R. M. Pauli, M.D., Ph.D.

Why has a baby been stillborn? In trying to answer that question there is a temptation to treat as causal anything that appears to be out of the ordinary. So, for example, if a nuchal cord is present, it is tempting to posit that it is this that resulted in a baby’s death. Yet every delivering physician and obstetrical nurse knows that nuchal cords are common in liveborn babies, too. How then can one assess whether intrauterine nuchal cords cause intrauterine death? First, rarely there is histopathological evidence that the nuchal cord was pulled so tightly that there was obstruction of blood flow through it (which, after all, is how a nuchal cord can cause death — it really matters little in utero if flow to the head is impeded).

An alternative approach to this question is the relevance of this article, for me at least. It looks at 13,895 consecutive singleton births and asks a series of questions regarding the frequency of nuchal cords. Their findings include the following. First, nuchal cords are rare before around 20 or 25 weeks gestation (mostly because the umbilical cord is shorter than the fetal body until around then and so has no opportunity to wrap around the neck or head). Secondly, nuchal cords are as common as many of you suspect — about 28% of all pregnancies have a nuchal cord (of which 3.7% have two or more loops). Third, the farther along in gestation does a delivery occur, the higher the probability of a nuchal cord being present — from around 10% at 24 weeks, to around 18% at 32 weeks and around 30% at term, following an almost perfectly linear distribution. Finally and most relevant to readers of this newsletter the authors found that the probability of fetal death did not increase when nuchal cords were present. In fact, the likelihood of antepartum intrauterine death was actually less when a nuchal wrappage was recognized.

So, in addition to providing normative data that are important, e.g., to those doing routine ultrasonographic evaluations, the data here also suggest that nuchal cord wrappage is not a frequent cause of intrauterine death. Therefore, it remains appropriate to use exceedingly conservative criteria (e.g. unequivocal histopathological evidence for obstruction of blood flow) in ascribing causality to nuchal cords when they are found in stillborn babies.

Outcome of nonimmune hydrops fetalis diagnosed during the first half of pregnancy. Iskaros J, Jauniaux E, Rodeck C. Obstet gynecol 90:321-325, 1997.

Generalized fetal edema and abnormal fluid compartmentalization (i.e. hydrops) is quite common. Historically, most fetal hydrops was secondary to blood group incompatibility (immune hydrops). Now, however, most instances are not related to hemolysis secondary to immune processes and, hence, are generically classed as nonimmune fetal hydrops. Previous studies have documented the incredible heterogeneity of causes of nonimmune hydrops.

As ultrasound becomes both more universal and more precise, features such as fetal hydrops are sometimes identified quite early. This article’s contribution is the documentation of causes of hydrops when it is identified between 11 and 17 gestational weeks. Retrospective review found 45 instances in a 4 year span in one large fetal medicine unit (in London). Among the 45 instances, 35 (78%) had cytogenetic abnormalities. Most common were trisomy 21 (17 instances), trisomy 18 (7 instances) and monosomy X (6 instances). Quite remarkably, specific causes were identified in 41 of the 45 cases.

There are some minor concerns about the data presented here. First, these are data from a referral center and referral biases may be substantial. Secondly, more than a third of these instances were picked up in ultrasound dating in women being seen for advanced maternal age. Obviously, the very reason these women are being assessed will make more likely nondisjunctional chromosomal abnormalities in their babies. This would enrich the population of babies with hydrops with those who also have chromosome problems. Nonetheless, the findings here are likely fairly closely representative of the causes of early recognized hydrops in general.

The authors conclude that cases of hydrops identified early in pregnancy are much more likely to be chromosomally abnormal than are those identified later. That is probably true. Certainly it is potent evidence that in every instance where hydrops is identified in the first half of pregnancy, amniocentesis for cytogenetic assessment should be offered.

Long-term impact of perinatal bereavement. Comparison of grief reactions after intrauterine versus neonatal death. Schaap AHP, Wolf H, Bruinse HW, Barkhof-van de Lande S, Treffers PE. Europ j obstet gynecol reproduct biol 75:161-167, 1997.

This study asks an important, practical question: Are there differences in long term grieving in couples who have experienced stillbirth compared with those whose baby died in the newborn period? The authors used semi-structured interviews with 19 couples to try to begin to answer that question. Note, however, that those who experienced stillbirth were a special subset — in every instance a process likely to be lethal was identified prenatally and then a policy of non-intervention was followed that resulted in the intrauterine death. So, the methodology is suspect, the sample size small and the circumstances quite special and not necessarily applicable to stillbirth in general.

Nonetheless some of the results are intriguing. Discongruent grieving in mother and father was much more likely after intrauterine death than after neonatal death. Most often this was reflected in mothers openly expressing grief and fathers assuming the role of the strong and controlled partner. That strength and support did not help; rather it seemed linked to a much higher probability that grief was not openly shared or talked about by the couples. The greater likelihood of discongruent grieving and the needs to engage the father more directly should be taken into account by those providing support for families of stillborns.

In addition, certain features and perceptions shared by both groups are sobering. Although most appreciated the support they received while in hospital and up through around 6 weeks post-partum, virtually all complained that needs for longer term contact and support were not being met. "They all expressed the need for a followup up at 4-6 months, when emotions of disorientation are most intense and when the external world does not welcome their need to repeatedly describe their experiences anymore." Likewise, most found the intensity of grief associated with anniversary dates (of delivery) to be more than they expected and that this was another time when contact was needed. This suggests that a ‘best’ program of support for families experiencing stillbirth would include in-hospital crisis support and, in addition, at least three followup consultations — at around 6 weeks, around 6 months and 1 year after the stillbirth of a baby.

The authors conclude, quite appropriately, I think, "Both intrauterine and neonatal death involves the loss of a loved one, the loss of the fantasy of what that person might have become and the lost opportunity to be a parent. These simultaneous losses make mourning extremely difficult."

Medical causes on stillbirth certificates in England and Wales: distribution and results of hierarchical classifications tested by the Office for National Statistics. Alberman E, Blatchley N, Botting B, Schuman J, Dunn A. Brit j obstet gynaecol 104:1043-1049, 1997.

I had hoped that this article might have a bearing on how we should (or should not) use data from fetal death reports in sorting out the epidemiology of stillbirth (a topic about which I have had some interest for a long time). Unfortunately, in many ways this is just one more example of grown men and women playing with numbers — without much insight regarding alternative sources of data (such as stillbirth assessment programs) or even the value of real assessments and investigation following a stillbirth. No surprise, then, that according to the authors 80% of antepartum stillbirths have no identifiable cause. Nonetheless the authors are to be commended for emphasizing one important point — they take pains to underscore the distinction between ‘associated mentions’ and ‘causal conditions’. That is, just because something is observed does not in itself mean that it has caused a baby’s death (see the comments, above, about nuchal cords).

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