Clinical trials

This study develops an end-to-end Vision Transformer (ViT)-based artificial intelligence system for ultrasound-based diagnosis of placenta accreta spectrum (PAS), aiming to improve the accuracy and efficiency of prenatal screening using standardized ultrasound video inputs.

According to the American College of Obstetricians and Gynecologists (ACOG), pregnancy-induced hypertension is defined as a new onset of systolic and/or diastolic blood pressure ≥140/90 mmHg after 20 weeks of gestation, with at least 4 hours between two blood pressure measurements, and blood pressure can return to normal after childbirth. Preeclampsia is defined as the presence of proteinuria or multi-organ dysfunction on the basis of pregnancy-induced hypertension. Obese women are a high-risk group for preeclampsia, and the preventive use of low-dose aspirin (LDA) is one of the currently recognized effective interventions. Obesity, as an independent risk factor for preeclampsia, can increase the risk of the disease by 2 to 3 times. With the rising global obesity rate, the prevention and control of preeclampsia in obese pregnant women has become an important challenge in the field of perinatal medicine. The WHO report indicates that the incidence of preeclampsia in obese women is significantly higher, with a 20-30% increase in preeclampsia risk for every 5-unit increase in BMI. The incidence of preeclampsia in obese women can reach 15-25%. At present, the clinical application of oral aspirin for the prevention of preeclampsia in China mainly follows authoritative consensuses such as the "Guidelines for the Diagnosis and Treatment of Hypertensive Disorders in Pregnancy (2020)", which recommends that high-risk pregnant women (such as those with obesity, chronic hypertension, and a history of preeclampsia in the previous pregnancy) take low-dose aspirin (50-150 mg/d) orally from 12 to 16 weeks of gestation for prevention. However, in actual clinical practice, a dose of 100 mg/d is commonly used, and there is still a lack of clear guidance on whether the dose needs to be adjusted for obese pregnant women. At present, the dose of aspirin mainly used in China is still 100 mg, while foreign studies are more inclined to use 150 mg. Therefore, this study is designed to conduct a randomized controlled trial to compare the efficacy and safety of 100 mg and 150 mg aspirin in preventing preeclampsia in obese pregnant women, to optimize the LDA strategy for the prevention of preeclampsia and provide high-quality evidence for clinical practice.

In 2017, the American College of Cardiology (ACC) and American Heart Association (AHA) guidelines built on evidence that elevated blood pressure increases cardiovascular mortality in the general population, Reclassification of BP; however, these diagnostic definitions do not include pregnant women, and whether newly diagnosed stage 1 hypertension affects pregnancy complications remains unclear. In this study, the combination of maternal factors, MAP and PLGF was used to comprehensively analyze the risk factors of preeclampsia through the "Bayesian rule" developed by the British Fetal Medicine Foundation (FMF). According to the guidelines and consensus, the pregnant women were considered to be at high risk when the calculated risk was higher than 1% of the population. To compare the pregnancy outcomes of women with normal blood pressure in the first trimester and stage 1 hypertension in different risk groups, and to find out whether screening for preeclampsia can be omitted for women with normal blood pressure in the first trimester, while screening for preeclampsia should still be performed for women with stage 1 hypertension as an independent moderate risk factor, and finally to optimize the screening strategy for preeclampsia.

Low-dose aspirin (LDA) is considered to be the most effective agent to prevent preeclampsia (PE). At present, there is little exploration about the timing of aspirin discontinuation. Most international guidelines default until 36 weeks of gestation or delivery. China Guideline (2020) recommended that aspirin should be preventively used until 26-28 weeks of gestation, but there was little direct evidence. According to the two-stage theory, placental dysplasia before 28 weeks of gestation is the key to developing PE, the significance of aspirin use after 28 weeks of gestation is debatable. If aspirin discontinuation at 28 weeks of gestation is proven to be feasible for preventing preterm PE, it will not only reduce the risk of Perinatal Haemorrhage but also save medical expenses.