Ultrasonographic evaluation of cervical length and amniotic fluid index as predictor of pregnancy outcome in case of preterm premature rupture of membrane
Keywords:AFI, PROM, Pregnancy outcome, Cervical length
Background: Preterm premature rupture of membrane (PPROM) is among the most important cause of the perinatal morbidity and mortality. We sought to determine whether cervical length and amniotic fluid index individually or in combination can predict the pregnancy outcome in cases of PPROM.
Methods: The prospective observational study was done on 170 women complicated by PPROM with gestational age between 24-36+6 weeks. They were categorized into three groups Group I.24-28 weeks, Group II.28+1 to 32 weeks and Group III. 32+1 to 36+6 weeks. Cervical length and amniotic fluid index were measured using trans abdominal ultrasound within 24 hr of admission. Maternal outcomes were recorded in terms of latency period, chorioamnionitis, and abruption , and neonatal outcomes were recorded in terms of birth weight, first minute APGAR score <7, NICU admission and early neonatal death. Qualitative variables were correlated using Chi-Square test /Fisher’s exact test. Univariate logistic regression was used to assess cervical length and AFI as a predictor of complication. A p value of <0.05 was considered statistically significant.
Results: Out of 170, majority (95) belonged to 28+1 to 32 weeks group. Latency was inversely related to period of gestation (p<0.0001). A long cervical length correlated with increased latency, increased risk of chorioamnionitis and increased neonatal complications in all three groups. Also, women with PPROM having AFI >5 cm had a greater mean latency period (8.32±1.25 days) which increased their risk of developing chorioamnionitis as compared to women with PPROM having AFI ≤5 cm, who had a shorter mean latency period (7.63±1.07 days) and a lower risk of developing chorioamnionitis (p value <0.0001).
Conclusions: Latency is inversely related to period of gestation. A long cervical length and increased amount of AFI correlates with increased latency, increased risk of chorioamnionitis and increased neonatal complications.
Blott M, Greenough A. Neonatal outcome after prolonged rupture of the membranes starting in the second trimester. Arch Dis Child. 1988;63:1146-50.
ACOG Practice bulletin no 1. Premature rupture of membranes. Clinical management guidelines for obstetrician-gynecologists. Int J Gynaecol Obstet. 1998;63(1):75-84.
Mercer B, Milluzzi C, Collin M. Periviable birth at 20 to 26 wk of gestation: proximate causes, previous obstetric history and recurrence risk. Am J Obstet Gynecol. 2005 Sep;193(3 Pt 2):1175-80.
Waters TP, Mercer BM. The management of preterm premature rupture of the membranes near the limit of fetal viability. Am J Obstet Gynecol. 2009 Sep;201(3):230-40.
ACOG Practice Bulletins No 80: premature rupture of membranes. Obstet Gynaecol. 2007;109(4):1007-19.
Gonan R, Hannah ME, Milligan JE. Does prolonged premature rupture of the membranes predispose to abruption placenta? Obstet Gynecol. 1989;74:347-50.
Ananth CC, Oyelese Y, Srinivas N, Yeo L, Vintzileos AM. Preterm premature rupture of membranes, intrauterine infection, and oligohydramnios: risk factors for placental abruption. Obstet Gynecol. 2004 Jul;104(1):71-7.
Mercer BM. Preterm premature rupture of the membranes. Obstet Gynecol. 2003;101(1):178-93.
Mercer BM, Rabello YA, Thumau GR, Modovnik M, Goldenberg RL, Das AF et al. The NICHD-MFMU antibiotic treatment of preterm PROM study: Impact of initial amniotic fluid volume on pregnancy outcome. Am J Obstet Gynecol. 2006 Feb;194(2):438-45.
Rizzo G, Capponi A, Angelini E, Vlachopoulou A, Grassi C, Romanini C. The value of transvaginal ultrasonographic examination of the uterine cervix in predicting preterm delivery in patients with preterm premature rupture of membranes. Ultrasound Obstet Gynecol. 1998;11:23-9.
Mehra S, Amon E, Hopkins S, Gavard JA, Shyken J. Transvaginal cervical length and amniotic ﬂuid index: can it predict delivery latency following preterm premature rupture of membranes? Am J Obstet Gynecol. 2015 Mar;212(3):400.e1-9.
Carlan SJ, Richmond LB, O’Brien WF. Randomized trial of endovaginal ultrasound in preterm premature rupture of membranes. Obstet Gynecol. 1997;89:458-61.
Tavassoli F, Ghasemi M, Mohamadzade A, Sharifian J, Survey of pregnancy outcome in preterm premature rupture of membranes with amniotic fluid index <5 and ≥5. Oman Med J. 2010;25(2):118-23.
Borna S, Borna H, Khazardoost S, Hantoushzadeh S. Perinatal outcome in preterm premature rupture of membranes with Amniotic fluid index <5 (AFI<5). BMC Pregnancy Childbirth. 2004 Aug;4(1):15.
Piazze J, Anceschi M, Cerekja A. Validity of amniotic fluid index in preterm rupture of membranes. J Perinat Med. 2007;35(5):394-8.
Vermillion ST, Kooba AM, Soper DE. Amniotic Fluid index value after preterm premature rupture of membrane and subsequent perinatal infection. Am J Obstet Gynecol. 2000;183(2):271-6.
Moberg IJ, Garete TJ, Freeman RK. Fetal heart rate patterns of fetal distress in patient with preterm premature rupture of membranes. Obstet Gynecol. 1984 Jul;64(1):60-4.