Anne-Maude Morency

Bacteriology of Amniotic Fluid in Women With Suspected Cervical Insufficiency

OBJECTIVE To determine the prevalence of mid-trimester microbial invasion of the amniotic cavity (MIAC) in women with suspected cervical insufficiency. METHODS A prospective observational cohort study was performed in women with suspected cervical insufficiency and visible fetal membranes who were undergoing amniocentesis to rule out MIAC between 16 and 26 weeks of gestation. Women with preterm premature rupture of membranes, regular uterine contractions, or who had a cervical cerclage were excluded. Gram staining of amniotic fluid, glucose and lactate dehydrogenase (LDH) levels in amniotic fluid, and aerobic and anaerobic amniotic fluid cultures were performed, along with polymerase chain reaction (PCR) for the detection of Ureaplasma and Mycoplasma species. RESULTS Fifteen women with a mean gestational age of 22.6 +/- 2.3 weeks were included in the study. The diagnosis of MIAC was confirmed in 47% (7/15), of whom 20% (3/15) were infected with more than one bacterial strain and 33% (5/15) with Ureaplasma species. According to receiver-operator curve analyses, amniotic fluid levels of glucose were associated with MIAC (P = 0.02), but not amniotic fluid LDH (P = 0.25). CONCLUSION MIAC is present in approximately one half of women with suspected cervical insufficiency and visible fetal membranes at speculum examination.

Invasion of the amniotic cavity by an uncultured bacterium, a Gram-positive coccus

Preterm premature rupture of the amniotic membranes (pPROM) has been associated with microbial invasion of the amniotic cavity (MIAC), evaluated by aerobic and anaerobic cultures, in approximately 30% of cases. We report herein the case of a 30-year-old woman at 32 weeks of gestation who presented at our institution with vaginal fluid loss and irregular uterine contractions. Her pregnancy had been uncomplicated until the day of admission. On examination, the patient had a low-grade fever (38.18C). Her uterus was non-tender, with no maternal or fetal tachycardia. Electronic fetal heart rate monitoring was reactive. Speculum examination revealed vaginal pooling of amniotic fluid, and a positive Fern test confirmed the pPROM. Complete blood count revealed a hemoglobin level of 121 g/L, and a white cell count of 15.016 10/L with 94% of neutrophils. Urine analysis was normal. Amniocentesis was performed to assess the presence of MIAC. Analysis of the amniotic fluid revealed a high leukocyte count (283610/L) and a glucose level of 1.0 mmol/L suggesting a high likelihood of MIAC. Amniotic fluid Gram staining showed Gram-positive cocci (Figure 1), confirmed by a positive acridine orange stain. Bacteriological cultures and analysis by polymerase chain reaction (PCR) for detection of Mycoplasma hominis, Ureaplasma urealyticum and Ureaplasma parvum were performed. A working diagnosis of MIAC, or subclinical chorioamnionitis, was considered. Ampicillin and gentamycin were given intravenously, and labor was induced with intravenous oxytocin. After 2 hours and 50 minutes of labor, the patient delivered a live female infant, with a birth weight of 1730 g and Apgar scores of 8, 8 and 9. The infant did not require ventilatory assistance but was transferred to the neonatal intensive care unit for a septic workup and intravenous antibiotherapy. The neonate was transferred to a level-I pediatric center after 10 days of hospitalization. No adverse neonatal outcome was noted. A six-month follow-up visit demonstrated a normal neurological exam and normal auditory evoked potential tests. According to the microbiology laboratory routine protocol, the amniotic fluid was inoculated in several culture media, including MacConkey agar incubated at 358C under aerobic conditions, Columbia 5% sheep blood agar [1], Thayer–Martin agar and chocolate agar (Oxoid) at 358C under 5% CO2, modified Columbia 5% sheep blood agar [1], and modified Columbia 5% sheep blood agar with 5.5 mg/mL gentamycin at 358C under anaerobic conditions [1]. One milliliter of amniotic fluid was placed in cooked meat broth, incubated at 358C under 5% CO2 and subcultured at 5 days of incubation on Columbia 5% sheep blood agar, and MacConkey agar, then incubated as above [1]. The cultures were all negative, as well as the PCR of M. hominis, U. parvum and U. urealyticum. An aliquot of amniotic fluid that had been frozen at 7708C was sent to the provincial public health reference laboratory (Laboratoire de santé publique du Québec). The presence of positive cocci on Gram staining was confirmed. No bacterial growth was recovered on the following media: Todd–Hewitt broth with bovine serum, Todd–Hewitt broth with The Journal of Maternal-Fetal and Neonatal Medicine, February 2007; 20(2): 185–187

Antibiotic therapy for preterm premature rupture of membranes.

Sir, August Fuhr et al. need to be congratulated for the completion of their randomized, double-blind, placebocontrolled trial w1x. They confirmed that antibiotic administration to a specific group of women with preterm premature rupture of membranes (PPROM) between 240 and 326 weeks’ gestation is associated with prolongation of pregnancy as well as reduction of neonatal infection and other neonatal morbidities w1, 3x. On the other hand, the ORACLE 1 trial, a very large randomized study of women with PPROM at all gestational ages (from 15–37 weeks’ gestation), reported marginal benefit from the use of erythromycin and no benefit from coamoxiclav over placebo w2x. Moreover, neonatal morbidity was found to be significantly higher in neonates whose mothers developed chorioamnionitis after PPROM, with the incidence of chorioamnionitis decreasing significantly with increasing gestational age (32%, 19% and 10% at 24–26, 27–29 and G30 weeks’ gestation, respectively) w4x. Therefore, it could be suggested that antibiotics in women with PPROM are mainly beneficial for neonates who have reached a viable gestational age (more than 23 weeks), and potentially before 27 or 30 weeks’ gestation, when the risk of chorioamnionitis is greater. We are wondering, first, if August Fuhr et al. noted greater benefit in neonatal morbidity with the use of mezlocillin compared to placebo prior to 27–30 weeks’ gestation, and, second, if data were collected on periventricular leukomalacia, which is the most common substrate of neurological disabilities.