The Pressure Points
There are two pressure points linked to miscarriages, or used later in pregnancy to induce labor. One is called "Three Yin Intersection" and is located approximately four finger widths above your inner ankle.
The other, named "Joining the Valleys", is in the webbing between your index finger and thumb, according to Maternity Corner (reference 1). You will know you have found the right area when it feels tender. According to Ecomii, avoid this pressure point if you may be pregnant because it can stimulate premature contractions, thus causing a miscarriage (reference 2).
Accupressure on Pressure Points
To cause a miscarriage, the pressure points would have to be rubbed firmly for at least a few minutes or in a circular motion for about 60 seconds, every two hours, according to Maternity Acupressure (reference 3); so don't worry if your husband accidentally rubs a pressure point during a foot massage, it generally takes more time and more pressure to cause harm.
During pregnancy, massage therapists, as well as health care providers, warn against rubbing these pressure points, validating the concerns that they may cause miscarriage. To be safe, avoiding firm pressure on any pressure points during pregnancy, according to Ecomii (reference 2).
Towards the end of the pregnancy, after 37 weeks when the baby is full-term, some women choose to rub the pressure points as a way to naturally induce labor. Again, there is no scientific analysis on the actual success of such attempts, but once the baby is full term there is no longer a danger with rubbing these pressure points, as the only side effect may be stimulation of contractions and ripen of the cervix.
Miscarriages have extensive psychological side effects on women for many years. Although there is no scientific data describing the effectiveness of pressure points with the correlation of miscarriages, it is best to avoid these areas during pregnancy. Doctors and massage therapists are trained to inform patients of the dangers.
If you are in the midst of an unplanned pregnancy, consider alternative options such as adoption. If for a medical reason you can not deliver a baby, consider a doctor or abortion clinic, to complete the procedure, as pressure points and acupressure are not guaranteed.