 We study exposures that include anything the fetus is exposed to as well as anything that may alter conditions within the womb. Because most structural development of the fetus occurs during early pregnancy, our studies usually focus on this "periconceptional" period—the month before and first 3 months after conception. conception.
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Exposures—anything that comes
into
direct contact with the mother or fetus—studied because
they may have a cause-and-effect link with birth defects.
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Risk factors—such as social
or economic conditions—may provide clues that can
help pinpoint causes. For example, educated women may
be more likely to take multivitamins, lowering the risk
for certain birth defects. |
INTERPRETING RESULTS
The type of studies conducted by the California Birth Defects
Monitoring Program cannot provide a yes or no
answer about whether an exposure causes birth defects. Instead,
results are reported as changes in birth defects risk for
exposed pregnancies compared to unexposed.
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Higher risks—a doubling or more—suggest
an association between the exposure and the condition
in question. This may mean the studied exposure (or a
closely related exposure or factor) contributes to the
birth defect. |
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Decreased risks—one half or
less—indicate a protective effect. In other words,
the exposure appears to prevent the birth defect from
occurring. |
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No change in risk implies the exposure
and the defect are not closely related. |
Many other factors can influence results, however. For this
reason, additional studies are always needed to confirm and
clarify research findings.
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