Pregnant women with low risk of pre-eclampsia assessment and no suspected pre-eclampsia symptoms in the later period are only followed up at delivery to register the outcome indicators. For pregnant women with high risk of preeclampsia evaluation, it is necessary to register the history of drug use (whether or not to use and the dosage), and follow up to register the outcome index at delivery.

Preeclampsia risk assessment should be carried out at 11-13+6 weeks and 20-36+6 weeks of pregnancy. For low-risk pregnant women (PlGF≥100pg/ml or sFlt-1 /PlGF <38), it is suggested to closely monitor maternal blood pressure and conduct routine prenatal examination. The basic information of pregnant women, medical and obstetric history, physical examination information, ultrasonic examination data, serum markers (PlGF, sFlt-1) test results, pre-eclampsia risk assessment results, medication history and so on were registered in the study. For high-risk pregnant women (PlGF<100pg/ml or sFlt-1/PlGF ≥ 38), we should pay close attention to the changes of maternal blood pressure and proteinuria. Dynamic monitoring of PlGF or sFlt-1/PlGF should be carried out when necessary, and baseline information should also be registered after joining the group.

All pregnant women in the group were screened for pre-eclampsia risk according to the clinical risk factors listed in NICE Guidelines (2019).

The criteria for diagnosis and treatment of Hypertensive diseases in Pregnancy (2020) are implemented according to the Guidelines for Diagnosis and Treatment of Hypertensive Diseases in Pregnancy (2020), that is, systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg after 20 weeks of pregnancy, accompanied by any one of the following: urinary protein quantity ≥0.3 g/24h, or urinary protein/creatinine ratio ≥0.3, or random urinary protein ≥ (+); No proteinuria, but accompanied by any of the following organs or systems: heart, lung, liver, kidney and other vital organs, or abnormal changes in the blood system, digestive system, nervous system, placenta - fetal involvement.

Premature infants refer to all live births with a gestational age of<37 weeks

Affected by pathological factors such as maternal, fetal, and placental factors, fetal growth has not reached its expected genetic potential, often manifested as fetal ultrasound estimated weight or abdominal circumference being lower than the 10th percentile of the corresponding gestational age.