SINGAPORE - Dr Oon Chiew Seng, one of Singapore's first obstetricians and gynaecologists, died on Thursday (March 31). She was 106.

She was said to have died of natural causes.

She had contracted Covid-19 in January this year, said her nephew, Dr Gabriel Oon. The elder Dr Oon had been unvaccinated.

Dr Oon, who never married, leaves behind nephews, nieces, and grand- and great-grand nephews and nieces.

"She was a strong woman in good health condition. After she recovered from Covid-19, she was able to walk around and do the things she enjoyed, like playing mahjong and reading newspapers," said Dr Gabriel Oon, 82, who is a retired oncologist.

Even though she had suffered from dementia since about 2013, she still continued playing mahjong, he added.

"But a week ago, she started to become more drowsy and refused to eat," said Dr Gabriel Oon.

She also did not want to open her mouth, and her symptoms progressed a couple of days later when she started clenching her fists and lost her vision.

President Halimah Yacob dedicated a post to Dr Oon Chiew Seng on Facebook on Saturday, recalling how she had spent her life in public service.

"Motivated by her observation that many women were more comfortable seeing female obstetrics and gynaecology (O&G;) specialists, she forged her path in the field during a time when girls were not encouraged to pursue higher studies," wrote Madam Halimah, adding that she was saddened to learn about Dr Oon's passing.

"She will be remembered for her service towards vulnerable communities. My heart is with her family."

Dr Oon received an honorary degree from the National University of Singapore (NUS) in 2021, presented by President Halimah, for her lifelong dedication to medical education and public service.

Dr Oon, the youngest of 10 children, was born in Penang in 1916. She was a nurse in the 1930s.

She then studied to become a doctor at King Edward VII Medical College in Singapore, a predecessor institution of NUS. She graduated in 1948.

During World War II, she continued her studies in India, where she lived in a flat shared by four families with 16 children. Rainwater was constantly leaking through its roof and walls.

Dr Oon was one of the first women in the region to qualify as a member of the British Royal College of Obstetricians and Gynaecologists in 1955. She was also the first O&G; specialist to start her own private practice in 1959 after leaving the then Kandang Kerbau Hospital.

She retired in 1991 at the age of 75 and travelled extensively.

She then worked on setting up the Apex Harmony Lodge for dementia patients in Pasir Ris and made trips to Australia to learn how dementia homes were run.

Singapore's first dementia home opened its doors in 1999, with Dr Oon serving as its founding chairman until 2012.

Among the numerous awards Dr Oon received for her clinical and humanitarian work were the Public Service Medal in 2000, the Lifetime Achievement Award from the Ministry of Health in 2011, and the Public Service Star in 2013.

She also received the President's Special Recognition Award for Volunteerism and Philanthropy in 2013, and was inducted into the Singapore Women's Hall of Fame in 2014.

Mr Phillip Tan, 72, chairman of Community Chest and Yellow Ribbon Singapore, said that Dr Oon had been an inspiration to him since they worked together to raise funds for Lasalle College of the Arts, which was having financial difficulty, more than 30 years ago.

Said Dr Gabriel Oon: "What people can learn from my aunt is to do whatever you do voluntarily and unconditionally. She was a living example of that through all her charity work. She has... accomplished many great things in her lifetime."

In a tribute to her, NUS president Tan Eng Chye said Dr Oon was an exemplary alumna who embodied the spirit of public service and compassion and inspired the NUS community through her life's work, especially in ageing and dementia.

Professor Chong Yap Seng, dean of NUS Medicine, said that Dr Oon had been a true visionary of her generation.

"(She) was a resourceful obstetrician and gynaecologist who continually sought to improve patient treatment, working alongside pioneering practitioners such as Dr Benjamin Sheares in Singapore's nascent years," said Prof Chong. Dr Sheares was a prominent O&G; doctor and former president of Singapore.

"Her tireless devotion to caring for the community and her steadfast drive to create impactful change will continue to be an inspiration to us all," added Prof Chong.