IN THE LIT

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

Intrauterine death of a twin: mechanisms, implications for surviving twin, and placental pathology. Benirschke K. Seminars Diagnost Pathol 10:222-231, 1993.

Intrauterine death in multiple gestation. Liu S, Benirschke K, Scioscia AL, Mannino FL. Acta Genet Med Gemellol 41:5-26, 1992.

These two articles can be considered companions: The first is a high quality, pathologically oriented review of risks associated with twinning, while the latter is a 'data paper' concerning the same issues. Emphasis is placed on the high frequency with which death of one twin occurs — increasingly recognized through sonographic identification early in pregnancy followed by the 'vanishing' of one twin. Both articles emphasize the time-dependent consequences of the death of one twin, the high risks particularly associated with monochorionic, monozygotic twin pairs and the substantial risks of later intrauterine death of a twin to the surviving co-twin. While the authors can be faulted for basing their conclusions on a non-representative and potentially biased sample, nonetheless these are very important contributions to our understanding of the consequences of twinning and its relationship to stillbirth. In particular I would strongly recommend the article published in Seminars in Diagnostic Pathology as the most cogent recent review of these issues.

Prognosis and long-term follow-up of a twin after antenatal death of the co-twin. Rydhström H, Ingemarsson I. J Repro Med 38:142-146, 1993.

This article reports on a study derived from the National Birth Registry of Sweden. It takes advantage of the Swedish system of assigning a permanent personal identification number to every person at their birth. Medical follow-up is, therefore, less problematic for a study such as this. The authors identified 206 gestations in which there was antenatal death of one co-twin. In 77 instances the second twin also died in the newborn period. Unfortunately for the remaining group of 129, only 65 could be followed up because of "faulty information in the Medical Birth Registry"! In those survivors (in whom follow-up was possible) only three were known to have either cerebral palsy or to be mentally retarded. This is not much greater than the overall population estimate in Sweden of the same handicapping conditions (1.9% overall). While limited by incomplete ascertainment and lack of direct evaluation of the survivors by the authors, this study suggests that mortality of co-twins after the death of one twin is quite high, but that most survivors are not severely disabled.

Perinatal grief: response to the loss of an infant. Harrigan R, Naber MM, Jensen KA, TSE A, Perez D. Neonatal Network 12[5]:25-31, 1993.

Despite its title, this paper specifically concerns the grieving which occurs following the death of a twin. The authors investigated a group of parents in which one twin died to assess if 'grieving and loving at the same time' resulted in demonstrable differences of the grieving process. A small convenience sample (19 mothers and 8 fathers) was assessed using a variety of testing instruments: Perinatal Grief Scale, Parental Response Scale, Life Experiences Survey, Jalowiec Coping Scale. While the authors were rigorous in their use of validated measuring instruments, the use of an extraordinarily small, nonrandom sample makes any conclusions reached highly suspect. For example, the study suggests that, overall, the total impact of life events was slightly positive for the group. Perhaps that is less surprising if one remembers that this is a group of parents who volunteered (wouldn't negatively affected parents be less likely to participate?) and that many of these were recruited from parent support organizations (might not those joining such organizations be looking for just such a positive impact on their lives?). So, too, for example, that this group would value 'supportant' coping strategies can't be generalized since they were recruited from support organizations! Similarly, I remain unconvinced that there are no significant differences in the responses of fathers and mothers. Certainly that was true in a statistical sense, but with n=8 for fathers such negative results are meaningless. Frankly, I find it frustrating that studies such as this continue to be published — while superficially rigorous, small, biased samples contribute nothing to our overall understanding of grieving following intrauterine death.