Preterm Birth and Cervical Incompetence
Preterm birth is a major cause of death and handicap in newborn babies affecting 6-8% of pregnancies. Some pregnancies are recognised as being at increased risk such as those who have had a previous very preterm birth (<32 weeks gestation), cervical surgery (eg. cervical cone biopsy), suspected cervical incompetence or multiple pregnancies. In many cases there are no warning signs. Cervical Incompetence Scan (16+ weeks). A transvaginal ultrasound scan (Cervical Incompetence Scan) can assess the cervix to identify pregnancies at increased risk of preterm delivery based on: • Length of the cervix (normally >25mm)
• Funneling of the membranes at the internal os.
• Dilatation of the cervix
• Location of a cervical suture (if present)
Fetal Fibronectin Test (22 to 25 weeks): Another useful way to predict preterm birth is based on a vaginal swab test to identify a substance called fetal fibronectin. The results are available in about 20 minutes. A negative result means that there is over a 99% reassurance that the woman would not go into labour in the next two weeks. This is particularly useful for those going on international holidays or whose partners are travelling or away during the pregnancy. A positive result indicates a high risk of early delivery.
An abnormal Cervical Incompetence scan or a positive Fetal Fibronectin Test allows various interventions to be discussed such as a cervical stitch (cervical cerclage), drugs to relax the uterus and steroids to reduce breathing difficulties (Respiratory Distress Syndrome) in the baby if it is born early.
Click on the links to read more about a Cervical Incompetence Scan or a Fetal Fibronectin Test