Please select the eligibility criteria that correspond to the clinical trial below.
Title: Effect of Oral N-Acetyl Cysteine on Pregnancy Outcome After Cervical Cerclage: a Randomized Controlled Trial
Brief Summary: The aim of the study is to evaluate the effect of N-acetyl cysteine (NAC) on pregnancy outcome in women undergoing cervical cerclage for cervical insufficiency.


Options:
A: Inclusion Criteria:

* women with history suggestive of cervical insufficiency together with ultrasound findings suggestive of cervical insufficiency undergoing elective cervical cerclage between the 11th and 12th gestational week.
* singelton viable fetus

Exclusion Criteria:

* women tested positive for bacterial vaginosis
* women currently with threatened abortion (vaginal bleeding or uterinecramps)
* age older than 35 years or younger than 20 years
* unwillingness to participate
* irregular and/or uncertain menstrual dates
* rupture of membranes
* previous cesarean delivery
* possible risks for preterm birth in the current or previous pregnancy such as twin pregnancy, IUFD, malpresentation, known fetal anomaly, progesterone or heparin treatment during the current pregnancy, hypertension, and/or seizure disorders.
* women with contra indications for cervical cerclage or anesthesia.
B: Inclusion Criteria:

1. Women aged: 20-38 years old.
2. Single living fetus.
3. The patient does not have history of preterm labor (before 37 weeks of gestation)
4. No history of cervical or uterine anomalies.

Exclusion Criteria:

1. Congenital anomalies in the fetus discovered during the follow up.
2. History of spontaneous preterm births.
3. Evidence of imminent delivery, or uterine contractions.
4. Evidence of rupture of membranes, or intra amniotic infection.
5. Intra uterine fetal death.
6. Uterine or cervical anomalies.
C: Inclusion Criteria:

* Age from 20 - 35 years old.
* Pregnant from (12- 14 weeks) gestation.
* Singleton pregnancy.
* The pregnant women who have a history of second trimester pregnancy loss with painless cervical dilatation or have prior cerclage placement for cervical insufficiency or have a history of spontaneous preterm.

Exclusion Criteria:

* Multiple gestations.
* Congenital fetal malformation in the current pregnancy.
* Women with history of thromboembolism or bleeding disorders.
* Uncontrolled diabetes mellitus.
* Chromosomal abnormalities affecting one of the couples.
* Women refuse to participate in the study
* Antiphospholipid syndrome
D: Inclusion Criteria:

1. The subject has a history of a documented spontaneous singleton preterm delivery (hospital or clinic record, letter from healthcare provider, or birth certificate) from 20 0/7 to 35 0/7 weeks gestational age with the immediate preceding pregnancy or has a cervical length of 2.5 cm or less measured by transvaginal ultrasound with the current pregnancy. "Spontaneous preterm delivery" is a delivery (\<35 weeks), either vaginal or cesarean, that is initiated by either preterm PROM followed by contractions or preterm labor initiated with in-tact membranes. A previous preterm delivery secondary to an incompetent cervix where a cerclage is considered for this pregnancy is not considered a preterm delivery (please see Exclusion Criteria No. 10). Subjects enrolled based on a history of preterm delivery may have had a pregnancy loss (or losses) at \<20 0/7 weeks gestational age between the preceding preterm delivery and the current pregnancy.
2. The female subject is between 18 and 45 years of age at the time of screening.
3. The pregnancy has an estimated gestational age between 16 0/7 weeks and 22 6/7 weeks.
4. The subject speaks either English or a common local language.
5. The subject has voluntarily signed the Informed Consent Form and associated forms after having the contents explained, and all her questions are answered to her satisfaction and understanding.
6. In the opinion of the investigator, the subject is able to understand the study and is able to give informed consent, as well as participate in it and adhere to study procedures.

Exclusion Criteria:

1. The subject has a previous history of an adverse reaction to progesterone or any component present in Prochieve® 8% vaginal gel.
2. The subject has been treated with a progestogen within the previous 4 weeks.
3. The subject is currently being treated for a seizure disorder, has an unstable psychiatric disorder, is taking antihypertensive therapy for chronic hypertension at the time of enrollment, has a history of congestive heart failure or chronic renal failure, or has uncontrolled diabetes mellitus (known end-organ dysfunction secondary to vascular disease).
4. The subject has active thrombophlebitis or a thromboembolic disorder, or a history of hormone-associated thrombophlebitis or thromboembolic disorders.
5. The subject has liver dysfunction or disease.
6. The subject has known or suspected malignancy of the breast or genital organs.
7. The subject is currently participating in another investigational study or has participated in an investigational drug study within one month prior to screening for this study.
8. The subject's current pregnancy is complicated by a major fetal anomaly or known chromosomal abnormality.
9. The subject has a uterine anatomic malformation (bicornuate uterus, septate uterus)
10. The subject has a multifetal gestation.
11. The subject has a cervical cerclage in place or has plans to have one placed during the current pregnancy.
12. The subject, in the judgment of the investigator, will be unable or unwilling to comply with study-related assessments and procedures.
13. The subject currently has preterm rupture of membranes, vaginal bleeding, known or suspected amnionitis, or signs or symptoms of preterm labor at the time of enrollment.
14. The subject is HIV positive with a CD4 count of _\<350 cells/mm3 and is receiving more than 1 medication to prevent the transfer of AIDS to the fetus.
15. The subject has placenta previa or a low-lying placenta. The subject will be considered for the study if she is not at risk for increased bleeding and has not been given any vaginal precautions.
16. The subject's qualifying preterm delivery was an indicated delivery without preterm labor (i.e. delivery performed for fetal distress, maternal eclampsia/preeclampsia, fetal death, or amnionitis in the absence of contractions).

Answer: A