Abstract
The maintenance of elevated progesterone concentrations is considered crucial for maintaining pregnancy, as well as normal fetal growth and development in bottlenose dolphins (Tursiops truncatus).1-3 Normal gestation ranges from 355–399 days, during which time progesterone is maintained above 5 ng/ml (average 15–20 ng/ml) until just before parturition.1,3 Progesterone insufficiency during pregnancy has previously resulted in fetal demise and abortion and exogenous progestin therapy has resulted in complications.3 This report highlights a successful pregnancy in a multiparous, 32-year-old bottlenose dolphin with progesterone levels that were lower than previously reported in the literature during the last 3 months of gestation. Maternal reproductive health and fetal growth and development were monitored with biweekly ultrasonographic examination and, after day 187, weekly blood tests including progesterone concentration. Ovulation date, presence of a viable embryo, and bi-parietal diameter were used to confirm conception and monitor fetal growth. The dam's progesterone levels decreased from 13.2 ng/ml (day 146) to 6.3 ng/ml (day 187) to 3.1 ng/ml (day 209). At day 321, levels increased to 10.7 ng/ml, but declined again to 4.8 ng/ml on day 327. Levels remained under 5 ng/ml until parturition. At day 396, the dam delivered a normally developed 18.18-kg calf that required short-term, peri-parturition veterinary support due to minor complications. This case serves to highlight the importance of weekly prenatal health evaluations using multimodal diagnostic tools, including progesterone concentrations and sonography, to provide optimal reproductive health management in cetaceans.
* Presenting authors
Literature Cited
1. Bergfelt DR, Steinetz BG, Lasano S, West KL, Campbell M, Adams GP. Relaxin and progesterone during pregnancy and the post-partum period in association with live and stillborn calves in bottlenose dolphins (Tursiops truncatus). General and Comparative Endocrinology. 2011;170(3):650–656.
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