Cholesterol deficit but not accumulation of aberrant sterols is the major cause of the teratogenic activity in the Smith-Lemli-Opitz syndrome animal model. (41/804)

Low cholesterol and high 7-dehydrocholesterol (7DHC) levels are associated with a blockade of Delta7-reductase in the Smith-Lemli-Opitz syndrome (SLOS) and in the animals treated with the inhibitor AY9944. The impact of the cholesterol deficit and of the accumulation of 7DHC on the embryo were investigated in AY9944-treated pregnant rats receiving an enriched cholesterol or 7DHC diet. Sterol profiling was performed under the various nutritional conditions. AY9944 caused a severe decrease in the maternal and embryo cholesterol. The deficit in the embryo was sustained by the embryonic uptake of the inhibitor. A cholesterol-rich diet was efficient in restoring the maternal and embryonic cholesterol and phenotype but a 7DHC-rich diet did not modify the sterol status compared with dams treated with only AY9944. The offspring phenotype remained deleterious whether or not the dams received 7DHC-rich diet. Over 80% of the 7DHC was absorbed, as was cholesterol, which was not quantitatively influenced by AY9944. When cholesterol and 7DHC were simultaneously administered, a competition for intestinal absorption enhanced the lowering cholesterol effect of AY9944. Whether or not the dams received a 7DHC dietary supplement, the offspring's phenotype became normal when the diet was supplemented with cholesterol. Under conditions in which the ratio of cholesterol/7DHC is substantially varied, the normal development of embryos can be achieved as long as the cholesterol is sufficient. The phenotype is reversed in vivo by cholesterol which contrasts with the irreversible effects manifested in vitro by oxidized 7DHC by-products.  (+info)

Are SSRIs safe for pregnant and breastfeeding women? (42/804)

OBJECTIVE: To summarize the literature on use of the selective serotonin reuptake inhibitor (SSRI) class of antidepressants for pregnant and breastfeeding women. DATA SOURCES AND STUDY SELECTION: MEDLINE was searched over the past 9 years. An examination of the literature over the last 8 years was included in this review. Primary studies consist of prospective investigations and case studies. Evidence for the safety of SSRIs is limited, but some good studies describe the effects of untreated depression. SYNTHESIS: All studies report that infants are exposed to SSRIs; the drugs can be measured in their plasma and urine. Some evidence shows an increase in minor perinatal complications among infants exposed to SSRIs late in gestation or while nursing. No studies, however, have found an increase in major fetal malformations or pregnancy-related complications. The only investigation of long-term neurodevelopmental outcomes found no negative outcomes among infants exposed to SSRIs during pregnancy. Data are scarce, and readers are cautioned to take into consideration the limitations of the studies reviewed before making definite treatment decisions. CONCLUSIONS: Major fetal malformations and exposure to SSRIs during pregnancy and lactation do not appear to be associated. Some minor perinatal complications have been reported. Data on the long-term developmental outcomes of children exposed to SSRIs in utero and during breastfeeding are limited.  (+info)

Prenatal toxicity of inhaled polymeric methylenediphenyl diisocyanate (MDI) aerosols in pregnant wistar rats. (43/804)

Mated Wistar rats, 25/group, were exposed to polymeric methylenediphenyl diisocyanate (MDI) aerosol of respirable size for 6 h/day, on gestational days (gd) 6 through 15, at 0, 1, 4, and 12 mg/m3. Maternal clinical signs, body weights, and feed and water consumption were measured throughout gestation. At scheduled sacrifice on gd 20, maternal body, gravid uterine, liver, and paired lung weights were documented. Corpora lutea were counted, implantation sites were identified: resorptions, dead and live fetuses, and placentas were weighed. All live fetuses were counted, sexed, weighed, and examined for external alterations; approximately 50% of the live fetuses/litter were preserved in Bouin's fixative and examined for visceral alterations, and the remaining live fetuses/ litter were cleared and stained with alizarin red S and examined for ossified skeletal alterations. Maternal toxicity was observed at 12 mg/m3, including mortality (2 of 24 pregnant), damage to the respiratory tract, reduced body weights and weight gain, reduced liver and increased lung weights, and reduced gravid uterine weight (the last not statistically significantly different from the control value). Developmental toxicity was also observed at 12 mg/m3, including reduced placental and fetal body weights and an increased incidence of fetal skeletal variations and skeletal retardations. There was no evidence of maternal or developmental toxicity at 1 or 4 mg/m3. The no observed adverse effect concentration for maternal and developmental toxicity was therefore 4 mg/m3. There were no treatment-related teratogenic effects at any concentrations evaluated.  (+info)

Developing diagnostic criteria for the fetal anticonvulsant syndromes. (44/804)

The prevalence of congenital malformations and cognitive disorders in children whose mothers took antiepileptic drugs in pregnancy is increased, compared with the background rate. Not all such cases are due to teratogenic effects of the mother's treatment. Certain problems, including neonatal withdrawal symptoms, some malformations, characteristics facial features and a typical developmental and behavioural pattern may be indicators of a probable teratogenic event. We describe a set of diagnostic criteria which may assist in defining which children are likely to have a fetal anticonvulsant syndrome. This may help future research to identify risk factors which predispose to an adverse fetal outcome.  (+info)

