Neonatal teratogenicity

Q7 has an increased risk of neonatal haemolysis during the third trimester Q8 may cause vestibular or auditory nerve damage Q9 should be stopped at least 2 days before delivery Q10 consists of a folate antagonist that poses a teratogenic risk... 

Co-trimoxazole is a folate antagonist and should be avoided in the first and the third trimesters of pregnancy. In the third trimester there is an increased risk of neonatal haemolysis and methaemoglobinaemia, whereas in the first trimester there is a teratogenic risk caused by the trimethoprim (folate antagonist) component. 

A single dose of nevirapine (200 mg) is effective in the prevention of transmission of HIV from mother to newborn when administered to women at the onset of labor and followed by a 2-mg/kg oral dose to the neonate within 3 days after delivery. There is no evidence of human teratogenicity. However, resistance has been documented after this single dose. 

We are also well aware of the addiction of newborns to heroin if their mothers were took the drug during pregnancy. So-called "cocaine babies" are restlessness, nervous and irritable. Fetal nicotine effects can be seen in low birth weight neonates. We are still not sure about the teratogenicity of heroin and cocaine. The latter can cause abortion and so could very well be teratogenic. 

Teratogenesis involves interference with the normal development of either the embryo or fetus in utero, giving rise to abnormalities in the neonate. This interference may take many forms, and there is therefore no general mechanism underlying this type of response. Many of the toxic effects described elsewhere in this book may be teratogenic in the appropriate circumstances. 

A foreign compound, which may act in this way is the herbicide nitrofen (2,4-dichloro-4 -nitro diphenyl ether), which causes a variety of malformations lethal to the neonate. There is no growth retardation or embryolethality at doses, which are teratogenic, however (Fig. 6.27), and therefore this exhibits the first type of dose-response relationship (see above). The... 

Differential reinforcement of low rate (DRL) responding in a Skinnerbox has been used in different studies as a test for teratogenic effects on behavior. Prenatal treatment of rats vith haloperidol resulted in normal baseline level of lever pressing in a Skinnerbox for a water reward. However, like after postnatal haloperidol treatment, an increase in the number of sessions to criterion for DRL responding was observed in these animals (ref. 41). Simple acquisition of the bar-press response for water reward was shown to be affected by prenatal treatment vith chlorpromazine, but not by prenatal amphetamine treatment (ref. 137). The response rate, but not response accuracy, in a left-right alternation learning test in a Skinnerbox was increased after neonatal clomipramine treatment ref. 34). 

SAFETY PROFILE Poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes, An experimental teratogen. Human reproductive effects by ingestion and possibly other routes fetal death, unspecified developmental abnormalities, stillbirth, and unspecified neonatal effects. An anticoagulant. 

SAFETY PROFILE Poison by ingestion, intravenous, intraperitoneal, and subcutaneous routes. Human reproductive effects. Human teratogenic effects by ingestion developmental abnormalities of the respirator and gastrointestinal systems, and effects on newborn including neonatal measures or effects. When heated to decomposition it emits vet toxic fumes of NOx and HCl. 

---