Search

The standard definition of a prolonged pregnancy is 42 completed weeks of gestation. The incidence of prolonged pregnancy varies depending on the criteria used to define gestational age at birth. It is estimated that 4 to 19% of pregnancies reach or exceed 42 weeks gestation. Several studies that have used very large computerized databases of well-dated pregnancies provided insights into the incidence and nature of adverse perinatal outcome such as an increased fetal and neonatal mortality as well as increased fetal and maternal morbidity in prolonged pregnancy. Fetal surveillance may be used in an attempt to observe the prolonged pregnancy while awaiting the onset of spontaneous labor. This article reviews the different methodologies and protocols for fetal surveillance in prolonged pregnancies. On the one hand, false-positive tests commonly lead to unnecessary interventions that are potentially hazardous to the gravida. On the other hand, to date, no program of fetal testing has been shown to completely eliminate the risk of stillbirth.

MODEL JUDETTE LOUIS, JOHN HOTRA, JAMES JANISSE, ROBERT SOKOL, CaseMetrohealth Medical Center, Cleveland, Ohio, Wayne State University, Detroit, Michigan OBJECTIVE: We recently reported a strong association between alcohol exposure during human pregnancy and extreme preterm delivery; here, we sought to validate a previously reported murine model to facilitate mechanistic studies. STUDY DESIGN: Nulliparous 10-12 week old female C57BL/6J mice were randomized to one of 20 treatment groups and bred using a timed breeding method. Each mouse received one of four doses of alcohol (0, 4, 5 or 6 grams of alcohol/kg body weight) on one of five gestational days (GD) (GD 10, 15, 16, 17, 18). Cages were monitored every 6h for deliveries. Data were analyzed utilizing a 4x5 ANOVA. RESULTS: The alcohol dose by day of exposure interaction was significant (p 0.015), while the main effects for alcohol dose (p 0.942), and day of exposure (p 0.157) on gestational length were not. Examination of the interaction revealed a differential effect of day of exposure on the control group, compared to the alcohol exposed groups. Among the control group mice receiving no alcohol, the GD 10 group had a significantly longer gestation (mean 20.5) than the GD15 (mean 19.2), 17 (mean 19.4) and 18 (mean 19.3) groups. However, the day of exposure was not related to length of gestation in the alcohol groups (p 0.157). Average length of gestation for the alcohol groups was 19.3 days. CONCLUSION: Failing to confirm a previous study in this murine prenatal alcohol exposure model, no relation to gestational duration was detected. An effect may have been cloaked by an apparent major effect of intubation. Again attempting to confirm this model with additional controls or another dosing method or finding other animal models would facilitate further study of prenatal alcohol exposure and preterm delivery risk.