title: Bacteria and endotoxin in meconium-stained amniotic fluid at term: could intra-amniotic infection cause meconium passage?
abstract: BACKGROUND
  Meconium-stained amniotic fluid (MSAF) is a common occurrence among women in spontaneous labor at term, and has been associated with adverse outcomes in both mother and neonate. MSAF is a risk factor for microbial invasion of the amniotic cavity (MIAC) and preterm birth among women with preterm labor and intact membranes. We now report the frequency of MIAC and the presence of bacterial endotoxin in the amniotic fluid of patients with MSAF at term.
  
  
  METHODS
  We conducted a cross-sectional study including women in presumed preterm labor because of uncertain dates who underwent amniocentesis, and were later determined to be at term (n = 108). Patients were allocated into two groups: (1) MSAF (n = 66) and (2) clear amniotic fluid (n = 42). The presence of bacteria was determined by microbiologic techniques, and endotoxin was detected using the Limulus amebocyte lysate (LAL) gel clot assay. Statistical analyses were performed to test for normality and bivariate comparisons.
  
  
  RESULTS
  Bacteria were more frequently present in patients with MSAF compared to those with clear amniotic fluid [19.6% (13/66) versus 4.7% (2/42); p < 0.05]. The microorganisms were Gram-negative rods (n = 7), Ureaplasma urealyticum (n = 4), Gram-positive rods (n = 2) and Mycoplasma hominis (n = 1). The LAL gel clot assay was positive in 46.9% (31/66) of patients with MSAF, and in 4.7% (2/42) of those with clear amniotic fluid (p < 0.001). After heat treatment, the frequency of a positive LAL gel clot assay remained higher in the MSAF group [18.1% (12/66) versus 2.3% (1/42), p < 0.05]. Median amniotic fluid IL-6 concentration (ng/mL) was higher [1.3 (0.7-1.9) versus 0.6 (0.3-1.2), p = 0.04], and median amniotic fluid glucose concentration (mg/dL) was lower [6 (0-8.9) versus 9 (7.4-12.6), p < 0.001] in the MSAF group, than in those with clear amniotic fluid.
  
  
  CONCLUSIONS
  MSAF at term was associated with an increased incidence of MIAC. The index of suspicion for an infection-related process in postpartum women and their neonates should be increased in the presence of MSAF.
authors.affiliation: Perinatology Research Branch, NICHD/NIH/DHHS , Bethesda, MD and Detroit, MI , USA .
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Bo Hyun
authors.initials: BH
authors.lastname: Yoon
authors.forename: Piya
authors.initials: P
authors.lastname: Chaemsaithong
authors.forename: Josef
authors.initials: J
authors.lastname: Cortez
authors.forename: Chan-Wook
authors.initials: CW
authors.lastname: Park
authors.forename: Rogelio
authors.initials: R
authors.lastname: Gonzalez
authors.forename: Ernesto
authors.initials: E
authors.lastname: Behnke
authors.forename: Sonia S
authors.initials: SS
authors.lastname: Hassan
authors.forename: Tinnakorn
authors.initials: T
authors.lastname: Chaiworapongsa
authors.forename: Lami
authors.initials: L
authors.lastname: Yeo
