Complicated pregnancy increased risk of premature death after 46 years

In a new large cohort study, researchers analyzed data from more than two million Swedish women. They confirmed that women who experience adverse pregnancy outcomes are in particular need of early prevention and long-term medical follow-up to detect chronic diseases in time to avoid premature death.

A team of epidemiologists and clinicians from Texas Medical Center in Houston, USA, and Lund University in Malmö, Sweden, calculated the long-term risks of all-cause mortality in women facing a complicated pregnancy. The study results are published in the journal JAMA Network Open.

Complications during the gestational period, when a woman is carrying a baby, involve physical and mental conditions that affect the health of the expectant mother and her fetus. And they can occur both before, during, and after pregnancy. The risk of pathological conditions can reduce healthy lifestyle, competent prenatal care and timely medical care. On the contrary, the factors that lead to the emergence of complications include the age of the woman in labor (up to 17 and after 38 years), her state of health before conception, the presence of bad habits, etc.

There are five main unfavorable outcomes of pregnancy: premature birth; small for their gestational age babies (we are talking about limited intrauterine development); pre-eclampsia (a complication associated with a sharp increase in blood pressure and protein levels in the woman's urine); other hypertensive disorders; gestational diabetes mellitus (hyperglycemia detected against the background of pregnancy). It is these conditions and how they may influence premature death that the authors of the new research paper looked at.

They used the Swedish Medical Birth Register (Swedish Medical Birth Register), which contains information on almost all births in this Northern European country since the 1970s. In total, the medics looked at data from 2,195,667 women who gave birth between 1973 and 2015 and for whom the necessary information was available: the length of pregnancy, the weight of the baby, unfavorable outcomes, and so on. In addition, the researchers took into account and made adjustments for other factors, excluding genetics and environmental influences, and applied Cox regression to calculate risk ratios.

Over 56 million person-years of follow-up, during which the average age of the participants was 52 years, 88,055 women (4%) died. At the time of passing away, they were on average 59 years old (50 to 67). All five adverse pregnancy outcomes were independently correlated with an increased likelihood of premature death, medics said.

"Throughout the entire follow-up period (up to 46 years postpartum), the adjusted risk ratios for all-cause mortality associated with specific adverse pregnancy outcomes were as follows: gestational diabetes, 1.52; preterm birth, 1.41; infant small for his or her gestational age, 1.30; preeclampsia, 1.13; and other hypertensive disorders, 1.27. All risk ratios remained significantly elevated even 30 to 46 years after delivery. These effects were attenuated only partially (0-45%) when we accounted for common familial factors in the pooled analysis. Women who experienced multiple adverse pregnancy outcomes had an even greater increase in risk. We also identified several leading causes of death, including cardiovascular and respiratory disease and diabetes," the authors of the paper said.

Now, according to medics, it is necessary to conduct additional research to double-check the conclusions on the example of residents of other countries and diverse populations. But scientists are already convinced: the period of waiting for a child can not be considered "in a vacuum", it must be integrated into the health history.

"Pregnant women need to be closely monitored by their primary care physician, which should begin shortly after delivery. This way, risks can be reduced and long-term health can be protected," summarized Casey Crump, who led the research team.