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Section 8 - Normal Values

Published online by Cambridge University Press:  15 November 2017

David James
University of Nottingham
Philip Steer
Imperial College London
Carl Weiner
University of Kansas
Bernard Gonik
Wayne State University, Detroit
Stephen Robson
University of Newcastle
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“Normal” has different meanings. In the context of physical or laboratory measurements, “normal” may mean “average,” “disease-free,” or “within a given statistical range.” However, it is important to know the characteristics of the population yielding “normal” values before deciding whether these values provide an appropriate reference range with which to compare an individual test result. Many laboratories now print reference ranges on their reports and highlight test values that fall outside these values as “abnormal.” When the test subject is a pregnant woman, a fetus, or a newborn, and the reference population is composed predominantly of middle-aged men, then comparisons are patently inappropriate. It is important to understand how the physiologic changes of pregnancy affect the results of various tests and measurements before deciding whether an out-of-range result is actually abnormal.

High-Risk Pregnancy
Management Options
, pp. 2087 - 2194
Publisher: Cambridge University Press
First published in: 2017

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Altman, DG. Practical Statistics for Medical Research. London: Chapman & Hall, 1991.
Altman, DG, Chitty, LS. Charts of fetal size: 1. Methodology. Br J Obstet Gynaecol 1994; 101: 2934.
Wald, NJ, George, L, Smith, D, et al. Serum screening for Down’s syndrome between 8 and 14 weeks of pregnancy. Br J Obstet Gynaecol 1996; 103: 407–12.
Kagan, KO, Etchegaray, A, Zhou, Y, Wright, D, Nicolaides, KH. Prospective validation of first-trimester combined screening for trisomy 21. Ultrasound Obstet Gynecol 2009; 34: 1418.
Dawes, MG, Grudzinkas, JG. Patterns of maternal weight gain in pregnancy. Br J Obstet Gynaecol 1991; 98: 195201.
Rasmussen, KM, Catalano, PM, Yaktine, AL. New guidelines for weight gain during pregnancy: what obstetrician/gynecologists should know. Curr Opin Obstet Gynecol 2009; 21: 521–6.
Rosso, P. A new chart to monitor weight gain during pregnancy. Am J Clin Nutr 1985; 41: 644–52.
Siega-Riz, AM, Laraia, B. The implications of maternal overweight and obesity on the course of pregnancy and birth outcomes. Maternal Child Health J 2006; 10: S153–6.
Carmichael, S, Abrams, B, Selvin, S. The pattern of maternal weight gain in women with good pregnancy outcomes. Am J Public Health 1997; 87: 1984–8.
Picciano, M. Pregnancy and lactation: physiological adjustment, nutritional requirements and the role of dietary supplements. J Nutr 2003: 133: 1997S2000S.
Mahendru, AA, Everett, TR, Wilkinson, IB, et al. A longitudinal study of maternal cardiovascular function from preconception to the postpartum period. J Hypertens 2014; 32: 849–56.
Grindheim, G, Estensen, ME, Langesaeter, E, et al. Changes in blood pressure during healthy pregnancy: a longitudinal cohort study. J Hypertens 2012; 30: 342–50.
Spatling, L, Fallenstein, F, Huch, A, et al. The variability of cardiopulmonary adaptation to pregnancy at rest and during exercise. Br J Obstet Gynaecol 1992; 99 (Suppl 8): 140.
Clapp, JF. Maternal heart rate in pregnancy. Am J Obstet Gynecol 1985; 152: 659–60.
Savu, O, Jurcuţ, R, Giuşcă, S, et al. Morphological and functional adaptation of the maternal heart during pregnancy. Circ Cardiovasc Imaging 2012; 5: 289–97.
Melchiorre, K, Sharma, R, Thilaganathan, B. Cardiac structure and function in normal pregnancy. Curr Opin Obstet Gynecol 2012; 24: 413–21.
Ducas, RA, Elliott, JE, Melnyk, SF, et al. Cardiovascular magnetic resonance in pregnancy: insights from the cardiac hemodynamic imaging and remodeling in pregnancy (CHIRP) study. J Cardiovasc Magn Reson 2014; 16: 1.
Clark, SL, Cotton, DB, Lee, W, et al. Central hemodynamic assessment of normal term pregnancy. Am J Obstet Gynecol 1989; 161: 1439–42.
Auler, JOC, Torres, MLA, Cardoso, MM, et al. Clinical evaluation of the flotrac/vigileoTM system for continuous cardiac output monitoring in patients undergoing regional anesthesia for elective caesarean section: a pilot study. Clinics 2010; 65: 793–8.
Carruth, JE, Mirvis, SB, Brogan, DR, Wenger, NK. The electrocardiogram in normal pregnancy. Am Heart J 1981; 102: 1075–8.
Goloba, M, Nelson, S, Macfarlane, P. The electrocardiogram in pregnancy. Comput Cardiol 2010: 37: 693–6.
Asher, UA, Ben-Shlomo, I, Said, M, Nabil, H. The effects of exercise induced tachycardia on the maternal electrocardiogram. Br J Obstet Gynaecol 1993; 100: 41–5.
Shivvers, SA, Wians, FH, Keffer, JH, Ramin, SM. Maternal cardiac troponin I levels during normal labor and delivery. Am J Obstet Gynecol 1999; 180: 122–7
Abramov, Y, Abramov, D, Abrahamov, A, Durst, R, Schenker, J. Elevation of serum creatine phosphokinase and its MB isoenzyme during normal labor and early puerperium. Acta Obstet Gynecol Scand 1996; 75: 255–60.
Hameed, AB, Chan, K, Ghamsary, M, Elkayam, U. Longitudinal changes in the B-type natriuretic peptide levels in normal pregnancy and postpartum. Clin Cardiol 2009; 32: E60–2.
Yurteri-Kaplan, L, Saber, S, Zamudio, S, et al. Brain natriuretic peptide in term pregnancy. Reprod Sci 2012; 19: 520–5.
