Hi,
Thanks for your query.

I shall address your concern based on your current given information.

The answer to your question logically is Yes, when all that is required to fertilize an ovum is a single motile spermatozoan. And one can pregnant even if that is the only sperm destined to do it.

But, the fine print however is medically, the answer to your question changes with many tails attached. Now, when a vasectomy has already been done for your partner 3 months on, that has meant an obvious no to pregnancy and even the surviving (approx 120 days lifespan of a sperm) sperms in the tract would be in a poor state of health that would lower chances of them reaching the ovum.

Second, occasional motile sperm - in the tests, indicates the poor count due to the first reason, and that would mean even mathematically fewer chances of reaching the journey to the ovum situated way above in your uterus.

Third, getting pregnant with that one motile occasional sperm has far lesser chances of success percentage wise, and no medical basis exists for it.

And above all, getting pregnant also requires assumption of your normalcy in being able to beget children. Evaluation would ideally include all these factors before hand.

There are many options which you and partner have to choose, like reversal of vasectomy amongst others which would make sense when pregnancy is a must. You need to discuss these with the attending physician.

I hope I have answered your concern on a broad sense, now.

If you have additional questions regarding these recommendations as you prepare to make decision regarding future care, you should not hesitate to contact me.

Wish you Good Health.

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