Screening for preterm birth
One of the most essential pregnancy complications is childbirth before the 32nd week of pregnancy. Most babies born before the 24th week of pregnancy die, and most babies born after the 32nd week of pregnancy survive.
One of the causes of prematurity is cervical insufficiency in a pregnant woman, as a result of which the cervix opens, the amniotic fluid breaks and premature labour begins. It is a disturbance in the relationship between the composition of the cervix - collagen and elastin, as a result of which the cervix cannot provide a support function, and it begins to open as the fetus grows due to increased intra-abdominal pressure.
To assess the risk of premature birth necessary to measure the length of the cervix through the vagina. The shorter a woman's cervix, the greater the chance of premature birth.
It is possible to measure the length of the cervix:
- In the first trimester, as an addition to the OSCAR test in the 12th-14nd gestational week
- In the II trimester, as an ultrasound examination supplement for developmental disorders of the fetus in the 19th-22nd gestational week
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Screening for preterm birth as an adjunct to the OSCAR test
For many years, women who have given birth to a premature baby have been helped by placing a support suture on the cervix at the end of the first trimester of pregnancy, on the 14th-15th week of pregnancy. Alternatively, cervical length assessment with 2-week dynamics up to 24 weeks of pregnancy is possible for a short cervix found during the OSCAR test. The prophylactic cervical suture is recommended to shorten the cervix below 25 mm. Both methods reduce the number of births before the 34th week of pregnancy by 25%, but with the second method, we reduce the need for unnecessary cervical stitches by 50%.
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Screening for preterm birth as an adjunct to fetal anatomy scan
At 20-21 weeks, as part of screening for fetal malformations, it is possible to re-evaluate the risk of premature birth by taking into account the mother's history and measuring the length of the cervix vaginally with the FMF (Fetal Medicine Foundation) risk calculation program. If there is an increased risk of preterm birth, one option is vaginal progesterone therapy until the 34th week of pregnancy- dynamic monitoring of cervical length at 2-week intervals. When using vaginal progesterone therapy, the number of births before the 34th week of pregnancy decreases by 45%.