Drugs
Certain teratogenic drugs taken during
pregnancy can cause cleft palate. Thalidomide
and aminopterin cause oral clefts. Diazepam
and other benzodiazepiness can cause oral cleft malformation and steroids
have also been implicated. Both however are considered weak teratogens.
Other drugs which are linked to oral clefts but with occurrence of other
anomalies are amphetamines.
Other medications produce syndromic clefts
and include hydantoin and trimethadione, both anticonvulasants. Fetal alcohol
syndrome occasionally exhibits oral clefts.
Maternal Health
Infection during pregnancy can lead to
oral clefting. Cytomegalovirus and rubella are linked to oral clefts with
the occurrence of other anomalies as is maternal diabetes.
Studies in the US have indicated that
maternal first trimester smoking is associated with non-syndromic CL+/-P.
A Danish case-control study revealed that smoking was associated with a
moderately increased risk of CL+/-P. No association between smoking and
isolated CP was observed. (Christensen et al, 1999)
Maternal Age
There is some evidence that women aged
over 35 years have double the risk of having a child with CL+/-P and women
aged over 39 years have a tripled risk of having a child with CP compared
with women between 25 and 29 years.
Seasonality
The incidence of CL+/-P is highest among
children born in April and lowest in those born in September for. CP shows
no significant seasonal difference.
Other
Other environmental agents implicated
are: smoking, agricultural pesticides, retinoid medications, nitrates compounds
and organic solvents.
|
