Use of monoclonal antibodies to enumerate spirochetes and identify Treponema denticola in dental plaque of children, adolescents and young adults.

Identification of spirochetes in dental plaque is difficult. Not all spirochetes can be cultured and microscopic analysis based on darkfield or phase optics cannot determine the genus and species of individual bacterial cells. The purpose of this study was to use monoclonal antibodies in an immunoenzyme technique to stain spirochetes in dental plaque. Separate mAb were used to estimate total spirochetes and relative numbers of 2 distinct types of Treponema denticola. Plaque samples were collected from 40 subjects grouped by age. Results showed that older subjects are more likely to have spirochetes, to have more spirochetes and to have more diverse populations or spirochetes than younger subjects. Our studies suggest that T. denticola may be the first treponeme to colonize the primary dentition, that T. denticola appears to comprise a major proportion of all spirochetes at all ages and that two distinct serotypes of T. denticola are found to coexist in plaque from most children.

Anti-Kell in pregnancy.

A review of data on haemolytic disease of the newborn (HDN) collected in Newcastle upon Tyne over 25 years revealed 194 pregnancies in which anti-Kell was the only antibody detected. Sixteen affected babies were born. None was hydropic, three had very severe disease but all survived. There were also three stillbirths, none of which had post-mortem appearances of HDN. The highest recorded anti-Kell titres in individual patients ranged from 1/1 to 1/2048 and bore no relation to the severity of the disease. Of the eight pregnancies in which amniotic fluid examination predicted a high risk of stillbirth, half resulted in unaffected babies. We suggest that haemolytic disease caused by anti-Kell is less severe than suggested by some workers. The use of guidelines developed from the study of Rhesus disease to determine the need for intervention in women with anti-Kell may be inappropriate.

Sexual activity in girls under 16 years of age.

Data on pregnancy, abortion, sexually transmitted disease and cervical dysplasia in girls under the age of 16 years were collected from British and American publications. Over half the pregnancies in girls under 16 ended in induced abortion, and those that continued had increased maternal and perinatal mortality, partly due to failure to attend for care. A prospective study in young teenagers found a high rate of fetal loss in pregnancies that followed abortions. Apart from an increased risk of cervical injury, abortion in girls under 20 carried the same risk of complications as for the American population as a whole. The risk of developing carcinoma of the cervix was doubled in women who began sexual activity before the age of 17 and a large survey found that 1.9% of the girls aged between 15 and 19 years had abnormal cervical cytology. Discouraging sexual activity before the age of consent seems to have a medical as well as a moral basis.

Abortion denied.

PIP: Throughout the world, legal abortion is now widely available, but nowhere is it available unconditionally. Most abortion laws seek to ensure that abortion is performed as safely as possible and only after careful thought. Restrictions may be minimal, but more usually 2 or more doctors have to be involved in certification with more stringent rules for abortion after 12 weeks' gestation. It follows that women who are denied abortion will include those who cannot negotiate the legal system (especially the very young and socially disadvantaged) or those who are ambivalent about the abortion. In Britain, the provisions of the Abortion Act call for 2 doctors to sign a certificate before the abortion. The limit of gestation is governed by the Infant Life Preservation Act, which protects the fetus beyond the limit of "viability," defined as 28 weeks. There is no legal restriction on 2nd trimester abortion, but there recently has been voluntary agreement to limit abortion to less than 24 weeks. There is considerable variation in the availability of abortion in the National Health Service (NHS), and delays may occur between the primary referral and the hospital consultation and again before admission to hospital. In Britain, the private clinics offer an alternative for women denied abortion in the NHS, especially for those in the 2nd trimester. In some regions, a large proportion of abortions are performed outside the NHS, often in private clinics run on a charitable basis. When more than 1 doctor is involved in the decision, as in Britain, Canada, and some parts of the US, the woman may be dissuaded, at the 1st consultation, from proceeding further. The woman denied a legal abortion is faced with 4 options: to seek a legal abortion elsewhere; to seek illegal abortion; to continue the pregnancy and accept motherhood; and to continue the pregnancy but arrange for the baby to be fostered or adopted. The Lane Committee, which reviewed the working of the Abortion Act in Britain, estimated that about 30% of those first refused eventually obtained an abortion. Reliable information about the use of illegal abortion is hard to find. Certainly deaths attributed to abortion in Britain and the US have declined since the liberalization of abortion laws. In many cases where abortion has been denied, it is because the request is made too late, owing either to ambivalence or to ignorance. More could be done to improve the early diagnosis of pregnancy and to improve the cumbersone delays in the referral system in many countries.^ieng

Some aspects of late abortion for congenital abnormality.

