Please select the arm or intervention descriptions that belong to the clinical trial below.
Title: "Comparison of Vaginal Progesterone With Arabin Cervical Pessary and Vaginal Progesterone Alone in the Prevention of Preterm Delivery in Singleton Pregnancies With Incidental Premature Shortening of Cervical Length"
Brief Summary: 1. This will be a randomized prospective and open-label study with no placebo control or blinding of the participants and the research team members. The study is to compare the effectiveness of vaginal progesterone versus combination of vaginal progesterone and Arabin cervical pessary in the prevention of preterm delivery among patients with incidental shortened cervical length.
2. As part of standard clinical care, all pregnant patients usually have cervical length measurements at the mid-trimester during the anatomy scan from 18 to 24 weeks with the GE ultrasound Volusion 8 using the vaginal probe.

   1. Patients with short cervix will be counseled and offered the opportunity to participate in the study.
   2. All participants will be taught how to use the vaginal progesterone once daily prior to bedtime. In addition, those in the combination group will have the cervical pessary placed in the clinic right away or within a week if they request for more time to brood over their diagnosis and weigh on the option of inserting Arabin pessary.
   3. All participants will be followed up in the high-risk obstetric clinic as per standard prenatal care. Frequency of follow up visits will be individualized depending on patient's need and comorbidities. , Participants will be requested to bring the remnant of the vaginal progesterone to the clinic to assess compliance.
   4. Participants in the study will continue their prenatal care with UIC high-risk obstetric clinic until delivery.
   5. The study recruitment will occur for a period of 2 years starting from November 2016 to October 2018 or until all the anticipated numbers of study subjects have been attained.
   6. There will be 10 % over-sampling to cater for those who will drop out from the study or loss to follow up after randomization, and those who delivered in another hospital.
   7. Participants will have access to one of the investigators or the high- risk clinic nurse for any complaints related to their conditions.
   8. Participants can opt out at any stage of the study if they do not want to continue further or if there are any adverse effects.


Options:
A: Arm Label: Intravaginal progesterone; Type: ACTIVE_COMPARATOR; Interventions: Drug: Prometrium | Arm Label: Intravaginal progesterone and pessary; Type: EXPERIMENTAL; Interventions: Drug: Prometrium, Device: Dr. Arabin, cerclage pessary perforated | Intervention Type: DRUG; Name: Prometrium; Assigned to Arm(s): Intravaginal progesterone, Intravaginal progesterone and pessary | Intervention Type: DEVICE; Name: Dr. Arabin, cerclage pessary perforated; Assigned to Arm(s): Intravaginal progesterone and pessary
B: Arm Label: Cervical Pessary-Group; Type: EXPERIMENTAL; Interventions: Device: cervical pessary | Arm Label: Control-Group; Type: OTHER; Interventions: Other: Control-Group | Intervention Type: DEVICE; Name: cervical pessary; Assigned to Arm(s): Cervical Pessary-Group | Intervention Type: OTHER; Name: Control-Group; Assigned to Arm(s): Control-Group
C: Arm Label: Progesterone; Type: ACTIVE_COMPARATOR; Interventions: Drug: Progesterone | Arm Label: Progesterone plus Experimental device; Type: EXPERIMENTAL; Interventions: Device: Pessary | Intervention Type: DEVICE; Name: Pessary; Assigned to Arm(s): Progesterone plus Experimental device | Intervention Type: DRUG; Name: Progesterone; Assigned to Arm(s): Progesterone
D: Arm Label: Vaginal progesterone and Pessary; Type: EXPERIMENTAL; Interventions: Drug: Arabin Pessary | Arm Label: Vaginal progesterone only; Type: ACTIVE_COMPARATOR; Interventions: Drug: Arabin Pessary | Intervention Type: DRUG; Name: Arabin Pessary; Assigned to Arm(s): Vaginal progesterone and Pessary, Vaginal progesterone only

Answer: D