Prevention of prematurity: Haguenau perinatal survey, 1971-1985

A preterm birth prevention program was instituted in France in the early 1970s. Its effectiveness has been assessed through a perinatal study in Haguenau. A relationship between prenatal care improvement and preterm birth rate decrease was noted, but a causal interpretation cannot be derived from such an observational study. However, some arguments do support this interpretation: no satisfactory alternative explanation (such as biases in pregnancy duration measurement, change in the composition of the population of pregnant women, or secular trend), a plausible causal pattern, and a dose-response relationship between prenatal care and preterm birth rate. The Haguenau study results can be applied to other French regions, but extrapolation to other countries would depend on their social, medical and cultural contexts.     

In vitro culture of functional human thymic epithelium.

Cultures of pure epithelial cells have been obtained from human thymus. Incubation of spleen cells from adult thymectomized mice on these cultures rendered RFC sensitive to inhibition by anti-theta serum, whereas no effect was obtained with fibroblasts or spleen cell cultures. The fact that theta conversion was obtained when spleen cells were incubated in the thymic culture placed within a Millipore chamber indicates that theta conversion was due to the effect of a humoral factor.     

Regionalization of perinatal care in Europe.

This review describes European health policies related to the place of birth of very preterm babies, and the organizational context in which these policies were enacted using data from two European studies. It also compiles available information on the place of birth of very preterm babies from the published literature. In Europe, there is significant diversity in approaches to the provision of intensive care services for the small proportion of pregnant women and babies that need it, both in terms of health policies and the supply and characteristics of maternity and neonatal units. These diverse models in countries with similar levels of development and medical technology could offer an opportunity to understand how different organizational characteristics affect access to care, health outcomes and resource use.     

Mouse mammary tumor virus production by thymic epithelial cells in vivo

Exogenous mouse mammary tumor viruses (MMTV) replicate in the mammary glands of infected females, and so infect the suckling pups. We have previously shown that the virus is rapidly disseminated to all the lymphoid organs, including the thymus. The present electron microscope immunohistochemical study describes the viral production site in the thymus. Viral buds and viral proteins were restricted to the thymus medullary epithelial cells. MMTV-encoded proteins were identified on the free viral particles and on the budding ones, the ribosomes, the membrane of the endoplasmic reticulum, and on the membrane of the medullary type II epithelial cell vacuolar network. The thymus medullary epithelial cells can thus integrate the virus and allow viral replication. The results support earlier results indicating that in some experimental conditions, epithelial cells may be involved in MMTV-induced negative selection by showing that thymic epithelial cells do express MMTV-encoded proteins.     

Trophoblast-like cells sorted from peripheral maternal blood using flow cytometry: a multiparametric study involving transmission electron microscopy and fetal DNA amplification.

Three monoclonal antibodies (MAbs) against trophoblast (GB17, GB21, and GB25) and flow cytometry were used to sort trophoblast-like cells (TLCs) from peripheral blood of pregnant women. Sorted TLCs were processed for electron microscopy and fetal DNA amplification of the Y-specific sequences from mothers carrying male fetuses. At the ultra-structural level, most of the nucleated cells had the morphology of leucocytes, suggesting maternal contaminants, and we did not find the characteristic features of the free intervillous trophoblast cells. Nevertheless, polymerase chain reaction (PCR) analysis showed an amplification of Y-specific sequences in two out of three samples of sorted TLCs. These results suggest that besides the maternal leucocytes, sufficient trophoblast nucleated fetal cells can be obtained using cell enrichment by sorting. This sensitive method holds promise for non-invasive prenatal diagnosis of fetal sex and if sufficient Y(positive) nuclei are found, for the diagnosis of selected numerical chromosome abnormalities.     

Intra-uterine device failure: relation with drug use

A case-control study was undertaken in order to test the relationship between commonly used anti-inflammatory agents and the efficacy of intra-uterine devices (IUDs). Women who had become pregnant while wearing an IUD were compared with non-pregnant IUD users. 717 cases and 717 controls were recruited from the same medical practices. The case-women (IUD failure) used anti-inflammatory drugs, particularly aspirin, more frequently than the controls (p less than 0.001). In contrast, oral progestins, taken in the second part of the cycle (16th to 25th day) were more frequently used by the control-women group (p less than 0.001). Although cases and controls differed in age and gravidity (younger and higher, respectively) standardization for these items did not change the findings for drug use.     

Risk factors for maternal mortality: results of a case-control study conducted in Conakry (Guinea).

OBJECTIVE: To assess the risk factors of maternal mortality in an urban area of West Africa (Conakry, capital of Guinea). METHOD: A case-control study where 102 maternal deaths were compared with 338 control women who had given birth and survived, during 1 year (from July 1, 1989 to June 30, 1990). RESULT: Of all the socio-demographic variables studied, only a low family income (R = 2.6; 1.1-6.5) was found to be a risk factor for maternal death In the obstetrical part of the survey, neither parity nor the number or location of pre-natal consultations constituted risk factors. However, the presence during pregnancy or delivery of signs of infection (R = 3.7; 1.4-9.8), anemia (R = 2.1; 1.1-4.1), hypertension (R = 19.8; 5.8-67.8) and dystocia (R = 9.0; 3.7-21.5) were found to be the main predictive risk factors of maternal death. The maternal mortality risk was multiplied by 12 if the women had had a cesarean section, and by 4 in the case of complications in the post-partum period. CONCLUSION: To achieve substantial reductions in maternal mortality levels, work must be done on these specific risk factors, and future programs must urgently be concentrated on a higher standard of pre-natal monitoring, obstetrical emergency facilities and training of obstetrical staff.     

Precocious cervical ripening and preterm labor

A group of 8303 women was studied to determine the timing of cervical ripening. It was confirmed that these signs of cervical change can be observed several weeks before preterm births. The precocious signs of external ripening can be recognized during a vaginal examination and may be useful in predicting preterm labor.