With this Mod it is possible for pregnant Sims to wake up with Cramps and Pain.
If that happens you need to go to the Hospital with them (via the Phone, you can go alone or with your Significant Other)
There is still a small chance that your Sims will come Home and the Baby is ok but mostly they will come back with very Sad News. Both Outcomes will affect the whole Household.
There are 3 Versions of Miscarriage Chances available. Only install one!