Physiology of amniotic fluid volume regulation
- Michael G Ross, MD, MPH
Michael G Ross, MD, MPH
- Distinguished Professor of Obstetrics and Gynecology
- David Geffen School of Medicine at UCLA
- Marie H Beall, MD
Marie H Beall, MD
- Clinical Professor of Obstetrics and Gynecology
- Geffen School of Medicine at University of California, Los Angeles
Amniotic fluid (AF) is the liquid that surrounds the fetus after the first few weeks of gestation. During much of pregnancy, AF is derived almost entirely from the fetus and has a number of functions that are essential for normal growth and development :
●It helps to protect the fetus from trauma to the maternal abdomen
●It cushions the umbilical cord from compression between the fetus and uterus
●It has antibacterial properties that provide some protection from infection
●It serves as a reservoir of fluid and nutrients for the fetus
- Brace RA. Physiology of amniotic fluid volume regulation. Clin Obstet Gynecol 1997; 40:280.
- Casey BM, McIntire DD, Bloom SL, et al. Pregnancy outcomes after antepartum diagnosis of oligohydramnios at or beyond 34 weeks' gestation. Am J Obstet Gynecol 2000; 182:909.
- Golan A, Wolman I, Sagi J, et al. Persistence of polyhydramnios during pregnancy--its significance and correlation with maternal and fetal complications. Gynecol Obstet Invest 1994; 37:18.
- Gulbis B, Jauniaux E, Cotton F, Stordeur P. Protein and enzyme patterns in the fluid cavities of the first trimester gestational sac: relevance to the absorptive role of secondary yolk sac. Mol Hum Reprod 1998; 4:857.
- Campbell J, Wathen N, Perry G, et al. The coelomic cavity: an important site of materno-fetal nutrient exchange in the first trimester of pregnancy. Br J Obstet Gynaecol 1993; 100:765.
- Campbell J, Wathen N, Macintosh M, et al. Biochemical composition of amniotic fluid and extraembryonic coelomic fluid in the first trimester of pregnancy. Br J Obstet Gynaecol 1992; 99:563.
- Abramovich DR. Fetal factors influencing the volume and composition of liquor amnii. J Obstet Gynaecol Br Commonw 1970; 77:865.
- Abramovich, DR. The volume of amniotic fluid and its regulating factors. In: Amniotic Fluid — Research and Clinical Applications, 2nd ed, Fairweather, DV, Eskes TK (Eds), Excerpta Medica 1978. p.31.
- Gilbert WM, Brace RA. The missing link in amniotic fluid volume regulation: intramembranous absorption. Obstet Gynecol 1989; 74:748.
- Brace RA. Progress toward understanding the regulation of amniotic fluid volume: water and solute fluxes in and through the fetal membranes. Placenta 1995; 16:1.
- Wang S, Kallichanda N, Song W, et al. Expression of aquaporin-8 in human placenta and chorioamniotic membranes: evidence of molecular mechanism for intramembranous amniotic fluid resorption. Am J Obstet Gynecol 2001; 185:1226.
- Hanson RS, Powrie RO, Larson L. Diabetes insipidus in pregnancy: a treatable cause of oligohydramnios. Obstet Gynecol 1997; 89:816.
- Ross MG, Nijland MJ, Kullama LK. 1-Deamino-[8-D-arginine] vasopressin-induced maternal plasma hypoosmolality increases ovine amniotic fluid volume. Am J Obstet Gynecol 1996; 174:1118.
- Wladimiroff JW, Campbell S. Fetal urine-production rates in normal and complicated pregnancy. Lancet 1974; 1:151.
- Rabinowitz R, Peters MT, Vyas S, et al. Measurement of fetal urine production in normal pregnancy by real-time ultrasonography. Am J Obstet Gynecol 1989; 161:1264.
- Hedriana HL, Moore TR. Accuracy limits of ultrasonographic estimation of human fetal urinary flow rate. Am J Obstet Gynecol 1994; 171:989.
- Brace, RA, Ross, MG. Amniotic fluid volume regulation. In: Fetus and Neonate — Volume 4: Body fluids and kidney function, Brace, RA, Hanson, MA, Rodeck CH (Eds), Cambridge University Press 1998. p.88.
- Hedriana HL. Ultrasound measurement of fetal urine flow. Clin Obstet Gynecol 1997; 40:337.
- Lee SM, Park SK, Shim SS, et al. Measurement of fetal urine production by three-dimensional ultrasonography in normal pregnancy. Ultrasound Obstet Gynecol 2007; 30:281.
- Roberts TJ, Nijland MJ, Curran M, Ross MG. Maternal 1-deamino-8-D-arginine-vasopressin-induced sequential decreases in plasma sodium concentration: ovine fetal renal responses. Am J Obstet Gynecol 1999; 180:82.
