Do not use any lotions or creams on your baby’s arms or legs for the 24 hours before the test (including moisturizing soaps). Be sure to dress your baby in warm clothing and allow him/her to have plenty to drink. No other special preparations are needed prior to your appointment.
You will meet with a genetic counselor on the day of the sweat test. The genetic counselor talks to you about how CF is inherited. They also talk about the possible results from the sweat test and what they mean.
What do the results mean?
The genetic counselor calls you with the test results. These results are also shared with your child’s primary care provider. Results differ by state, but there are four possible results for Ohio:
Negative Result: This means that a normal amount of salt was found in the sweat. It is very rare for a person to have CF if the sweat test result is negative. Your baby should get regular medical care, but no additional follow up is needed. However, this result means your baby is most likely a CF carrier.
Positive Result: A positive sweat test means that your baby probably has CF. A second sweat test should be done to confirm a CF diagnosis. Your primary care doctor will help you get an appointment with a doctor and team of clinicians who specialize in treating CF.
Borderline Results: Sometimes the sweat test result will be in between positive and negative. Your baby will need another sweat test, and perhaps an exam and blood test.
“QNS” (Quantity Not Sufficient): QNS means there was not enough sweat collected. You will be asked to bring your baby back for further testing when he/she is bigger, usually in about two weeks.
What does it mean to be a CF carrier?
CF carriers are healthy, and their sweat test results usually are normal. A CF carrier has one gene for CF, but doesn’t have the two genes required to cause CF. If your baby is a CF carrier, then one of the parents must also be a CF carrier. And there is the possibility that both parents are CF carriers. This means that they could have a child with CF in the future.
The genetic counselor meets with you while your baby’s sweat test is done. The counselor answers questions about being a CF carrier and gives you written information.
To learn more about CF newborn screening, sweat testing, and CF carriers visit the CF Foundation website at these links:
Should I be worried?
Remember, most babies who get a sweat test do not have CF, but this can still be a stressful time.
Please reach out to your primary care provider, or our CF team, with any questions that aren’t fully answered here. Some parents may need help with the stress of a possible CF diagnosis, and have found the following resources helpful: