Is it Islamically permissible to conceal from family members the reason for delayed conception and the hardships of treatment, with the intention of using this concealment to focus on needs and avoid bothering them?

There is no harm in concealing the reason for not having children from one's parents, especially if it will distress them and there is no benefit in informing them. We advise the couple to supplicate and seek help through patience and prayer, in accordance with the Almighty's saying: "And seek help through patience and prayer," and His saying: "And your Lord says: 'Call upon Me; I will respond to you.'"