Hyperemesis gravidarum and long-term mortality: a population-based cohort study

Area of Science:

• Obstetrics and Gynecology
• Epidemiology
• Public Health

Background:

• Hyperemesis gravidarum (HG) is a severe form of nausea and vomiting during pregnancy.
• Long-term maternal mortality risks associated with HG require further investigation.

Purpose of the Study:

• To determine if exposure to hyperemesis gravidarum (HG) is linked to an elevated risk of long-term maternal mortality.

Main Methods:

• A population-based cohort study utilized data from Norway's Medical Birth Registry (1967-2002) linked to the Cause of Death Registry.
• Women with singleton births were followed until 2009 or death, with Cox proportional hazard regression models used to estimate mortality risks.
• Primary outcome was all-cause mortality; secondary outcomes included cause-specific mortality (cardiovascular, cancer, external causes, mental/behavioral disorders).

Main Results:

• The study included 999,161 women, with 1.3% experiencing HG. Over a median follow-up of 26 years, 4.4% of women died.
• Initially, HG exposure showed a lower crude risk of all-cause mortality, but this was not significant after adjusting for confounders (adjusted HR 0.92; 95% CI 0.84-1.01).
• Women with HG had a similar risk of cardiovascular death but a significantly lower risk of cancer mortality compared to unexposed women.

Conclusions:

• Hyperemesis gravidarum is not associated with an increased risk of long-term all-cause maternal mortality.
• While cardiovascular mortality risk was not elevated, a reduced risk of cancer mortality was observed in women with a history of HG.