The time of fetal death.

A pregnant woman arrives at the hospital in her third trimester The physician uses an electronic fetal heart monitor to determine if the fetus is in distress The findings reveal that the baby is suffering from fetal distress, but the physician misinterprets them He improperly sends the woman home, telling her that the baby is fine and that there is nothing to worry about The woman returns to the hospital 12 hours later, and the baby is dead

This scenario, much too common, presents the lawyer with a formidable medical-legal issue: Would the baby have been healthy and normal if the baby had been delivered when the mother first went to the hospital? Attorneys can take a series of steps to investigate this question Its answer is a vital link in establishing causation.(1)

Perinatal Pathology

This analysis focuses on perinatal pathology, the science concerned with the nature and cause of diseases in a baby after the 28th week of pregnancy through 28 days after birth Using principles of this discipline, experts can determine the time of fetal death by examining the fetus, the placenta, and the fetal organs

Historically, the time of fetal death was determined principally by external examination of the fetus Different observers often came to different conclusions because describing the degree of visible skin changes was often subjective Because of this, determining the precise time of death using skin changes a,one was often difficult

In the past year, a more precise analysis has been reported in the medical literature.(2) This approach involves studying microscopic structural changes --pathologists call these "histologic" changes--that can be detected in the placenta and fetal organ tissues Now, in addition to examining the external appearance of the fetus, the pathologist can correlate histologic changes in the placenta and organs with a specific period during which the fetus has died

Timely diagnosis of fetal distress allows a physician to remedy the distress by treating the underlying cause or by promptly delivering the fetus The earlier fetal distress is diagnosed and eliminated, the more likely permanent dam age or death will be avoided.(3)

Many doctors, like the one in the example above, rely on readings from a fetal monitor to determine whether a fetus is in distress As valuable as these monitors are, there are drawbacks to using them Doctors may misinterpret the findings and fail to intervene Also, if the monitor is positioned incorrectly on the mother, the physician may mistake the mother's heart rate for the baby's When either of these problems occurs, the results clearly can be disastrous

The goal of the plaintiff's attorney is to show that the baby was viable and healthy when the mother first went to the hospital This presents a two-edged sword To prove negligence, the attorney must show that immediate intervention by the physician was warranted Arguing that intervention was required, however, plays into the defendant's argument that the baby was doomed Conversely, the defense attorney must argue either that intervention was not warranted or that the baby was doomed from the outset. For both sides, the issue must be carefully analyzed

The time of fetal death can be approximated using a pathological examination of the fetus, placenta, and fetal organs During an autopsy, the pathologist performs an external examination of the body and an internal examination of the organs and tissues The findings may provide useful information about both the cause and time of death

External Examination

Despite recent advances in perinatal pathology, findings from the external examination of the fetus are still valuable This is especially true when an internal examination has not been performed

At the beginning of the external examination, the pathologist should meticulously examine the condition of the skin Because tissue quickly loses its tone after death, the skin is examined principally for signs of peeling At about four to six hours after death, the skin takes on a "parboiled" appearance, where the outer layer of skin (the epidermis) slips away from the underlying layer (the dermis).(4) The peeled skin is autolyzed, or digested, by enzymes released from the cells The degree of skin slippage--pathologists use the term "maceration"(5)--has been correlated with the time of fetal demise before delivery(6) This analysis has traditionally been performed using the Langley and Bain Scale.(7)

If only an external examination was performed, the pathologist's report should include a clear description of the extent of skin peeling, if any, and photographs of the fetus The peeling can be described by labor and delivery nurses who saw the condition of the baby on delivery Generally, it is prudent to interview or depose the nurses They usually have more extensive physical contact with patients than other health care professionals do and are accustomed to conveying details about their patients

Because aspects of this examination are subjective, this method can lead to disagreement about the precise time of death For example, skin changes might be due to death, or they might have been caused by the handling of the fetus during delivery and examination Also, the body temperature of the fetus contributes to the degree of skin peeling, further complicating the correlation

Nevertheless, the external examination remains especially valuable when a complete autopsy cannot be performed It allows detection of external anomalies and can provide a rough estimate of the time of fetal death depending on other variables.(8)

