According to MBRRACE-UK (2015) 27.1% of stillbirths were caused by placental insufficiencies/problems. Becher et al (BJOG 2006) found that intrapartum (during labour) stillborn babies did not have brain damage in 50% of cases, but at Post-Mortem in stillborn full-term infants 38% had placental inflammation and 13% a placenta below the 10th centile for gestational age.
What to look for on the Placenta Histology Report
Placenta histology can differentiate between an acute and chronic insult, it can assist with the timing of death [very important if a stillbirth is thought to be complicated by reduced fetal movements] and can assist with determining the nature of the insult to the fetus.
Placental findings indicating acute in utero compromise include a normal placental weight appropriate for fetal weight, acute villous oedema (chorioamnionitis), intravillous haemorrhage and/or acute retroplacental haemorrhage (indicative of placental abruption). Acute meconium staining (a sign of fetal distress in labour) may be present. In a more chronic in utero compromise the placenta may be an abnormal weight in relation to fetal weight. Acute or necrotising funisitis (infection) may be evident. The presence of significant chronic villitis is an important cause of intrauterine growth restriction (IUGR, SGA) and can be seen on placentas with fetal loss. Chronic fetal vascular obstruction/fetal thrombotic vasculopathy may be seen alongside other contributing factors such as maternal diabetes or fetal cardiac insufficiency. This can be helpful if mismanagement or undiagnosed gestational diabetes is a potential element of the claim (Redline 2007, Chang 2009).
In terms of causation, the placenta histology can assist with hypoxia, sepsis and fetal loss. There are many other findings that can help with diagnosis/causation but whilst this will be extremely helpful it is also important to remember that many stillbirths in particular have an unknown cause and placenta histology may be normal and unremarkable. Therefore, a normal placenta does not adversely affect the claim. However, having a little understanding of how valuable this incredible organ can be in supporting clinical negligence claims can go a long way.