To help evaluate a pregnant woman’s risk of preterm delivery
To help evaluate a pregnant woman’s risk of preterm delivery
When you are 22 to 35 weeks pregnant and are having symptoms of premature labor; sometimes if you are at high risk, such as if you have had a previous preterm delivery or have a short cervix
A swab is used to take a sample of cervical or vaginal fluid from the posterior portion of the vagina or from the area just outside the opening of the cervix.
Anything that physically disturbs the cervix or uterus has the potential to elevate fFN levels. Therefore, your health care practitioner should collect the sample before a pelvic examination or vaginal ultrasound. Semen may contain enough fFN to create a positive test result, so sexual intercourse should be avoided within 24 hours of sample collection. Avoid lubricants, lotions, soaps, and douches at least a day before the test.
Fetal fibronectin (fFN) is a protein produced at the boundary between the amniotic sac (which surrounds the baby) and the lining of the mother’s uterus (the decidua). Fetal fibronectin is largely confined to this junction and is thought to help “glue” or maintain the integrity of the boundary between the amniotic sac and the lining of the uterus. A fetal fibronectin test detects fFN in vaginal fluid to help predict the short-term risk of premature delivery.
According to the American College of Obstetricians and Gynecologists (ACOG), a normal pregnancy is about 40 weeks, with a woman going into labor between 37 and 42 weeks. A preterm delivery is one that occurs between 20 and 37 weeks of pregnancy.
fFN is found in vaginal fluids early in pregnancy because of the normal growth and establishment of tissues at the junction between the amniotic sac and uterus, with levels falling when this phase is complete. fFN is also found in fluids from the vagina after 36 weeks when it is often released into vaginal fluids as the body gets ready for childbirth.
However, fFN should not be detectible between 22 and 35 weeks of pregnancy. Elevated levels during this period reflect a disturbance at the junction between the amniotic sac and the lining of the uterus. Elevated fFN in vaginal fluids during these weeks of pregnancy has been associated with an increased risk of preterm labor and delivery. Many pregnant women experience symptoms that suggest preterm labor. These may include uterine contractions, changes in vaginal discharge, backaches, abdominal discomfort, pelvic pressure, cramping, and dilation of the cervix. However, not all symptomatic women will actually have a preterm delivery. The majority will go on to deliver at term.
Unfortunately, while premature births can have successful endings, serious complications are possible when a baby leaves the womb early. Premature babies frequently have difficulty breathing and feeding. Their lungs and other organs are immature and do not function normally, and the strain on them can cause persistent health problems. The more premature the newborn, the more likely it is that he or she will experience complications.
If a health care practitioner thinks that a woman might deliver early, she will consider treatments designed to delay delivery. These treatments can have unwanted side effects, however, so knowing whether or not a woman is likely to deliver prematurely helps in the decision on the best course of action. The fFN test is a relatively noninvasive tool that can help distinguish between those women who are likely to deliver shortly and those who are not.
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