Amniocentesis for PPROM management: a feasibility study.

OBJECTIVE: In Canada, most mothers whose amniotic membranes rupture before 34 weeks' gestation are hospitalized and delivered when signs of chorioamnionitis or fetal distress are observed or when a predetermined gestational age between 34 and 37 weeks is reached. This management approach can be questioned because in utero exposure to infection is a risk factor for cerebral palsy in neonates. Amniocentesis has the potential to detect markers of intra-amniotic infection. Our objective was to determine the acceptability of a randomized study comparing expectant management with amniocentesis-based management in women with premature rupture of the membranes. METHODS: Between November 2005 and January 2007, we conducted a qualitative study involving 40 patients admitted to a tertiary care centre with premature rupture of the membranes between 28 and 34 weeks. The participants read an information booklet and answered a questionnaire. They were asked if they would agree to participate in a randomized study comparing expectant management with amniocentesis-based management. They graded the importance of a series of statements in their decision-making process. RESULTS: Seventy percent (28/40) of patients would have participated in the proposed study. Determining the presence of amniotic fluid infection or lung maturity was the main reason motivating their choice. The reasons for refusing to participate were related to complications of amniocentesis (fetal trauma, iatrogenic preterm labour, infection, or pain). CONCLUSION: The majority of patients with premature rupture of the membranes would participate in a study comparing expectant management to management based on amniocentesis results. This study helped us to better understand their motivations and fears.

Routine third trimester ultrasound: what is the evidence?

Policies for routine third trimester obstetrical ultrasound examinations differ among countries. In Canada, a routine third trimester ultrasound scan is not offered in the low-risk pregnancy population. This practice is based mainly on results of a meta-analysis published in 2001 that concluded "routine late pregnancy ultrasound in low-risk or unselected populations does not confer benefit on mother or baby." We reviewed in detail each study included in this meta-analysis in order to re-evaluate the Canadian practice regarding routine third trimester ultrasound in the low-risk pregnant population. The meta-analysis included outdated techniques and ultrasound examinations performed in the late 1970s and early 1980s. To assess the effect of routine third trimester ultrasound on perinatal outcome, the interventions prompted by an abnormal diagnostic test result must be considered. None of the trials included in the meta-analysis evaluated the effect of routine third trimester ultrasound on perinatal outcomes in a low-risk population when ultrasound assessment was followed by an altered perinatal management plan. Our assessment of the published evidence regarding routine third trimester ultrasound puts in question the contemporary validity of the conclusion of the 2001 meta-analysis. In fact, the 2001 meta-analysis has recently been withdrawn by the authors.