The relationship between oligohydramnios and the onset of preterm labor in preterm premature rupture of membranes.
OBJECTIVE
The objective of this study was to determine whether a reduced amniotic fluid volume was associated with the onset of preterm parturition in patients with preterm premature rupture of membranes.


METHODS
An amniotic fluid index was determined before transabdominal amniocentesis in 129 patients with preterm premature rupture of membranes (gestational age < or = 35 weeks). Amniotic fluid was cultured for aerobic and anaerobic bacteria, as well as for mycoplasmas. Survival techniques were used for analysis.


RESULTS
Amniotic fluid index was < or = 5 cm in 29% of patients (38/129). Patients with an amniotic fluid index of < or = 5 cm had a significantly higher rate of positive amniotic fluid culture than those with an amniotic fluid index of >5 cm (42% [16/38] vs 18% [16/91]; P<.01). Spontaneous preterm delivery within 24 hours and 48 hours was more frequent among patients with an amniotic fluid index of < or = 5 cm than those with an amniotic fluid index of >5 cm (for 24 hours, 29% vs 12%; for 48 hours, 42% vs 21%; P<.05 for each). The amniocentesis-to-delivery interval was significantly shorter in patients with an amniotic fluid index of < or = 5 cm than in patients with an amniotic fluid index of >5 cm (median, 38 hours; range, 0.2-1310 hours; vs median, 100 hours; range 0.1-2917 hours; P<.01). Moreover, Cox proportional hazards model analysis indicated that an amniotic fluid index of < or = 5 cm was a significant predictor of the duration of the pregnancy after adjustment for gestational age and the results of amniotic fluid culture (odds ratio, 2.4; 95% confidence interval, 1.4-3.9; P<.001).


CONCLUSIONS
Patients with preterm premature rupture of membranes and an amniotic fluid index of < or = 5 cm are at increased risk for a shorter interval to delivery.
Park
J S
JS
Department of Obstetrics and Gynecology, Seoul National University College of Medicine, and the Laboratory of Fetal Medicine Research, Clinical Research Institute, Seoul National University Hospital, Korea.
Yoon
B H
BH
Romero
R
R
Moon
J B
JB
Oh
S Y
SY
Kim
J C
JC
Jun
J K
JK
D000328:Adult; D000649:Amniocentesis; D000653:Amniotic Fluid / Q000382:microbiology; D002821:Chorioamnionitis / Q000175:diagnosis; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000150:complications* / Q000382:microbiology; D006801:Humans; D007752:Obstetric Labor, Premature / Q000209:etiology* / Q000382:microbiology; D016104:Oligohydramnios / Q000150:complications* / Q000382:microbiology; D011247:Pregnancy; D016016:Proportional Hazards Models; D016019:Survival Analysis