Is a woman required to offer expiation for delaying the fulfillment of her vow to remove a contraceptive device, due to her husband's inability to take her to the doctor?

Refraining from procreation due to poverty is not permissible, for Allah is the Provider, and He has forbidden the killing of children for fear of poverty. As for the vow, if the husband commands the removal of the contraceptive, then obedience to him is obligatory, and the vow becomes a vow of an obligation. However, if the husband does not command it, then the vow is considered a permissible vow. If the vow is binding, there is no sin in delaying its fulfillment if the delay is due to the unavailability of the means to fulfill it.