mesh_terms: D000293:Adolescent; D000328:Adult; D000653:Amniotic Fluid / Q000737:chemistry / Q000378:metabolism* / Q000382:microbiology; D001419:Bacteria / Q000302:isolation & purification*; D002821:Chorioamnionitis / Q000453:epidemiology* / Q000378:metabolism / Q000382:microbiology; D003430:Cross-Sectional Studies; D004731:Endotoxins / Q000302:isolation & purification*; D005260:Female; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000453:epidemiology / Q000209:etiology; D008470:Meconium / Q000378:metabolism* / Q000382:microbiology; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology* / Q000378:metabolism / Q000382:microbiology; D011644:Puerperal Disorders / Q000453:epidemiology / Q000209:etiology; D047929:Term Birth / Q000378:metabolism; D055815:Young Adult
chemical_list: D004731:Endotoxins
references.citation: Lancet. 2012 Jun 9;379(9832):2151-61
references.pmid: 22579125
references.citation: Acta Obstet Gynecol Scand. 2003 Feb;82(2):120-8
references.pmid: 12648172
references.citation: J Matern Fetal Neonatal Med. 2006 Aug;19(8):477-82
references.pmid: 16966112
references.citation: BJOG. 2002 Oct;109(10):1171-4
references.pmid: 12387472
references.citation: J Perinatol. 2008 Dec;28 Suppl 3:S1-2
references.pmid: 19057597
references.citation: J Pediatr Surg. 1994 Nov;29(11):1487-90
references.pmid: 7844729
references.citation: Obstet Gynecol. 1997 Oct;90(4 Pt 1):519-23
references.pmid: 9380308
references.citation: Am J Reprod Immunol. 1992 Apr-May;27(3-4):117-23
references.pmid: 1418402
references.citation: Am J Obstet Gynecol. 1979 Feb 15;133(4):405-10
references.pmid: 434005
references.citation: Am J Physiol Lung Cell Mol Physiol. 2012 Feb 15;302(4):L380-9
references.pmid: 22160306
references.citation: J Matern Fetal Neonatal Med. 2002 Jan;11(1):54-9
references.pmid: 12380610
references.citation: N Engl J Med. 2005 Sep 1;353(9):909-17
references.pmid: 16135835
references.citation: FEMS Microbiol Rev. 2005 Jan;29(1):83-98
references.pmid: 15652977
references.citation: Am J Obstet Gynecol. 1993 Nov;169(5):1299-303
references.pmid: 8238198
references.citation: Am J Reprod Immunol. 1996 Jan;35(1):23-9
references.pmid: 8789556
references.citation: Am J Obstet Gynecol. 1981 Nov 1;141(5):516-20
references.pmid: 7294078
references.citation: Am J Obstet Gynecol. 1979 Sep 1;135(1):71-6
references.pmid: 38667
references.citation: Am J Obstet Gynecol. 1989 Aug;161(2):336-41
references.pmid: 2764054
references.citation: Obstet Gynecol. 1989 Feb;73(2):175-8
references.pmid: 2911423
references.citation: Am J Obstet Gynecol. 2006 Sep;195(3):755-9
references.pmid: 16949409
references.citation: N Engl J Med. 1980 Jan 10;302(2):99-101
references.pmid: 6985701
references.citation: Pediatrics. 2008 Apr;121(4):e748-53
references.pmid: 18346989
references.citation: Obstet Gynecol. 1989 Nov;74(5):715-21
references.pmid: 2812647
references.citation: Am J Obstet Gynecol. 1998 Nov;179(5):1254-60
references.pmid: 9822511
references.citation: Lancet. 2013 Apr 20;381(9875):1405-1416
references.pmid: 23582727
references.citation: Paediatr Perinat Epidemiol. 2001 Jul;15 Suppl 2:41-56
references.pmid: 11520399
references.citation: Biochem J. 1980 Mar 15;186(3):693-700
references.pmid: 7396834
references.citation: Am J Obstet Gynecol. 2000 Nov;183(5):1130-7
references.pmid: 11084554
references.citation: J Matern Fetal Neonatal Med. 2011 Sep;24(9):1079-83
references.pmid: 21314292
references.citation: Am J Obstet Gynecol. 1992 Jan;166(1 Pt 1):171-83
references.pmid: 1733193
references.citation: Infect Dis Obstet Gynecol. 1995;2(5):210-2
references.pmid: 18475394
references.citation: N Engl J Med. 1976 Oct 14;295(16):849-53
references.pmid: 785259
references.citation: Obstet Gynecol. 1992 May;79(5 ( Pt 1)):760-6
