Incompetent cervix is a condition during which the cervix of a pregnant woman opens before the completion of gestational period and is mainly because of the weakness of the cervix or thinning or shortening of the cervical wall.
This condition leads to premature birth and may even leads to the loss of baby during the second trimester. When the cervix is weak then it is difficult to hold the weight of the baby, fluid and the placenta inside the womb.
This is because when the baby grows it will exert more pressure on the cervix and then the cervix dilates on its own without having any contractions of the uterus and pain.
This dilation of cervix leads to the bulging of amniotic membranes through the opening and finally ruptures the amniotic membrane and this stimulates the uterus and results to pre-term labor. Cervical incompetence is the major reason for most of the pregnancy losses in second trimester and is noticed mostly when the labor is most advanced and can’t stop.
Causes of Incompetent Cervix
Those who had a previous cervical surgery are more prone to develop cervical incompetence. Similarly women exposed to DES (diethylstilbestrol) or had a previous pregnancy with incompetent cervix, cervical anatomic abnormalities etc are also at greater risk of having incompetent cervix.
Women having a family history of incompetent cervix or shortened cervix are also at risk. Any damage to cervix due to a D&C, difficult birth, cervical cautery, cone biopsy etc may also cause this condition.
Symptoms of Cervical Incompetence
It is difficult to detect the cervical incompetence before or during the first trimester of pregnancy. Usually women have silent cervical dilation that has minimal uterine contraction and is difficult to sense and this happens mainly during 16th week to 28th week of pregnancy.
When the cervical dilation are less than 4 cm, symptoms won’t be pronounced, but when it exceed to 4 cm or more then significant uterine contractions occur and may end up with the rupture of amniotic membrane.
Cervical incompetence can be diagnosed either manually or through ultrasonography. If the cervical opening is 2.5 cm or more or when the cervical length is less than 20 mm the chances for cervical incompetence are more.
If the incompetent cervix is detected earlier in pregnancy or during earlier abortions then the doctor recommends cervical cerclage which is a process of stitching the cervix and is done in between 14 to 16 weeks of pregnancy.
This stitch helps to reinforce the cervix and continue the pregnancy and is usually removed between 36 to 38 weeks of pregnancy. Cervical cerclage helps about 80 to 90% women to give birth to healthy children.