Lucius, H, Gahlenbeck, H, Kleine, HO, et al. Respiratory functions, buffer system, and electrolyte concentrations of blood during human pregnancy. Resp Physiol 1970; 9: 311–17.
Gazioglu, K, Kaltreider, NL, Rosen, M, Yu, PN. Pulmonary function during pregnancy in normal women and in patients with cardiopulmonary disease. Thorax 1970; 25: 445–50.
Grindheim, G, Toska, K, Estensen, ME, Rosseland, L. Changes in pulmonary function during pregnancy: a longitudinal cohort study. BJOG 2012; 119: 94101.
Lemos, A, de Souza, A, Figueiroa, J, Cabral-Filho, J, de Andrade, A. Respiratory muscle strength in pregnancy. Resp Med 2010; 104: 1638–44.
Morris, JK, Mutton, DE, Alberman, E. Revised estimates of the maternal age specific live birth prevalence of Down’s syndrome. J Med Screen 2002: 9: 26.
Ferguson-Smith, M. Prenatal chromosome analysis and its impact on the birth incidence of chromosome disorders. Br Med Bull 1983; 39: 355–64.
Loane, M, Morris, JK, et al. Twenty year trends in the prevalence of Down syndrome and other trisomies in Europe: impact of maternal age and prenatal screening. Eur J Hum Genet 2013; 21: 2733.
Robertson, EG, Cheyne, GA. Plasma biochemistry in relation to oedema of pregnancy. J Obstet Gynaecol Br Commonw 1972; 79: 769–76.
Larsson, A, Palm, M, Hansson, LO, et al. Reference values for alpha 1-acid glycoprotein, alpha 1-antitrypsin, albumin, haptoglobin, C-reactive protein, IgA, IgG and IgM during pregnancy. Acta Obstet Gynecol Scand 2008; 87: 1084–8.
Larsson, A, Palm, M, Hansson, LO, Axelsson, O. Reference values for clinical chemistry tests during normal pregnancy. BJOG 2008; 115: 874–81.
Rustad, P. Reference intervals for 25 of the most frequently used properties in clinical chemistry. Proposal by the Nordic Reference Interval Project (NORIP). Klinisk Biokemi i Norden 2003; 15: 1017.
Adeniyi, FA, Olatunbosun, DA. Origins and significance of the increased plasma alkaline phosphatase during normal pregnancy and pre-eclampsia. Br J Obstet Gynaecol 1984; 91: 857–62.
Girling, JC, Dow, E, Smith, JH. Liver function tests in pre-eclampsia: Importance of comparison with a reference range derived for normal pregnancy. Br J Obstet Gynaecol 1997; 104: 246–50.
David, AL, Kotecha, M, Girling, JC. Factors influencing postnatal liver function tests. Br J Obstet Gynecol 2000; 107: 1421–6.
Xydas, NP, May, JH, Henson, MC. Maternal serum amylase and lipase profiles in pregnancy: determinations in both once-sampled and multisampled patient cohorts. South Med J 1996; 89: 199203.
Kratz, A, Ferraro, M, Sluss, PM, Lewandrowski, KB. Laboratory reference values. N Engl J Med 2004; 351: 1548–63.
Heikkinene, J, Mäentausta, O, Ylöstalo, P, Jänne, O. Changes in serum bile acid concentrations during normal pregnancy, in patients with intrahepatic cholestasis of pregnancy and in pregnant women with itching. Br J Obstet Gynaecol 1981; 88: 240–5.
Egan, N, Bartels, Ä, Khashan, A, et al. Reference standard for serum bile acids in pregnancy. BJOG 2012;1 19: 493–8. doi: 10.1111/j.1471-0528.2011.03245.x.
Kiilholma, P, Gronroos, M, Liukko, P, et al. Maternal serum copper and zinc concentrations in normal and small-for-date pregnancies. Gynecol Obstet Invest 1984; 18: 212–16.
Louro, MO, Cocho, JA, Tutor, JC. Assessment of copper status in pregnancy by means of determining the specific oxidase activity of ceruloplasmin. Clin Chim Acta 2001; 312: 123–7.
Potter, JM, Nestel, PJ. The hyperlipidemia of pregnancy in normal and complicated pregnancies. Am J Obstet Gynecol 1979; 133: 165–70.
Lind, T, Godfrey, KA, Otun, H. Changes in serum uric acid concentrations during normal pregnancy. Br J Obstet Gynaecol 1984; 91: 128–32.
Davison, JM, Noble, MCB. Serial changes in 24 hour creatinine clearance during normal menstrual cycles and the first trimester of pregnancy. Br J Obstet Gynaecol 1981; 88: 1017.
Davison, JM, Dunlop, W, Ezimokhai, M. 24-hour creatinine clearance during the third trimester of normal pregnancy. Br J Obstet Gynaecol 1980; 87: 106–9.
Davison, JM, Dunlop, W. Renal haemodynamics and tubular function in normal human pregnancy. Kidney Int 1980; 18: 152–61.
Hytten, FE, Cheyne, GA. The aminoaciduria of pregnancy. J Obstet Gynaecol Br Commonw 1972; 79: 424–32.
Maybury, H, Waugh, J. Proteinuria in pregnancy: just what is significant? Fetal Matern Med Rev 2005; 16: 7195.
Risberg, A, Larsson, A, Olsson, K, et al. Relationship between urinary albumin and albumin/creatinine ratio during normal pregnancy and pre-eclampsia. Scand J Clin Lab Invest 2004; 64: 1724.
Lind, T, Billewicz, WZ, Brown, G. A serial study of changes occurring in the oral glucose tolerance test during pregnancy. J Obstet Gynaecol Br Commonw 1973; 80: 1033–9.
Mills, JL, Jovanovic, L, Knopp, R, et al. Physiological reduction in fasting plasma glucose concentration in the first trimester of normal pregnancy: the Diabetes in Early Pregnancy study. Metabolism 1998: 47: 1140–4.
Chen, X, Scholl, TO. Ethnic differences in C-peptide/insulin/glucose dynamics in young pregnant women. J Clin Endocrinol Metab 2002; 87: 4642–6.
