Exploring fetal response to acidosis in ewes: Choosing an adequate experimental model

INTRODUCTION

Knowledge of fetal physiology during labor has been largely generated from animal models. Our team recently developed a new index to assess parasympathetic activity using different experimental protocols to obtain acidosis. The objective of the present study was to discuss the different protocols and to review other models proposed in the literature.

MATERIAL AND METHODS

Pregnant ewes underwent a surgical procedure at the 123±2 days gestational age (term=145 days). Three experimental protocols were used: protocol A consisted of 25%, 50% and 75% umbilical cord occlusion (UCO) for 20min. Protocol B consisted of partial 75% UCO until reaching a pH<7.10. Protocol C consisted of brief, repetitive complete occlusion until severe acidosis occurred. Hemodynamic and blood gas parameters were compared to those of the stability period before UCO.

RESULTS

Protocol A led to a progressive response depending on the degree of occlusion (decrease in fetal heart rate, arterial hypertension and pH). Protocol B led to severe acidosis, although the duration of UCO varied per animal. Protocol C also progressively led to acidosis. We observed high inter individual variability in the acidosis response.

CONCLUSION

Pregnant ewes are a relevant model for exploring fetal response to acidosis. The frequency of UCO and partial or complete occlusion should be adapted to the expected effects. Knowledge of these protocols is important to respect ethical guidelines and to reduce the required number of animals. Moreover, it is important to consider the high individual variability of the acidosis response in the interpretation of the results.

[Zavanelli maneuver in a breech presentation: to be kept in mind]

Since its first description in 1980, the Zavanelli maneuver - reintroduction of the fetus in the uterus after failure of maneuver to reduce shoulder dystocia - remains an extraordinary and nearly unknown remedy. We report a Zavanelli maneuver performed in a case of irreducible raising arm of a fetus in breech presentation. Literature and our observation indicate that fetal and neonatal prognosis in Zavanelli maneuver is pretty good if breech presentation. This exceptional situation should remain in mind of obstetricians.

How to improve the preoperative staging of presumed early-stage endometrioid endometrial cancer?

PURPOSE OF INVESTIGATION

Accurate preoperative staging of early-stage endometrioid endometrial cancer (EEC) is necessary to avoid under or over surgical treatment. The objective is to determine the rate of understaging and to evaluate the accuracy of different methods: hysteroscopy-curettage versus endometrial biopsy in predicting the final stage.

MATERIALS AND METHODS

This retrospective single-centre study led from 2000 to 2010, included women with EEC preoperatively assessed at low- or intermediate-risk. Understaging was defined as a postoperative FIGO Stage > 1 or a determination of high risk after the final histopathologic diagnosis.

RESULTS

The study included 101 women (75 low-risk and 26 intermediate-risk). Final diagnosis was upstaged for 26 of them, more frequently in the presumed intermediate-risk group (57.7% vs 14.7%, p < 0.001). The rate of preoperative understaging was higher in the women with endometrial biopsies than those with curettage (34.5% vs 15.2%, p = 0.04).

CONCLUSIONS

Hysteroscopy-curettage combined with magnetic resonance imaging (MRI) may improve preoperative staging of early-stage EEC, especially for presumed intermediate-risk disease.