references.pmid: 1565362
references.citation: J Pediatr. 1993 Jan;122(1):152-4
references.pmid: 8419604
references.citation: Obstet Gynecol. 1976 May;47(5):521-4
references.pmid: 944404
references.citation: Obstet Gynecol. 2006 Aug;108(2):345-9
references.pmid: 16880305
references.citation: Br J Obstet Gynaecol. 1986 Mar;93(3):217-22
references.pmid: 3964596
references.citation: Am J Obstet Gynecol. 1988 May;158(5):1044-9
references.pmid: 3369483
references.citation: Am J Obstet Gynecol. 1991 Mar;164(3):859-62
references.pmid: 1900664
references.citation: Am J Obstet Gynecol. 1998 Nov;179(5):1248-53
references.pmid: 9822510
references.citation: J Perinat Med. 2001;29(4):308-16
references.pmid: 11565199
references.citation: J Obstet Gynaecol. 2006 Aug;26(6):518-20
references.pmid: 17000496
references.citation: Pediatrics. 1978 Oct;62(4):454-9
references.pmid: 714576
references.citation: Pediatrics. 2008 Mar;121(3):e496-505
references.pmid: 18299306
references.citation: Pathol Res Pract. 1996 Nov;192(11):1121-8
references.pmid: 9122031
references.citation: Obstet Gynecol Surv. 2005 Jan;60(1):45-56; quiz 73-4
references.pmid: 15618919
references.citation: Compr Ther. 1999 Feb;25(2):82-9
references.pmid: 10091012
references.citation: Am J Obstet Gynecol. 2004 Oct;191(4):1339-45
references.pmid: 15507963
references.citation: Ultrasound Obstet Gynecol. 1997 Apr;9(4):257-61
references.pmid: 9168577
references.citation: Am J Obstet Gynecol. 2008 Jan;198(1):43.e1-5
references.pmid: 18166302
references.citation: BMJ. 2000 May 6;320(7244):1229-36
references.pmid: 10797030
references.citation: Arch Gynecol Obstet. 1992;252(2):109-12
references.pmid: 1471911
references.citation: Pediatr Dev Pathol. 1999 Nov-Dec;2(6):544-51
references.pmid: 10508878
references.citation: J Matern Fetal Neonatal Med. 2005 Dec;18(6):417-22
references.pmid: 16390808
references.citation: J Invest Dermatol. 1979 Oct;73(4):269-74
references.pmid: 383852
references.citation: Am J Obstet Gynecol. 2001 Jun;184(7):1422-5; discussion 1425-6
references.pmid: 11408862
references.citation: Semin Neonatol. 2001 Jun;6(3):225-31
references.pmid: 11520187
references.citation: J Pediatr. 1994 Mar;124(3):477-9
references.pmid: 8120725
references.citation: J Matern Fetal Neonatal Med. 2005 Jun;17(6):365-73
references.pmid: 16009638
references.citation: Morphologie. 1999 Sep;83(262):23-5
references.pmid: 10546243
references.citation: Am J Obstet Gynecol. 1998 Jul;179(1):186-93
references.pmid: 9704786
references.citation: Obstet Gynecol. 1957 Jan;9(1):91-103
references.pmid: 13388213
references.citation: J Perinat Med. 2001;29(6):465-8
references.pmid: 11776676
references.citation: Obstet Gynecol. 1995 Nov;86(5):830-3
references.pmid: 7566858
references.citation: Am J Obstet Gynecol. 1991 Oct;165(4 Pt 1):1010-3
references.pmid: 1951504
references.citation: Semin Neonatol. 2002 Aug;7(4):259-74
references.pmid: 12401296
references.citation: Nat Rev Microbiol. 2004 Feb;2(2):123-40
references.pmid: 15040260
references.citation: J Pediatr Surg. 1996 Oct;31(10):1409-12
references.pmid: 8906674
references.citation: J Matern Fetal Neonatal Med. 2003 Aug;14(2):85-90
references.pmid: 14629087
references.citation: Am J Obstet Gynecol. 2010 Jan;202(1):77.e1-9
references.pmid: 19801145
references.citation: Obstet Gynecol. 1994 Mar;83(3):329-32
