The Bill & Melinda Gates Foundation announced on Thursday that Susan Desmond-Hellmann will step down from his post after five years of leading the charitable group. Mark Suzman, the group's chief strategy officer, will take over by February 1.

According to Forbes, Desmond-Hellmann said in a statement that she had to make the "toughest the decision" in her career since she can no longer balance the time she has for her family and health while juggling the demands of leading the foundation.

Suzman, who worked with the Financial Times and the United Nations in the past said he is "humbled and excited by the opportunity" to work alongside the power couple in helping change lives.

The South African native will be the fourth chief who will lead the Gates Foundation, while Bill and Melinda will retain their place as the group's co-chairs. Melinda said in a statement that Desmond-Hellmann helped the foundation in many ways in her five years of leadership.

Some charity experts noted that Desmond-Hellman's exit could have a major impact on what has been recognized as a leader in tech charities and advocate groups.

In the global philanthropy setting, some form of criticism has risen due to increasing questions about income inequality and whether advocacy groups are doing enough to make a change in the world.

With Desmond-Hellmann's exit, it is expected that people will now set their sights on Suzman, who will take over the reins during a critical time in philanthropist works and activities.

Desmond-Hellman's run as CEO was met with challenges, especially in 2016, after she acknowledged that the Gates Foundation fell through some pits along the way. At that time, she was referring to the group's work on American education reform.

Despite her surprise announcement, Desmond-Hellmann will be remembered as the leader who oversaw some notable achievements that the Gates Foundation achieved in the last five years.

Her leadership helped deliver the Gates Median Research Institute's establishment, a health research grant to the University of Washington, and a major anti-poverty investment in the U.S.

The former physician and research scientist also helped the charitable foundation obtain increased funding for Gates' cause on women empowerment in developing countries that need more awareness and assistance in birth control.

The Gates Foundation was founded by Bill and Melinda Gates in 2000 and is estimated to hold nearly $50 billion in assets worldwide. The U.S. private foundation pledges to help transform lives through funding in various aspects of philanthropy including healthcare, education, innovation, and women empowerment.