Effects of massive doses of ergocalciferol plus cholesterol on pregnant rats and their offspring. (45/804)

Ergocalciferol (320,000 or 480,000 IU/kg) plus cholesterol (60 mg/kg) in olive oil solution was administered daily on 1, 2, or 4 consecutive days to pregnant rats from 9,10, 14, or 18 of gestation. The control animals received only olive oil. Disseminated lesions of metastic calcinosis were found in various tissues, in the coronary arteries and myocardium, in the media of the abnormal aorta, in the lung and pleura, in the gastoinstestinal tract, and in the kidney. This is in contrast to the atherosclerosis described in nonpregnant rats fed a similiar diet. A significant decline in maternal weight as well as a high rate of morbidity and mortality was observed. In mothers killed on day 22 of pregnancy, fetal and placental growths appeared significantly retarded suggesting a direct effect of the steroid or its more active metabolite, 1,25-dihydroxycholecalciferol, on the fetus or the trophoblastic tissue. Fetal bone lesionsassociated with a generalized retardation of ossification, placental edema, or calcification accompanied by a loss of the normal structure of the placenta and degenerative manifestation at this level were observed. Moreover, we noted a striking alteration of the fetal face in 33-39% of experimental fetuses, called by us carnival fetuses.  (+info)

The effects of mefloquine treatment in pregnancy. (46/804)

We investigated the relationship between mefloquine antimalarial treatment and the outcome of pregnancy in Karen women living in an area along the western border of Thailand where multidrug-resistant Plasmodium falciparum infections are common. Of 3,587 pregnancies investigated, 208 (5.8%) were exposed to mefloquine, 656 (18.3%) to quinine only, and 909 (25.3%) to other antimalarials, and 2,470 (68.9%) had no documented malaria. There were 61 stillbirths and 313 abortions. Women who received mefloquine treatment during but not before pregnancy had a significantly greater risk of stillbirth than did women treated with quinine alone (odds ratio [OR], 4.72; 95% confidence interval [CI], 1.7-12.7), women exposed to other treatments (OR, 5.10; 95% CI, 2-13.1), and women who had no malaria (OR, 3.50; 95% CI, 1.6-7.6) (P < .01). This association remained after adjustment for all identified confounding factors. Mefloquine was not associated with abortion, low birth weight, neurological retardation, or congenital malformations. Mefloquine treatment during pregnancy was associated with an increased risk of stillbirth.  (+info)

Gestational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin induces developmental defects in the rat vagina. (47/804)

At puberty, female rats exposed in utero to 2,3,7, 8-tetrachlorodibenzo-p-dioxin (TCDD) exhibit a persistent thread of mesenchymal tissue surrounded by keratinized epithelium that partially occludes the vaginal opening. Our objective was to determine the earliest time during fetal development that morphological signs of this vaginal canal malformation could be detected and to obtain greater insight into mechanisms involved in this effect. Pregnant rats were administered a single dose of vehicle (control) or TCDD (1.0 microg/kg, po) on gestation day (GD) 15 and were sacrificed on GD 18, 19, 20, and 21 for histological evaluation of female. Gestational exposure to TCDD affected vaginal morphogenesis as early as GD 19, 4 days after exposure of pregnant dams. In exposed fetuses, the thickness of mesenchymal tissue between the caudal Mullerian ducts was increased, which resulted in a failure of the Mullerian ducts to fuse, a process normally completed prior to parturition. In addition, TCDD exposure appeared to inhibit the regression of Wolffian ducts. Thus, TCDD interferes with vaginal development by impairing regression of the Wolffian ducts, by increasing the size of interductal mesenchyme, and by preventing fusion of the Mullerian ducts. Taken together, these effects appear to cause the persistent vaginal thread defect observed in rats following in utero and lactational TCDD exposure.  (+info)

Effects of acetaminophen on preimplantation embryo glutathione concentration and development in vivo and in vitro. (48/804)

This study investigated the effects of high doses of acetaminophen (APAP) on preimplantation embryos. Previous studies indicate that cleavage-stage embryos cannot synthesize reduced glutathione (GSH) de novo and may be sensitive to GSH-depleting toxicants. Alternatively, there may be maternal mechanisms that protect the embryos from the adverse effects of these toxicants. To address these possibilities, we cultured two-cell stage embryos in 0, 375, 750, or 1500 microM APAP and evaluated GSH concentration and development. APAP depressed embryo development to the morula and blastocyst stages in vitro, but a decrease in embryo GSH concentration was not detected. Furthermore, administration of 800 or 1430 mg/kg APAP to female mice 12 h prior to embryo collection on day 2 of gestation, or administration of 800 mg APAP/kg/day from day -8 to day 1 or day 3 of gestation, did not significantly affect ovary or embryo GSH concentration or embryo development. Liver GSH, however, was significantly decreased. Moreover, no adverse effects on embryo development to term were observed after treatment of female mice with 1430 mg APAP/kg/day from day -8 to day 3 of gestation. In summary, in vitro embryos were adversely affected, in terms of development, by APAP. In vivo, large doses of APAP depleted liver GSH but did not affect development of preimplantation embryos. In conclusion, preimplantation embryos appear to be protected from GSH-depleting toxicants such as APAP in vivo.  (+info)