Research has found that vaginal lubricants can be toxic to sperm and interfere with a female’s cervical mucus, preventing it from protecting the sperm from the vagina’s own acidic secretions (which can kill sperm) just before ovulation. Artificial lubricants prevent sperm from reaching the cervical mucus quickly, causing them to die in the vagina’s acidic environment before they get to the uterus.
Therefore, if you’re in need or desire the use of lubricant while trying to conceive, your best bet is to increase your own natural lubrication. This can be done by spending more time on foreplay, taking your time in maximizing sexual excitement before thrusting. Warm water is also a lube option in not being toxic, with the brand Pre-Seed being the only lube on the market specially designed to not damage sperm.