Open AccessEFFECTS ON FETAL BREATHING MOVEMENTS OF MATERNAL CHALLENGES
Author(s) -
Maršál Karel,
Gennser Gerhard,
Löfgren Olof
Publication year - 1979
Publication title -
acta obstetricia et gynecologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.401
H-Index - 102
eISSN - 1600-0412
pISSN - 0001-6349
DOI - 10.3109/00016347909154592
Subject(s) - hyperventilation , medicine , isometric exercise , fetus , heart rate , cardiology , anesthesia , arterial ph , blood pressure , incidence (geometry) , pregnancy , mathematics , geometry , biology , genetics
. Ten women in the last trimester of a normal pregnancy were subjected to five different loads in a cross‐over study. Fetal breathing movements (FBM), fetal heart rate (FHR), maternal heart rate (MHR), and mean arterial pressure (MAP), maternal transcutaneously measured pO 2 (Tc‐pO 2 ), and the energy supply to the Tc‐pO 2 electrode were recorded continuously before, during, and after the load. Maternal capillary pH and pCO 2 were measured at three representative time points. The immediate responses of the incidence of FBM to the different challenges were: increase after dynamic work (bicycle test); no change after static work (isometric muscle contraction) and passive movements; decrease after hyperventilation and hyperoxygenation. FHR was unaffected by all challenges. The FBM incidence varied in parallel with pCO 2 after dynamic work and hyperventilation and inversely with the Tc‐pO 2 rise caused by hyperoxygenation. Maternal pH was increased after passive movements (no change in FBM) and after hyperventilation (decreased incidence of FBM). FBM seem to be more sensitive to environmental changes than is the FHR. Mechanical stimuli to the uterus were not responsible for the augmentation of FBM seen after the bicycle test. The present observations reveal the multifactorial nature of the regulation of FBM, and support the role of CO 2 as a major stimulator of breathing movements also in prenatal life.