Mild maternal undernutrition in the first half of ovine pregnancy influences placental morphology but not fetal Doppler flow velocity waveforms and fetal heart size

AIMS

We wanted to investigate whether experimental dietary manipulations during early pregnancy influence placental growth and subsequently the cardiovascular system as assessed non-invasively by ultrasonography in the sheep fetus.

METHODS

21 ewes bearing singletons of uniform age were randomly assigned for the first half of pregnancy to one of the following study groups: fed 100% of their nutritional requirements (i.e. controls), global reduction in total intake by 30% (i.e. 70% global) and reduction in protein intake by 30% (i.e. 70% protein).

RESULTS

Placentas from the 70% protein group had significantly more small placentomes, but significantly fewer large placentomes compared to the 70% global group. However, there were no significant differences between the three dietary groups for either the aortic or the umbilical Doppler velocimetry parameters and the fetal heart rate or heart size.

CONCLUSIONS

The present study shows that early mild maternal undernutrition produces subtle changes in cotelydonary weight. However, Doppler and echocardiographic parameters were not affected by these changes.

Visualisation and measurement of tracheal diameter in the sheep fetus: an ultrasound study with stereomicroscopic correlation

OBJECTIVE

There is no information on ultrasonographic visualisation of the upper airways in the sheep fetus, but this species permits to examine the accuracy of ultrasonography in measuring the inner tracheal diameter. This was the aim of our study.

METHODS

Transabdominal ultrasonography to visualise the trachea was attempted in 16 unsedated Welsh Mountain ewes with a singleton pregnancy at 70 (SD 2) days gestation (term 148 days). The ultrasonographically measured inner tracheal diameter was compared with the actual inner tracheal diameter obtained by stereomicroscopy post-mortem.

RESULTS

High-resolution ultrasonography permitted clear imaging of the fetal trachea in 87% (14/16) of the cases analysed. The ultrasound measurements were smaller than the corresponding stereomicroscopic measurements, the mean +/- SD difference between the measurements being 0.40 +/- 0.12 mm.

CONCLUSIONS

Improvements in ultrasound have led to increased interest in the assessment of the trachea in human fetuses. Our study in the ovine fetus at mid gestation shows that optimal views of the fetal trachea allowing accurate measurements can be obtained in almost all the cases.

Ectopic pregnancy with levonorgestrel releasing intrauterine system

The levonorgestrel releasing intrauterine system has been received with enthusiasm by all involved in women's health for both its contraceptive and non-contraceptive uses. This case illustrates a rare event and a possible note of caution.