A 24-year-old woman with the gestation term of 18-19 weeks was hospitalized into the gynecological department of a hospital because of isthmic-cervical insufficiency diagnosed during an ultrasound scan. Examination shows that the cervix is shortened to 1.5 cm, the epithelium is without pathological changes, the cervical canal allows inserting one finger. The amniotic sac is intact, the uterus is enlarged to 18-19 weeks of pregnancy and normotonic. What aid must be provided for the pregnant woman?