Placental transmission

Human exposure to environmental contaminants has been investigated through the analysis of adipose tissue, breast milk, blood and the monitoring of faecal and urinary excretion levels. However, while levels of persistent contaminants in human milk, for example, are extensively monitored, very little is known about foetal exposure to xenobiotics because the concentrations of persistent compounds in blood and trans-placental transmission are less well studied. Also, more information is needed in general about the behaviour of endocrine disruptive compounds (and their metabolites) in vivo, for example the way they bind to blood plasma proteins. 

Rainaldi MP, Busi T, MeUoni C, Boschi S. Pharmacokinetics and placental transmission of fazadinium in elective caesarean sections. Acta Anaesthesiol Scand 1984 28(2) 222-5. 

MacAulay MA, Charles D, Burgess FM. Placental transmission of colistimethate. Clin Pharmacol Ther 1967 8(4) 578-86. 

Moya F, Kvisselgaard N. The placental transmission of succinylcholine. Anesthesiology 1961 22 1-6. 

Charles D, Obst D. Placental transmission of antibiotics. J Obstet Gynaecol Br Emp 1954 61(6) 750-7. 

The ethical use of placebos as the gold standard to establish efficacy and safety of new agents in clinical trials has recently come into question. In order to establish efficacy of antiretroviral therapy in decreasing placental transmission of HIV, the HIV-infected pregnant females in Thailand and Uganda received placebo therapy, despite the known efficacy of zidovudine in decreasing placental transfer. Concern regarding the use of placebos when effective antiretroviral therapies are... 

M14. Migeon, C. J., Bertrand, J., Wall, P. E., Stempfel, R. S., and Prystowsky, H., Metabolism and placental transmission of hydrocortisone during pregnancy near term. Am. J. Diseases Children 94, 502-504 (1957). 

Kivalo, I., and S. Saarikoski. 1977. Placental transmission of atropine at full-term pregnancy. Br. J. Anaes. 49(10) 1017-1021. Lange, A., and P. Toft. 1990. Poisoning with deadly nightshade (Atropa belladonna). Ugeskr. Laeger 152 1096. 

Snyder, F. F. and Speert, H., 1938, The placental transmission of neoarsphenamine in relation to the stage of pregnancy. Amer. J. Obstet. Gynecol., 36 579-586. 

Schlieben DJ, Korbet SM, Kimura RE, et al. Pulmonary-renal syndrome in a newborn with placental transmission of ANCAs. Am J Kidney Dis 2005 45(4) 758-761. 

In a short essay on childhood lead poisoning, Holt (1923, p. 232) wrote Only a few reports could be found in the literature in which the placental transmission of lead was beyond question. Ganyaire demonstrated the presence of lead in the placenta, liver and brain of an infant dying when 48 hours old. Legrand and Winter report a similar case. But such cases, according to Holt, were few and far between. 

Some P-gp inhibitors have been tested in clinical trials (e.g., GF120918, PSC 833) [88, 89], Shortly before birth, it is often desirable to expose the fetus to anti-HIV medications to prevent HIV transmission from the mother to the fetus during delivery. Preperfusion with P-gp inhibitors increased fetal penetration of the protease inhibitor saquinavir in in vitro placental models, and it has been hypothesized that P-gp may be responsible for limiting fetal exposure to HIV protease inhibitors, methadone, anthracyclines, and taxanes [90-93],... 

According to Coura and Dias (2009), the transmission mechanisms for Chagas infection can be divided into two groups (i) the principal mechanisms, by means of vectors (triatomines), blood transfusion, oral transmission, contaminated food and placental, or birth canal transmission and (ii) secondary mechanisms, by means of laboratory accidents, management of infected animals, organ transplants, sexual transmission, wounds, contact with sperm or menstrual fluid contaminated with T. cruzi and, hypothetically, deliberate criminal inoculation or contamination of food with the parasite (Coura and Dias, 2009). 

Ciguatera, caused by ingested ciguatoxins and maitotoxins, can reportedly be sexually transmitted. There are also reports of acute health effects of ciguatera toxin in the fetus and newborn child exposed through placental and breast milk transmission from the mother. 

Following intravenous injection in the mother, placental transfer of Metubine iodide occurs rapidly, and, after 6 minutes, the fetal plasma concentration is approximately one-tenth the maternal level. Metocurine does not inhibit vagal transmission or sympathetic ganglionic blockade, and therefore produces minimal hemodynamic changes in humans. The relatively stable heart rate and blood pressure associated with its use make it a useful agent for patients with coronary artery disease and hypertension. 

Spiramycin, which concentrates in placental tissue, is used to treat acute acquired toxoplasmosis in pregnancy to prevent transmission to the fetus. If fetal infection is detected, the combination of pyrimethamine and sulfadiazine is administered to the mother (only after the first 12-14 weeks of pregnancy) and to the newborn in the postnatal period. 

Poapolathep A, Sugita-Konishi Y, Phitsanu T, Doi K, Kumagai S (2004) Placental and milk transmission of trichothecene mycotoxins, nivalenol and fusarenon-X, in mice. Toxicon 44 111... 

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