New Approach

The authors of a recent series of articles published in the journal Obstetrics and Gynecology describe how the placenta and fetal organs can be used to establish the time of death.(9) While external examination of the fetus can provide a correct estimate of this time, examining the placenta and organs can help the pathologist determine it more precisely.(10)

Placenta. Until recently, little attention has been given to the placenta as a tool for determining the time of fetal death.(11) In fact, examination of the placenta has been neglected often by both the clinician and the pathologist.(12)

The placenta reveals histologic abnormalities when the fetus dies These changes have been correlated with how long the fetus has been dead before the delivery was performed

The approach to examining the placenta during the autopsy varies among institutions The general procedure, however, begins with an external examination of the whole placenta The pathologist then slices it, inspects areas of damaged tissue or hemorrhage, and microscopically examines representative sections This last step lends promise to determining the time of death more accurately

Histologic changes that occur after fetal death will likely appear in the placenta's blood vessels When the fetal heart stops, fetal blood no longer is supplied to the placenta As a result, histologic changes occur Three in particular correlate with the time of death.(13)

* Intravascular karyorrhexis When the nucleus of a blood vessel cell disintegrates, the cell's genetic material (chromatin) fragments This change usually is found in cases where death occurred more than six hours before delivery.(14)

* Vascular abnormalities in the stem villi. The villi are fingerlike projections on the surface of the placental membrane They are divided into groups according to their structure and position Stem villi serve as mechanical supports to the entire group of villi.(15)

The blood vessels in the stem villi take on an abnormal appearance when death occurs The extent to which this abnormality is seen correlates with how long the fetus was dead before delivery Extensive abnormalities (appearing in more than 25 percent of the villi) are usually found in cases w here the death of the fetus occurred more than 14 days before delivery.(16)

* Villous fibrosis This is formation of abnormal, scarlike tissue within the villi This change is usually found in cases where death occurred more than 14 days before delivery.(17)

These placental changes can be correlated to periods indicating how much time has passed since the fetus died

These periods include the following recent (fewer than 6 hours before birth), short (more than 6 hours but fewer than 48 hours), intermediate (more than 48 hours but fewer than two weeks), and prolonged (more than two weeks).(18) Other variables must be taken into consideration, however Factors such as prolonged refrigeration have been shown to arrest some of the changes.(19)

Organs. Eleven reliable histologic changes in the fetal organs have been shown to correlate with death within certain time intervals Those intervals range from fewer than four hours to more than eight weeks

The principal histologic change observable in fetal organs after death is disappearance of nuclear basophilia, or staining characteristics The pathologist tests for this loss using a process that stains the cell Because the nucleus disintegrates when a cell dies, there will be less basophilia staining present in a dead cell than in a living one.(20)

At various times after fetal death, nuclear basophilia staining may be lost in the kidneys, liver, heart, lungs, gastrointestinal tract, adrenal gland, and trachea The earliest loss of basophilia occurs is in the cortical tubules of the kidneys This change occurs approximately four hours after fetal death.(21)

Case Investigation

The attorney must obtain the medical records and autopsy materials These should include the final autopsy report (not an interim investigation report), original or "recut" microscopic slides of fetal organs,(22) and photographs of the baby and placenta The attorney should also request slides of placental tissue The autopsy report may be included with the medical records, or it may be in the hospital's pathology department or the medical examiner's office.

The attorney may have to obtain microscopic slides directly from the pathologist If recuts are not available and the pathologist will not release the original slides, most advanced microscopes will make color photographs of the image observed under the lens Finally, some institutions take photographs of the baby and placenta before the autopsy begins The parents may have taken photographs of the baby (probably not of the placenta), which may also be useful

Few medical fields are as complex as perinatal pathology; Most physicians and attorneys are not qualified to conduct an analysis without an expert The hospital pathologists may be reluctant to speak with plaintiffs, counsel if the pathologists are affiliated or friendly with the prospective defendant Moreover, hospital pathologists are often generalists without specific training in perinatal pathology A thorough review of the medical literature will help identify experts Teaching hospitals may also be good places to find perinatal pathologists

Pathologic analysis is an invaluable method for determining the time of fetal death It is less subjective than relying on the fetal heart monitor and the mother's subjective description of fetal movement Using this tool will greatly enhance counsel's ability to prosecute or reject cases appropriately.