Hatem, M, Anthony, F, Hogston, P, Rowe, DJ, Dennis, KJ. Reference values for 75 g oral glucose tolerance test in pregnancy. Br Med J 1988; 296: 676–8.
Forest, JC, Garrido-Russo, M, LeMay, A, et al. Reference values for the oral glucose tolerance test at each trimester of pregnancy. Am J Clin Pathol 1983; 80: 828–31.
Agardh, CD, Aberg, A, Norden, N. Glucose levels and insulin secretion during a 75 g glucose challenge test in normal pregnancy. J Intern Med 1996; 240: 303–9.
Roberts, AB, Baker, JR. Serum fructosamine: a screening test for diabetes in pregnancy. Am J Obstet Gynecol 1986; 154: 1027–30.
O’Connor, C, O’Shea, PM, Owens, LA, et al. Trimester-specific reference intervals for haemoglobin A1c (HbA1c) in pregnancy. Clin Chem Lab Med 2012; 50: 905–9.
Wang, Y, Walsh, SW, Guo, J, Zhang, J. Maternal levels of prostacyclin, thromboxane, vitamin E, and lipid peroxides throughout normal pregnancy. Am J Obstet Gynecol 1991; 165: 1690–4.
Ortega, RM, Quintas, ME, Andres, P, et al. Ascorbic acid levels in maternal milk: Differences with respect to ascorbic acid status during the third trimester of pregnancy. Br J Nutr 1998; 79: 431–7.
Milman, N, Bergholt, T, Byg, KE, et al. Reference intervals for haematological variables during normal pregnancy and postpartum in 434 healthy Danish women. Eur J Haematol 2007; 79: 3946.
Edelstam, G, Lowbeer, C, Kral, G, et al. New reference values for routine blood samples and human neutrophilic lipocalin during third trimester pregnancy. Scand J Clin Lab Invest 2001; 61: 583–92.
Taylor, DJ, Lind, T. Red cell mass during and after normal pregnancy. Br J Obstet Gynaecol 1979; 86: 364–70.
Kuvin, SF, Brecher, G. Differential neutrophil counts in pregnancy. N Engl J Med 1962; 266: 877–8.
Valdimarsson, H, Mulholland, C, Fridriksdottir, V, Coleman, DV. A longitudinal study of leucocyte blood counts and lymphocyte responses in pregnancy: a marked early increase of monocyte-lymphocyte ratio. Clin Exp Immunol 1983; 53: 437–43.
James, TR, Reid, HL, Mullings, AM. Are published standards for haematological indices in pregnancy applicable across populations: an evaluation in healthy pregnant Jamaican women. BMC Pregnancy Childbirth 2008; 8: 811.
Fay, RA, Hughes, AO, Farron, NT. Platelets in pregnancy: hyperdestruction in pregnancy. Obstet Gynecol 1983; 61: 238–40.
Boehlen, F, Hohlfeld, P, Extermann, P, et al. Platelet count at term pregnancy: a reappraisal of the threshold. Obstet Gynecol 2000; 95: 2933.
Fenton, V, Saunders, K, Cavill, I. The platelet count in pregnancy. J Clin Pathol 1977; 30: 68–9.
Beilin, Y, Arnold, I, Hossain, S. Evaluation of the platelet function analyzer (PFA-100®) vs. the thromboelastogram (TEG) in the parturient. Int J Obstet Anesth 2006; 15: 712.
Fenton, V, Cavill, I, Fisher, J. Iron stores in pregnancy. Br J Haematol 1977; 37: 145–9.
Cikot, R, Steegers-Theunissen, R, Thomas, C, et al. Longitudinal vitamin and homocysteine levels in normal pregnancy. Br J Nutr 2001; 85: 4958.
Milman, N, Byg, KE, Hvas, AM, et al. Erythrocyte folate, plasma folate and plasma homocysteine during normal pregnancy and postpartum: a longitudinal study comprising 404 Danish women. Eur J Haematol 2006; 76: 200–5.
Chanarin, I, Rothman, D, Ward, A, Perry, J. Folate status and requirement in pregnancy. Br Med J 1968; 2: 390–4.
Walker, MC, Smith, GN, Perkins, SL, et al. Changes in homocysteine levels during normal pregnancy. Am J Obstet Gynecol 1999; 180: 660–4.
McDonald, SD, Perkin, SL, Jodouin, CA, Walker, MA. Folate levels in pregnant women who smoke: An important gene/environment interaction. Am J Obstet Gynecol 2002; 187: 620–5.
Letsky, E. The haematological system. In Hyten, F, Chamberlain, G (eds), Clinical Physiology in Obstetrics, 2nd edn. Oxford: Blackwell, 1991, pp. 3982.
Koebnick, C, Heins, UA, Dagnelie, PC, et al. Longitudinal concentrations of vitamin B12-binding proteins during uncomplicated pregnancy. Clin Chem 2002; 48: 928–33.
Clark, P, Brennand, J, Conkie, JA, et al. Activated protein C sensitivity, protein C, protein S and coagulation in normal pregnancy. Thromb Haemost 1998; 79: 1166–70.
Stirling, Y, Woolf, L, North, WR, et al. Haemostasis in normal pregnancy. Thromb Haemost 1984; 52: 176–82.
Bonnar, J, McNicol, GP, Douglas, AS. Fibrinolytic enzyme system and pregnancy. Br Med J 1969; 3: 387–9.
Cadroy, Y, Grandjean, H, Pichon, J, et al. Evaluation of six markers of haemostatic system in normal pregnancy and pregnancy complicated by hypertension or pre-eclampsia. Br J Obstet Gynaecol 1993; 100: 416–20.
Gallery, ED, Raftos, J, Gyory, AZ, Wells, JV. A prospective study of serum complement (C3 and C4) levels during normal human pregnancy: effect of the development of pregnancy-associated hypertension. Aust N Z J Med 1981; 11: 243–5.
Schena, FP, Alanno, C, Selvaggi, L, et al. Behaviour of immune complexes and the complement system in normal pregnancy and pre-eclampsia. J Clin Lab Immunol 1982; 7: 21–6.
