Use of Transabdominal Ultrasound and Maternal Hormone Testing for the Prenatal Monitoring of Equine Fetal Enlarged Bladder.
Authors: Gao Yuanzhi, Yoshida Sakura, Takeyama Akiko, Tagami Masaaki, Rajabi-Toustani Reza, Tsogtgerel Munkhtuul, Nambo Yasuo
Journal: Journal of equine veterinary science
Summary
# Editorial Summary: Prenatal Detection of Equine Fetal Enlarged Bladder Fetal urological abnormalities remain poorly documented in equine practice, making their antenatal recognition clinically challenging. A Japanese research team documented a rare case of progressive fetal bladder enlargement in a Hokkaido pony mare using serial transabdominal ultrasound examinations combined with maternal progesterone monitoring throughout gestation, detecting initial bladder abnormalities at 215 days and the development of a second bladder by day 257 whilst renal structures remained sonographically normal. Maternal plasma progesterone concentrations remained within expected ranges until 36 weeks of gestation, after which levels elevated significantly until parturition—a finding that may reflect the mare's physiological response to fetal pathology rather than indicating specific diagnostic value for bladder dysfunction. Despite the congenital bladder disorder, the foal was delivered successfully at 363 days following induced parturition, suggesting that careful late-gestation monitoring and timely intervention may permit positive outcomes even with significant fetal abnormalities. For practitioners involved in late-gestation mare management, this case highlights the diagnostic potential of routine transabdominal ultrasonography for detecting subtle fetal pathology and emphasises the importance of establishing baseline hormone profiles during pregnancy—knowledge that can inform decision-making about timing of delivery and foal management when structural abnormalities are identified prenatally.
Read the full abstract on PubMed
Practical Takeaways
- •Late-gestation transabdominal ultrasound can detect rare fetal urological abnormalities such as enlarged or duplicate bladders, enabling informed management decisions during pregnancy
- •Progressive enlargement of fetal bladder structures may be compatible with successful live delivery, warranting consideration of induction timing and monitoring strategies rather than assumed poor prognosis
- •Maternal progesterone monitoring during gestation with suspected fetal abnormalities may provide additional information about placental function and pregnancy viability alongside ultrasound assessment
Key Findings
- •Transabdominal ultrasound successfully detected fetal bladder abnormalities at 215 days of gestation in a Hokkaido pony
- •Bladder volume increased progressively with gestational age, and a second bladder was observed at 257 days of gestation
- •Maternal plasma progesterone concentration remained elevated from 36 weeks of gestation until parturition
- •Successful foal delivery was achieved at 363 days following parturition induction despite significant fetal urological abnormality