- Ülker K, Çeçen K, Temur İ, et al. Effects of the maternal position and rest on the fetal urine production rate: a prospective study conducted by 3-dimensional sonography using the rotational technique (virtual organ computer-aided analysis). J Ultrasound Med 2011; 30:481.
- Stigter RH, Mulder EJ, Bruinse HW, Visser GH. Fetal urine production in late pregnancy. ISRN Obstet Gynecol 2011; 2011:345431.
- Touboul C, Boulvain M, Picone O, et al. Normal fetal urine production rate estimated with 3-dimensional ultrasonography using the rotational technique (virtual organ computer-aided analysis). Am J Obstet Gynecol 2008; 199:57.e1.
- Harding, R. Development of the respiratory system. In: Textbook of Fetal Physiology, Thorburn, GD, Harding, R (Eds), Oxford Medical Publications, 1994. p.140.
- Brace RA, Wlodek ME, Cock ML, Harding R. Swallowing of lung liquid and amniotic fluid by the ovine fetus under normoxic and hypoxic conditions. Am J Obstet Gynecol 1994; 171:764.
- Jellyman JK, Cheung CY, Brace RA. Amniotic fluid volume responses to esophageal ligation in fetal sheep: contribution of lung liquid. Am J Obstet Gynecol 2009; 200:313.e1.
- Grassi R, Farina R, Floriani I, et al. Assessment of fetal swallowing with gray-scale and color Doppler sonography. AJR Am J Roentgenol 2005; 185:1322.
- Miller JL, Sonies BC, Macedonia C. Emergence of oropharyngeal, laryngeal and swallowing activity in the developing fetal upper aerodigestive tract: an ultrasound evaluation. Early Hum Dev 2003; 71:61.
- Ross MG, Nijland MJ. Fetal swallowing: relation to amniotic fluid regulation. Clin Obstet Gynecol 1997; 40:352.
- Jang PR, Brace RA. Amniotic fluid composition changes during urine drainage and tracheoesophageal occlusion in fetal sheep. Am J Obstet Gynecol 1992; 167:1732.
- Kullama LK, Nijland MJ, Ervin MG, Ross MG. Intraamniotic deamino(D-Arg8)-vasopressin: prolonged effects on ovine fetal urine flow and swallowing. Am J Obstet Gynecol 1996; 174:78.
- Wilson SM, Olver RE, Walters DV. Developmental regulation of lumenal lung fluid and electrolyte transport. Respir Physiol Neurobiol 2007; 159:247.
- Bock JL. Metabolic profiling of amniotic fluid by proton nuclear magnetic resonance spectroscopy: correlation with fetal maturation and other clinical variables. Clin Chem 1994; 40:56.
- Yoshimura S, Masuzaki H, Gotoh H, Ishimaru T. Fetal redistribution of blood flow and amniotic fluid volume in growth-retarded fetuses. Early Hum Dev 1997; 47:297.
- Kimble RM, Harding JE, Kolbe A. Does gut atresia cause polyhydramnios? Pediatr Surg Int 1998; 13:115.
- Moore TR. Amniotic fluid dynamics reflect fetal and maternal health and disease. Obstet Gynecol 2010; 116:759.
- Faber JJ, Anderson DF. Regulatory response of intramembranous absorption of amniotic fluid to infusion of exogenous fluid in sheep. Am J Physiol 1999; 277:R236.
- Matsumoto LC, Cheung CY, Brace RA. Effect of esophageal ligation on amniotic fluid volume and urinary flow rate in fetal sheep. Am J Obstet Gynecol 2000; 182:699.
- Matsumoto LC, Bogic L, Brace RA, Cheung CY. Prolonged hypoxia upregulates vascular endothelial growth factor messenger RNA expression in ovine fetal membranes and placenta. Am J Obstet Gynecol 2002; 186:303.
- Matsumoto LC, Cheung CY, Brace RA. Increased urinary flow without development of polyhydramnios in response to prolonged hypoxia in the ovine fetus. Am J Obstet Gynecol 2001; 184:1008.
- Thurlow RW, Brace RA. Swallowing, urine flow, and amniotic fluid volume responses to prolonged hypoxia in the ovine fetus. Am J Obstet Gynecol 2003; 189:601.
- Daneshmand SS, Cheung CY, Brace RA. Regulation of amniotic fluid volume by intramembranous absorption in sheep: role of passive permeability and vascular endothelial growth factor. Am J Obstet Gynecol 2003; 188:786.
- Brace RA, Vermin ML, Huijssoon E. Regulation of amniotic fluid volume: intramembranous solute and volume fluxes in late gestation fetal sheep. Am J Obstet Gynecol 2004; 191:837.
