When a family experiences the loss of a pregnancy through stillbirth, they may observe physical characteristics that are confusing or unexpected. Stillbirth is defined as the death of a fetus at or after the 20th week of pregnancy. The appearance of the infant upon delivery often reflects the time that has passed since the fetal death occurred in the womb. A reddish or “cherry red” coloration, particularly on the lips, is a specific observation medical professionals recognize as a consequence of biological changes following fetal demise. This article provides a physiological explanation for this phenomenon within the context of other post-mortem observations.
Understanding Stillbirth
Stillbirth is medically classified as a fetal death occurring at or beyond a specific gestational age, commonly defined as 20 weeks gestation. This event is distinct from a miscarriage, which is the loss of a pregnancy before this mark. Stillbirths are categorized as antepartum, meaning the death happened before the onset of labor, or intrapartum, meaning the death occurred during labor.
The infant’s appearance is directly related to the time elapsed between fetal death and delivery. When a fetus dies and remains inside the uterus, the body is exposed to amniotic fluid, initiating post-mortem changes. This process is known as maceration, a form of tissue breakdown that occurs because the body is retained in a fluid environment. Physical findings observed at delivery serve as important clues for medical professionals to estimate the time of death.
The Physiological Explanation for Red Coloration
The bright red coloration observed on a stillborn infant’s lips is a localized manifestation of a systemic post-mortem change involving the blood. This change is primarily driven by the process of red blood cell breakdown, known as hemolysis, which begins after circulation ceases. Hemolysis causes the release of hemoglobin, the oxygen-carrying protein responsible for the red color of blood, into the surrounding tissues and bodily fluids.
Once hemoglobin is released, it begins to diffuse through the fetal tissues, leading to a uniform reddish discoloration of internal organs and moist membranes. The lips, being a mucosal surface with thin underlying tissue, are particularly susceptible to this staining from the leaked hemoglobin pigment. The resulting color is often described as a bright, “cherry red.”
This bright red hue contrasts with the purple or blue coloration typically associated with deoxygenated blood. The bright color results from the chemical stability of the released hemoglobin, which can maintain a color similar to its oxygenated state. As the maceration process progresses, the hemoglobin pigment stains the tissues, creating the visible red color on the lips and other areas. The extent of this red coloration is one feature pathologists use to grade the stage of maceration and estimate the interval between death and delivery.
Other Common Post-Mortem Observations
The red coloration of the lips is often accompanied by other physical signs resulting from the maceration process. One of the earliest signs is the slippage and peeling of the skin, which begins approximately 6 to 12 hours after fetal death. This occurs because the epidermis detaches from the underlying dermis due to tissue breakdown.
Other common observations include:
- Fluid accumulation, or edema, causing tissues to appear swollen or puffy.
- Skin blisters, which may rupture during delivery, leaving raw areas.
- Softening of internal tissues and organs.
- Overlapping of the skull bones, known as Spalding’s sign, due to the loss of tissue volume.
The severity of these physical findings is directly proportional to the length of time the fetus remained in the amniotic fluid after death.
The Role of Medical Examination and Autopsy
The physical signs of maceration, including lip coloration, are not the cause of the stillbirth but provide important diagnostic clues for medical investigation. Pathologists use the degree of these post-mortem changes to estimate the time of fetal death. For example, extensive skin peeling and uniform reddish discoloration suggest death occurred at least several days before delivery.
A comprehensive medical examination, often including a fetal autopsy and placental examination, is performed to determine the underlying cause of the stillbirth. These investigations identify factors such as placental insufficiency, infections, or genetic anomalies that led to the fetal demise. Integrating maceration observations with autopsy findings helps healthcare providers establish a definitive etiology, which is essential for parental counseling regarding future pregnancies.