New study on Reproductive History and Mortality Rates Using National Data from Denmark Just published in the Medical Science Monitor.

The objectives of the paper titled “Short and Long Term Mortality Rates Associated with First Pregnancy Outcome: Population Register Based Study for Denmark 1980-2004” were  to examine mortality rates associated with first pregnancy outcome  and to explore differences in mortality rates associated with early abortion and late abortions (after 12 weeks). The population was comprised of a total of 463,473 Danish women who had their first pregnancy between 1980 and 2004 (2,238 died across the study period).  

Compared to women who carried their first pregnancy to term, after adjusting for age and birth year, the cumulative risk of death for women who had a 1st trimester abortion was significantly higher in all periods examined from 180 days (84%) through 10 years (39%). The risk of death was likewise significantly higher for women who had abortions after 12 weeks from one year (331%) through 10 years (141%) when compared to women who delivered a first pregnancy. Finally, for women who miscarried, the risk was significantly higher for cumulative deaths through 4 years (75%) and at 10 years (48%).

Why is this study important?

1)      Record-based studies provide complete reproductive history data for all residents.  There are very few record-based studies of mortality risks associated with reproductive loss available in the published literature.  Without data-linkage to complete reproductive histories (as in this study), results are highly unreliable as prior research suggests as much as 73% of all pregnancy associated deaths are not evident from death certificates. 

2)      This study eliminates the potential confounding effect of unknown prior pregnancy history by examining mortality rates associated with first pregnancy outcome alone.

3)      No previous record-based studies have compared early induced abortions to later abortions. There is consensus that late-term abortions are associated with more physiological risks and higher rates of maternal mortality in the short term compared to early abortions. However, longer term mortality risks have not been previously examined with record-based data.

The paper is available for free download (personal use):  

A second paper titled “Reproductive History Patterns and Long-Term Mortality Rates: A Danish, Population-Based Record Linkage Study” is beyond the proofs stage and is expected to be published soon in the European Journal of Public Health (An Oxford Journal with an impact factor of 2.7).The general purpose of this study was to explore the effects of particular patterns of pregnancy resolution (induced abortion, miscarriage, and birth) on mortality rates over an extended time frame (25 years).  Specifically to examine:  1) detrimental and/or protective effects of distinct forms of pregnancy resolution over time; 2) detrimental and/or protective effects of distinct forms of pregnancy resolution occurring repeatedly over time; and 3) elevated or attenuated mortality risks when distinct pregnancy outcomes are combined with other forms of pregnancy resolution.