Jenkins, JS, Powell, RJ. C3 degradation products (C3d) in normal pregnancy. J Clin Pathol 1987; 40: 1362–3.
Hytten, FE, Lind, T. Volume and composition of the blood. In Diagnostic Indices in Pregnancy. Basel: Documenta Geigy, 1973, pp. 3654.
O’Leary, PC, Boyne, P, Atkinson, G, et al. Longitudinal study of serum thyroid hormone levels during normal pregnancy. Int J Gynecol Obstet 1992; 38: 171–9.
Stricker, R, Echenard, M, Eberhart, R, et al. Evaluation of maternal thyroid function during pregnancy: the importance of using gestation age-specific reference intervals. Eur J Endocrinol 2007; 175: 509–14.
Man, EB, Reid, WA, Hellegers, AE, Jones, WS. Thyroid function in human pregnancy. Am J Obstet Gynecol 1969; 103: 338–47.
Haddow, JE, Knight, GJ, Palomaki, GE, et al. The reference range and within-person variability of thyroid stimulating hormone during the first and second trimesters of pregnancy.J Med Screen 2004; 11: 170–4.
Stagnaro-Green, A, Abalovich, M, Alexander, E, et al. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid 2011; 21: 145.
Shen, FX, Xie, ZW, Lu, SM, et al. Gestational thyroid reference intervals in antibody-negative Chinese women. Clin Biochem 2014; 47: 673–5.
Marwaha, RK, Chopra, S, Gopalakrishnan, S, et al. Establishment of reference range for thyroid hormones in normal pregnant Indian women. BJOG 2008; 115: 602–6.
De Leo, V, La Marca, A, Lanzetta, D, Morgante, G. Thyroid function in early pregnancy: I. Thyroid-stimulating response to thyrotropin-releasing hormone. Gynecol Endocrinol 1998; 12: 191–6.
Soldin, OP, Hilakivi-Clarke, L, Weiderpass, E, Soldin, SJ. Trimester-specific reference intervals for thyroxine and triiodothyronine in pregnancy in iodine-sufficient women using isotope dilution tandem mass spectrometry and immunoassays. Clin Chim Acta 2004; 349: 181–9.
Kahric-Janicic, N, Soldin, SJ, Soldin, OP, et al. Tandem mass spectrometry improves the accuracy of free thyroxine measurements during pregnancy. Thyroid 2007; 17: 303–11.
Soldin, OP, Tractenberg, RE, Holowell, JG, et al. Trimester-specific changes in maternal thyroid hormone. Thyrotropin, and thyroglobulin concentrations during gestation: trends and associations across trimesters in iodine sufficiency. Thyroid 2004; 14: 1084–90.
Natrajan, PG, McGarrigle, HHG, Lawrence, DM, Lachelin, GCL. Plasma noradrenaline and adrenaline levels in normal pregnancy and in pregnancy-induced hypertension. Br J Obstet Gynaecol 1982; 89: 1041–5.
Rubin, PC, Butters, L, McCabe, R, Reid, JL. Plasma catecholamines in pregnancy-induced hypertension. Clin Sci 1986; 71: 111–15.
Beilin, LJ, Deacon, J, Michael, CA, et al. Diurnal rhythms of blood pressure, plasma renin activity, angiotensin II and catecholamines in normotensive and hypertensive pregnancies. Clin Exp Hypertens B 1983; B2: 271–93.
Carr, BR, Parker, CR, Madden, JD, et al. Maternal plasma adrenocorticotrophin and cortisol relationships throughout human pregnancy. Am J Obstet Gynecol 1981; 139: 416–22.
Nolten, WE, Lindheimer, MD, Rueckert, PA, et al. Diurnal patterns and regulation of cortisol secretion in pregnancy. J Clin Endocrinol Metab 1980; 51: 466–72.
Suri, D, Moran, J, Hibbard, JU, et al. Assessment of adrenal reserve in pregnancy: Defining the normal response to the adrenocorticotrophin stimulation test. J Clin Endocrinol Metab 2006; 91: 3866–72.
Demey-Ponsart, E, Foidart, JM, Sulon, J, Sodoyez, JC. Serum CBG, free and total cortisol and circadian patterns of adrenal function in normal pregnancy. J Steroid Biochem 1982; 16: 165–9.
Rees, LH, Burke, CW, Chard, T, et al. Possible placental origin of ACTH in normal human pregnancy. Nature 1975; 254: 620–2.
Doe, RP, Fernandez, R, Seal, US. Measurement of corticosteroid- binding globulin in man. J Clin Endocrinol 1964; 24: 1029–39.
Migeon, CJ, Kenny, FM, Taylor, FH. Cortisol production rate: VIII. Pregnancy. J Clin Endocrinol 1968; 28: 661–6.
Pearson Murphy, BE, Okouneff, LM, Klein, GP, Ngo, SH. Lack of specificity of cortisol determinations in human urine. J Clin Endocrinol Metab 1981; 53: 91–9.
Nolten, WE, Lindheimer, MD, Oparil, S, Ehrlich, EN. Desoxycorticosterone in normal pregnancy: I. Sequential studies of the secretory patterns of desoxycorticosterone, aldosterone, and cortisol. Am J Obstet Gynecol 1978; 132: 414–20.
Garner, PR. Pituitary and adrenal disorders. In Burrow, GN, Ferris, TF (eds), Medical Complications during Pregnancy, 4th edn. Philadelphia, PA: Saunders, 1995, pp. 188209.
Biswas, S, Rodek, CH. Plasma prolactin levels during pregnancy. Br J Obstet Gynaecol 1976; 83: 683–7.
Boyer, RM, Finkelstein, JW, Kapen, S, Hellman, L. Twenty-four hour prolactin (Prl) secretory patterns during pregnancy. J Clin Endocrinol Metab 1975; 40: 1117–20.
Rigg, LA, Yen, SSC. Multiphasic prolactin secretion during parturition in human subjects. Am J Obstet Gynecol 1977; 128: 215–18.
