Seyyed Bab says:

"فرض لکل احد ان یتتاهل لیبقی عنه من نفس یوحدالله ربها و لابدان یجتهد فی ذلک و ان یظهر من احدهما ما یمنعهما عن ذلک حل علی کل واحد باذن دونه لان یظهر عنه الثمره و لایجوز الاقتران لمن لایدخل فی الدین"[1]

“It is obligatory on every person to get married in order for a generation to be remained from him/her who is monotheist and God-fearing. They should be serious in this way. If one of them can’t have a baby, it will be permissible for him/her to get married with the one who doesn’t belong to the Bayan religion.

Then, he says: If the cause of prevention is observed in one side, it is permissible for him/her to have sexual intercourse with another to have a baby.

Consequently, according to Seyyed Bab: A woman who can’t have a baby by her own husband can have a baby with another man[2].