Dr. Chang has given lectures on high-risk pregnancies and Obstetric Ultrasound at numerous Scientific Congress and Meetings throughout the world (in UK, USA, Canada, New Zealand, Taiwan, Hong Kong and Singapore). Dr. Chang also teaches Obstetric Ultrasound at numerous ultrasound courses that he organises in Singapore. In 2003, he organised a Certificate Course in Obstetric Ultrasound jointly with Monash University, Australia. In 2006, he organised a Certificate Course in Obstetric Ultrasound with the College of Obstetricians and Gynaecologists, Singapore. He is also the co-chairman of the organising committee, International Society of Ultrasound in Obstetrics and Gynaecology Outreach Course/ College of O & G Singapore Congress in November 2008.

As President of the College of O & G, Singapore (2007 - 2009), Dr. Chang also represented the College at official functions and international Medical Congresses. In 2006, Dr. Chang was part of the entourage to greet Prime Minister Lee when he was awarded the Fellowship of the Academy of Medicine, Singapore at the 41st Singapore-Malaysia Congress of Medicine. In 2008, Dr. Chang also represented the College at the 42nd Malaysia-Singapore Congress of Medicine in Kuala Lumpur; he was part of the medical entourage to greet DYTM Raja Muda Perak Darul Ridzuan Raja Nazsin Shah. At the same congress, Dr. Chang was also conferred the Honorary Fellowship of the Academy of Medicine, Malaysia in recognition of his contributions to Obstetrics and Gynaecology.

INTERNATIONAL SCIENTIFIC DELIVERED:

• British Medical Ultrasound Society - Bournemouth, United Kingdom
  (December 1991)
• Blair-Bell Research Society - London, United Kingdom
  (January 1992)
• 12th Annual American Society of Perinatal Obstetricians Meeting - Florida, U.S.A.
  (February 1992)
• British Congress of Obstetrics and Gynaecology - Manchester, United Kingdom
  (July 1992)
• Physiological Society Meeting - Cambridge, United Kingdom
  (September 1992)
• Ontario-Quebec Perinatal Investigators Meeting - Kingston, Ontario, Canada
  (November 1992)
• Second International Scientific Meeting of the Royal College of Obstetricians and Gynaecologists - Hong Kong
  (September 1993)
• 15th Annual American Society of Perinatal Obstetricians - Atlanta, U.S.A.
  (February 1995)
• 16th Annual American Society of Perinatal Obstetricians - Hawaii, U.S.A
  (January 1996)
• International Perinatal Doppler Society, Taipeh, Taiwan
  (June 2000)
• A Day in Obstetric Doppler, Mount Sinai Hospital, University of Toronto, Toronto, Canada –
  (Dec 2003)
• First Certificate Course in Obstetric Ultrasound, Thomson Medical Centre and Monash University, Australia
  (2003)
• 1st International Scientific Meeting, ISUOG, Singapore
  (2004)
• Second Certificate Course in Obstetric Ultrasound, Thomson Medical Centre and College of Obstetricians and Gynaecologists, Singapore
  (2006)
• ISUOG Outreach Course / College of O & G, Singapore Scientific Congress
  (2008)
• 20th HK College of O & G Anniversary / International Scientific Meeting
  (2008)