Yes! and its a well know fact you can speedup a pregnancy by using more women :S
(would be nice though).
Stupid comparison is stupid. Sure, multiple women cannot collaborate on a single pregnancy, but multiple developers can collaborate on a single release and/or feature so your analogy doesn't really apply.
However, to stay with your analogy: You may not be able to speed up a single pregnancy, but you can improve "throughput". Lets say you want to have 10 babies. With a single female this would take you approximately 15-20 years (considering you shouldn't have pregnancies one right after the other). However, with 10 females you could have 10 babies in a single year. Which means with 10 developers you can add 10 features in a single release, whereas a single developer might only add one