Midtrimester Intra-Amniotic Sludge and the Risk of Spontaneous Preterm Birth

ABSTRACT

We examined the association between midtrimester intra-amniotic sludge and spontaneous preterm birth (PTB) in asymptomatic women undergoing amniocentesis. We performed a prospective cohort study of women having an amniocentesis for fetal karyotyping between 14 and 24 weeks’ gestation. Cervical length and the presence of amniotic sludge were assessed by transvaginal ultrasound. Amniotic fluid concentrations of matrix metalloproteinase-8, glucose and lactate were measured. Early (<32 weeks) and late (32 to 36 weeks) preterm premature rupture of membranes (PPROM) and spontaneous PTB constituted primary outcomes. Nonparametric analyses were conducted. Three hundred ten women, including 94 (30%) with free-floating echogenic particles and 16 (5%) with dense amniotic sludge, were recruited. Dense amniotic sludge was linked with early (13%) but not with late (0%) primary outcome (p < 0.01). Two women with combined dense amniotic sludge and short cervix delivered 4 and 10 weeks later (at 20 and 25 weeks, respectively) and had a higher median amniotic lactate concentration than controls (p < 0.05). A third woman with dense amniotic sludge at 15 weeks was diagnosed with a short cervix and an intra-amniotic infection at 22 weeks that was eradicated with intravenous antibiotics. Midtrimester dense amniotic sludge is associated with early PPROM and spontaneous PTB.

KEYWORDS

Pregnancy - preterm birth - ultrasound - intra-amniotic infection - inflammation

REFERENCES

• 1 Martin J A, Hamilton B E, Sutton P D et al.. Births: final data for 2006.  Natl Vital Stat Rep. 2009;  57 1-104
• 2 Yoon B H, Romero R, Moon J B et al.. Clinical significance of intra-amniotic inflammation in patients with preterm labor and intact membranes.  Am J Obstet Gynecol. 2001;  185 1130-1136
• 3 Gravett M G, Hummel D, Eschenbach D A, Holmes K K. Preterm labor associated with subclinical amniotic fluid infection and with bacterial vaginosis.  Obstet Gynecol. 1986;  67 229-237
• 4 Romero R, Mazor M. Infection and preterm labor.  Clin Obstet Gynecol. 1988;  31 553-584
• 5 Romero R, Sirtori M, Oyarzun E et al.. Infection and labor. V. Prevalence, microbiology, and clinical significance of intraamniotic infection in women with preterm labor and intact membranes.  Am J Obstet Gynecol. 1989;  161 817-824
• 6 Skoll M A, Moretti M L, Sibai B M. The incidence of positive amniotic fluid cultures in patients preterm labor with intact membranes.  Am J Obstet Gynecol. 1989;  161 813-816
• 7 Espinoza J, Gonçalves L F, Romero R et al.. The prevalence and clinical significance of amniotic fluid “sludge” in patients with preterm labor and intact membranes.  Ultrasound Obstet Gynecol. 2005;  25 346-352
• 8 Kusanovic J P, Espinoza J, Romero R et al.. Clinical significance of the presence of amniotic fluid “sludge” in asymptomatic patients at high risk for spontaneous preterm delivery.  Ultrasound Obstet Gynecol. 2007;  30 706-714
• 9 Bujold E, Pasquier J C, Simoneau J et al.. Intra-amniotic sludge, short cervix, and risk of preterm delivery.  J Obstet Gynaecol Can. 2006;  28 198-202
• 10 Gauthier S, Tétu A, Himaya E et al.. The origin of Fusobacterium nucleatum involved in intra-amniotic infection and preterm birth.  J Matern Fetal Neonatal Med. 2011;  24(11) 1329-1332
• 11 Romero R, Schaudinn C, Kusanovic J P et al.. Detection of a microbial biofilm in intraamniotic infection.  Am J Obstet Gynecol. 2008;  198 135, e1-e50
• 12 Romero R, Kusanovic J P, Espinoza J et al.. What is amniotic fluid “sludge”?.  Ultrasound Obstet Gynecol. 2007;  30 793-798
• 13 Gorski L A, Huang W H, Iriye B K, Hancock J. Clinical implication of intra-amniotic sludge on ultrasound in patients with cervical cerclage.  Ultrasound Obstet Gynecol. 2010;  36 482-485
• 14 Hassan S, Romero R, Hendler I et al.. A sonographic short cervix as the only clinical manifestation of intra-amniotic infection.  J Perinat Med. 2006;  34 13-19
• 15 Morency A M, Rallu F, Laferrière C, Bujoldg E. Eradication of intra-amniotic Streptococcus mutans in a woman with a short cervix.  J Obstet Gynaecol Can. 2006;  28 898-902
• 16 Morency A M, Bujold E. The effect of second-trimester antibiotic therapy on the rate of preterm birth.  J Obstet Gynaecol Can. 2007;  29 35-44