1. Maternal Adaptations to Pregnancy
Chapter 43
Maternal Adaptations to Pregnancy
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

2. FIGURE 43.1 Changes in basal metabolic rate (BMR) during pregnancy at three time points, 9 weeks, 22 weeks, and 36 weeks, in three groups of women. The first group with a below-average body mass index before conception (BMI < 19.8 kg/m2, hatched bar); the second group, a normal BMI (19.8–26.0 kg/m2, unfilled bar); the third group, a high BMI (>26.0 kg/m2, filled bar). Source: Data from Ref. 11.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

3. FIGURE 43. 2 Increases in energy expenditure during pregnancy
FIGURE 43.2 Increases in energy expenditure during pregnancy. Source: Data from Forsum E, Lof M. Energy metabolism during human pregnancy. Annu Rev Nutr 2007;27:277–292.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

4. FIGURE 43.3 Increases in basal oxygen consumption (ml/min) for individual organs in near-term pregnancy compared to nonpregnant consumption rates. Source: Data from Ref. 18.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

5. FIGURE 43. 4 Placental phenotypes related to offspring disease
FIGURE 43.4 Placental phenotypes related to offspring disease. Source: Data from Ref. 37.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

6. FIGURE 43.5 Average red cell mass (filled bar) and blood volume (open bar) increase over the course of pregnancy. Source: Data from Ref. 41.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

7. FIGURE 43.6 Plasma atrial natriuretic peptide (ANP) and cGMP at each trimester (Tm) of pregnancy and postpartum in 15 healthy women in the supine and upright positions (mean ± SEM). *P < 0.05 versus postpartum in the same position; §P < 0.05 versus corresponding supine value. Source: From Ref. 59, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

8. FIGURE 43.7 Plasma angiotensin II concentration ([ANG II]) at rest and at two work rates as a percentage of the estimated anaerobic threshold or ventilatory threshold (VT). *Significant difference (P < 0.05) between groups. #Significant change (P < 0.05) within group from rest. Source: From Ref. 61, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

9. FIGURE 43.8 Cardiac output (closed circles) increases over gestation as the product of increased stroke volume (open circles) and heart rate (solid line). Source: Data from Ref. 80. Reproduced from Ref. 17, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

10. FIGURE 43.9 Total peripheral resistance decreases dramatically over the first 16 weeks of pregnancy. Source: Data from Ref. 80. Reproduced from Ref. 17, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

11. FIGURE Two-dimensional parasternal long axis echocardiographic view showing measurements of left ventricular outflow tract diameter (LVOT). Simultaneous EKG, flow velocity (CW Doppler) and pressure profile from subclavian pulse tracing (SPT) in pregnant woman. Source: From Ref. 79, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

12. FIGURE Increases in steady (W˙ STD) and oscillatory (W˙ OSC) power during gestation. Data are normalized to 8-week postpartum control values (mean ± SEM *p < 0.05 versus control, †p < 0.05 versus first trimester). Source: From Ref. 83, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

13. FIGURE Hematocrit (filled bars ± SD) and plasma erythropoietin concentrations (unfilled bars) in nonpregnant women and in pregnant women in each trimester. Source: Data from Ref. 119.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

14. FIGURE 43. 13 Lung volumes before and during term pregnancy
FIGURE Lung volumes before and during term pregnancy. IRV = inspiratory reserve volume; TV = tidal volume; ERV = expiratory reserve volume; RV = residual volume. Source: Data from Ref. 104.
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15. FIGURE Maximal percent changes in respiratory parameters during pregnancy compared to the nonpregnant state. TLC, total lung capacity; FRC, functional residual capacity; TV, tidal volume; VD, dead space volume; VEmin, minute volume, rate of expired gas per minute. Source: Data from Ref. 105.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

16. FIGURE Changes in renal plasma flow and glomerular filtration rate in normal human pregnancy. Percent changes in glomerular filtration rate (GFR; black line), effective renal plasma flow (ERPF; red line), and calculated filtration fraction (FF; GFR/ERPF) over the course of gestation and early postpartum are shown relative to the nonpregnant state. Data were drawn from published studies based on clearance of inulin or iodothalamate for GFR and on clearance of PAH for ERPF. Source: From Ref. 157, with permission.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

17. FIGURE 43. 16 Regulation of glomerular ultrafiltration
FIGURE Regulation of glomerular ultrafiltration. At any point along the length of a glomerular capillary, the force driving filtration is a function of net hydrostatic pressure favoring filtration (ΔP = glomerular capillary pressure Pgc minus the opposing intratubular pressure Pt) less the net colloid osmotic pressure (πgc) which also opposes filtration. Increased GFR can be induced by increase in plasma flow, by decrease in oncotic pressure, or by increase in glomerular capillary pressure. GFR is proportional to net ultrafiltration pressure (Puf), defined as the area dilineated by the, Pgc and πgc profiles (e.g., shaded area for πgc profile A). “Filtration equilibrium” refers to an oncotic pressure profile (e.g., solid line A or dashed line B) where filtration ceases prior to the end of the capillary. The rat operates in filtration equilibrium under basal conditions: With increased plasma flow rate, the πgc profile can shift to e.g., line B or line C; The parallel increase in Puf area reflects the increase in GFR due to elevation of plasma flow. In “filtration pressure disequilibrium” (πgc profile C), πgc rises sufficiently slowly that it never reaches ΔP; thus filtration continues to occur along the entire capillary length. Humans, in contrast to rat, are believed to operate basally in filtration disequilibrium. An increase in RPF thus cannot increase filtration surface area and thus has much more limited impact on GFR. Source: Adapted from Ref. 158.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition

18. FIGURE Enzymatic pathways for formation of the vasodilator angiotensin 1–7. Ang 1–7 can be formed from either Ang II by the action of angiotensin converting enzyme ACE2 or from angiotensin I via a two-step reaction requiring ACE 2 followed by ACE. Ang 1–7 has been reported to increase in the 3rd trimester of normal pregnancy, whereas levels in preeclamptic pregnancies were significantly reduced as compared to normal pregnancy. Source: From Ref. 256.
© 2015, Elsevier, Inc., Plant and Zeleznik, Knobil and Neill's Physiology of Reproduction, Fourth Edition