references.pmid: 8127520
references.citation: Obstet Gynecol. 1998 May;91(5 Pt 1):741-5
references.pmid: 9572222
references.citation: Am J Obstet Gynecol. 1993 Jul;169(1):61-70
references.pmid: 8333477
references.citation: Am J Reprod Immunol. 1993 Sep-Oct;30(2-3):167-83
references.pmid: 8311926
references.citation: Semin Perinatol. 1988 Oct;12(4):262-79
references.pmid: 3065940
references.citation: Int J Pediatr. 2012;2012:321545
references.pmid: 22187569
references.citation: Am J Obstet Gynecol. 1999 Oct;181(4):867-71
references.pmid: 10521744
references.citation: J Perinatol. 2000 Jun;20(4):257-61
references.pmid: 10879341
references.citation: J Reprod Med. 1995 May;40(5):375-9
references.pmid: 7608879
references.citation: Innate Immun. 2009 Apr;15(2):101-7
references.pmid: 19318420
references.citation: Fetal Diagn Ther. 2002 Mar-Apr;17(2):78-82
references.pmid: 11844910
references.citation: Ultrasound Obstet Gynecol. 2004 Jan;23(1):94-5
references.pmid: 14971008
references.citation: Am J Obstet Gynecol. 1975 Jul 15;122(6):732-3
references.pmid: 1155513
references.citation: Obstet Gynecol. 2007 Mar;109(3):739-49
references.pmid: 17329528
references.citation: Eur J Obstet Gynecol Reprod Biol. 2002 Jan 10;100(2):167-70
references.pmid: 11750958
references.citation: J Matern Fetal Neonatal Med. 2009 Nov;22(11):983-92
references.pmid: 19900036
references.citation: Life Sci. 2005 Mar 4;76(16):1849-58
references.pmid: 15698862
references.citation: Semin Reprod Med. 2007 Jan;25(1):21-39
references.pmid: 17205421
references.citation: Biotechnol Prog. 2005 Jan-Feb;21(1):192-7
references.pmid: 15903258
references.citation: Am J Obstet Gynecol. 2003 Jan;188(1):153-6
references.pmid: 12548210
references.citation: Pediatr Res. 2004 Nov;56(5):810-7
references.pmid: 15347770
references.citation: Obstet Gynecol. 1973 Jul;42(1):87-92
references.pmid: 4198270
references.citation: Am J Obstet Gynecol. 2011 Apr;204(4):364.e17-24
references.pmid: 21257142
references.citation: Scand J Immunol. 2005 Mar;61(3):217-25
references.pmid: 15787738
references.citation: Am J Obstet Gynecol. 1993 Apr;168(4):1318-22
references.pmid: 8475982
references.citation: Am J Obstet Gynecol. 2003 Oct;189(4):919-24
references.pmid: 14586326
references.citation: PLoS One. 2011 Mar 29;6(3):e18355
references.pmid: 21479249
references.citation: Am J Obstet Gynecol. 2000 Jul;183(1):94-9
references.pmid: 10920315
references.citation: J Surg Res. 1995 Jan;58(1):90-5
references.pmid: 7830412
references.citation: Acta Obstet Gynecol Scand. 1993 Oct;72(7):538-42
references.pmid: 8213100
references.citation: Eur J Biochem. 1995 Oct 15;233(2):467-72
references.pmid: 7588789
references.citation: Pediatr Res. 2008 Mar;63(3):251-6
references.pmid: 18287962
references.citation: Turk J Pediatr. 1998 Jan-Mar;40(1):45-53
references.pmid: 9673528
references.citation: J Perinat Med. 2003;31(1):12-22
references.pmid: 12661139
references.citation: Early Hum Dev. 2009 Oct;85(10):617-20
references.pmid: 19833459
references.citation: Semin Fetal Neonatal Med. 2009 Feb;14(1):2-7
references.pmid: 18845493
references.citation: Am J Perinatol. 1993 Mar;10(2):143-5
references.pmid: 8476478
references.citation: J Matern Fetal Neonatal Med. 2007 Feb;20(2):167-73
references.pmid: 17437216
references.citation: Obstet Gynecol. 1986 Feb;67(2):229-37
references.pmid: 3003634
references.citation: J Perinatol. 2008 Dec;28 Suppl 3:S102-7
