As to your desire and that of your husband to avoid any action which would permanently prevent you from bearing children, the only text we have so far found on the subject is in a letter to an individual believer from the beloved Guardian. The question asked was whether after a few children it would be permissible to have a surgical operation on the wife to prevent further conception. His reply was that such an act was inacceptable and unworthy, and those who commit the act were responsible before God.
When the Guardian was asked whether the exercise of birth control constitutes a sin in a case where the number of children would prevent the father from fulfilling his obligation to educate his children, he stated that it is the duty of Baha'is to uphold moderation in all things, and avoid illegal methods.
- The Universal House of Justice (From a letter to an individual believer, July 31, 1970; compilation: ‘Lights of Guidance’)