"There are now much evidence that a 'low birth weight' can have long term impact on health and disease, such as high blood pressure, cardiovascular diseases, type 2 diabetes, and other chronic conditions. Our study clearly adds the 'preterm birth factor' to the 'low birth weight' factor," Dr Anne Monique Nuyt from University of Montreal, Montreal, Quebec, Canada said.
"Overall," she added, "circumstances of one's birth (gestational age, birth weight and probably soon specific foetal-neonatal health conditions) should more and more be part of the medical history we routinely ask for."
Dr Nuyt and colleagues used a record linkage of administrative birth-related data files in Quebec to examine the relation between preterm birth and later pregnancy complications (gestational diabetes, gestational hypertension, preeclampsia, and eclampsia), as well as chronic hypertension, kidney diseases, and type 1 and type 2 diabetes.
How the study was done
The study - reported online in the Canadian Medical Association Journal (CMAJ) - analysed 7 405 preterm women and 16 714 women born at term.
Eighty-eight preterm women had at least one pregnancy complication, compared with 1 535 women born at term (17.0% vs 9.6%). The percentage of women with at least one pregnancy complication increased significantly with decreasing gestational age at their own birth (p<0.001).
The percentages of women with gestational diabetes, gestational hypertension, and preeclampsia or eclampsia were consistently higher among preterm women, but the difference was significant only for gestational diabetes (p<0.001).
Compared with women born at term, women born preterm were 70% more likely to develop chronic hypertension and 75% more likely to develop type 2 diabetes. The 2 groups did not differ significantly in their risk of chronic kidney disease or type 1 diabetes.
What was included in the study
"An epidemiological study such as ours demonstrates correlation (between premature birth, as well as small for gestational age, and preeclampsia, gestational hypertension, and gestational diabetes) but does not demonstrate causality," Dr Nuyt cautioned. "Our study needs to be repeated and validated by other researchers in other populations."
"Nevertheless," she said, "a study like ours is important to indicate new pathophysiological mechanisms for these pregnancy complications. It might allow this at-risk population (preterm born women) to be identified and benefit from future new strategies of prevention and therapies for these pregnancy complications."
"As well," she continued, "our study might suggest that prematurity leads to changes in cardiovascular and metabolic physiology rendering a woman at risk of developing complications during a pregnancy, and therefore suggest pathways we need to study."
"The pregnancy complications we studied are already systematically screened for in all pregnancy follow-up," Dr Nuyt added. "Nevertheless, we bring a 'new' risk factor, and knowing a woman might be at increased risk for pregnancy complications might guide tighter follow-up."
(Reuters Health, Will Boggs, September 2012)