Atlas of Neonatal Pathology

3.6 Stillbirth and perinatal mortality

3.6.1 Stillbirth

Introduction:

A fetus that shows no signs of life and weighs 1000 g or more is classified as stillborn child.

Maceration (from Latin macerare — soften by soaking) includes all the changes which occur in a fetus retained in utero after death.

Mors fetus intrauterina — fetal demise during pregnancy, usually shows maceration
Mors fetus intrapartum — death occurs during delivery, fresh stillborn fetus

The risk of intrauterine demise increases toward term, approximately one third occurs at full term. A direct cause of death is found in only 50% of stillbirths. Full autopsy including examination of placenta, umbilical cord and membraned should be performed in all cases.

Classification:

Sateges of maceration:

0. — parboiled, reddened skin
I. — skin slippage and peeling
II. — extensive skin peeling, red serous effusions in chest and abdomen
III. — yellow-brown liver, turbid effusion, mummification

Estimating the time of death in stillborn fetus

Desquamated skin measuring 1 cm or more in diameter and red or brown discoloration of the umbilical cord correlated with fetal death 6 or more hours before birth.
Dequamation involving the skin of face, back or abdomen (12 or more hours)
Desquamation of 5% or more of the body surface (18 or more hours)
Moderate to severe desquamation, brown skin discoloration of the abdomen (24 or more hours)
Mummification is seen in fetuses who had died 2 or more weeks before birth

Macroscopic appearance:

Skin — the earliest sign of macerations are seen in the skin 4 – 6 hours after intrauterine death.The epidermis separates from the dermis on applying a pressure (skin slipping). Bullae appear with collection of fluid beneath the epidermis. The desquamation regularly progresses in time to extensive skin separation on the face, neck, abdomen, limbs and external genitalia exposing red and moist dermal surface.
Head — collapse of the skull with overlapping bones, cranial bones become separated from the dura and periosteum. Widely open mouth and eyes are frequent with progressive maceration.
Internal organs — uniform reddish discoloration due to progressive hemolysis, yellow-brown discoloration occurs with retention for several weeks, dystrophic calcification is possible. Organs most severely affected by autolysis are those from abdominal cavity (liver, spleen, adrenals) and brain which is very soft or semiliquid in severe maceration
Softening of all organs and connective tissues, laxity of joints.
Exsudation of fluid and hemolyzed blood into pleural, pericardial and peritoenal cavities
The fetus looks edematous (hydrops-like), later progressive loss of fluid results in mummification.
Placenta — remains viable after fetal death in utero. Placental abnormalities can be found in many cases (infarction, retroplacental hemorrhage, cord accidents). Placenta should be always submitted to postmortem examination with the fetus.

Clinical signs:

Cause of death in macerated stillbirth

Autoptic signs of asphyxia are often found: small hemorrhages over the thymus, lungs and heart, congestion of internal organs. The lungs are airless. Light microscopy reveals amniotic fluid aspiration. Exact cause of death often remains unexplained but the mode of death (acute asphyxia of chronic fetal hypoxia) can be established in most cases unless severe maceration. Gross malformations or multiple congenital defects are occasionaly seen. On the other hand minor malformations and anomalies are unlikely to be the cause of death but sometimes may lead to diagnosis of chromosomal disorder (triploidy, trisomies). Negative findings (no congenital malformations or anomalies, normal growth and developement) are also helpful to both the parents and clinicans/genetics.