Notes

(1) Studies evaluating the time of fetal death estimate that 30 percent occur during labor and 70 percent before labor. See David R. Genest ct al., Estimating the Time of Death in Stillborn Fetuses I. Histologic Evaluation of Fetal Organs; An Autopsy Study of 150 Stillborns, 80 OBSTETRICS & GYNECOLOGY 575, 576 (1992) [hereinafter Genest I] (citing Outi Hovatta et al., Causes of Stillbirth: A Clinico-pathological Study of 243 Patients 90 BRIT. J. OBSTETRICS & GYNECOLOGY 691 (1983); J.S. Wigglesworth, Monitoring Perinatal Mortality: A Pathophysiological Approach 2 LANCET 684 (1980) (issue 8196)). (2) Examination of the placenta and fetal organs and external examination of the fetus have been discussed in a recent series of articles. See Genest I, supra note 1; David R. Genest, Estimating the Time of Death in Stillborn Fetuses 17. Histologic Evaluation of the Placenta; A Study of 71 Stillborns 80 OBSTETRICS & GYNECOLOGY 585 (1992) [hereinafter Genest II]; David R. Genest & Don B. Singer, Estimating the Time of Death in Stillborn Fetuses III. External Fetal Examination; A Study of 86 Stillborns 80 OBSTETRICS & GYNECOLOGY 593 (1992) [hereinafter Genest III]. (3) John F. Huddleston, Management of Acute Fetal Distress in the Intrapartum Period 27 CLINICAL OBSTETRICS & GYNECOLOGY GY 84 (1984). See also J.T. Parer & E.G. Livingston, What Is Fetal Distress? 162 AM. J. OBSTETRICS & GYNECOLOGY 1421 (1990). (4) 1 JONATHAN S. WIGGLESWORTH & DON B. SINGER, TEXTBOOK OF FETAL AND PERINATAL PATHOLOGY 270-71 (1991). (5) See id. at 270. "Desquamation" also refers to an area where the epidermis is missing, exposing the underlying dermis. See Genest I, supra note 1, at 594. (6) 15 MAJOR PROBLEMS IN PATHOLOGY, PERINATAL PATHOLOGY, 85 (James L. Bennington ed., 1984) (citing EDITH L. POTTER & JOHN M. CRAIG, PATHOLOGY OF THE FETUS AND THE INFANT 84-85 (1975); Gilbert L. Strachen, The Pathology of Foetal Maceration, 2 BRIT. MED. J. 80 (1922). (7) 1 WIGGLESWORTH & SINGER, supra note 4, at 278. (8) Genest I, supra note 1, at 593; Strachen, supra note 6; POTTER & CRAIG, supra note 6. Other authors have concluded that gross skin changes are not reliable for accurately estimating the time of death. See, e.g., 15 MAJOR PROBLEMS IN PATHOLOGY, supra note 6; M.J. Becker & A.E. Becker, PATHOLOGY OF LATE FETAL STILLBIRTH 56-57 (1989) (cited in Genest I, supra note 1, at 576). (9) See Genest I, supra note 1; Genest II, Genest III, supra note 2. (10) Genest III, supra note 2, at 599. (11) The exception is the study by H. Fox, Morphological Changes in the Human Placenta Following Fetal Death, 75 J. OBSTETRICS & GYNECOLOGY BRIT. COMMONWEALTH 839 (1968). (12) 1 WIGGLESWORTH & SINGER, supra note 4, at 210. (13) Genest II, supra note 2, at 585. (14) Id. at 588. (15) KURT BENIRSCHKE & PETER KAUFMANN, PATHOLOGY OF THE HUMAN PLACENTA 81, 86 (2d ed. 1990). (16) Genest II, supra note 2, at 588-89. (17) Id. (18) Id. at 591. (19) Id. at 589. (20) See generally EDNA PROPHET ET AL., LABORATORY METHODS IN HISTOTECHNOLOGY (1992). (21) Genest I, supra note 1, at 581. (22) New slides created from organs retained in a parafin block are called "recuts."

Robert K. Jenner is a partner and Barbara E. Hirsch is a nurse-attorney associate in the firm of Freeman & Jenner in Bethesda, Maryland.