A beluga whale (approximately 10 years of age) aborted two male calves 4 months prior to the expected delivery date. The calves appeared to be normal. They weighed 13.64 and 12.45 kilograms (kg) and both were 96.5 centimeters (cm) in length. Two normal placentas were passed 8 and 12 hours after the second calf was aborted. Weights of the placentas were 4 and 4.9 kg respectively. Culture results, abortion screens (IBR, leptospira, vibrio, brucella, BVD, and hemophilus), and histology of all the major organ systems of the fetuses did not indicate any pathological process responsible for the miscarriages. Hematology and serum chemistries were within normal parameters for the cow. She continued to eat and display normal behavior after the second placenta was expelled.

Multiple fetuses have been found in utero in cetaceans, but no documentation of a mature delivery of multiple calves could be found. Since multiple fetuses are known to occur, it is speculated that they are not carried to term or the female dies during delivery. The literature indicates that multiple fetuses appear to occur with less frequency in odontocetes than in mysticetes (approximately 0.6% vs 1.0%). There have been multiple sightings in the wild of two calves swimming with a single female and it has been speculated that the calves may be twins. However, at Sea World of Texas, it is not uncommon for two or even three calves to swim with a single female for extended periods of time before returning to their mother. Whaling records archived in Barrow, Alaska, did not indicate any multiple fetuses in 100 pregnant belugas examined between 1990 and 1995, suggesting that multiple fetuses in belugas are rare.