Is a Saliva Ovulation Kit Better Than Urine?

Women who are trying to conceive a baby often use ovulation predictor kits (OPKs) to pinpoint the time of ovulation. OPKs usually become positive about 36 hours before an egg is released, allowing the woman to plan intercourse. You can buy urine or saliva OPKs. Both work well, so selection is based on preference in the testing method.

Function

• Urine OPKs detect the presence of lutenizing hormone (LH), which surges up to 36 hours before an egg releases. Saliva OPKs detect the rise in estrogen that precedes ovulation, which causes higher salinity in saliva. The salinity forms discernible "ferning" pattern that looks like the leaves of a fern.

Use

• Urine OPKs are much easier to use and read, since saliva OPKs require the woman to use a microscope to look for ferning. Saliva OPKs are less expensive in the long term, because you only have to buy the equipment once. Urine OPKs are disposable and can't be reused, so you must purchase a new package each month, which costs about $15.

Types

• There are two types of saliva OPKs. The first involves using a microscope and slides on which you collect your saliva. The initial purchase of microscope and slides can be up to $50. The second is electronic and reads the saliva results for you. The electronic OPK costs around $40 and requires batteries that cost about $5 every few months.

Accuracy

• Saliva OPKs are about 98 percent accurate versus urine OPKs that have 99 percent accuracy, but only if used correctly.

Warning

• Don't eat or drink for two hours before testing your saliva, because food or water can disrupt the salinity of the saliva.