Modifications to selective conservative management in preterm premature rupture of the membranes

Selective conservation in preterm premature rupture of the membranes (PPROM) reduces risks of infection and pulmonary hypoplasia associated with expectant management by delivering those at greatest risk, while permitting continuation of pregnancy in the remainder. Although patient selection has traditionally been a clinical decision, more accurate criteria are now available. The role of biochemical, biophysical and microbiological predictors of chorioamnionitis and fetal pulmonary status in PPROM is reviewed, and the resultant modifications to selective conservative management discussed.

Transvaginal ultrasound in suspected ectopic pregnancy

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Is C-reactive protein really useful in preterm premature rupture of the membranes?

In a prospective blind study 380 daily serum samples from 55 women with preterm premature rupture of the membranes were analysed for C-reactive protein (CRP). Although the last CRP before delivery was higher in patients with histological chorioamnionitis (P = 0.007), considerable overlap between infected and non-infected pregnancies occurred, precluding the use of CRP as a diagnostic test if published normal levels were used. When upper limits were set at 30, 35, or 40 mg/l, the last CRP before delivery proved 90, 95 and 100% specific and 88, 92 and 100% positively predictive of infection in singleton pregnancies. Such high specificities are needed to prevent inappropriate intervention based on false positive results. We therefore propose upper limits for single estimations of 30, 35, or 40 mg/l depending on the relative risks of preterm delivery versus infection at various gestational ages. In addition, consecutive values greater than 20 mg/l appeared highly predictive of infection.

Avoidance of maternal morbidity in acute intrauterine infection following chorionic villus sampling

Serious maternal morbidity has been a feature of the few documented cases of acute intrauterine infection after chorionic villus sampling. A case is described in which infection manifested 14 days after transcervical chorion biopsy. Broad-spectrum antibiotics were begun, and ultrasound demonstrated a live fetus. After vacuum curettage was performed, repeat scan showed an empty uterus. Anaerobes isolated from the cervix both before chorionic villus sampling and during the infection were also implicated in published reports of patients developing life-threatening complications, but were not treated specifically until after morbid sequelae had occurred. Serious morbidity was avoided in this patient by aggressive management with early anaerobic cover, uterine evacuation despite the presence of a live fetus, and confirmation of complete evacuation by ultrasound.

A dipstick test for infection in preterm premature rupture of the membranes

Microbiological analysis of amniotic fluid obtained by amniocentesis is increasingly employed in preterm premature rupture of the membranes (PPROM) to predict those patients at increased risk of chorioamnionitis. Although liquor culture appears the most accurate predictor, a role exists for rapid but slightly less accurate testing. In this study, a dipstick (Cytur-test) which predicts the presence of leukocytes was evaluated in amniotic fluid. Twenty-one samples were obtained by amniocentesis from 25 women with PPROM at gestation 26-34 weeks. The dipstick predicted 5 out of 6 specimens with a positive culture and 12 of 14 with a negative culture (figure 1). Its accuracy as a predictor of a positive culture was similar to microscopy for polymorphs, with sensitivities of 83.3% and 80% respectively and specificities of 85.7% and 92.3%. Neither test proved as predictive of histological chorioamnionitis due to 6 patients delivering greater than 48 hours after amniocentesis who may have developed infection subsequent to the demonstration of sterile liquor.