references.pmid: 19057598
references.citation: Clin Perinatol. 2012 Dec;39(4):817-31
references.pmid: 23164180
references.citation: J Appl Physiol (1985). 1986 Jan;60(1):160-5
references.pmid: 3944027
references.citation: Pediatrics. 2000 Jan;105(1 Pt 1):1-7
references.pmid: 10617696
references.citation: Pediatrics. 2006 May;117(5):1712-21
references.pmid: 16651329
references.citation: Obstet Gynecol. 1996 Jan;87(1):122-7
references.pmid: 8532246
references.citation: Am J Obstet Gynecol. 2000 Feb;182(2):401-8
references.pmid: 10694344
references.citation: Obstet Gynecol. 1988 Dec;72(6):823-8
references.pmid: 3186087
references.citation: Am J Obstet Gynecol. 1988 Sep;159(3):661-6
references.pmid: 3421266
references.citation: Am J Obstet Gynecol. 1987 Sep;157(3):770-3
references.pmid: 3307431
references.citation: Am J Physiol Lung Cell Mol Physiol. 2001 Mar;280(3):L527-36
references.pmid: 11159037
references.citation: J Matern Fetal Med. 1999 Jul-Aug;8(4):159-63
references.pmid: 10406298
references.citation: J Nutr. 2003 May;133(5 Suppl 2):1668S-1673S
references.pmid: 12730483
references.citation: J Pediatr. 1994 Mar;124(3):471-6
references.pmid: 8120724
references.citation: J Pediatr. 1989 Sep;115(3):474-7
references.pmid: 2769510
references.citation: Am J Obstet Gynecol. 2001 Nov;185(5):1232-8
references.pmid: 11717662
references.citation: Fetal Pediatr Pathol. 2013 Jun;32(3):222-34
references.pmid: 23002960
references.citation: Am J Obstet Gynecol. 1992 Dec;167(6):1583-8
references.pmid: 1471670
references.citation: Ment Retard Dev Disabil Res Rev. 2002;8(1):3-13
references.pmid: 11921380
references.citation: Am J Obstet Gynecol. 2003 Sep;189(3):746-50
references.pmid: 14526306
references.citation: JAMA. 1978 Jul 7;240(1):35-6
references.pmid: 660808
references.citation: Obstet Gynecol. 1994 Jul;84(1):115-20
references.pmid: 8008304
references.citation: Lancet. 1998 Jul 11;352(9122):102-5
references.pmid: 9672275
references.citation: Br J Obstet Gynaecol. 1987 Aug;94(8):813-4
references.pmid: 3663539
references.citation: Prenat Diagn. 2000 Jan;20(1):45-50
references.pmid: 10701851
references.citation: Dev Med Child Neurol. 2013 Jun;55(6):499-508
references.pmid: 23181910
references.citation: Am J Obstet Gynecol. 1987 Aug;157(2):353-8
references.pmid: 3618684
references.citation: Ciba Found Symp. 1992;167:205-20; discussion 220-3
references.pmid: 1425014
references.citation: Am J Obstet Gynecol. 2005 Nov;193(5):1663-9
references.pmid: 16260207
references.citation: Indian J Pediatr. 2004 Mar;71(3):195-201
references.pmid: 15080404
references.citation: Gastroenterology. 1976 May;70(5 PT.1):790-810
references.pmid: 770227
references.citation: Eur J Pediatr. 2000 Nov;159(11):819-26
references.pmid: 11079194
references.citation: J Perinatol. 2008 Dec;28 Suppl 3:S8-13
references.pmid: 19057616
references.citation: Am J Obstet Gynecol. 1995 Apr;172(4 Pt 1):1212-5
references.pmid: 7726258
references.citation: Eur J Obstet Gynecol Reprod Biol. 1998 Oct;80(2):169-73
references.pmid: 9846662
references.citation: J Clin Invest. 1990 May;85(5):1392-400
references.pmid: 2332497
references.citation: Am J Obstet Gynecol. 1989 May;160(5 Pt 1):1117-23
references.pmid: 2786341
references.citation: Acta Obstet Gynecol Scand. 1982;61(3):275-7
references.pmid: 7124360
references.citation: BJOG. 2002 May;109(5):514-9
