Story highlights "We are so excited," says Michelle Duggar

"Josie is the most energetic, busy little almost-2-year-old," says Michelle

"We are just going to do the best we can," says Michelle

They're going for an even 20!

Michelle and Jim Bob Duggar, stars of TLC's "19 Kids and Counting," are expecting their 20th child this spring.

"We are so excited," says Michelle, 45, who is now about three-and-a-half months into her pregnancy and due in April. "I feel good. I am past the sickness stage now."

The Tontitown, Ark., couple, who are parents to children Joshua, 23 (who is married to Anna, 23 and has two children , Mackynzie, 2 and Michael, 4 months), twins Jana and John-David, 21; Jill, 20; Jessa, 19; Jinger, 17; Joseph, 16; Josiah, 15; Joy-Anna, 14; twins Jedidiah and Jeremiah, 12; Jason, 11; James, 10; Justin, 8; Jackson, 7; Johanna, 6; Jennifer, 4; and Jordyn, 3, weathered the medical emergency of their youngest daughter, Josie's birth on Dec. 10, 2009

She was born following Michelle's preeclampsia diagnosis at a mere 25 weeks, weighing only 1lb., 6 oz.

Josie's medical drama -- and Michelle's own fight for survival -- was documented throughout their TV series. Josie will turn 2 in December and is developing normally, without any longterm effects from her premature birth.

"It is a miracle. Josie is the most energetic, busy little almost-2-year-old," says Michelle. "She is short, and yet she can keep up with the big girls and she thinks she is just as big as they are. We are amazed at what she can do."

Questions About the Pregnancy

Following Josie's life-threatening arrival into the world, the Duggars understand that some might question their latest pregnancy.

"Michelle is probably in better health now than she was 10 years ago," says Jim Bob, 46. "She has been getting on an elliptical for about an hour a day and is very careful of what she eats."

Michelle, who is under the care of a high-risk pregnancy doctor, says she is being cautious, eating a lot of protein and green vegetables and abstaining from caffeine. Approximately 10 to 15 percent of women have preeclampsia -- Michelle had it with her second pregnancy -- and the condition can strike randomly. Women who have had it previously are at higher risk, however.

"We are just going to do the best we can," says Michelle. "I am taking a nap every day, and we are just taking good care."

Jim Bob agrees: "If we had lived by fear after Michelle had preeclampsia after her second delivery, we would have missed out on all our wonderful blessings," he says. "So many of her pregnancies have gone extremely well."

One completely new aspect of this pregnancy? Michelle will have her very first scheduled Cesarean section since Josie's premature birth required a special cut on the inside of her uterus.

"I've never had a planned C-section," Michelle says. "So this one will be different."

Spreading the News

Also different: how to tell 19 siblings that one more is on the way. Jim Bob gathered all the kids together for a family picture, but instead of telling them to say "cheese," told them to say, "Mom's going to have another baby!"

"The kids were all asking, 'Are you joking or are you serious?' " says Michelle. "It was a big surprise. The little ones started jumping up and down when they realized he was serious."

After hugs and high fives all around, the siblings are now debating the baby's gender and name. The Duggars, who heard the baby's heartbeat in a recent ultrasound, expect to find out whether they are having a boy or girl around Christmas.

The Season 5 finale of "19 Kids and Counting" airs 9 p.m. Tuesday on TLC. The special "Duggars World Tour: Scotland & Ireland," showing a newly pregnant Michelle traveling to Europe with the whole family, premieres November 13, at 8 p.m. on TLC.