All perfect praise be to Allah, The Lord of The Worlds, and may His peace and blessings be upon our Prophet Muhammad and upon all of his family and companions.
Islam encourages on the increase of one's offspring in order to preserve the existence of the Islamic nation, attain strength and raise its standing among other nations, since the Prophet (PBUH) said (What means): "Marry women who are loving and very prolific, for I shall outnumber the peoples by you." [Related by Al-Hakem].
In addition, Islam urges on seeking for medication from various illnesses and to immune the offspring from bodily disorder and insanity so that a weak or sick one won't exist.
Therefore, there is no harm on making birth control if it was approved by a reliable medical committee that a great risk over the mother will take place due to pregnancy, giving birth, death of the newborn or the existence of bodily disorder and insanity within the offspring as stated by the Board of Iftaa' in resolution No. (
65).
However, if the risk was unlikely as is the case with the (Questioner), then making birth control is impermissible since he already have sound kids; besides, if the medical report shows that the percent of having an afflicted kid is only (25%); then the percentage of having a sound one is much higher as (75%).
Finally, we advise you (Questioner) to look for a medication's methods that assure you the avoidance of the previous percentage as well as eliminating the idea of long-acting reversible contraceptives (LARCs). And Allah Knows Best.