Jacobs, HS. The hypothalamus and pituitary gland. In Hytten, F, Chamberlain, G (eds), Clinical Physiology in Obstetrics, 2nd edn. Oxford: Blackwell, 1991, pp. 345–56.
Pitkin, RM, Reynolds, WA, Williams, GA, Hargis, GK. Calcium metabolism in normal pregnancy: a longitudinal study. Am J Obstet Gynecol 1979; 133: 781–7.
Zhang, JY, Lucey, AJ, Horgan, R, Kenny, LC, Kiely, M. Impact of pregnancy on vitamin D status: a longitudinal study. Br J Nutr 2014; 112: 1081–7.
Seki, K, Makimura, N, Mitsui, C, et al. Calcium-regulating hormones and osteocalcin levels during pregnancy: A longitudinal study. Am J Obstet Gynecol 1991; 164: 1248–52.
Biagiotti, R, Brizzi, L, Periti, E, et al. First trimester screening for Down’s syndrome using maternal serum PAPP-A and free β-HCG in combination with fetal nuchal translucency thickness. Br J Obstet Gynaecol 1998; 105: 917–20.
Seppala, M, Ruoslahti, E. Radioimmunoassay of maternal alpha fetoprotein during pregnancy and delivery. Am J Obstet Gynecol 1972; 112: 208–12.
Haddow, JE, Palomaki, GE. Maternal protein enzyme analyses. In Reece, EA, Hobbins, JC, Mahoney, MJ, Petrie, RH (eds), Medicine of the Fetus and Mother. Philadelphia, PA: Lippincott, 1992, pp. 653–67.
Batzer, FR, Schlaff, S, Goldfarb, AF, Corson, SL. Serial β-subunit human chorionic gonadotropin doubling time as a prognosticator of pregnancy outcome in an infertile population. Fertil Steril 1981; 35: 307–11.
Brody, S, Carlstrom, G. Human chorionic gonadotropin pattern in serum and its relation to the sex of the fetus. J Clin Endocrinol 1965; 25: 792–7.
Josimovich, JB, Kosor, B, Boccella, L, et al. Placental lactogen in maternal serum as an index of fetal health. Obstet Gynecol 1970; 36: 244–50.
Beck, P, Parker, ML, Daughaday, WH. Radioimmunologic measurement of human placental lactogen in plasma by a double antibody method during normal and diabetic pregnancies. J Clin Endocrinol 1965; 25: 1457–62.
Mills, MS. Ultrasonography of Early Embryonic Growth and Fetal Development. MD thesis, University of Bristol, 1992.
Papageorghiou, AT, Kennedy, SH, Salomon, LJ, et al. International standards for early fetal size and pregnancy dating based on ultrasound measurement of crown-rump length in the first trimester of pregnancy. Ultrasound Obstet Gynecol 2014; 44: 641–8.
Ioannou, C, Sarris, I, Hoch, L, et al. Standardisation of crown-rump length measurement. Br J Obstet Gynaecol 2013; 120 (Suppl 2): 3841.
Robinson, HP, Fleming, JEE. A critical evaluation of sonar crown-rump length measurements. Br J Obstet Gynaecol 1975; 82: 702–10.
Pexters, A, Daemen, A, Bottomley, C, et al. New crown-rump length curve based on over 3500 pregnancies. Ultrasound Obstet Gynecol 2010; 35: 650–5.
Napolitano, R, Dhami, J, Ohuma, EO, et al. Pregnancy dating by fetal crown-rump length: a systematic review of charts. Br J Obstet Gynaecol 2014; 121: 556–65.
Nicolaides, KH, Azar, G, Byrne, D, et al. Fetal nuchal translucency: Ultrasound screening for chromosomal defects in first trimester of pregnancy. BMJ 1992; 304: 867–9.
Pandya, PP, Snijders, RM, Johnson, SP, et al. Screening for fetal trisomies by maternal age and fetal nuchal translucency thickness at 10–14 weeks of gestation. Br J Obstet Gynaecol 1995; 102: 957–62.
Nicolaides, KH, Brizot, ML, Snijders, RJM. Fetal nuchal translucency: Ultrasound screening for fetal trisomy in the first trimester of pregnancy. Br J Obstet Gynaecol 1994; 101: 782–6.
Papageorghiou, AT, Ohuma, EO, Altman, DG, et al. International standards for fetal growth based on serial ultrasound measurements: the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project. Lancet 2014; 384: 869–79.
Chitty, LS, Altman, DG, Henderson, A, Campbell, S. Charts of fetal size: 2. Head measurements. Br J Obstet Gynaecol 1994; 101: 3543.
Ioannou, C, Talbot, K, Ohuma, E, et al. Systematic review of methodology used in ultrasound studies aimed at creating charts of fetal size. Br J Obstet Gynaecol 2012: 119: 1425–39.
Kurmanavicius, J, Wright, EM, Royston, P, et al. Fetal ultrasound biometry: 1. Head reference values. Br J Obstet Gynaecol 1999; 106: 126–35.
Chitty, LS, Altman, DG, Henderson, A, Campbell, S. Charts of fetal size: 3. Abdominal measurements. Br J Obstet Gynaecol 1994; 101: 125–31.
Kurmanavicius, J, Wright, EM, Royston, P, et al. Fetal ultrasound biometry: 2. Abdomen and femur length reference values. Br J Obstet Gynaecol 1999; 106: 136–43.
Chitty, LS, Altman, DG, Henderson, A, Campbell, S. Charts of fetal size: 4. Femur length. Br J Obstet Gynaecol 1994; 101: 132–5.
Snijders, RJM, Nicolaides, KH. Fetal biometry at 14–40 weeks’ gestation. Ultrasound Obstet Gynecol 1994; 4: 3448.
Papageorghiou, AT, Kemp, B, Stones, W, et al. Ultrasound-based gestational-age estimation in late pregnancy. Ultrasound Obstet Gynecol 2016; 48: 719–26.
Chitty, LS, Altman, DG. Charts of fetal size. In Dewbury, K, Meire, H, Cosgrove, D (eds), Ultrasound in Obstetrics and Gynaecology. Edinburgh: Churchill Livingstone, 1993, pp. 513–95.
