The 37-year-old singer - who was joined in the band by Victoria Beckham, Mel B, Geri Halliwell and Emma Bunton - admitted while she would love the five-piece to get together for a reunion tour there are "babies everywhere", which could make it "difficult".
Mel - who has two-year-old daughter Scarlett with her partner Thomas Starr - exclusively told BANG Showbiz: "I didn't think it would happen the first time around and it did, and it was such good fun. I would love to do it but the timing would have to be right and we've got to make sure all the other girls are up for it.
"It's difficult with all the Spice babies though, everyone has got so much on their plates right now and of course we've got Victoria and Melanie's babies due to be born in the next few months.
"There are literally babies everywhere at the moment - there's so many of them now, it's incredible."
Mel B is currently pregnant with her third child, but her first with husband Stephen Belafonte, while Victoria - who already has three sons with her husband David - is due to give birth to a girl on July 4.
Emma has two sons, three-year-old Beau and newborn Tate, with her fiance Jade Jones and Geri has a five-year-old daughter Bluebell.
The 'When You're Gone' singer admits she still misses her time with the globe-conquering girl group, and would love to "re-live" it again.
She added: "We've had such great success and we've got such great fans out there, it's really nice to get back together because people want to see it.
"When you're in something you really take it for granted but then when you step away from the situation you miss it, so it would be nice to re-live it again. It seems like a lifetime ago. I still think, 'Did that really happen?' I've got so many great memories of that time."