- Gesteland KM, Anderson DF, Davis LE, et al. Intramembranous solute and water fluxes during high intramembranous absorption rates in fetal sheep with and without lung liquid diversion. Am J Obstet Gynecol 2009; 201:85.e1.
- Brace RA, Anderson DF, Cheung CY. Regulation of amniotic fluid volume: mathematical model based on intramembranous transport mechanisms. Am J Physiol Regul Integr Comp Physiol 2014; 307:R1260.
- Cho GJ, Hong HR, Kim SW, et al. Decreased umbilical orexin-A level is associated with idiopathic polyhydramnios. Acta Obstet Gynecol Scand 2015; 94:295.
- Wang S, Chen J, Beall M, et al. Expression of aquaporin 9 in human chorioamniotic membranes and placenta. Am J Obstet Gynecol 2004; 191:2160.
- Mann SE, Ricke EA, Torres EA, Taylor RN. A novel model of polyhydramnios: amniotic fluid volume is increased in aquaporin 1 knockout mice. Am J Obstet Gynecol 2005; 192:2041.
- Beall MH, Wang S, Yang B, et al. Placental and membrane aquaporin water channels: correlation with amniotic fluid volume and composition. Placenta 2007; 28:421.
- Prat C, Blanchon L, Borel V, et al. Ontogeny of aquaporins in human fetal membranes. Biol Reprod 2012; 86:48.
- Liu H, Zheng Z, Wintour EM. Aquaporins and fetal fluid balance. Placenta 2008; 29:840.
- Zheng Z, Liu H, Beall M, et al. Role of aquaporin 1 in fetal fluid homeostasis. J Matern Fetal Neonatal Med 2014; 27:505.
- Sha XY, Xiong ZF, Liu HS, et al. Pregnant phenotype in aquaporin 8-deficient mice. Acta Pharmacol Sin 2011; 32:840.
- Shioji M, Fukuda H, Kanzaki T, et al. Reduction of aquaporin-8 on fetal membranes under oligohydramnios in mice lacking prostaglandin F2 alpha receptor. J Obstet Gynaecol Res 2006; 32:373.
- Tanahashi H, Tian QB, Hara Y, et al. Polyhydramnios in Lrp4 knockout mice with bilateral kidney agenesis: Defects in the pathways of amniotic fluid clearance. Sci Rep 2016; 6:20241.
- Cheung CY, Anderson DF, Brace RA. Aquaporins in ovine amnion: responses to altered amniotic fluid volumes and intramembranous absorption rates. Physiol Rep 2016; 4.
- Bednar AD, Beardall MK, Brace RA, Cheung CY. Differential expression and regional distribution of aquaporins in amnion of normal and gestational diabetic pregnancies. Physiol Rep 2015; 3.
- Huang J, Qi HB. [Expression of aquaporin 8 in human fetal membrane and placenta of idiopathic polyhydramnios]. Zhonghua Fu Chan Ke Za Zhi 2009; 44:19.
- Zhu X, Jiang S, Hu Y, et al. The expression of aquaporin 8 and aquaporin 9 in fetal membranes and placenta in term pregnancies complicated by idiopathic polyhydramnios. Early Hum Dev 2010; 86:657.
- Zhu XQ, Jiang SS, Zhu XJ, et al. Expression of aquaporin 1 and aquaporin 3 in fetal membranes and placenta in human term pregnancies with oligohydramnios. Placenta 2009; 30:670.
- Brace RA, Wolf EJ. Normal amniotic fluid volume changes throughout pregnancy. Am J Obstet Gynecol 1989; 161:382.
- Magann EF, Bass JD, Chauhan SP, et al. Amniotic fluid volume in normal singleton pregnancies. Obstet Gynecol 1997; 90:524.
- Ounpraseuth ST, Magann EF, Spencer HJ, et al. Normal amniotic fluid volume across gestation: Comparison of statistical approaches in 1190 normal amniotic fluid volumes. J Obstet Gynaecol Res 2017; 43:1122.
- SOURCES OF AMNIOTIC FLUID
- Early gestation
- - Coelomic fluid
- - Amniotic fluid
- Mid gestation
- Late gestation
- - Fetal urination
- - Fetal lung secretions
- - Fetal swallowing
- - Intramembranous flow
- - Oral-nasal secretions and transmembranous flow
- AMNIOTIC FLUID OSMOLALITY, SODIUM, AND CHLORIDE
- REGULATION OF AMNIOTIC FLUID VOLUME
- NORMAL AMNIOTIC FLUID VOLUME ACROSS GESTATION
- SUMMARY AND RECOMMENDATIONS