for a day on the cord unless it increases its purity in its cord."  

الدارمي:٩٦٣ – أَخْبَرَنَا حَجَّاجٌ حَدَّثَنَا حَمَّادُ بْنُ سَلَمَةَ عَنْ عَاصِمٍ الْأَحْوَلِ

عَنْ عِكْرِمَةَ فِي هَذِهِ الْآيَةِ {اللَّهُ يَعْلَمُ مَا تَحْمِلُ كُلُّ أُنْثَى وَمَا تَغِيضُ الْأَرْحَامُ وَمَا تَزْدَادُ وَكُلُّ شَيْءٍ عِنْدَهُ بِمِقْدَارٍ} [الرعد 8] قَالَ «ذَلِكَ الْحَيْضُ عَلَى الْحَبَلِ لَا تَحِيضُ يَوْمًا فِي الْحَبَلِ إِلَّا زَادَتْهُ طَاهِرًا فِي حَبَلِهَا»