The NICHD-MFMU antibiotic treatment of preterm PROM study: impact of initial amniotic fluid volume on pregnancy outcome.
OBJECTIVE
The purpose of this study was to evaluate the associations between measured amniotic fluid volume and outcome after preterm premature rupture of membranes (PROM).


METHODS
This was a secondary analysis of 290 women, with singleton pregnancies, who participated in a trial of antibiotic therapy for preterm PROM at 24(0) to 32(0) weeks. Each underwent assessment of the 4 quadrant amniotic fluid index (AFI) and a maximum vertical fluid pocket (MVP) before randomization. The impact of low AFI (< 5.0 cm) and low MVP (< 2.0 cm) on latency, amnionitis, neonatal morbidity, and composite morbidity (any of death, RDS, early sepsis, stage 2-3 necrotizing enterocolitis, and/or grade 3-4 intraventricular hemorrhage) was assessed. Logistic regression controlled for confounding factors including gestational age at randomization, GBS carriage, and antibiotic study group.


RESULTS
Low AFI and low MVP were identified in 67.2% and 46.9% of women, respectively. Delivery occurred by 48 hours, 1 and 2 weeks in 32.4%, 63.5% and 81.7% of pregnancies, respectively. Both low AFI and low MVP were associated with shorter latency (P < .001), and with a higher rate of delivery at 48 hours, 1, and 2 weeks (P = .02 for each). However, neither test offered significant additional predictive value over the risk in the total population. Low AFI and low MVP were not associated with increased amnionitis. After controlling for other factors, both low MVP and low AFI were associated with shorter latency (P < or = .002), increased composite morbidity (P = .03), and increased RDS (P < or = .01), but not with increased neonatal sepsis (P = .85) or pneumonia (P = .53). Alternatively, after controlling for fluid volume, gestational age, and GBS carriage, the antibiotic study group had longer latency, and suffered less common primary outcomes and neonatal sepsis.


CONCLUSIONS
Oligohydramnios should not be a consideration in determining which women will be candidates for expectant management or antibiotic treatment when it is identified at initial assessment of preterm PROM remote from term.
Mercer
Brian M
BM
NICHD-MFMU Network, Bethesda, MD, USA.
Rabello
Yolanda A
YA
Thurnau
Gary R
GR
Miodovnik
Menachem
M
Goldenberg
Robert L
RL
Das
Anita F
AF
Meis
Paul J
PJ
Moawad
Atef H
AH
Iams
Jay D
JD
Van Dorsten
J Peter
JP
Dombrowski
Mitchell P
MP
Roberts
James M
JM
McNellis
Donald
D
D000653:Amniotic Fluid; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000188:drug therapy*; D006801:Humans; D016015:Logistic Models; D011247:Pregnancy; D011256:Pregnancy Outcome; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors
D000900:Anti-Bacterial Agents