Chemical and physical exposures of parents: effects on human reproduction and offspring

Trends and Determinants of Small Birth Weight in Ethiopia: Further Analysis of Ethiopian Demographic and Health Surveys

Background

Globally, Low Birth Weight (LBW) prevalence is estimated to be 14.6%. It is a major cause of neonatal mortality in developing countries including Ethiopia. Despite extensive institution-based studies in Ethiopia, there is no comprehensive study using countrywide data. Thus, this study aimed to investigate trends and determinants of Small Birth Weight (SBW) among under-five children in Ethiopia.

Methods

Under-five children data from 2000, 2005, 2011, and 2016 Ethiopian Demographic and Health Surveys (EDHS) were used. However, only 2787 children were weighed at birth and used for analysis in this study. Descriptive statistics and the logistic regression model were used to determine trends and determinants of SBW respectively.

Results

The prevalence of SBW increased from 7.0% (95% CI; 3.1–10.0) to 13.2% (95% CI; 11.4–15.0) between 2000 and 2016. The odds of SBW increased by being a female child (AOR 1.50; 95% CI [1.07–2.09]), mother's with partner occupation of agriculture (AOR 1.54; 95% CI [1.05–2.26]) and mothers who did not know their partner's occupation (AOR 7.35; 95% CI [1.96–27.48]). However, infants born to mothers with primary (AOR 0.43; 95% CI [0.29–0.65]), secondary (AOR 0.30; 95% CI [0.16–0.55]) and higher (AOR 0.55; 95% CI [0.31–0.97]) educational status versus no education and grandmultiparous mothers (OR 0.39; 95% CI [0.19–0.78]) versus primiparous had lower odds of SBW.

Conclusion

In Ethiopia, during the survey period, there was an increment in prevalence of SBW, and maternal related factors were significant determinants. Therefore, empowering mothers through education and improving the socioeconomic status of the household can be one strategy to reduce SBW.

Paternal factors and low birthweight, preterm, and small for gestational age births: a systematic review

A systematic review of the risks of a low birthweight (LBW), preterm, and small-for-gestational-age births in relation to paternal factors was performed. Medline, Embase, Cumulative Index of Nursing and Allied Health Literature, and bibliographies of identified articles were searched for English-language studies. Study qualities were assessed according to a predefined checklist. Thirty-six studies of low-to-moderate risk of bias were reviewed for various paternal factors: age, height, weight, birthweight, occupation, education, and alcohol use. Extreme paternal age was associated with higher risk for LBW. Among infants who were born to tall fathers, birthweight was approximately 125-150 g higher compared with infants who were born to short fathers. Paternal LBW was associated with lower birthweight of the offspring. In conclusion, paternal characteristics including age, height, and birthweight are associated with LBW. Paternal occupational exposure and low levels of education may be associated with LBW; however, further studies are needed.

Potential workplace hazards to reproductive health. Information for primary prevention

Each year in the United States, more than two million employed women become pregnant. Reproductive hazards in the workplace threaten a large number of these pregnancies. Information is presented on the potential hazards to reproductive health that exist in the workplace.

A genotoxic study of metal workers exposed to trichloroethylene. Sperm parameters and chromosome aberrations in lymphocytes

Metal workers exposed to trichloroethylene for the degreasing of metals were studied to evaluate the genotoxicity of this exposure. For 15 workers presently exposed to high doses of trichloroethylene there was no difference from unexposed persons with respect to sperm count and morphology, and a small increase of two fluorescent bodies (YFF%) in spermatozoa. In contrast, there was a highly significant increase in frequency of structural aberrations (breaks, gaps, translocation, deletions, inversions) and hyperdiploid cells in cultured lymphocytes from trichloroethylene degreasers. As control groups, physicians from chemically non-exposed surroundings and a concurrently sampled reference from cytogenetic investigations were used. This study indicates positive correlations between exposure to trichloroethylene and somatic chromosome aberrations, whereas no effect on male germ cells could be demonstrated.

Spermicide use and pregnancy outcome

The relation between periconceptional vaginal spermicide use and sex ratio at birth, birthweight, and the frequency of congenital anomalies was examined in a cohort of 2,712 New York City obstetric patients, 149 of whom (5.5 per cent) became pregnant while using spermicides or had used spermicides before and after conception. Periconceptional spermicide use was not associated with any important variation in the expected sex ratio at birth, nor with major or minor congenital anomalies. Exposure to spermicides in the periconceptional period, defined dichotomously as present or absent, was not associated with decreased birthweight in male or female infants. There was a slight decrease in birthweight among female infants with increasing duration of postconceptional spermicide use; an estimated 7.4 grams decrease with each day of use. The size of the effect and its selectivity by sex suggest a chance finding.

