Please select the eligibility criteria that correspond to the clinical trial below.
Title: Implementation of First-trimester Screening and Prevention of Preeclampsia: a Stepped Wedge Cluster-randomized Trial in Asia
Brief Summary: This implementation study aims to evaluate the efficacy, acceptability, and safety of first-trimester screening and prevention for preterm-preeclampsia. It is a multicenter stepped wedge cluster randomized trial including maternity / diagnostic units from ten regions in Asia. The study involves a period where no intervention will take place at all recruiting units, and then at regular intervals, one cluster will be randomized to transit from non-intervention group to intervention group in which first-trimester screening for preterm-preeclampsia by the Bayes based method followed by the commencement of low-dose aspirin in high-risk women.


Options:
A: Inclusion Criteria:

* age \< 40 years
* \< 4 previous ovarian stimulations

Exclusion Criteria:

* allergy for acetylsalicylic acid
B: Inclusion Criteria:

* Singleton pregnancy;
* Live fetus;

Exclusion Criteria:

* Multiple pregnancy;
* Major fetal defects identified at 11-13 weeks of assessment;
* Non-viable fetus (missed spontaneous abortion or stillbirth).
C: Inclusion Criteria:

* Nulliparous women between 18 - 40 years of age. Minors who are ≥ 14 years of age may be enrolled if permitted by the country's ethical guidelines.
* No more than two previous first trimester pregnancy losses
* No medical contraindications to aspirin;
* Single live intrauterine pregnancy (IUP) between 6 0/7 and 13 6/7 weeks GA corroborated by an early dating ultrasound and with presence of a heartbeat.

Exclusion Criteria:

* Women prescribed daily aspirin for more than 7 days;
* Multiple gestations;
* Fetal anomaly by ultrasound (Note most fetal anomalies are not detectable by ultrasounds done at this early gestation. Subsequent discovery of a fetal anomaly is not viewed as an exclusion.);
* Hemoglobin \< 7.0 gm/dl at screening;
* Any other medical conditions that may be considered a contraindication per the judgment of the site investigator (e.g., Lupus, Type 1 Diabetes, or any other known significant disease)
* Blood pressure ≥ 140/90 (Systolic blood pressure ≥ 140 and diastolic ≥ 90 at screening)
D: Inclusion Criteria:

1. Gestational age between 12+ and 20 weeks of pregnancy
2. High risk of preeclampsia, based in clinical risk factors as:

   2.1 if they have one or more of the following risk factors： Preeclampsia in a previous pregnancy ,Diabetes Mellitus(Type 1 or 2),Chronic Hypertension .

   2.2 if they have two or more of the following risk factors: Pre-pregnancy Body Mass Index ≥28kg/m2, Elderly pregnancy(age ≥35 years), Mother or sisters with preeclampsia in a previous pregnancy, Primiparity or Famliy history (Mother or sister that developed preeclampsia in a previous pregnancy）.
3. Signed informed consent.

Exclusion Criteria:

1. Allergy to aspirin
2. Asthma
3. Peptic ulcers
4. Severe heart, liver, renal disease who can not burden the experiment
5. Rheumatic immune disease
6. Mental disease
7. Alcohol and drug abuse
8. Being in another drug experiment within 3 months
9. Difficult to follow-up

Answer: B