references.pmid: 12066940
references.citation: J Perinatol. 2008 Dec;28 Suppl 3:S120-2
references.pmid: 19057602
references.citation: J Surg Res. 1998 Jan;74(1):34-8
references.pmid: 9536970
references.citation: Am J Obstet Gynecol. 1992 Jan;166(1 Pt 1):129-33
references.pmid: 1301006
references.citation: Am J Obstet Gynecol. 2000 Jan;182(1 Pt 1):135-41
references.pmid: 10649168
references.citation: Lancet. 2004 Aug 14-20;364(9434):597-602
references.pmid: 15313360
references.citation: Obstet Gynecol. 1996 Aug;88(2):216-20
references.pmid: 8692505
references.citation: J Perinatol. 2008 Dec;28 Suppl 3:S3-7
references.pmid: 19057607
references.citation: Obstet Gynecol. 2002 May;99(5 Pt 1):731-9
references.pmid: 11978280
references.citation: J Clin Ultrasound. 1978 Apr;6(2):100-2
references.pmid: 96144
references.citation: Am J Physiol Lung Cell Mol Physiol. 2009 Sep;297(3):L512-9
references.pmid: 19574422
references.citation: BMC Pediatr. 2010 Jun 04;10:39
references.pmid: 20525358
references.citation: Appl Microbiol. 1974 Nov;28(5):867-71
references.pmid: 4613271
references.citation: J Reprod Med. 1993 Jul;38(7):543-8
references.pmid: 8410850
references.citation: Am J Obstet Gynecol. 2008 Jan;198(1):1-3
references.pmid: 18166295
references.citation: J Exp Med. 1960 Nov 1;112:783-92
references.pmid: 13739891
references.citation: Am J Obstet Gynecol. 1989 Sep;161(3):817-24
references.pmid: 2675611
references.citation: J Matern Fetal Neonatal Med. 2009 Oct;22(10):905-16
references.pmid: 19603351
references.citation: Am J Obstet Gynecol. 2013 Jul;209(1):29.e1-29.e19
references.pmid: 23524176
references.citation: Am J Respir Crit Care Med. 2009 May 15;179(10):955-61
references.pmid: 19234101
references.citation: J Pediatr Surg. 1999 Feb;34(2):246-50
references.pmid: 10052797
references.citation: Obstet Gynecol. 1985 Jul;66(1):59-62
references.pmid: 4011072
references.citation: Am J Obstet Gynecol. 1972 Jan 1;112(1):46-9
references.pmid: 5007507
references.citation: Sex Transm Dis. 1983 Oct-Dec;10(4 Suppl):294-302
references.pmid: 6665671
references.citation: J Matern Fetal Med. 2000 Jul-Aug;9(4):201-3
references.pmid: 11048828
references.citation: Dis Colon Rectum. 1991 Mar;34(3):262-6
references.pmid: 1999134
references.citation: Early Hum Dev. 2009 Oct;85(10):605
references.pmid: 19822400
references.citation: Am J Obstet Gynecol. 1994 Feb;170(2):587-90
references.pmid: 8116718
references.citation: N Engl J Med. 1975 Sep 18;293(12):567-72
references.pmid: 1097914
references.citation: J Child Neurol. 2011 Apr;26(4):453-9
references.pmid: 21270469
references.citation: J Matern Fetal Neonatal Med. 2011 Jul;24(7):880-5
references.pmid: 21410421
references.citation: Eur J Obstet Gynecol Reprod Biol. 1998 Oct;81(1):9-13
references.pmid: 9846706
references.citation: Obstet Gynecol. 1992 Mar;79(3):351-7
references.pmid: 1738513
references.citation: Clin Chem. 1988 Nov;34(11):2372-3
references.pmid: 3180439
references.citation: Am J Obstet Gynecol. 2000 Jun;182(6):1545-53
references.pmid: 10871477
references.citation: J Clin Endocrinol Metab. 2003 Aug;88(8):3835-44
references.pmid: 12915677
references.citation: Am J Obstet Gynecol. 2001 Nov;185(5):1130-6
references.pmid: 11717646
references.citation: Am J Obstet Gynecol. 1995 Mar;172(3):960-70
references.pmid: 7892891
references.citation: Prenat Diagn. 1992 Feb;12(2):111-7
references.pmid: 1553356
