ABSTRACT
Preterm premature rupture of the membranes (PPROM) is a significant cause of prematurity,
accounting for approximately one third of preterm births in the United States. PPROM
occurs in approximately 0.7-2% of all pregnancies nationally, and has a reported recurrence
rate of 21%. The elucidation of potential risk factors for PPROM could contribute
to a better understanding of its etiology. To study the contributions of 20 potential
risk factors, we undertook a case-control study in our clinic population, which has
a 5-6% incidence of PPROM. One hundred and thirty-three patients experiencing PPROM
were matched for race, age, parity and gestational age with undelivered patients.
Studies performed included ultrasonographic examinations, blood levels of ascorbic
acid and zinc, microbiologic assays, patient questionnaires, and chart reviews. After
stratification of both groups into subgroups based on matching criteria, summary tests
of significance and Mantel-Haenszel tests of odds ratios were performed. On univariate
analysis the following factors achieved significance at the p < 0.05 level with 95%
confidence intervals: 1) previous history of PPROM 2) smoking (dose related) 3) fundal
location of the placenta in the present pregnancy. 4) a prior history of cerclage.
After regression analysis, we concluded that smoking and history of previous PPROM
were found to be risk factors for PPROM in our inner city black population.
