Info about Dna Testing
4 Different Kinds of Preterm Labor Tests
• Fetal Fibronectin
A gluelike protein, called cervicovaginal fetal fibronectin (fibronectin for short) connects the amniotic sac to the inner wall of the uterus. When fibronectin is found in vaginal fluid, it's an indicator that preterm delivery is possible. A relatively new test, approved by the FDA, cultures a swab of vaginal fluid to look for fibronectin.
The fetal fibronectin test feels like a pap test and does not hurt. If the test is negative for the protein, the manufacturer feels that your doctor can be 95 percent confident that you're unlikely to deliver within the next two weeks. Currently, this test is very expensive. It would be done only when your doctor is quite sure about the probability of premature birth. Some complications preclude the use of this test, such as a cerclage or ruptured membranes.
• Salivary Estriol
Another new test examines a sample of your saliva because higher than normal levels of the hormone estriol indicate a risk for preterm labor. The test is thought to be about 68 to 87 percent reliable as a predictor.
Currently, you would have the test if you have a higher than normal number of contractions before 37 weeks gestation without cervical changes. The test helps your OB provider decide if you should get more aggressive preterm labor treatment that includes bed rest and medications, or if you do not need these measures because the test is normal and you will probably not be headed toward preterm labor.
• Ruptured Membranes
If there's concern that you may have ruptured membranes or that your amniotic sack is leaking, your doctor will perform two separate tests. The first is a vaginal exam with a sterile speculum in which the doctor looks for evidence of fluid from your cervix. You may be asked to bear down as if for a bowel movement to see if any fluid emerges; this is called "pooling." For the other test, the doctor places litmus paper inside your vagina near your cervix. Paper color changes will indicate that amniotic fluid is in the vagina. Sometimes a fluid sample taken from your cervix is viewed under a microscope to see if there is amniotic fluid present. This is called ferning, because amniotic salt crystals look similar to a fern plant.
• Testing for Infection
Infections of the uterus, cervix, and urinary tract can lead to a preterm labor event. Culturing samples of blood and urine will reveal if infection is present. The tests usually need a period of time for results, so definitive diagnosis cannot be made for 24 hours or even several days. If there are clear indications of infection, such as fever, you may be pm on antibiotics immediately pending the results.