The Treatment Plan

A cerclage placed at 13 weeks.
Injections of progesterone.

Things to note:

Progesterone
Progesterone, often given in the form of 17-hydroxyprogesterone caproate, relaxes the uterine musculature, maintains cervical length, and has anti-inflammatory properties, and thus exerts activities expected to be beneficial in reducing preterm birth. Two meta-analyses demonstrated a deduction in the risk of preterm birth in women with recurrent preterm birth by 40–55%. However, progesterone is not effective in all populations, as a study involving twin gestations failed to see any benefit.

Cervical cerclage
In preparation for childbirth, the woman's cervix shortens. Preterm cervical shortening is linked to preterm birth and can be detected by ultrasonography. Cervical cerclage is a surgical intervention that places a suture around the cervix to prevent its shortening and widening. Numerous studies have been performed to assess the value of cervical cerclage and the procedure appears helpful primarily for women with a short cervix and a history of preterm birth. Instead of a prophylactic cerclage, women at risk can be monitored during pregnancy by sonography, and when shortening of the cervix is observed, the cerclage can be performed. Women with a short cervix but no history of preterm birth, and women with twin gestation, do not benefit from a cerclage.