Answered by: Maulana Muhammad Asadullah Anwar Adam
What does Islam say about a husband who stops his wife from seeing her parents? Is there any sin in that?
Should she obey him because of that?
In the name of Allah, the Most Gracious, the Most Merciful
The basic principle is that a woman should not leave her husband’s home without his permission, and if she leaves without his permission, then she will be considered to be in the wrong for her actions. 
However, there are some cases where the wife is excused from this obligation such as:
“The husband should not prevent his wife from leaving to visit her parents once a week if they are not able to visit her nor should he prevent them from visiting her.” 
The meaning of this is that the wife has an Islamic right to visit her parents at least once a week, but can’t stay overnight with them without permission and you can’t prevent them from visiting her or speaking to her.
The conclusion we can come to is that the husband should not stop his wife from seeing her parents. It doesn’t necessarily have to be once a week. The time can be something agreed between the husband and wife whether once a week or once a fortnight etc.., but the basic rule is that the husband should not stop his wife from being in contact with her parents.
Only Allah knows best
Written by Maulana Muhammad Asadullah Anwar Adam
Checked and approved by Mufti Mohammed Tosir Miah
Darul Ifta Birmingham
[Raddul Muhtar p.286 v.5]
[Raddul Muhtar p.323 –p.324 v.5]
[Sahih Muslim p.151 book 1 Bushra print]