Re: Other Important Considerations in Interpregnancy Interval
We are gratified by the interest in our study expressed by Linnane et
It is worthwhile to mention that all their concerns regarding the
methodology of our research were discussed by us in the paper.
since less than 2% of all Latin American births are represented by our
database, our results may not be generalised to the whole of the Latin
American population and to the developed world. However, when we
replicated the entire analyses by country, the effects of interpregnancy
interval on maternal morbidity were essentially unchanged. The few
maternal deaths did not allow us to analyse by country.
Secondly, of the
520 689 parous women recorded in our database, we excluded 63 800 (12.3%)
for whom information on interpregnancy interval or adverse maternal
outcomes was missing or implausible. As stated in our paper, the accuracy
of specific diagnoses registered in our database has not been extensively
checked and only local medical record verifications were done. Therefore,
our data are limited to a certain extent. However, overall rates of
adverse maternal outcomes in this data set were similar to those reported
in other studies, which would add support to the accuracy of diagnoses.
Thirdly, in the present study we were unable to evaluate socio-economic
factors other than maternal education and cohabitation of parents because
these data were not available from the database. We agree that future
studies could consider other socio-economic factors such as family income
and race. However, it is not easy to include a variable relating to
ethnic origin due to the great mixture of races in Latin America and the
Caribbean. With regard to religious persuasion, it is doubtful that this
variable is related to socio-economic condition in Latin America and the
Fourthly, we agree that the relation between long
interpregnancy interval and preeclampsia-eclampsia could be confounded by
change of partner. However, we have controlled for the influence of other
possible confounding factors of this relation, such as older age, history
of chronic hypertension, and elevated body mass index before pregnancy,
and lack of previous miscarriage and smoking. The variable change in
paternity was not available to us for analysis.
Thanks again for their interest in our work.
Agustín Conde-Agudelo and José M. Belizán
Competing interests: No competing interests