Confirming the Pregnancy

Staff monitored Ibu making behavioral observations, but a human urine pregnancy test and ultrasound confirmed she was pregnant.

The female orangutan's menstrual cycle is 28 to 30 days, with menstruation lasting three to five days. The gestation period is approximately eight and a half months, so orangutans are pregnant for about 245 days. This is very close to the pregnancy periods of humans. Female Sumatran orangutans will generally give birth to one infant. Multiple births are possible, though they are rare. In face, Ibu was born a twin. Newborn orangutans weigh about 2 to 4 pounds. 

Behavioral Observations

The first signs Ibu was pregnant came from physical and behavioral observations. First, a normally very cheerful and bubbly Ibu appeared to become more calm and reserved. Likewise, normally Ibu is one of the first animals to come when the trainers call her at noon for training, but after becoming pregnant, she seemed more tired. 

As her keepers observed these changes, they began letting Ibu sleep in longer.  If she still feels up to training, they do an abbreviated 15-minute session. Ibu’s training includes exercises that appear like a work out warm up. It includes stretching, reaching her arms up high, getting her knees up like a march, expanding her hips, climbing and squats, as well as mental exercises for her inquisitive mind.

Physical Observations

Ibu was also going through physical changes in the early months of her pregnancy. Ibu’s keepers and the veterinary staff always monitor her health and well-being, but they are now also regularly monitoring physical changes specific to pregnancy in other to give Ibu the highest level of care possible.

The first changes keepers noticed was that Ibu began sleeping and urinating more than usual. Moreover, her nipples became enlarged and her normally gelatinous, doughy stomach was becoming more firm. Ibu’s hormonal cycle stopped, though she was still spotting at times.

Pregnancy Testing

After her menstruation changed, a human pregnancy test kit was the first confirmation that Ibu was pregnant.

Zoo keepers regularly monitor Ibu’s hormonal cycles and after changes were noted in her cycle, the zoo keepers used a human pregnancy test kit to confirm the pregnancy. Certain brands of over-the-counter tests are known to react accurately with orangutan hormones, and are recommended by the AZA Orangutan Husbandry and Breeding guide.

Ultrasound

The pregnancy was further confirmed through an ultrasound and sonogram. Ibu was trained to present her abdomen for ultrasounds. As part of her prenatal monitoring plan, Ibu will allow the veterinary staff to put the ultrasound probe with gel on her belly. Ibu likes watching the machine and seeing the sonograms.

An ultrasound is a procedure that uses high-frequency sound waves to scan the abdomen and pelvic cavity to create a sonogram picture of a baby and placenta. Though an ultrasound and sonogram are technically different, they are frequently used interchangeably in reference to the same exam.