Volume 04 · Issue 03 · 2022

Fetal growth restriction (FGR) is a common complication of pregnancy associated with higher rates of perinatal mortality and morbidity, as well as a variety of long-term adverse outcomes. To standardize the clinical practice for the management of FGR in China, Fetal Medicine Subgroup, Chinese Society of Perinatal Medicine, Chinese Medical Association and Maternal-Fetal Medicine Committee, Chinese Society of Obstetrics and Gynecology,Chinese Medical Association organized an expert committee to provide official consensus-based recommendations on FGR. We evaluated the evidence provided by relevant high-quality literature, performed a three-round Delphi study and organized face-to-face meetings with experts from multidisciplinary backgrounds. The consensus includes the definition, prenatal screening, prevention, diagnosis, monitoring and management of FGR.

Fetal growth restriction (FGR) is the condition in which a fetus does not reach its intrinsic growth potential and in which the shortterm and long-term risks of severe complications are increased. FGR is a frequent complication of pregnancy with a complex etiology and limited management options, other than timely delivery. The most common pathophysiological mechanism is placental insufficiency, due to many underlying causes such as maternal vascular malperfusion, fetal vascular malperfusion and villitis.

Identifying truly growth restricted fetuses remains challenging. To date, FGR is often defined by a cut-off of the estimated fetal weight below a certain percentile on a population-based standard. However, small fetal size as a single marker does not discriminate adequately between fetuses or newborns that are constitutionally small but healthy and fetuses or newborns that are growth restricted and thus at risk for adverse outcomes. In 2016, the consensus definition of FGR was internationally accepted to better pinpoint the FGR population.

In this review we will discuss the contemporary diagnosis and management issues. Different diagnostic markers are considered, like Doppler measurements, estimated fetal growth, interval growth, fetal movements, biomarkers, and placental markers.

Choosing a fetal growth standard or reference is crucial when defining normal and abnormal fetal growth. We reviewed the recently published standards and compared them with a customized fetal growth chart based on a nationwide population in China. There were substantial discrepancies in the fetal growth pattern, suggesting that these standards may not be applicable to Chinese fetuses. Developing a Chinese-specific standard may better meet our clinical requirements. We also discuss the steps to establish a Chinese fetal growth standard and the potential challenges, including regional disparities and accuracy of sonographic estimated fetal weight. Standardized ultrasound measurement protocol and the introduction of new ultrasonography technology may be helpful in developing a more precise standard than existing ones for the Chinese population.

Fetal growth restriction (FGR) is associated with multiple adverse perinatal outcomes, such as increased risk of intrauterine death, neonatal morbidity and mortality, and long-term adverse outcomes. Genetic etiological factors are critical in fetuses with intrauterine growth restriction, including chromosomal abnormalities, copy number variants, single gene disorders, uniparental disomy, epigenetic changes, and confined placental mosaicism. This paper aims to provide an overview of genetic defects related to FGR and to highlight the importance of prenatal genetic counseling and testing for precise diagnosis and management of FGR.

Fetal growth restriction (FGR) has a prevalence of about 10% worldwide and is associated with an increased risk of perinatal mortality and morbidity. FGR is commonly caused by placental insufficiency and can begin early (<32 weeks) or in late (≥32 weeks) gestational age. A false positive antenatal diagnosis may lead to unnecessary monitoring and interventions, as well as cause maternal anxiety. Whereas a false negative diagnosis exposes the fetus to an increased risk of stillbirth and renders the pregnancy ineligible from the appropriate care and potential treatments. The clinical management of FGR pregnancies faces a complex challenge of deciding on the optimal timing of delivery as currently the main solution is to deliver the baby early, but iatrogenic preterm delivery of infants is associated with adverse short-and long-term outcomes. Early and accurate diagnosis of FGR could aid in better stratification of clinical management, and the development and implementation of treatment options, ultimately benefiting clinical care and potentially improving both short-and long-term health outcomes. The aim of this review is to present the new insights on biomarkers of placenta insufficiency, including their current and potential value of biomarkers in the prediction and prevention for FGR, and highlight the association between biomarkers and adverse outcomes in utero to explore the specific mechanism of impaired fetal growth that establish the basis for disease later in life.

Stillbirth is a devastating pregnancy complication that still affects many women, particularly from low and middle-income countries. It is often labeled as "unexplained" and therefore unpreventable, despite the knowledge that placental dysfunction has been identified as a leading cause of antepartum stillbirth. Currently, screening for pregnancies at high-risk for placental dysfunction relies on checklists of maternal risk factors and serial measurement of symphyseal-fundal height to identify small for gestational age fetuses. More recently, the first-trimester combined screening algorithm developed by the Fetal Medicine Foundation has emerged as a better tool to predict and prevent early-onset placental dysfunction and its main outcomes of preterm preeclampsia, fetal growth restriction and stillbirth by the appropriate use of Aspirin therapy, serial growth scans and induction of labour from 40 weeks for women identified at high-risk by such screening. There is currently no equivalent to predict and prevent late-onset placental dysfunction, although algorithms combining an ultrasound-based estimation of fetal weight, assessment of maternal and fetal Doppler indices, and maternal serum biomarkers show promise as emerging new screening tools to optimize pregnancy monitoring and timing of delivery to prevent stillbirth. In this review we discuss the strategies to predict and prevent stillbirths based on first-trimester screening as well as fetal growth and wellbeing assessment in the second and third trimesters.

In the United States, pulmonary embolism (PE) accounts for approximately 10% of all pregnancy related deaths. The standard treatment for a patient with high-risk PE is systemic thrombolysis. Systemic thrombolysis in pregnancy is associated with the risk of maternal hemorrhage and fetal complications, including spontaneous abortion, preterm delivery, and fetal bleeding. Currently, there is limited evidence for a standardized approach for the treatment and management of intermediate-and high-risk PEs in pregnancy. A 36-year-old gravida 3 para 2002 woman at 31⁺¹ weeks of gestation with a history of deep vein thrombosis in her prior pregnancy presented with shortness of breath. A computed tomography angiogram revealed a large pulmonary embolus with a saddle component that extended into the bilateral upper and lower lobes and into the secondary and tertiary pulmonary branches. A subsequent bedside echocardiogram demonstrated a dilated right ventricle with severely reduced right ventricular systolic function. The patient was successfully treated with bilateral ultrasound-assisted catheter-directed thrombolysis. She subsequently delivered a healthy male infant at term. Reported cases of ultrasound-assisted catheter-directed thrombolysis in pregnant patients is limited. Our case demonstrates that localized thrombolysis is a viable treatment option for life-threatening PE in pregnancy. Catheter-directed thrombolysis can be efficacious in treating intermediate-and high-risk PEs in pregnancy while simultaneously reducing the risk of bleeding complications.