The need for better maternal mental health planning

In the cohort study of more than 2 million women in Sweden, preeclampsia, other hypertensive pregnancy disorders, and additional maternal factors were considered.

The risk of high blood pressure decreased but remained significantly increased 40 years after delivery, but was largely independent of other maternal and common familial factors.

“These results suggest that premature births are a lifelong risk factor for high blood pressure in women,” the authors write

The national cohort study looked at all 2,195,989 women in Sweden with a single birth between January 1973 and December 2015.

New chronic hypertension was identified on the basis of administrative data from general practitioner, outpatient and inpatient diagnoses.

In 46.1 million person-years of follow-up, 16.0% of women with a mean age of 55.4 years were diagnosed with high blood pressure.

Within 10 years of delivery, the adjusted hazard ratio (aHR) for hypertension associated with premature birth (gestational age <37 weeks) was 1.67; 95% confidence interval (CI): 1.61 to 1.74.

Compared to full-time birth (39 to 41 weeks of gestation), the aHR was 2.23 for extremely premature birth (22 to 27 weeks of gestation); 1.85 for moderately premature babies (28 to 33 weeks gestation); 1.55 for late premature babies (34 to 36 weeks gestation); and 1.26 for the early period (37 to 38 weeks of gestation).

These risks decreased, but remained significantly increased 10 to 19 years after delivery: aHR of 1.40 for premature birth vs. full-time birth.

In addition, the aHR was 1.20 for 20 to 29 years and 1.12 for 30 to 43 years after delivery when comparing a premature birth with a full-time birth.

“These results were not explained by common determinants of premature birth and high blood pressure within the family,” the authors write.

Women with recurrent premature births were at another increased risk. For example, the aHR for each additional premature birth after a follow-up period of less than 10 years was 1.51; which decreased to 1.28 after 10 to 19 years of follow-up, to 1.12 after 20 to 29 years of follow-up, and to 1.10 after 30 to 43 years of follow-up (P <0.001 for each).

Both spontaneous and medically indicated delivery of premature or premature births were associated with an increased risk of chronic hypertension compared to full-time delivery: aHR of 1.25 (P <0.001) and 1.46 P <0.001, respectively.

A medically indicated premature birth specifically associated with preeclampsia or other hypertensive pregnancy disorders had an aHR of 1.67; 95% CI: 1.62 to 1.73 (P <0.001).

Likewise, chronic hypertension from premature birth had an aHR of 1.41 in other indications, primarily diabetes; 95% CI: 1.35 to 1.47; (P <.001).

The results of the study are consistent with the previously reported relationships between premature birth and long-term risks for stroke, ischemic heart disease, and all-cause mortality and cardiovascular disease, according to the authors.

“Preterm birth should now be recognized throughout life as a risk factor for high blood pressure,” they wrote.

The authors also found that women with a history of premature birth need early preventive assessment and long-term risk reduction and monitoring for hypertension.



  1. Crump C, Sundquist J, Sundquist K. Premature birth and long-term risk of hypertension in women. JAMA Cardiol. Published online 13 October 2021. doi: 10.1001 / jamacardio.2021.4127

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