references.citation: Pediatr Res. 2004 Feb;55(2):326-33
references.pmid: 14605247
references.citation: Am J Obstet Gynecol. 1993 Oct;169(4):805-16
references.pmid: 7694461
references.citation: Am J Physiol. 1993 Mar;264(3 Pt 2):R610-4
references.pmid: 8457016
references.citation: J Infect Dis. 1973 Sep;128(3):349-52
references.pmid: 4580673
references.citation: J Matern Fetal Neonatal Med. 2003 Jan;13(1):32-8
references.pmid: 12710854
references.citation: Am J Obstet Gynecol. 1975 Jan 1;121(1):45-50
references.pmid: 1115114
references.citation: Arch Gynecol Obstet. 2012 Feb;285(2):323-9
references.pmid: 21735187
references.citation: Am J Obstet Gynecol. 1991 Oct;165(4 Pt 1):1105-10
references.pmid: 1951523
references.citation: Arch Dis Child Fetal Neonatal Ed. 2013 May;98(3):F233-9
references.pmid: 22791468
references.citation: Ultrasound Obstet Gynecol. 1996 Aug;8(2):109-13
references.pmid: 8883313
references.citation: Am J Obstet Gynecol. 2007 Sep;197(3):292.e1-5
references.pmid: 17826425
references.citation: J Perinatol. 2005 May;25 Suppl 2:S31-5
references.pmid: 15861169
references.citation: PLoS One. 2008 Aug 26;3(8):e3056
references.pmid: 18725970
references.citation: Am J Obstet Gynecol. 1998 Jul;179(1):194-202
references.pmid: 9704787
references.citation: Am J Obstet Gynecol. 1995 Oct;173(4):1301-5
references.pmid: 7485342
references.citation: Acta Obstet Gynecol Scand. 2003 May;82(5):423-31
references.pmid: 12752072
references.citation: Obstet Gynecol. 1980 Jul;56(1):60-4
references.pmid: 7383489
references.citation: Am J Perinatol. 1987 Oct;4(4):356-9
references.pmid: 3307803
references.citation: Am J Obstet Gynecol. 1979 Jun 15;134(4):376-84
references.pmid: 453272
references.citation: J Pediatr. 1987 May;110(5):765-70
references.pmid: 3572631
references.citation: Am J Physiol Gastrointest Liver Physiol. 2012 Aug 15;303(4):G490-7
references.pmid: 22723263
references.citation: J Surg Res. 1997 Jan;67(1):54-7
references.pmid: 9070181
references.citation: Am J Obstet Gynecol. 1978 Jul 1;131(5):509-13
references.pmid: 677193
references.citation: Pediatr Infect Dis J. 2012 Aug;31(8):821-6
references.pmid: 22565291
references.citation: Pediatr Dev Pathol. 2009 Nov-Dec;12(6):438-42
references.pmid: 19323599
references.citation: Am J Obstet Gynecol. 2005 Feb;192(2):452-7
references.pmid: 15695986
references.citation: Am J Infect Control. 1984 Feb;12(1):19-25
references.pmid: 6561001
references.citation: J Gastroenterol Hepatol. 2008 Sep;23(9):1390-3
references.pmid: 18853996
references.citation: Am J Obstet Gynecol. 1980 Aug 15;137(8):936-43
references.pmid: 7405991
references.citation: Nutr Rev. 2007 Dec;65(12 Pt 2):S194-202
references.pmid: 18240548
references.citation: Br Med Bull. 1975 Jan;31(1):3-7
references.pmid: 1237340
references.citation: Pediatr Clin North Am. 1998 Jun;45(3):511-29
references.pmid: 9653434
references.citation: Am J Obstet Gynecol. 2006 Dec;195(6):1578-89
references.pmid: 17132473
references.citation: Am J Obstet Gynecol. 1987 Oct;157(4 Pt 1):815-9
references.pmid: 2445204
references.citation: Am J Obstet Gynecol. 1974 Jan 15;118(2):251-5
references.pmid: 4809412
references.citation: J Perinat Med. 1990;18(5):345-9
references.pmid: 2292757
references.citation: PLoS One. 2009 Jun 08;4(6):e5837
references.pmid: 19503810
references.citation: Eur J Obstet Gynecol Reprod Biol. 2007 May;132(1):46-50
