The second analysis of stillbirth risk factors was included in the Stillbirth Collaborative Research Network study described earlier. he validity of stillbirth prediction was assessed based on risks identified in early pregnancy. They found that pregnancy factors known at the start of pregnancy accounted for only a small proportion of stillbirth risk. Except for prior stillbirth or pregnancy loss from causes such as preterm birth or fetal-growth restriction, other risks had limited predictive value (Stillbirth Collaborative Research Network Writing Group, 2011a). he importance of prior stillbirth as a risk for recurrence has been emphasized by Sharma and associates (2006). Specifically, the stillbirth risk was ivefold higher in women with a prior stillbirth. From another report, prior preterm birth, fetal-growth restriction, preeclampsia, and placental abruption were strongly associated with subsequent stillbirth (Rasmussen, 2009). Table 35-2 lists estimates of stillbirth risk according to maternal factors.
Determining the cause of fetal death aids maternal coping, helps assuage any perceived guilt, permits more accurate counseling regarding recurrence risk, and may prompt therapy or intervention to prevent a similar outcome in subsequent pregnancies (American College of Obstetricians and Gynecologists, 20 16a). Identification of inherited syndromes also provides useful information for other family members.
Important tests in stillbirth evaluation are neonatal autopsy, chromosomal analysis, and examination of the placenta, cord, and chorioamnionic membranes (Pinar, 2014). Page and coworkers (2017) found placental pathology and fetal autopsy to be the most useful. One algorithm from the American College of Obstetricians and Gynecologists (2016a) is shown in
Figure 35-4. Findings are documented in the medical record, and relevant prenatal events are delineated. Photographs are taken whenever possible, and a full radiograph of the fetusa etogram-may be performed. Postnatal magnetic resonance (MR) imaging or sonography may be especially important in providing anatomical information if parents decline a full autopsy (McPherson, 2017; Shruthi, 2017).
If autopsy and chromosomal studies are performed, up to 35 percent of stillborn fetuses are discovered to have major
TABLE 35-2. Estimated Maternal Risk Factors and Risk
Inspect fetus and placenta:
Weight, head circumference, and length of fetus Weight of placenta Photographs of fetus and placenta
Frontal and profile photographs of whole body, face, extremities, palms, and any abnormalities Document finding and abnormalities
Obtain consent from parents for cytologic specimens:
Obtain cytologic specimens with sterile techniques and instruments -Amniotic fluid obtained by amniocentesis at time of prenatal diagnosis of demise: paticularly valuable if delivery is not expected imminently -Placental block (1 x 1) cm taken from below the cord insertion site on the unfixed placenta -Umbilical cord segment (1e.5 cm) -Internal fetal tissue specimen, such as costochondral junction or patella; skin is not recommended
Place specimens in a sterile tissue culture medium of lactated Ringer's solution and keep at room temperature when transported to cytology laboratory
Fetal autopsy and placental If no consent is given for pathology (may include autopsy, send placenta fetal whole-body X-ray) alone for pathology (Chap. 13, p. 271). CMA does not require dividing cells and is reported to be more useful in the evaluation of fetal death. his is especially true because the culturing of macerated fetal tissue is frequently unsuccessful (Reddy, 2012). Both the American College of Obstetricians and Gynecologists (2016c) and the Society for Maternal-Fetal Medicine (2016) now endorse the use of CMA for stillborn fetuses.