I agree with Eidotemit here, if they would have maybe just flashed at the birth real quick like, same with the women screaming and etc (I'm talking flashes here)... I think it would have played out much better. Would have been scary, disturbing, and retained a sense of mystery without going "here, look at this!"
To me the movie didn't hold much dramatic value, and it wanted you to care about the characters only as much as you do in, say, slasher films. So I got into 'blood and guts' mode only to see something that honestly personally offends me while also being so strangely outside of Alien canon that I'm confused as well as angry, not just more movie violence, and it's not going to work on the emotional appeal level.
The first thing I thought of was not how savage or creepy the aliens were, but how large of Jackasses the brothers were. That's not what they were going for, I think.