Does perseverance in supplication relieve distress and aid in pregnancy, given that doctors have stated there is no hope for pregnancy for a 40-year-old woman?

Allah commanded us to supplicate and promised to answer, as He Almighty said: "And your Lord said, 'Call upon Me; I will respond to you.'" The servant's supplication is answered as long as he does not pray for a sin or the severing of kinship ties. Thus, the Muslim who supplicates with a prayer that contains neither sin nor the severing of kinship ties will be granted one of three things by Allah: either the hastening of the supplication's fulfillment, or its storage for the Hereafter, or the averting of evil equivalent to it. Therefore, increase your supplications and have a good opinion of Allah; for Allah answered the supplication of Zakariya and blessed him with Yahya. It is not a prerequisite for the answer that exactly what was requested be fulfilled; evil may be averted, or reward may be stored.