pregnancy". Production Staff member André Bormanis later explained that the inclusion of a Klingon battlecruiser design similar to what had been used previously in the franchise (in time periods set later in the timeline) was to indicate the slow evolution of Klingon ship design. He compared this to the speed of changes seen in the rockets used by the Russian Space Agency, and said that the philosophy for the Klingons was that "if the design works, why change it?" Connor Trinneer loved the episode concept: "How often do you get the opportunity as an actor to tackle things like this?" Michael Westmore created the nipple effect using gelatin, same as you can buy in the supermarket, as it offered greater luminosity than latex or rubber, and better resembled human skin. Reception Unexpected was first aired in the United States on UPN on October 17, 2001. According to Nielsen Media Research, it received a 5.2/8 rating share among adults. It had an average of 8.2 million viewers. Sunny Lee of Entertainment Weekly said the comedic episode "mixed irreverent wit [...] with a bit of inter-galactic pondering about biological reproduction" but that it was resolved before things got too sentimental or serious. Daryl H Miller of the Los Angeles Times called Unexpected "one of the cleverest episodes on any channel". About.com's Julia Houston gave the episode a positive review, and wrote: "Funny without being sentimental, a good adventure with enough outrageousness to compensate for the lack of any real danger. It's too fluffy to watch every week, but a few times a season will keep us smiling." Jason Bates of IGN rated it 4 out of 5. He liked the humor, saying it had "some genuinely funny moments". He also appreciated that "the aliens were alien for a change". Bates would have liked the supporting characters to have had something to do in a subplot and was disappointed by Blalock's muted performance, but found the episode "a fun ride overall." Keith DeCandido of Tor.com gave it 3 out of 10. In 2017, Screen Rant ranked the Xyrillians, the aliens featured in this episode, as the 14th most bizarre aliens in Star Trek. This episode was noted for alien Xyrillian impregnating Trip, and for showing a nipple on screen, but not in the way the audience might expect. In 2011, Star Trek Magazine rated this episode 1 out of 5 and named it