Cervical insufficiency is painless opening of the cervix that results in delivery of the baby during the 2nd trimester (typically between 16 and 22 weeks) of pregnancy.
Connective tissue disorders that are present at birth and injuries can make tissues of the cervix weak.
When the cervix is weak, the baby may be delivered too early.
Cervical insufficiency is identified only after a woman becomes pregnant.
To prevent early delivery, doctors may stitch the cervix closed or prescribe a hormone to be inserted into the vagina.
Normally, the cervix (the lower part of the uterus) dilates only when labor starts, in response to contractions of the uterus. However, in some women, tissues of the cervix are weak. When the growing fetus and placenta put pressure on the weak tissues, the cervix may open (dilate) long before the baby is due. As a result, the baby may be delivered too early. If cervical insufficiency has occurred, the risk that it will recur in a subsequent pregnancy is probably less than 30%. The risk is higher for women who have had three or more miscarriages during the 2nd trimester.