The new rule lets employers restrict employees' access to birth control if they morally or religiously object.
But the 55 million or so women - according to a study commissioned by the Obama administration - whose access to no-cost birth control has just disappeared will now be forced to find alternatives such as abortion, research (and logic) suggests.
A 2012 study found that the number of unplanned pregnancies and abortions fell by between 62 and 78 per cent when women get free birth control.
The study's lead author, Dr Jeff Peipert, said in a statement:
This study shows that by removing barriers to highly effective contraceptive methods such as IUDs and implants, we can reduce unintended pregnancies and the need for abortions.
The results of this study demonstrate that we can reduce the rate of unintended pregnancy, and this is key to reducing abortions in this country.
The most effective forms of birth control - intrauterine devices (IUDs) and injected or implanted contraceptives - are the hardest for women to get on their own, partly due to the initial cost.
Without the contraceptive mandate, some highly effective methods of birth control, such as intra-uterine devices (IUDs) and sterilization, could cost women more than $1,000, putting these options out of reach for many women.
Affordable family planning options and contraceptive choice help to prevent unintended pregnancies.