Pictures

Minimal maceration of grade 0, skin slippage on pressure. 40-week gestation stillbirth. The mode of death was acute intrauterine asphyxia from unknown causes. The placenta was stained by meconium.
Maceration, meconium staining, Macro, autopsy (73872)
Maceration, meconium staining, Macro, autopsy (73871)
Maceration, meconium staining, Macro, autopsy (73873)

Macerated stillbirth (stage I. maceration), true umbilical knot:
Umbilical knot, Macro, autopsy (73881)

Macerated full term stillbirth with stage I. maceration. True umbilical knot is the cause of intrauterine death.
Umbilical knot, Macro, autopsy (73883)
Umbilical knot, Macro, autopsy (73882)

Macerated 39-week stillbirth, stage II. maceration. Compression of abnormal velamentous vessels by fetal presenting parts and subsequent thrombosis was the cause of death.
Maceration, gr. 2, Macro, autopsy (73833)

Macerated term stillbirth, stage II. maceration, intrauterine death at 39 week's gestation from acute intrauterine asphyxia of unknown cause.
Maceration, mature child, Macro, autopsy (73837)

Maceration stage II.; head collapse with overlapping cranial bones:
Maceration, collaps of the calva, Macro, autopsy (73835)
Maceration, collaps of the calva, Macro, autopsy (73836)
Maceration, collaps of the calva, Macro, autopsy (73834)

Intrauterine fetal death at 31 week's gestation. Maceration stage II. Stillbirth fetus with intrauterine growth retardation of malnutrition type, birth weight 1000g. The cause of stillbirth is chronic intrauterine hypoxia from large central placental infarcts.
Placental infarctions, Macro, autopsy (73822)
Intrauterine death due to placental infarctions, Macro, autopsy (73820)
Intrauterine death due to placental infarctions, Macro, autopsy (73821)
Intrauterine death due to placental infarctions, Macro, autopsy (73818)
Intrauterine death due to placental infarctions, Macro, autopsy (73819)

Brain malformation (semilobar holoprosencephaly] incompatible with survival in 32-week stillbirth. No signs of maceration. Elective preterm delivery because of fatal malformation. Malformation of brain is associated with malformation of the central part of the face.
Holoprosencephaly, Macro, autopsy (73887)

Mumification:
Fetus, mumification, Macro, autopsy (73992)

3.6.2 Perinatal mortality

Introduction:

Perinatal mortality is the sum of still births and deaths under 7 days per 1000 total births. Stillbirths are the major component of perinatal mortality, twice as common as early neonatal deaths. More than 300 stillbirths occur annually in the Czech republic. The number of stillbirths remains largely unchanged in recent years while the neonatal mortality has been declined significantly.

Definition of terms

Sillbirth rate — stillbirths per 1000 total births
Early neonatal mortality rate — number of deaths under 7 days i.e. at age of 0 – 6 days per 1000 live births
Perinatal mortality rate — the sum of stillbirth and deaths under 7 days per 1000 total births
Neonatal mortality — under 28 days i.e. at age of 0 – 27 days per 1000 live births
Infant mortality rate — under 1 year per 1000 live births

Etiology:

causes of death in the perinatal period:
disorders related to short gestation and low birth weight
congenital malformations and chromosomal abnormalities
newborn affected by maternal complications of pregnancy
- hypertension
- preeclampsia and ecclampsia
- diabetes mellitus
- autoimunity disorders
- heavy smoking
- drug abuse etc.
newborn affected by complications of placenta, umbilical cord and membranes
- placental abruption
- long cord
- true knot
- chorioamnionitis
- fetofetal transfusion in twins
respiratory distress of newborn
bacterial sepsis of newborn
intrauterine hypoxia and birth asphyxia
diseases of the circulatory system
intrauterine infections

Clinical signs:

Mortality rates in the Czech republic in 2007:

Stillbirth rate was 2.74 per 1000 total birth.
Early neonatal mortality rate was 1.25 per 1000 live births.
Neonatal mortality and infant mortality rate in the Czech republic are one of the lowest in the world. Neonatal mortality rate was 2.5 per 1000 live births and infant mortality rate 3.14 per 1000 live births.

Stillbirth and perinatal mortality

3 Neonatal pathology

3.6 Stillbirth and perinatal mortality

3.6.1 Stillbirth

3.6.2 Perinatal mortality