The definition of stillbirth is the birth of a baby who shows no signs of life after a pregnancy of at least 22 weeks gestation or weighing 500 grams or more. A baby may have died naturally during late pregnancy (called intrauterine death). Sometimes it may be necessary to medically terminate a pregnancy after 22 weeks due to serious medical abnormalities. More unusually, a baby may have died during labour or birth (called intrapartum death).
Stillbirth is uncommon, but unfortunately, it is not rare. In Israel approximately 1 in 120 births will be a stillbirth or a newborn death.
A newborn death (also known as neonatal death) is one that occurs in the first 28 days after birth.
We don’t always know why a baby dies but there are a range of problems known to either increase the risk of or be a cause of stillbirth. The following are some of the commonly reported risk factors for and causes of stillbirth in developed countries:
Congenital anomalies: These describe conditions where the development of the baby has been affected and are often present from conception or early in pregnancy. They may involve problems with chromosomes or important structures such as the brain, heart, spinal cord or kidneys.
Premature birth: 7% of women in Israel deliver their baby preterm. Although the majority of preterm babies now do well with modern obstetric and neonatal care, if the birth is extremely early, the baby can be too immature to survive and can be stillborn. Underlying reasons for preterm birth are not well understood but include infection and maternal medical conditions necessitating earlier delivery.
Problems with the placenta or cord: A variety of issues may lead to placental problems including conditions such as diabetes and high blood pressure. These can impair placental development and mean the placenta is unable to nourish the baby and can result in stillbirth. Placental abruption is a relatively common cause of stillbirth and occurs if there is bleeding between the placenta and the wall of the womb which can acutely reduce blood supply to the baby. Rarer placental problems such as vasa praevia and fetal maternal haemorrhage can also affect blood supply to the baby. Cord “accidents” are often implicated in stillbirth but the diagnosis should be made with caution as cord problems are often seen in healthy liveborn babies. A baby’s death should not be attributed to a cord accident unless there is both evidence of true obstruction and exclusion of other problems.
Fetal growth restriction: This term refers to babies that do not reach their full growth potential. This is associated with a significant increase in risk for stillbirth with up to half of babies who are stillborn being smaller than expected. It can be secondary to impaired placental function, chromosomal problems with the baby, smoking and maternal medical conditions such as high blood pressure. It can be very difficult to diagnose these babies during routine antenatal care.
Maternal medical conditions: Pre-existing medical conditions are associated with increased risks of stillbirth. Commonly reported conditions are diabetes, renal disease, thyroid disorders, cardiac disease, systemic lupus erythematosus and obstetric cholestasis. Although regular antenatal care can help reduce the risk of stillbirth, sadly stillbirth still occurs, world-wide.