Intended for healthcare professionals

Rapid response to:

Research

Migraines during pregnancy linked to stroke and vascular diseases: US population based case-control study

BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b664 (Published 11 March 2009) Cite this as: BMJ 2009;338:b664

Rapid Response:

Deeply flawed data

The large amount of data and the statistical analyses in this paper
look impressive and unfortunately may fool many readers into believing the
conclusions made by the authors. The authors do acknowledge that the
discharge diagnostic codes miss many patients who suffer from migraine
headaches. This diagnosis is not only missed upon discharge, but it is an
established fact that migraine is significantly underdiagnosed by the
majority of primary care doctors. Obstetricians are not likely to do a
better job in distinguishing sinus and tension-type headaches from
migraines, or diagnosing a migraine aura, particularly when managing a
pregnant woman in the hospital. It is true that migraines improve in
pregnancy, but considering that about 18% of women suffer from migraine
headaches, it is hard to believe that only one in 100 of these women will
continue having migraines during pregnancy. Obviously, when a
complication, such as stroke occurs the diagnosis of migraine is much more
likely to be recorded than when no complications occur.
The authors provide many disclaimers and state that "On the basis of the
select group of pregnant women with migraines coded during the hospital
admission, this may not represent the population of women with migraine as
a whole". Nevertheless, they go on to present and analyze this highly
inaccurate data and even draw conclusions. It is very unfortunate that
the publicity associated with this paper (I first saw it reported on
Yahoo.com) will cause unnecessary anxiety to millions of pregnant women.

Competing interests:
None declared

Competing interests: No competing interests

18 March 2009
Alexander Mauskop
Director
New York Headache Center, 10021