Merz, E, Kim-Kern, MS, Pehl, S. Ultrasonic mensuration of fetal limb bones in the second and third trimesters. J Clin Ultrasound 1987; 15: 175–83.
Jeanty, P. Fetal biometry. In Fleischer, AC, Romero, R, Manning, FA, et al. (eds), The Principles and Practice of Ultrasonography in Obstetrics and Gynecology, 4th edn. Norwalk, CT, Appleton & Lange, 1991, pp. 93108.
Romero, R, Athanassiadis, AP, Sirtori, M, Inati, M. Fetal skeletal anomalies. In Fleischer, AC, Romero, R, Manning, FA, et al. (eds), The Principles and Practice of Ultrasonography in Obstetrics and Gynecology, 4th edn. Norwalk, CT: Appleton & Lange, 1991, pp. 277306.
Grannum, P, Bracken, M, Silverman, R, Hobbins, JC. Assessment of fetal kidney size in normal gestation by comparison of ratio of kidney circumference to abdominal circumference. Am J Obstet Gynecol 1980; 136: 249–54.
Mayden, KL, Tortora, M, Berkowitz, RL, et al. Orbital diameters: A new parameter for prenatal diagnosis and dating. Am J Obstet Gynecol 1982; 144: 289–97.
International Society of Ultrasound in Obstetrics and Gynecology. Sonographic examination of the fetal central nervous system: guidelines for performing the “basic examination” and the “fetal neurosonogram”. Ultrasound Obstet Gynecol 2007; 29: 109–16.
Goldstein, I, Reece, EA, Pilu, G, et al. Cerebellar measurements with ultrasonography in the evaluation of fetal growth and development. Am J Obstet Gynecol 1987; 156: 1065–9.
Roberts, AB, Mitchell, JM, Pattison, NS. Fetal liver length in normal and isoimmunized pregnancies. Am J Obstet Gynecol 1989; 161: 42–6.
Shimizu, T, Salvador, L, Allanson, J, et al. Ultrasonographic measurements of fetal ear. Obstet Gynecol 1992; 80: 381384.
Birnholz, JC, Farrell, E. Fetal ear length. Pediatrics 1988; 81: 555–8.
Chitkara, U, Rosenberg, J, Chervenak, FA, et al. Prenatal sonographic assessment of the fetal thorax: normal values. Am J Obstet Gynecol 1987; 156: 1069–74.
Ong, S, Lim, MN, Fitzmaurice, A, et al. The creation of twin centile curves for size. BJOG 2002; 109: 753–8.
Stirrup, OT, Khalil, A, D’Antonio, F, et al. Fetal growth reference ranges in twin pregnancy: analysis of the Southwest Thames Obstetric Research Collaborative (STORK) multiple pregnancy cohort. Ultrasound Obstet Gynecol 2015; 45: 301–7.
Reece, EA, Yarkoni, S, Abdalla, M, et al. A prospective longitudinal study of growth in twin gestations compared with growth in singleton pregnancies: I. The fetal head. J Ultrasound Med 1991; 10: 439–43.
Reece, EA, Yarkoni, S, Abdalla, M, et al. A prospective longitudinal study of growth in twin gestations compared with growth in singleton pregnancies: II. The fetal limbs. J Ultrasound Med 1991; 10: 445–50.
Shushan, A, Mordel, N, Zajicek, G, et al. A comparison of sonographic growth curves of triplet and twin fetuses. Am J Perinatol 1993; 10: 388–91.
Wilcox, M, Gardosi, J, Mongelli, M, et al. Birth weight from pregnancies dated by ultrasonography in a multicultural British population. BMJ 1993; 307: 588–91.
Yudkin, PL, Aboualfa, M, Eyre, JA, et al. New birthweight and head circumference centiles for gestational ages 24 to 42 weeks. Early Hum Dev 1987; 15: 4552.
Thompson, AM, Billewicz, WZ, Hytten, FE. The assessment of fetal growth. J Obstet Gynaecol Br Commonw 1968; 75: 903–16.
Wilcox, MA, Johnson, IR, Maynard, PV, et al. The individualised birthweight ratio: A more logical outcome measure of pregnancy than birthweight alone. Br J Obstet Gynaecol 1993; 100: 342–7.
Williams, RL, Creasy, RK, Cunningham, GC, et al. Fetal growth and perinatal viability in California. Obstet Gynecol 1982; 59: 624–32.
Campbell, S, Wilkin, D. Ultrasonic measurement of fetal abdomen circumference in the estimation of fetal weight. Br J Obstet Gynaecol 1975; 82: 689–97.
Shepard, MJ, Richards, VA, Berkowiiz, RL, et al. An evaluation of two equations for predicting fetal weight by ultrasound. Am J Obstet Gynecol 1982; 142: 4754.
Hadlock, FP, Harrist, RB, Carpenter, RJ, et al. Sonographic estimation of fetal weight. Radiology 1984; 150: 535–40.
Brace, RA, Wolf, EJ. Normal amniotic fluid volume changes throughout pregnancy. Am J Obstet Gynecol 1989; 161: 382–8.
Moore, TR, Cayle, JE. The amniotic fluid index in normal human pregnancy. Am J Obstet Gynecol 1990; 162: 1168–73.
Fisk, NM, Ronderos-Dumit, D, Tannirandorn, Y, et al. Normal amniotic pressure throughout gestation. Br J Obstet Gynaecol 1992; 99: 1822.
Gilbert, WM, Moore, TR, Brace, RA. Amniotic fluid volume dynamics. Fetal Med Rev 1991; 3: 89104.
Lind, T, Parkin, FM, Cheyne, GA. Biochemical and cytological changes in liquor amnii with advancing gestation. J Obstet Gynaecol Br Commonw 1969; 76: 673–83.
Saddiqi, TA, Meyer, RA, Korfhagen, J, et al. A longitudinal study describing confidence limits of normal fetal cardiac, thoracic and pulmonary dimensions from 20 to 40 weeks gestation. J Ultrasound Med 1993; 12: 731–6.
