Radcliffe and her husband Gary Lough, whose daughter Isla was born in January 2007, are delighted that she will soon be joined by a sibling, she said.
The 36-year-old has always insisted she planned on having another child before Games in London, where she will be aiming for her first-ever Olympic medal in what would be her fifth appearance.
With no global championships taking place this year and a full year to return comfortably to marathon racing, 2010 offered the perfect opportunity to fulfil their desire to have a second child, Radcliffe said.
"We're very pleased," Radcliffe said.
"We are very lucky that everything so far has worked out as we had hoped.
"As always when nature is involved it's very hard to plan, but the idea was that we could get pregnant this year and have 2011 to comfortably come back to racing.
"I plan to run through as before but to come back a bit slower than last time when I was back a bit too quickly.
"[London] 2012 is the big goal and we think this works out perfectly for that."
Radcliffe has not competed since finishing fourth in last November's New York City Marathon and, given the timescale of the baby's arrival, it seems likely she will not run a marathon this year.
Radcliffe is still in full-time training and recently returned from a camp in Portland, Oregon, where she opted for a different approach to her preparations.
Instead of going to a high-altitude location in Albuquerque, New Mexico, she trained with some of the United States top runners.
Story supplied by: www.insidethegames.biz