Nicotine and cotinine effects on development of two-cell mouse embryos in vitro

The independent and interactive effects of nicotine and cotinine on the development of cultured two-cell embryos were investigated. Cultures were maintained for 120 h and developmental stages of embryos were scored after 72 h and at the termination of culture. Concentrations of nicotine at or below 0.5 mM, and concentrations of cotinine at or below 0.008 mM, did not adversely affect development. In addition, neither nicotine nor cotinine produced synergistic effects at higher concentrations at which both independently impaired development. These data show, therefore, that nicotine and its major metabolite, cotinine, significantly interfere with preimplantation development of mouse embryos only at concentrations far in excess of those anticipated to be present in the blood of an "average" smoker. Thus, we conclude that the well documented adverse effects of smoking during pregnancy are unlikely to be attributable to a direct effect of nicotine or cotinine on the preimplantation embryo.

Spontaneous abortions among women working in the pharmaceutical industry

A register based study was conducted on the pregnancy outcome of female workers in eight Finnish pharmaceutical factories to determine whether they had a higher risk of spontaneous abortion than the general population or matched controls. Information about all female workers who had been employed in the factories during the years 1973 or 1975 (four factories) to 1980 was obtained from the employers. The workers' pregnancy data were collected from the nation wide hospital discharge register and polyclinic data of hospitals from 1973 to 1981. The total number of 1795 pregnancies included 1179 deliveries, 142 spontaneous abortions, and 474 induced abortions. The spontaneous abortion rate (the number of spontaneous abortions X 100, divided by the number of spontaneous abortions plus the number of births) during employment was 10.9% and before/after employment 10.6%. The rate for all the women in the corresponding central hospital districts was 11.3% [corrected] during the study period. A case-control study was also carried out in which the cases were 44 women who had a spontaneous abortion during employment in the pharmaceutical factory. Three age matched female pharmaceutical factory workers who had given birth to a child were chosen as controls for every case. The information about occupational exposures was collected from questionnaires completed by the occupational physician or nurse at the factory. The response rate was 93%. Exposure to chemicals was more common among the cases than among the controls. For methylene chloride, a solvent commonly used in the pharmaceutical industry, the increase in odds ratio of borderline significance (odds ratio 2.3, p = 0.06). In a logistic regression model (which included oestrogen exposure, solvent exposure frequency of the usage, and heavy lifting) the odds ratio was increased for oestrogens (odds ratio 4.2, p = 0.05) and for continuous heavy lifting (odds ratio 5.7, p = 0.02). The odds ratio for spontaneous abortions was greater among those exposed to four or more solvents (odds ratio 3.5, p=0.05) than among those exposed to one to three solvents (odds ration 0.8, p=0.74).

Transmission of occupational disease to family contacts

As recognition of occupational illness increases, the scope of health problems related to work widens. An important area of concern is the worker's family, which has been shown to be at increased risk of disease attributable to the hazards previously thought to be relevant only to the worker. Such "para-occupational" disease occurs particularly in spouses and children through transport by the worker of hazardous materials from the worksite into the home. The most common vehicle has been contaminated work clothing brought home for cleaning. Outbreaks of severe illness caused by lead, beryllium, asbestos, and other compounds have been traced to home contamination by industrial dust. In this review, we describe reports of "para-occupational" illness that demonstrate the importance of early recognition by medical professionals of this cause of illness and of strict control of the dissemination of hazardous materials outside the workplace.

Fetal loss and work in a waste water treatment plant

We investigated pregnancy outcomes in 101 wives of workers employed in a waste water treatment plant (WWTP), and verified fetal losses by hospital records. Paternal work histories were compiled and each of the 210 pregnancies was assigned a paternal exposure category. The relative risk of fetal loss was increased when paternal exposure to the WWTP occurred around the time of conception.

Diet policies of PKU clinics in the United States

About two-thirds of 90 clinics treating phenylketonuria (PKU) now recommend indefinite continuation of a low phenylalanine diet as compared to 1978 when fewer than one-fourth had this policy. The percentage of children maintained on diet has increased markedly for six to eight year-olds. Greater conservatism in clinic diet recommendations likely reflects reports of adverse consequences following diet discontinuation and negative individual clinic experiences.

Maternal exposure to environmental chemicals and the aetiology of teratogenesis

Data on exposure of 10,879 pregnant women to various household and agricultural chemicals were obtained by interview; 6,267 of these women were seen both antenatally and postnatally, enabling a genuine prospective study of the association between chemical exposure and congenital abnormalities in the infant. The remaining 4,612 women were privately booked and were first seen postnatally. Statistical analysis of the 2 groups revealed a strong association of malformations with chemical exposure in both groups, even after other known risk factors were taken into account.

