When plotting to reissue an classic album, it's always best to sift through the vaults for any material that might help promote the record. In the case of the upcoming Nirvana reissue of 'In Utero,' a little digging unearthed a bizarre trailer the band shot to originally promote the 1993 release.

The obscure clip features the three Nirvana members dressed up as pregnant women led through a birthing class taught by comedian Bobcat Goldthwait, also dressed up in drag. Watch as Kurt Cobain, Dave Grohl and Krist Novoselic use the proper breathing techniques to squeeze out -- and we do mean squeeze out -- several offspring.

The clip itself is a fun watch, as you see the humor that all three members had in putting this promo together, plus the dress-up comedy that followed Dave Grohl over to the Foo Fighters for some of their more hilarious videos. It's also a reminder of the comedy gold that was Bobcat Goldthwait during the peak of his celebrity in the late '80s and early '90s.

Luckily Nirvana didn't have any trouble at all birthing their follow-up to the mega-huge breakout of 'Nevermind.' The 'In Utero' album picked right up with the band remaining on top thanks to songs like 'Heart-Shaped Box,' 'Rape Me,' 'Dumb,' 'All Apologies' and 'Pennyroyal Tea' among others. The 1993 release went straight to the top of the charts and has been certified five-times platinum by the RIAA.

Little is known about the 'In Utero' reissue at this point, other than that the 20th anniversary edition is expected to surface in September. Stay tuned for more information on Nirvana's 'In Utero' update.