'Bachelor' Baby Boom: A Look at the Expectant Reality TV Stars' Relationships

— -- "The Bachelor" and "The Bachelorette" don't always result in long-lasting relationships.

But in more recent years, many of the show's stars have found love -- and now, they're starting families of their own.

On Tuesday, it was revealed that season nine Bachelorette Desiree Hartsock Siegfried and her husband one of one year, Chris Siegfried, were expecting their first child in October.

"We have a bun in the oven and it's not the warm pastry kind!" she wrote on Instagram. "We are beyond excited to share that we have a little one on the way!! A new chapter we are both looking forward to."

Baby Siegfried is in good company. Two other former "Bachelorettes" are also currently pregnant, as is the wife of a former "Bachelor" star. Here's a look back on how they got here.

Jillian Harris and Justin Pasutto

Jillian Harris placed second in season 13 of "The Bachelor," but had a second chance to find love on television when became the season five star of "The Bachelorette." She accepted a proposal from Ed Swiderski, though they split in 2010. "It was the last thing I wanted to do," she told Us Weekly at the time. "It's terrible to leave because the other person doesn't know what they want." However, a few years later, she found love with Justin Pasutto, and in March, they revealed that she was pregnant with their first baby. "So everyone has been waiting and waiting and waiting and frankly I'm tired of everyone telling me to lock it up... I mean if you know Jill she will loose [sic] the ring," he wrote on Instagram. "So I came up with the best invention ever for the love of my life. A little baby miracle in her tummy. Words can't express how lucky and blessed we feel."

Ali Fedotowsky and Kevin Manno

We first met Ali Fedotowsky during season 14 of "The Bachelor," when she left pilot Jake Pavelka to return to her job at Facebook. That didn't last long, though, and that same year, she was tapped to star in season six of "The Bachelorette." Ultimately, she accepted a proposal from Roberto Martinez, but their relationship ended in 2011. A few years later, she met Kevin Manno through her travel show, "1st Look," and in 2015, they announced their engagement. A few months later, she revealed she was expecting the couple's first child -- a girl -- later this year.

Emily Maynard and Tyler Johnson

Emily Maynard got engaged twice on national television -- to Brad Womack on "The Bachelor" and to Jef Holm on "The Bachelorette." However, it wasn't to be with either man. Then, in 2013, she found lasting love with Tyler Johnson, whom she married the next year. Maynard is currently pregnant with the couple's second child; she also has a daughter from a previous relationship.

Catherine Giudici Lowe and Sean Lowe

Theirs was a slow-developing relationship on "The Bachelor," but in the 2013 finale, Lowe proposed to a clearly-shocked Giudici in Thailand. The most publicized part of their relationship? Their decision to wait to until marriage to have sex. "We made a really good decision for us and we're excited to consummate as husband and wife," Giudici told ABC News. "It's something that is a benefit of being married." In 2014, they wed in a two-hour ABC special, and continued their reality TV careers by appearing on "Celebrity Family Feud," "Celebrity Wife Swap," and "Marriage Boot Camp." Then, last December, they revealed they were taking on a new job: parenthood. "There's been no problems! No sickness. I think being tired is the extent of my symptoms," Giudici told ABC News in February. "I've been very blessed. We're very, very lucky."

Desiree Hartsock Siegfried and Chris Siegfried

In the 2013 installment of "The Bachelorette," Desiree Hartsock was sent reeling after front-runner Brooks Forester eliminated himself from the show in the season's penultimate episode. However, in the finale, she told Chris Siegfried that it was after her heartbreak that she realized "the one thing that I always needed was right in front of me." "Sometimes you have to get through the hard to get to the good," Hartsock explained during an appearance on "Good Morning America." "I think that helped me, getting past the hurt of Brooks leaving and being able to see all that was clear in Chris." The couple married last year and discovered that they were expecting this past Valentine's Day.