Please assess the completion status of the following clinical trial:

Trial Title: Are Uterine Natural Killer Cells Involved in the Initiation of Preterm Labor ?

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: CASE_CONTROL
- Primary Purpose: None
- Time Perspective: CROSS_SECTIONAL
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~1. Maternal age: 18-35 years old (to decrease the incidence of preterm labor related to age factor).~2. Women who present with viable pregnancy (between 28 and 37 weeks' gestation), and having a threatened preterm labor (which is defined as ≥ 2 uterine contractions at 28-37 weeks' gestation, The onset of labor may be determined by documented uterine contractions (at least one every 10 minutes) and ruptured fetal membranes or documented cervical change with an estimated length of less than 1cm or cervical dilation of more than 2 cm. Threatened preterm labor may be diagnosed when there are documented uterine contractions but no evidence of cervical change.~Exclusion Criteria:~1. Multiple pregnancy.~2. Documented uterine anomalies.~3. Oligohydramnios and polyhydramnios .~4. Medical disorders as Diabetes mellitus and hypertension.~5. Preterm premature rupture of membranes.~6. Conditions that may have an influence on immune reaction e.g. history of chorioamnionitis.~7. Smoking as a risk factor for preterm labor.~8. Patients having Autoimmune disorder as it may affect Uterine NK( natural killer ) cells level .

- Gender: FEMALE
- Minimum Age: 18 Years
- Maximum Age: 35 Years
- Healthy Volunteers: f

Study Arms:
- Preterm labor (Type: None): Patients who has threatened preterm labor and will receive tocolysis and these patients will either not respond to tocolysis and delivered preterm or will respond to tocolysis and will deliver at term .
- Term labor (Type: None): Patient delivered vaginally at term with no history of having tocolysis for preterm labor at the current pregnancy .

Based on this trial design, predict the completion outcome and termination type (if applicable).