Trailer and poster reveal too much ?

Okay, I love a good trailer but I do not want to know everything, especially in a thriller type movie...
Since I have not actually seen Hindsight I can't say this is a Spoiler..
but
This movie seems to end very much like last year's French film "Inside".. Maybe not close to all the gore (thankfully) but as in the trailer it shows in the end the woman with a knife approaching the pregnant woman who has been seriousily injured, and in the film poster at the producer's website it shows her holding the baby in her arms.. doh..
Can't no one make a film with the 9 month pregnant woman winning the fight ??
It happened in real life, just google Sarah Brady (who appeared on Oprah), who despite being 9 months pregnant and overdue for delivery,had a 20 min knock-down drag out struggle with a woman with a knife who was intent on taking her unborn. Sarah eventually turned the tables on her assailant and killed her.
Now THAT would of made an exciting film...