Maternal residential exposure to hazardous wastes and risk of central nervous system and musculoskeletal birth defects.

The authors used a case-control design to evaluate the risk of central nervous system and musculoskeletal birth defects relative to exposure to solvents, metal, and pesticide contaminants from hazardous waste sites. Cases included 473 central-nervous-system-defect births and 3305 musculoskeletal-defect births to residents of 18 counties in New York State; controls comprised 12,436 randomly chosen normal births. For each address at birth, the authors assigned a probability of exposure to solvents, metals, and pesticides from hazardous waste sites in the study area (n = 643). They also rated residences by proximity to air releases from industrial facilities and by contamination of community water supplies. Compared with individuals for whom a low probability of exposure existed, mothers who resided in areas assigned a medium or high probability of exposure to hazardous waste contaminants did not show an increased risk of either type of birth defects. After adjusting for mother's race and age, prenatal care initiation, and population density, the resulting relative risks were as follows: central nervous system defects and exposure to solvents, 0.8 (95% confidence interval [CI] = .4, .6); central nervous system and metals, 1.0 (95% CI = 0.7, 1.7); musculoskeletal defects and solvents, 0.9 (95% CI = 0.5, 1.3); and musculoskeletal defects and pesticides, .8 (95% CI = .5, 1.3). With respect to central nervous system defects, there was an elevated risk associated with living near industrial facilities that emitted solvents (odds ratio = 1.3 [95% CI = 1.0, 1.7]) or metals (OR = 1.4, [95% CI = 1.0, 1.8]) into the air. The low proportion of individuals who had a medium or high probability of residential exposure to hazardous waste-site contaminants limited the investigation of particular pathways, disease subgroups, and/or geographic areas. Associations between central nervous system defects and industrial releases of solvents and metals need to be investigated further.

The effects of prenatal diagnosis, population ageing, and changing fertility rates on the live birth prevalence of Down syndrome in New York State, 1983-1992.

The incidence of Down syndrome (DS) at conception is highly dependent on the maternal age distribution and age-specific pregnancy rates. The live birth prevalence of DS reflects these factors and fetal deaths. This study examined DS live birth prevalence from 1983 to 1992 in New York State and analysed the effects of demographic changes and prenatal diagnosis use on the observed live birth prevalence. Expected DS live birth prevalence without prenatal diagnosis was calculated and compared with observed. Data were obtained from birth defects registries, vital records, and population data maintained by the New York State Department of Health. Over time, DS live birth prevalence was stable at about 10.4 per 10,000 live births. The percentage and number of women in the population above age 30 increased, as did birth rates among these women. Birth rates among younger women decreased. The proportion of DS babies born to women aged 35 and over increased from 27.1 to 34.1 per cent. Use of prenatal diagnosis by this age group ranged from 39.6 to 43.2 per cent, and increased steadily from 1.8 to 4.3 per cent among women under 35. Detection of DS fetuses increased from 82 in 1985 to 233 in 1992. Without prenatal diagnosis, DS live birth prevalence in 1992 would have reached 15.3 per 10,000 live births compared to the 10.2 observed. Prenatal diagnosis has prevented an increase in DS live birth prevalence but has not been sufficient to reduce live birth prevalence significantly.

Examining potential demographic risk factors for congenital cardiovascular malformations on a time-developmental model.

A descriptive epidemiological study of congenital cardiovascular malformations (CCM) was performed to evaluate the use of a model which groups selected cardiac lesions according to time of embryonic origin. Infants born from 1983-1986 to residents of New York State excluding New York City and reported to the Congenital Malformation Registry (CMR) were first grouped into those with (n = 299) and without (n = 4424) chromosomes anomalies. Infants were then categorised according to the time of gestation of their earliest occurring CCM into one of the seven cardiac groups of the model. The categories were analysed by infant race, gender, birthweight, gestation, maternal age and education, and the presence of additional malformations. The group without chromosomal anomalies showed an increasing proportion of non-whites, females, and preterm births and a decreasing proportion of infants with other malformations in the embryonically later categories. The group with chromosomal anomalies was too small to exhibit any significant demographic patterns. The findings suggest associations between characteristics of the infant and the embryonic period in which the CCM occurred, thus demonstrating the usefulness of a time-based model. Further research should concentrate on confirming these associations with more complete data and on investigating their biological bases.

Comparison of mother's occupation and industry from the birth certificate and a self-administered questionnaire.

Maternal occupations recorded on birth certificates are a potential data source for evaluation of reproductive hazards, but may not accurately identify jobs held during the sensitive first trimester. Mothers' occupation and industry during 1 month before and 3 months after conception were reported on 1,760 mailed questionnaires. These were compared to mothers' most recent occupation and industry recorded on birth certificates. Overall, 72% of occupations and 77% of industries reported on the birth certificate agreed with that recorded on the questionnaire. Agreement was similar for mothers of normal and malformed infants. Among those that did not agree, 344 (75%) disagreed on the mother's employment status during the periconceptional period, rather than the actual occupation. For surveillance and hypothesis-generation using birth certificate data, it is important to obtain a correct description of whether the mother held a job outside the home during sensitive periods of her pregnancy.

The use of epostane, a 3(beta)-hydroxysteroid dehydrogenase delta 4-5 isomerase enzyme inhibitor, in oil suspension as a mismating agent in the dog.

Administration of epostane as a single subcutaneous injection in sesame oil prevented or terminated pregnancy in bred beagle bitches (P = 0.002). Doses of 15 and 20 mg/kg prevented or terminated pregnancy in all of 14 bred beagle bitches studied but demonstrated a high rate of serious abscess formation at the injection site. A dose of 10 mg/kg was partially effective in 3 of 12 subjects whelping live pups, and a dose of 2.5 mg/kg was completely ineffective in 12 of 12 subjects whelping live pups. Plasma progesterone levels were lowered in dose-related fashion with respect to both depth of depression (P < 0.01) and length of time (P < 0.05). Subjects in which pregnancy was maintained had significant differences (P < 0.01) in progesterone patterns compared with nonpregnant subjects, as measured by area under the curve. No clinically significant differences were seen between treated and control females with respect to return to estrus, subsequent fertility, or in a battery of serum electrolytes, blood parameters and serum enzymes.