Which of the following is the LEAST likely physiological change in pregnancy?
High-Yield Explanation
Blood volume expansion begins early in the first trimester, increases rapidly in the second trimester, and plateaus at about the 30th week. Cardiac output increases approximately 40% during pregnancy, with maximum values achieved at 20-24 weeks' gestation. Stroke volume increases 25-30% during pregnancy, reaching peak values at 12-24 weeks' gestation. Vascular resistance decreases in the first trimester, reaching a nadir of approximately 34% below nonpregnancy levels by 14 to 0 weeks of gestation with a slight increase toward term. Ref: Flick A.A., Kahn D.A. (2013). Chapter 8. Maternal Physiology during Pregnancy & Fetal & Early Neonatal Physiology. In DeCherney A.H., Nathan L, Laufer N, Roman A.S. (Eds), CURRENT Diagnosis & Treatment: Obstetrics & Gynecology, 11e.