references.pmid: 16837118
references.citation: Am J Obstet Gynecol. 1976 May 1;125(1):73-8
references.pmid: 5894
references.citation: J Clin Invest. 1988 Nov;82(5):1714-21
references.pmid: 3183065
references.citation: Am J Obstet Gynecol. 1992 May;166(5):1576-87
references.pmid: 1595815
references.citation: Am J Obstet Gynecol. 1975 Jul 1;122(5):573-80
references.pmid: 238396
references.citation: Ann Otol Rhinol Laryngol. 1991 Sep;100(9 Pt 1):743-7
references.pmid: 1952668
references.citation: J Physiol. 1983 Jun;339:495-504
references.pmid: 6887031
references.citation: J Gastrointest Surg. 1998 Jul-Aug;2(4):391-8
references.pmid: 9841998
references.citation: Clin Infect Dis. 1993 Aug;17 Suppl 1:S148-53
references.pmid: 8399906
references.citation: Am J Obstet Gynecol. 1971 Jun 1;110(3):336-42
references.pmid: 5088371
references.citation: J Reprod Immunol. 1998 Feb;37(2):155-61
references.pmid: 9571569
references.citation: J Clin Endocrinol Metab. 2008 Sep;93(9):3604-9
references.pmid: 18559919
references.citation: Adv Pediatr. 1979;26:275-310
references.pmid: 396776
references.citation: Obstet Gynecol Surv. 1975 Oct;30(10):675-91
references.pmid: 1161224
references.citation: Am J Obstet Gynecol. 2008 Oct;199(4):375.e1-5
references.pmid: 18928978
references.citation: J Perinatol. 2001 Dec;21(8):537-40
references.pmid: 11774015
references.citation: Acta Paediatr. 1993 Feb;82(2):182-9
references.pmid: 8477165
references.citation: Ultrasound Obstet Gynecol. 2005 Dec;26(7):794-5
references.pmid: 16247736
references.citation: Am J Obstet Gynecol. 1991 Oct;165(4 Pt 1):813-20
references.pmid: 1951537
references.citation: Mol Immunol. 2009 Feb;46(4):688-94
references.pmid: 18950866
references.citation: Am J Obstet Gynecol. 1984 Jul 1;149(5):570-2
references.pmid: 6742027
references.citation: N Engl J Med. 2005 Sep 1;353(9):946-8
references.pmid: 16135842
references.citation: Am J Respir Crit Care Med. 2000 Nov;162(5):1656-61
references.pmid: 11069792
references.citation: Am J Obstet Gynecol. 2000 Oct;183(4):914-20
references.pmid: 11035337
references.citation: Pediatrics. 2000 Aug;106(2 Pt 1):256-63
references.pmid: 10920148
references.citation: J Matern Fetal Neonatal Med. 2008 Aug;21(8):529-47
references.pmid: 18609361
references.citation: J Clin Ultrasound. 1986 Mar-Apr;14(3):229-30
references.pmid: 3084578
references.citation: Am J Reprod Immunol. 1994 Sep;32(2):108-13
references.pmid: 7826499
references.citation: Am J Reprod Immunol. 2011 Jun;65(6):549-56
references.pmid: 21214658
references.citation: Am J Obstet Gynecol. 2000 Mar;182(3):675-81
references.pmid: 10739529
references.citation: Clin Perinatol. 1989 Dec;16(4):825-38
references.pmid: 2686889
references.citation: Obstet Gynecol. 1995 May;85(5 Pt 1):656-8
references.pmid: 7536907
references.citation: Obstet Gynecol. 2004 Jan;103(1):57-62
references.pmid: 14704245
references.citation: Clin Obstet Gynecol. 1988 Sep;31(3):553-84
references.pmid: 3066544
references.citation: J Pediatr. 1969 Jan;74(1):111-4
references.pmid: 4973352
references.citation: Arch Gynecol Obstet. 2000 Sep;264(2):84-7
references.pmid: 11045329
references.citation: Obstet Gynecol. 1986 Oct;68(4):488-94
references.pmid: 3748497
references.citation: Pediatrics. 1992 Jan;89(1):107-13
references.pmid: 1727992
references.citation: J Surg Res. 1996 Feb 1;60(2):307-11
references.pmid: 8598659