DESPITE the recognized importance of the ABO and Lewis antigens in blood typing and transfusion, few physicians appreciate the extraordinary complexity of this system and its association with human disease. These antigens are found in secretions throughout the body and on the surface of epithelial and endothelial cells. Current interest in kidney transplantation has directed attention to their presence in the renal vascular endothelium. ABO incompatibility between mother and fetus may produce infertility or hemolytic disease of the newborn, and persons of certain blood groups have an increased susceptibility to peptic ulcer or gastric cancer. The purpose of this review . . .

The ABO and Lewis blood-group system. Immunochemistry, genetics and relation to human disease.

OBJECTIVE To study the characteristics of pregnancies that resulted in stillbirth and to determine which may possibly predict intrauterine fetal death (IUFD). STUDY DESIGN A total of 161 singleton pregnancies resulting in stillbirth at Nottingham City Hospital from 1991 to 1997 were compared with 499 live births randomly selected from the same period of time. The variables studied were the following: customized birth weight for gestational age, fetal sex, histopathologic cause of IUFD, maternal age, ethnic group, parity, maternal body mass index (BMI), smoking habit, and maternal blood group. RESULTS In 54.7% of the cases of stillbirth at our institution women presented with reduction or absence of fetal movements before the diagnosis of IUFD. Almost half of the stillbirths (48.4%) were small for gestational age (< 10th percentile) on the basis of gestational age-specific weight. The difference in customized birth weight between stillbirths and live births was statistically significant (P <.0001). Increased maternal body mass index (BMI) was positively associated with stillbirth rate (P <.001), as was increased maternal age (P =.0012). Women with blood group O (P =.014) had an even higher stillbirth rate. There was no association between stillbirth rate and maternal ethnic group, maternal smoking, maternal Rhesus status, or fetal sex. CONCLUSIONS This study found that almost half of stillborn babies were small for gestational age. Reduced fetal activity should be investigated thoroughly, with formal measurement of fetal growth as part of this assessment. Maternal blood group and maternal age were found to be important factors in IUFD. Smoking was not confirmed in this study to be a significant factor.

Case-control study of factors associated with intrauterine fetal deaths.

Abo blood-groups in trophoblastic neoplasia

Foeto-maternal ABO incompatibility is associated with increased placental weight; the observation, however, was valid only in the male placentas of primigravidas. It is suggested that a cumulative effect of two incompatibilities, Y chromosome-dependent incompatibility and ABO incompatibility, is needed for this influence on placental weight to be manifested, since male placentas were heavier than female placentas in ABO incompatible cases but not in ABO compatible cases. Also, this effect was found only in the first pregnancy. It is concluded that in later pregnancies the effect of multiparity masks the influence of ABO incompatibility and foetal sex. Different foeto-maternal Rh combinations were not found to have any effect on placental weight.

Placental weight in human foeto-maternal incompatibility

An evaluation of the maternal effect on spontaneous abortion and the genetic contribution to various reproductive variables was made using like-sexed twins born between 1915–1946. Health and reproductive questionnaires were sent to 2,365 twin pairs listed in the Norwegian Twin Registry. Zygosity was determined by a questionnaire which proved to be 98% accurate in discriminating between monozygotic (MZ) and dizygotic (DZ) twins. Verification of the zygosity questionnaire was accomplished by blood cell marker zygosity determination in 200 twin pairs. Data from 428 monozygotic twin pairs (174 male pairs and 254 female pairs) were analyzed by a new model for qualitative traits and a striking maternal effect was found. The results suggested that over 54% of all women may belong to a high risk group who have approximately a 13% risk of early fetal loss. The incidence of first trimester abortions and spontaneous abortion reported by a sample of 915 like-sexed twin pairs and spouses was .079 and .089, respectively; there were no significant differences between male and female pairs.Other reproductive variables were studied in both MZ and DZ twins including the age of menarche and menopause, the age at marriage and birth of the first child, and the interval between marriage and the first birth. These variables were examined for evidence of genetic effects and secular trends. The mean age of menarche had decreased significantly between the years 1915–1935 and 1936–1946. The secular trend appeared to be environmental in nature and accounted for more than 7% of the overall variation in age of menarche. Sixty-five percent of the variation in the age of menarche was attributed to genetic factors. The mean age of marriage and the mean age at the first birth decreased significantly between 1915–1935 and 1936–1946. Twins born between 1936–1946 also reported fewer pregnancies than did twins born between 1915–1946, but this was statistically significant among MZ twins only; no significant difference in the frequency of spontaneous abortions was found between the 1915–1935 and the 1936–1946 groups.Although there were occasional groups in which differences were statistically significant, no general trends were identified in comparing couples who reported a spontaneous abortion with those who did not. Traits compared were: the age of menarche, age of marriage, age at first birth, the interval between marriage and first birth and the mean present age of the twins and spouses. Couples reporting a first trimester spontaneous abortion had significantly more total pregnancies than those not reporting a spontaneous abortion. Unaffected pregnancies were also significantly more numerous in couples with a spontaneous abortion compared to those without, suggesting over-compensation for fetal loss.A maternal effect in spontaneous abortion was indicated by the correlation coefficients found; significant positive correlations were found in both MZ and DZ females but not in males. For total pregnancies and unaffected pregnancies, MZ twins, both male and female, had significant correlation coefficients while DZ twins did not.

J E Sayre

Papers

Further observations on the relationship of maternal ABO and Rh types to fetal death.