Kazan medical journalKazan medical journal0368-48142587-9359Eco-Vector7660910.17816/kazmj76609Research ArticleFetal heartbeat Sachs'a (Zeit. f. Geb. u. Gyn., Bd. LXXXII, H. 2)G.V.info@eco-vector.com150619242055485492407202124072021Copyright © 2021, G. V.2021<p>Numerous observations have convinced Sachs (Zeit. F. Geb. u. Gyn., Bd. LXXXII, H. 2) that the normal fetal heart rate during childbirth fluctuates between 132 and 144 per minute, although fluctuations between 120 and 160 occur so often, without any harmful consequences for the fetus, that it is impossible to see anything pathological in them. On the contrary, lowering the frequency to 100 and increasing more than 160 are already out of physiological limits.</p>Kazan Medical archiveКазанский медицинский архив