Spontaneous abortions in an industrialized community in Finland

Spontaneous abortions were analyzed in an industrialized Finnish community according to the occupation and workplace of both the women and their husbands. Information about spontaneous abortions and births was obtained from the hospital discharge register, and data about the women and their families were collected from census files. When compared with all women employed outside the home, women who worked at a textile plant (factory A, a clothing manufacturer) had an increased rate of spontaneous abortion (16.7 per cent vs 11.4 per cent). The rate of spontaneous abortions among women employed at factory A differed according to the husband's workplace. The odds ratio for women employed at factor A whose husbands worked at a large metallurgical factory was 3.8, whereas the odds ratio for women whose husbands worked elsewhere was 1.2. Between 1973 and 1976, the rate of spontaneous abortions in this town was consistently lower for the summer period. (May-August) than for the other periods of the year.

Community study of spontaneous abortions: relation to occupation and air pollution by sulfur dioxide, hydrogen sulfide, and carbon disulfide

Spontaneous abortions were analyzed in an industrial community in Finland in relation to the occupation of women and their husbands, and to the level of air pollution in the family's residential area. Information on abortions and births was obtained from the hospital discharge register; information on the women and their families was obtained from the files of the population and housing census. Women who were employed in rayon textile jobs and paper products jobs had an increased rate (P less than 0.10) of spontaneous abortions; the wives of men employed in transport and communication, in rayon textile jobs, and in chemical process jobs also had an increased rate of spontaneous abortions. In material stratified for age, parity, and socioeconomic class no evidence was found that the level of sulfur dioxide or carbon disulfide could be associated with a risk of spontaneous abortions. More spontaneous abortions were noted in all socioeconomic classes in areas where the mean annual level of hydrogen sulfide exceeded 4 micrograms m-3. However, the difference (total rates 7.6 and 9.3, respectively) was not significant statistically.

Teratogenesis: a review of the basic principles with a discussion of selected agents: Part III

Before a woman realizes she is pregnant, a large amount of development has occurred in the embryo. If she consumes a drug during her pregnancy, the possibility exists that the drug could harm the fetus. The most important variable is timing, with the fetus showing the highest degree of susceptibility during the first trimester of gestation.

This article presents data on the relative time a pregnancy test becomes positive as compared to fetal development; passage of drugs across the placenta; placental and fetal drug metabolism; and the availability of teratogenic information to health professionals. Teratogenic effects of specific substances or classes of substances are discussed, including alcohol, analgesics, antibiotics, anticoagulants, anticonvulsants, antithyroid/thyroid drugs, various environmental agents, and paternal drug exposure.

Analysis of human spermatozoa for Y chromosomal nondisjunction

The YFF sperm assay, which is a quantification of the incidence of sperm with two fluorescent bodies (YFF = two fluorescent bodies), was performed to measure Y chromosomal nondisjunction. Three categories of human subjects were analyzed: 1) nonexposed, 2) exposed to antineoplastic agents - ie, chemo- and radiation therapy, and 3) dibromochloropropane (DBCP)-exposed. The nonexposed individuals demonstrated a relatively constant mean YFF value of 1.3%, which was consistent with historical controls in this laboratory and with the results of other investigators. Further, a one-way analysis of variance among the means of the control samples revealed no statistical differences either between these men or within each man's samples. The individuals exposed to antineoplastic agents showed a three- to four-fold increase in the incidence of YFF sperm three to six weeks after the initiation of exposure to Adriamycin and X-irradiation. The maximum percentages of YFF per 1,000 sperm for each individual in this exposed group was analyzed by Wilcoxon's distribution free rank sum test using a one-sided alternative. The exposed individuals' maximum YFF percentages were statistically significantly increased when compared to the maximum YFF values of the nonexposed controls. The individuals exposed to the nematocide DBCP also exhibited a statistically significant increase in the number of sperm containing two Y chromosomes as determined by chi-square analysis with one degree of freedom (P less than 0.01). Data presented herein show statistically significant increases in the incidence of double Y chromosomes as measured by the presence of YFF sperm following exposure to Adriamycin, X-irradiation, and DBCP. It is suggested that men who have a history of antineoplastic therapy could be evaluated for evidence of Y-Y nondisjunction with this method. In the event of an increased YFF sperm level, genetic counseling and amniocentesis should be made available to the spouse where pregnancy has occurred. Further, because this procedure measures gametic mutation, is relatively simple, and is noninvasive, it should be considered for inclusion as part of a battery of medical tests for monitoring industrial populations.