Steed, RD, Strickland, DM, Swanson, MS, et al. Normal fetal cardiac dimensions obtained by perpendicular imaging. Am J Cardiol 1998; 81: 1059–61.
Tan, J, Silverman, NH, Hoffman, JIE, et al. Cardiac dimensions determined by cross-sectional echocardiography in the normal human fetus from 18 weeks to term. Am J Cardiol 1992; 70: 1459–67.
Rizzo, G, Capponi, A, Arduini, D, Romanini, C. Ductus venosus velocity waveforms in appropriate and small for gestational age fetuses. Early Hum Dev 1994; 39: 1526.
Hecher, K, Campbell, S, Snijders, R, Nicolaides, K. Reference ranges for fetal venous and atrioventricular blood flow parameters. Ultrasound Obstet Gynecol 1994; 4: 381–90.
Rizzo, G, Arduini, D, Romanini, C. Inferior vena cava flow velocity waveforms in appropriate- and small-for-gestational-age fetuses. Am J Obstet Gynecol 1992; 166: 1271–80.
Rizzo, G, Capponi, A, Talone, PE, et al. Doppler indices from inferior vena cava and ductus venosus in predicting pH and oxygen tension in umbilical blood at cordocentesis in growthretarded fetuses. Ultrasound Obstet Gynecol 1996; 7: 401–10.
Hecher, K, Snijders, R, Campbell, S, Nicolaides, K. Fetal venous, intracardiac, and arterial blood flow measurements in intrauterine growth retardation: Relationship with fetal blood gases. Am J Obstet Gynecol 1995; 173: 1015.
Rizzo, G, Arduini, D. Fetal cardiac function in intrauterine growth retardation. Am J Obstet Gynecol 1991; 165: 876–82.
Van Splunder, P, Stijnen, T, Wladimiroff, JW. Fetal atrioventricular, venous and arterial flow velocity waveforms in the small for gestational age fetus. Pediatr Res 1997; 42: 765–75.
Mari, G, Deter, RL, Uerpairojkit, B. Flow velocity waveforms of the ductus arteriosus in appropriate and small-for-gestational age fetuses. J Clin Ultrasound 1996; 24: 185–96.
Rizzo, G, Capponi, A, Chaoui, R, et al. Blood flow velocity waveforms from peripheral pulmonary arteries in normally grown and growth-retarded fetuses. Ultrasound Obstet Gynecol 1996; 8: 8792.
Arduini, D, Rizzo, G. Normal values of pulsatility index from fetal vessels: a cross-sectional study on 1556 healthy fetuses. J Perinat Med 1990; 18: 165–72.
Kurmanavicius, J, Streicher, A, Wright, EM, et al. Reference values of fetal peak systolic blood velocity in the middle cerebral artery at 19–40 weeks of gestation. Ultrasound Obstet Gynecol 2001; 17: 50–3.
Mari, G, Deter, RL. Middle cerebral artery flow velocity waveforms in normal and small-for-gestational-age fetuses. Am J Obstet Gynecol 1992; 166: 12621270.
Veille, JC, Hanson, R, Tatum, K. Longitudinal quantitation of middle cerebral artery blood flow in normal human fetuses. Am J Obstet Gynecol 1993; 169: 1393–8.
Kurmanavicius, J, Florio, I, Wisser, J, et al. Reference resistance indices of the umbilical, fetal middle cerebral and uterine arteries at 24–42 weeks of gestation. Ultrasound Obstet Gynecol 1997; 10: 112–20.
Vyas, S, Nicolaides, KH, Bower, S, Campbell, S. Middle cerebral artery flow velocity waveforms in fetal hypoxaemia. Br J Obstet Gynaecol 1990; 97: 797803.
Sherer, DM. Prenatal ultrasonographic assessment of the middle cerebral artery: A review. Obstet Gynecol Surv 1997; 52: 444–55.
Mari, G, Adrignolo, A, Abuhamad, AZ, et al. Diagnosis of fetal anemia with Doppler ultrasound in the pregnancy complicated by maternal blood group immunisation. Ultrasound Obstet Gynecol 1995; 5: 400–5.
Mari, G. Noninvasive diagnosis by Doppler ultrasonography of fetal anemia due to maternal red-cell alloimmunization. N Engl J Med 2000; 342: 914.
Erskine, RLA, Ritchie, JWK. Umbilical artery blood flow characteristics in normal and growth-retarded fetuses. Br J Obstet Gynaecol 1985; 92: 605–10.
Bahado-Singh, RO, Kovanci, E, Jeffres, A, et al. The Doppler cerebroplacental ratio and perinatal outcome in intrauterine growth restriction. Am J Obstet Gynecol 1999; 180: 750–6.
Weiner, CP, Sipes, SL, Wenstrom, K. The effect of fetal age upon normal fetal laboratory values and venous pressure. Obstet Gynecol 1992; 79: 713–18.
Weiner, CP, Heilskov, J, Pelzer, G, et al. Normal values for human umbilical venous and amniotic fluid pressures and their alteration by fetal disease. Am J Obstet Gynecol 1989; 161: 714–17.
Weiner, CP. Intrauterine pressure: amniotic and fetal circulation. In Ludomirski, A, Nicolini, U, Bhutani, UK (eds), Therapeutic and Diagnostic Interventions in Early Life. New York, NY: Futura, 1995.
Sadovsky, G, Nicolaides, KH. Reference ranges for fetal heart rate patterns in normoxaemic nonanaemic fetuses. Fetal Ther 1989; 4: 61–8.
Arulkumaran, S, Ingemarsson, I, Montan, S, et al. Guidelines for Interpretation of Antepartum and Intrapartum Cardiotocography. Bracknell: Hewlett Packard, 1992.
National Institute of Child Health and Human Development Research Planning Workshop. Electronic fetal heart rate monitoring: research guidelines for interpretation. Am J Obstet Gynecol 1997; 177: 1385–90.
