Chulalongkorn University veterinary reproduction expert Sudson Sirivaidyapong said the news suggested two different scenarios, which would be clarified by another ultrasound test next week.
The first was that the pregnancy was “early”, hence the embryo was too small to show vital signs, he said. Panda pregnancies yary from 83-197 days so Lin Hui’s 107-day pregnancy may just be early. The average pregnancy for pandas at Atlanta Zoo was 135 days and embryo’s vital sign could not be detected till the 125th day, only 10 days ahead of birth.
He said the Chiang Mai Zoo may have been comparing the latest pregnancy to Lin Hui’s first cub, which was born after only a 97-day pregnancy.
Pregnancy ‘may have failed’
Secondly, the pregnancy may have failed and the embryo stopped growing. That would also explain no vital signs, he said. This could stem from it being an unseasonal pregnancy or an unfertilised embryo. If this were the case, Lin Hui’s body would absorb the embryo and discharge it without any harm.
However, veterinarian Boripat Siriaroonrat, who heads the panda-breeding unit at the Zoological Park Organisation’s panda-research project, remained positive that the embryo might continue to grow. So, the team will conduct an ultrasound once a week to detect any growth by the embryo and let Lin Hui rest fully and naturally. He said Lin Hui continued to show behaviour that suggested an upcoming birth.