While neither husband nor wife may consistently withhold marital relations, if both spouses agree the couple may forgo intimacy as much as they choose.
Abstinence is a halachically permissible method of birth control (for couples who have halachic permission to use birth control) . However, we do not recommend it unless for very short periods of time, and only if there aren't any other reasonable alternative methods of birth control.
Intimacy is a very healthy and important part of a marriage. It is not clear to us why a couple would choose abstinence over other methods of birth control. If there are other issues involved (such as shalom bayit, pain during intercourse, etc.) we strongly recommend seeking professional help to address those issues. If you are choosing abstinence for lack of a better contraceptive method, we recommend speaking to your doctor (or getting back to us with more details) to help you find a better solution.
Please feel free to get back to us with any further questions.
B'Hatzlacha!