Serena Williams confirmed rumors that she was pregnant earlier this week. With pretty much immediate effect all the major sportsbooks, like bet365, eliminated her betting odds from the sports futures/antepost markets that are commonly available for tennis. However, there is a scenario where a pregnant Serena Williams actually regains the No. 1 ranking on the women's tour in the very-near future.

Understanding WTA rankings

The WTA employs a 52-week rollover system when determining its professional tennis rankings. Williams is currently ranked 2nd in the world behind Angelique Kerber of Germany from that point of view.

Williams' high ranking is largely due to the American's titles in both Melbourne Park earlier this season and Wimbledon last season. Meanwhile Kerber won Flushing Meadows and made the Wimbledon final last season.

The German herself will be in the soon-to-be-released WTA Stuttgart draw, an event that Maria Sharapova will also be in. Last year Kerber won the clay-court event in what was her best tournament between the Australian Open and Wimbledon. Accordingly, Kerber has a small chunk of ranking points to defend at this year's event. If she falls early in Stuttgart then she would lose all or many of those ranking points. With Kerber potentially turning in a negative 'net' gain and Serena staying still, in effect Serena Williams could back into the World No.

1 ranking despite not playing since the Australian Open and despite being 20 weeks pregnant.

Kerber could suffer an early exit

Kerber's chances of going out early aren't as horribly unrealistic as her ranking suggests. She is the World No. 1, but her tournament results since getting to the top of the world for the first time are littered with some early-round exits and plenty of middle-round ones.

When I adjust off Kerber's points from last year, I see Williams holding almost a 100-point lead over Kerber on live rankings. I think Kerber would need to make the quarterfinals or the semifinals of Stuttgart to guard against losing her spot to Williams.

The Stuttgart draw will become available this weekend. The players' list is loaded and the tournament takes on heightened significance because it marks the return of Maria Sharapova, a wild card in the event.

Besides Kerber and the Russian all of Karolina Pliskova, Dominica Cibulkova, Simona Halep, Garbine Muguruza, Agnieszka Radwanska, Svetlana Kuznetsova, and Johanna Konta are expected to be in the draw.