Predictors of perinatal survival in a cohort of pregnancies with severe oligohydramnios due to premature rupture of membranes at <26 weeks managed with serial amnioinfusions.
OBJECTIVE
To evaluate whether successful amnioinfusion is an independent predictor of perinatal survival in a cohort of cases with extreme and persistent oligohydramnios due to preterm premature rupture of membranes (pPROM) who reached viability and were managed with serial amnioinfusions.


METHODS
We included all consecutive singleton pregnancies with pPROM at <26 weeks and oligohydramnios lasting >4 days between 1/1991 and 12/2001 and who consented to undergo amnioinfusion (n=77). Women received serial transabdominal amnioinfusions in an attempt to maintain a pocket of fluid >2 cm. The procedure was deemed successful if the median deepest pocket of fluid during the latency period was >2 cm. Excluded were miscarriages (n=10), fetal deaths before viability (24 weeks) (n=15), and cases that did not develop oligohydramnios (n=17). Prenatal predictors of outcome were compared between cases who survived the perinatal period and those who did not using Wilcoxon rank-sum test, Fisher's exact test and stepwise logistic regression analysis, with a two-tailed P<0.05 considered significant.


RESULTS
Of the 35 patients fulfilling the study criteria, 20 (57%) survived the perinatal period. Perinatal survivors had similar gestational age at pPROM (P=0.68) and at first amnioinfusion (P=0.53) as those who died in the perinatal period, but longer latency (P=0.013). Consequently, median gestational age at delivery [29.2 (25.4-35.3) weeks versus 26.1 (24.0-34.0) weeks, P<0.001] and median birth weight [1220 (650-2240) g versus 863 (520-2200) g, P=0.001] were significantly greater among survivors than among those who died. Significant predictors of survival at univariate analysis were entered into a stepwise logistic regression analysis in the chronological order in which they normally occur. The analysis demonstrated that successful amnioinfusion (OR=6.9, 95% CI 1.2-40.4) and administration of steroids (OR=14.6, 95% CI 1.5-144.1) were independent and significant predictors of perinatal survival.


CONCLUSIONS
In a cohort of women with pPROM at <26 weeks and severe oligohydramnios managed with serial amnioinfusions, successful procedures and prenatal administration of corticosteroids are the only independent predictors of perinatal survival.
Department of Obstetrics and Gynaecology, University of Milano-Bicocca, Ospedale San Gerardo, Via Solferino 16, 20052 Monza, Italy. anna.locatelli@unimib.it
Anna
A
Locatelli
Alessandro
A
Ghidini
Maria
M
Verderio
Marianna
M
Andreani
Nicola
N
Strobelt
John
J
Pezzullo
Patrizia
P
Vergani
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000328:Adult; D000650:Amnion / Q000002:abnormalities*; D000653:Amniotic Fluid; D015331:Cohort Studies; D005260:Female; D005313:Fetal Death; D005322:Premature Rupture of Fetal Membranes / Q000628:therapy*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007267:Injections; D016104:Oligohydramnios / Q000401:mortality / Q000628:therapy*; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth; D011379:Prognosis; D016019:Survival Analysis
D000305:Adrenal Cortex Hormones