P大師，8大師，請看這個父母延期的理由可以嗎？

parents are visiting on B2. now almost 6 months in usa. would like to extend for 6 months.

the reason i want to use is: i am pregnant. will deliver early next year. i want my parents to enjoy the moment when the baby is born. (of course, all is true.)

i have read P大師' blogs, reminding that not to use the reason for taking care of baby. so i am not sure if the above reason is ok.

Thank you very much!