Present methods of prenatal diagnosis are not applicable until at least 16 weeks of gestation. Most abortions for suspected congenital abnormality are therefore usually done in the second trimester of pregnancy. Abortions at over 20 weeks of gestation account for about 0.8% of all abortions for residents of England and Wales, but the operations are unpleasant and carry a significant morbidity. Screening the population for neural tube defects has led to a marked reduction in the recorded incidence of infants born with the condition. A survey in the Northern Region of England, with official statistics from Scotland, shows that in spite of the contribution made by selective abortion, there appears to be a genuine reduction in the population incidence of neural tube defect in Scotland. The diagnosis of chromosomal abnormalities, and to a lesser extent of neural tube defects, depends on amniocentesis and there is evidence of more delay in initiating amniocentesis for neural tube defect than for chromosomal tests, probably because of administrative delay associated with the use of serum alphafetoprotein screening. The possible impact of proposals to change the law concerning the limit of viability of the fetus on the practice of late abortion for congenital abnormality is examined. Abortion for congenital abnormality should be permitted after 22 weeks' gestation.

Birthweight and ethnicity.

PIP: The systematic recording of birthweight seems to have begun in Paris in 1802 and now birthweight is an essential piece of information which is part of the statutory notification of birth. Low birthweight infants make a disproportionate contribution to perinatal mortality. Reducing the incidence of low birthweight is more significant, clinically, than a rise in mean birthweight. Genetic factors, important in determining ultimate size, do not seem to have much influence on birthweight. The variation in birthweight between different ethnic groups is well documented. Meredith (1970) reviewed the world literature. Low mean birthweights were recorded almost exclusively in Africa, India, and the Far East, whereas the high means occurred mainly among Europeans and white Americans. In areas with high levels of immigration, medical professionals are conscious of the need for accurate information about ethnic groups, but the subject is associated with numerous problems. To compare ethnic groups, for whatever purpose , the epidemiologist needs to negotiate a "minefield" of social variables, nutritional uncertainties, and racial sensitivities. The members of a given ethnic group share both a genetic inheritance and a similar geographical, social, and cultural background. All of these must be considered. Immigration has provided an opportunity to study the effect of social and cultural adaptation and to identify those features which are apparently immutable. At the recent conference at the Royal College of Obstetricians and Gynecologists on the obstetric problems of Asian immigrants in Britain, it was shown that poor fetal growth is associated with deficiencies of minerals and protein due to dietary habits. Viegas et al. (1982) suggested that birthweights can be increased by giving protein supplements to Asian women during the 3rd trimester. In Israel the problems are very different. Israel contains a variety of immigrants at various stages of cultural assimilation. Marked differences have been observed between Jewish immigrants from Europe, the US, North Africa, and the Middle East who, although all Jewish, differed in cultural and genetic background. Babies born to mothers who came from North Africa were, on the average, heavier than those of other ethnic groups, in spite of lower social class. Yet, the birthweight advantage was eroded with adaptation to Israeli culture. The issue is whether these differences in birthweight matter.^ieng

Home and hospital confinement in Newcastle upon Tyne, 1960 to 1969.

During the decade 1960 to 1969, perinatal mortality rates in Newcastle upon Tyne fell in parallel with national trends, in association with a marked reduction of domiciliary midwifery. Analysis of the records of women booked for confinement at home or in specialist hospitals showed that the reduction of mortality occurred with unexpected uniformity in both categories, in low risk as well as high risk patients, and in all causes of mortality except congenital malformations. It could not be attributed to improvements in maternal characteristics nor to increased size of babies at birth. The most probably explanation seems to be a combination of many improvements in the quality of care, with increased awareness of risks, better selection of high-risk groups, and improved supervision and management throughout. There is no indication that single factor in obstetric management, such as more intervention during labour, had a dominant effect.

Massive chronic feto-maternal bleeding associated with placental chorioangiomas.

After pregnancy complicated by polyhydramnios and the antenatal discovery of a very large placenta a newborn infant suffered from anemia, thrombocytopenia and hypoproteinemic edema, and was successfully treated by exchange transfusion. The placenta contained two chorioangiomas and there was diffuse placental hypertrophy with edema and patchy chorioangiomatosis. There was evidence of major chronic feto-maternal bleeding which could be the explanation for most of the hematological and biochemical problems which occurred. The child was developing normally at subsequent follow-up aged 15 weeks.