What indication warrants the placement of a cervical cerclage in a singleton pregnancy?

The placement of a cervical cerclage is indicated in a singleton pregnancy primarily for cases of painless cervical dilation that is accompanied by a history of pregnancy loss, particularly in the second trimester. This procedure involves stitching the cervix closed to provide support and can help prevent premature labor and delivery in women who have a weak cervical structure, known as cervical insufficiency.

A history of loss indicates that there is a significant risk of preterm birth due to cervical incompetence. In clinical practice, cerclage is often recommended when these risk factors are present, as the treatment can help sustain the pregnancy for a longer duration, giving the fetus a better chance of survival and health outcomes upon delivery.

In scenarios such as cervical dilation due to labor, fetal distress, or placental abruption, the priorities shift towards managing the immediate conditions rather than preventative measures like cerclage placement, which would not address the acute issues present in such situations. Therefore, the key in this case is the context of a prior loss coupled with asymptomatic cervical changes, which strongly supports the need for cervical cerclage.