Manning, FA, Platt, LD, Sipos, L. Antepartum fetal evaluation: Development of a fetal biophysical profile. Am J Obstet Gynecol 1980; 136: 787–95.
Manning, FA, Baskett, TF, Morrison, I, Lange, I. Fetal biophysical profile scoring: A prospective study in 1184 high-risk patients. Am J Obstet Gynecol 1981; 140: 289–94.
Manning, FA. Fetal biophysical profile: a critical appraisal. Clin Obstet Gynecol 2002; 45: 975–85.
Takagi, K, Tanaka, H, Nishijima, S, et al. Fetal blood values by percutaneous umbilical blood sampling. Fetal Ther 1989; 4: 152–60.
Forestier, F. Some aspects of fetal biology. Fetal Ther 1987; 2: 181–7.
Weiner, CP. Human fetal bilirubin levels and fetal hemolytic disease. Am J Obstet Gynecol 1992; 166: 1449–54.
Ecomomides, DL, Nicolaides, KH, Campbell, S. Metabolic and endocrine findings in appropriate and small for gestational age fetuses. J Perinat Med 1991; 19: 97105.
Nicolini, U, Fisk, NM, Rodeck, CH, Beacham, J. Fetal urine biochemistry: an index of renal maturation and dysfunction. Br J Obstet Gynaecol 1992; 99: 4650.
Nicolaides, KH, Cheng, HH, Snijders, RJM, Moniz, CF. Fetal urine biochemistry in the assessment of obstructive uropathy. Am J Obstet Gynecol 1992; 166: 932–7.
Evans, MI, Sacks, AJ, Johnson, MP, et al. Sequential invasive assessment of fetal renal function and the intrauterine treatment of fetal obstructive uropathies. Obstet Gynecol 1991; 77: 545–50.
Wilkins, IA, Chitkara, U, Lynch, L, et al. The nonpredictive value of fetal urinary electrolytes: preliminary report of outcomes and correlations with pathological diagnosis. Am J Obstet Gynecol 1987; 157: 694–8.
Huch, A, Huch, R, Rooth, G. Guidelines for blood sampling and measurement of pH and blood gas values in obstetrics. Eur J Obstet Gynaecol Reprod Biol 1994; 54: 165–75.
Nicolaides, KH, Economides, DL, Soothill, PW. Blood gases, pH, and lactate in appropriate- and small-for-gestational-age fetuses. Am J Obstet Gynecol 1989; 161: 9961001.
Soothill, PW, Nicolaides, KH, Rodeck, CH, Campbell, S. Effect of gestational age on fetal and intervillous blood gas and acid-base values in human pregnancy. Fetal Ther 1986; 1: 168–75.
Nicolaides, KH, Thilaganathan, B, Mibashan, RS. Cordocentesis in the investigation of fetal erythropoiesis. Am J Obstet Gynecol 1989; 161: 1197–200.
Weiner, CP, Williamson, RA, Wenstrom, KD, et al. Management of fetal hemolytic disease by cordocentesis: I. Prediction of fetal anemia. Am J Obstet Gynecol 1991; 165: 546–53.
Davies, NP, Buggins, AGS, Snijders, RJM, et al. Blood leucocyte count in the human fetus. Arch Dis Child 1992; 67: 399403.
Abbas, A, Thilaganathan, B, Buggins, AGS, et al. Fetal plasma interferon gamma concentration in normal pregnancy. Am J Obstet Gynecol 1993; 168: 1414–16.
Nicolaides, KH, Rodeck, CH, Mibashan, RS, Kemp, JR. Have Liley charts outlived their usefulness? Am J Obstet Gynecol 1986; 155: 90–4.
Thorpe-Beeston, JG, Nicolaides, KH, Felton, CV, et al. Maturation of the secretion of thyroid hormone and thyroid stimulating hormone in the fetus. N Engl J Med 1991; 324: 532–6.
Duignan, NM, Studd, JW, Hughes, AO. Characteristics of normal labour in different racial groups. Br J Obstet Gynaecol 1975; 82: 593601.
National Institute for Health and Care Excellence. Intrapartum Care for Healthy Women and Babies. NICE Clinical Guideline CG190. London: NICE, 2017. (accessed September 2018).
Ayres-de-Campos, D, Spong, CY, Chandraharan, E; FIGO Intrapartum Fetal Monitoring Expert Consensus Panel. FIGO consensus guidelines on intrapartum fetal monitoring: Cardiotocography. Int J Gynaecol Obstet 2015; 131: 1324. doi: 10.1016/j.ijgo.2015.06.020.
Eskes, TK, Jongsma, HW, Houx, PC. Percentiles for gas values in human umbilical cord blood. Eur J Obstet Gynecol Reprod Biol 1983; 14: 341–6.
Wiberg, N, Kallen, K, Olofsson, P. Delayed umbilical cord clamping at birth has effects on arterial and venous blood gases and lactate concentrations. BJOG 2008; 115: 697703.
Wiberg, N, Kallen, K, Herbst, A, et al. Lactate concentration in umbilical cord blood is gestation age-dependent: a population-based study of 17,876 newborns. BJOG 2008; 115: 704–9.
Westgren, M, Divon, M, Horal, M, et al. Routine measurements of umbilical artery lactate levels in the prediction of perinatal outcome. Am J Obstet Gynecol 1995; 173: 1416–22.
Mercelina-Roumans, P, Breukers, R, Ubachs, J, Van Wersch, J. Hematological variables in cord blood of neonates of smoking and nonsmoking mothers. J Clin Epidemiol 1996; 49: 449–54.
Paterakis, GS, Lykopoulou, L, Papassotiriou, J, et al. Flow-cytometric analysis of reticulocytes in normal cord blood. Acta Haematol 1993; 90: 182–5.
Walka, MM, Sonntag, J, Kage, A, et al. Complete blood counts from umbilical cords of healthy term newborns by two automated cytometers. Acta Haematol 1998; 100: 167–73.
Perkins, SL, Livesey, JF, Belcher, J. Reference intervals for 21 clinical chemistry analytes in arterial and venous cord blood. Clin Chem 1993; 39: 1041–4.

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