While there are indications, when and how often for prenatal fetal monitoring to monitor stillbirth, obstetricians / gynecologists should tailor the guidelines to each patient, according to two leading medical companies.
Surveillance should be considered for conditions that carry a doubled risk of stillbirth, as well as those in which stillbirth is greater than 0.8 per 1,000 pregnancies (false negative rate of the biophysical profile), experts from the American College of Obstetricians and Gynecologists (ACOG) and the Society of Maternal Fetal Medicine (SMFM).
Fetal surveillance can begin as early as 32 weeks gestation, but the timing of testing should be carefully considered for patients with multiple co-morbidities, as this could lead to interventions such as preterm delivery. Clinicians and patients should weigh the benefits and consequences of when to begin testing, given optimal perinatal health outcomes, the experts wrote in a published joint committee opinion. Obstetrics and Gynecology.
The document recommends that clinicians test at-risk patients at least once a week, but abnormal test results or deteriorating patient health may warrant more frequent testing.
“This is the first time that there have ever been national guidelines for the indications, timing and frequency of fetal antepartum surveillance,” said Rita Wesley Driggers, MD, co-author of the opinion. Due to the difficulties in conducting prospective studies in pregnant women at risk of stillbirth, there is a lack of data on the effectiveness of the tests, and many clinicians have therefore used their best judgment, she said. declared.
“It’s a bit of the Wild West out there, in terms of what people do with the tests,” Driggers said. MedPage today.
She stressed that shared decision-making on prenatal fetal surveillance between pregnant patients and clinicians is essential and that physicians should consider health equity given that racial disparities are present in outcomes. stillbirths.
In addition, she said, the advice is offered only as a suggestion, not a mandate, and that due to the lack of data on the effectiveness of antenatal fetal surveillance, the guidelines are informed by expert consensus and observational studies.
Fetal hypoxia and acidosis are a common route to stillbirth, the committee wrote. This condition can lead to changes in amniotic fluid, fetal movements, and fetal heart rate characteristics, so there is a rationale for using prenatal fetal monitoring, with techniques such as assessment of fetal movements, testing stress test, contraction stress test, fetal biophysical profile, and Doppler velocimetry of the umbilical artery.
However, the lack of data from randomized trials to describe the effectiveness of these tests made it difficult to establish a list of indications.
The committee recommends monitoring all conditions for which stillbirth occurs more than 0.8 per 1,000 pregnancies, or those associated with double the relative risk of stillbirth. The paper suggests the immediate initiation of testing for pregnancies diagnosed with fetal growth retardation, multiple gestation and decreased fetal movement.
For pregnancies with fetal abnormalities or aneuploidy, the timing of testing should be individualized, the panel noted.
Maternal conditions that may require testing include hypertensive disorders, diabetes, lupus, sickle cell disease, autoimmune disease, thyroid disorders, kidney disease, substance use, in vitro fertilization, and a mass index body elevated before pregnancy. In addition, a history of stillbirth or other adverse pregnancy outcomes may indicate the need for testing.
In the absence of data on the risk of stillbirth adjusted for gestational age, the authors classified the suggested time for initiation of the test into three different age groups:
There are no data from randomized trials to characterize the optimal frequency of testing, but the opinion indicates that stable maternal health and fetal well-being tests should be tested once a week. Additionally, when certain high-risk conditions are present, some vendors may choose to conduct testing more frequently, the document advises.