Ethical issues in prenatal diagnosis

Excitatory VTA to DH projections provide a valence signal to memory circuits

The positive or negative value (valence) of past experiences is normally integrated into neuronal circuits that encode episodic memories and plays an important role in guiding behavior. Here, we show, using mouse behavioral models, that glutamatergic afferents from the ventral tegmental area to the dorsal hippocampus (VTA→DH) signal negative valence to memory circuits, leading to the formation of fear-inducing context memories and to context-specific reinstatement of fear. To a lesser extent, these projections also contributed to opioid-induced place preference, suggesting a role in signaling positive valence as well, and thus a lack of dedicated polarity. Manipulations of VTA terminal activity were more effective in females and paralleled by sex differences in glutamatergic signaling. By prioritizing retrieval of negative and positive over neutral memories, the VTA→DH circuit can facilitate the selection of adaptive behaviors when current and past experiences are valence congruent.

The neuronal pathway that signals the positive or negative value of memories is not well understood. Here, the authors report that an excitatory projection from the ventral tegmental area to the dorsal hippocampus carries the valence information, contributing, especially in females, to the recurrence of fear and to drug seeking behavior.

Early amniocentesis: a clinical review

Early amniocentesis at less than 14 weeks gestation is becoming more common in prenatal diagnosis populations. Randomized studies are minimal and have not had the power to determine the accuracy and safety of the procedure compared to chorionic villus sampling or mid-trimester amniocentesis. Procedures at 11+0-12+6 weeks should be considered experimental. This clinical review considers the ethics, embryology, and clinical experience (cytogenetics, AFP, AChE, procedure and cytogenetic failures, spontaneous and therapeutic pregnancy losses, congenital anomalies) of early amniocentesis.

Future use and development of prenatal diagnosis. Consumers' attitudes

The rapid progress of prenatal diagnosis and genetic tests makes it important to investigate attitudes towards this development. A total of 40 women and 20 men with personal experience of prenatal diagnosis for chromosome aberrations were interviewed about their moral opinion of the development. The majority (88 per cent) considered it certain or probable that all new methods developed will also be used in the future. The majority (62 per cent) were hesitant about testing for common disorders, e.g., diabetes mellitus and rheumatoid arthritis, but regarded it justified in some situations. One-third of the individuals (31 per cent) wanted some kind of restrictions for the use of the tests, but only 13 per cent recommended legislation for this purpose. The majority (84 per cent) believed that ethical principles are influenced by scientific progress. In most aspects, the women and their partners had similar attitudes. However, 82 per cent of the women but only 20 per cent of the men considered that the couple itself should decide about prenatal diagnosis. The results demonstrated a considerable respect regarding the difficult choices associated with the development of prenatal diagnosis, also among those who have decided favour of the test. The study indicated a greater need for autonomy among women than among men.

The loss of early pregnancy

It is often assumed that early loss of pregnancy is not followed by emotional distress. When such distress does occur, it often goes undetected. Early loss of pregnancy is frequently followed by typical grief such as that occurring after any bereavement. Most recent studies have shown that although social termination of pregnancy in the first trimester has few adverse psychological sequelae for most women, there are vulnerable women who do experience significant emotional distress afterwards. Risk factors for poor psychological outcome include poor social support, past psychiatric history and ambivalence about the termination. The procedures used for second trimester terminations of pregnancy are likely to be a particular source of distress. Psychiatric disorder may also follow if termination is refused. Careful assessment of all women before social termination will identify vulnerable women who may benefit from counselling and support afterwards. After spontaneous abortion or miscarriage, many women experience significant emotional distress, which persists for several months. Guilt and anger are common. Some women are particularly vulnerable to developing psychiatric disorder after spontaneous abortion, for example women with a past psychiatric history, poor social support, previous spontaneous abortion and personality traits such as neuroticism. Many women would benefit from follow-up and support afterwards; extra support and reassurance are often needed during the next pregnancy. Termination for fetal abnormality is more likely to induce grief than relief for many women; these pregnancies are usually wanted, second trimester terminations are distressing, and there is often guilt at destroying a life and/or opting out of rearing a handicapped child. Recent research has demonstrated substantial levels of psychiatric morbidity after termination for fetal abnormality, particularly in those with a past psychiatric history, those with poor social support, and those who feel they have opted out of bearing a handicapped child. Women receive little support of follow-up after such terminations, yet many would benefit from it. Such women are in particular need of reassurance and support during a subsequent pregnancy.

Examination of products of conception terminated after prenatal investigation

A large number of district general hospitals have access to diagnostic ultrasonography and other methods of prenatal diagnosis, resulting in an increased supply of freshly terminated malformed fetuses to general histopathology departments, and there is now more open discussion of malformation and greater concern over fetal wastage. General pathologists are therefore under greater pressure to produce complete and detailed descriptions of a wide range of often complex anomalies. The dismissal of specimens as "multiple congenital anomalies" is becoming increasingly unacceptable to couples who wish to embark on further pregnancies and to their medical attendants. As in other fields an understanding of the methods and terminology in clinical use and a consistent diagnostic approach should help pathologists to extract sufficient information for accurate counselling.

Prenatal diagnosis of thalassemia and of the hemoglobinopathies; a review

Prenatal diagnosis of thalassemia and of the hemoglobinopathies is now accepted as an effective measure to reduce the impact of these diseases in populations where they occur in high frequencies. The procedure has been carried out on more than 5,000 cases over the past decade. Evaluation of the results shows a significant decrease of the yearly number of affected newborns and reflects a considerable gain in economic and medical resources. Methodology has improved over the years so as to make the procedure safer, faster, and less expensive. Among recent advances, gene mapping on trophoblast DNA (as early as the 9th week of pregnancy) represents a major step which will gradually replace conventional procedures (performed during the 18-20th week of pregnancy) in concerned laboratories.