Professor Senanayake has extensive experience in administration and in obstetrics & gynaecology at hospitals with different levels of resources. Six years of his career were spent in the United Kingdom, first as a trainee and later as a Consultant.
He has delivered invited lectures in the United States of America, United Kingdom, Italy, Singapore and India, including a Plenary Lecture at the 2000 FIGO (International Federation of Obstetrics & Gynecology) World Congress of Obstetrics and Gynaecology in Washington DC.
More recently he has been involved in administrative duties, in his own Department as Head, the Research Ethics Committee (ERC) of the Faculty of Medicine, Colombo and the Colombo Task Force for the Reproductive Health Research, the latter two of which he Chairs. In the Ethics Review Committee he successfully managed and led their efforts to gain SIDCER (Strategic Initiative for Developing Capacity in Ethics Review of the World Health Organization) and Federalwide Assurance of the US Government, leading it to be the preeminent ethics committee in the country.
In research, he is now managing a multicentre study to develop a symphysiofundal height chart for Sri Lanka. The project is funded by the World Health Organization. In addition, he is supervising research projects on postpartum hemorrhage, heavy metal levels in endometrial deposits and the effects of heavy metals on endometrial cell cultures.
As a member of the Board of Study in Obstetrics & Gynaecology, I contribute to decisions regarding the postgraduate training programme in his speciality in Sri Lanka.