Pregnancy Complications More Likely in Women Born Prematurely

Women who are born prematurely have a significantly increased risk of having pregnancy complications later in life, according to the results a population-based cohort study conducted in the province of Quebec, Canada.1 In this province, weight and gestational age have been recorded in a registry for all births since 1976 and data on hospital-based diagnoses have been collected since 1987.¹

The evolution of neonatal medicine over the past 3 decades has substantially increased the percentage of preterm babies who survive to adulthood. Previous studies have shown that preterm babies are at greater risk for both metabolic syndromes and cardiovascular dysfunction.^2-4 Therefore, there is “a growing population at risk for conditions related to the metabolic syndrome as they get older,” write the study authors.¹

To determine whether prematurity is associated with pregnancy complications later in life-gestational diabetes, gestational hypertension, preeclampsia, and eclampsia-researchers identified 7405 women born before 37 weeks and a matched cohort of 16,714 women born at term between 1976 and 1995 who had a live birth or stillbirth between 1987 and 2008. Of the women born preterm, 554 were born before 32 weeks, and 6851 were born between 32 and 36 weeks. Data on diagnoses such as chronic hypertension, kidney diseases, and type 1 diabetes and type 2 diabetes were also collected.

At least 1 pregnancy complication was recorded during the study period for 19.9% of women born before 32 weeks, 13.2% of women born between 32 and 36 weeks, and 11.7% of women born at term. In addition, women born small for gestational age regardless of whether they were born at term or preterm had significantly increased odds of having at least 1 pregnancy complication compared with women born at term who were the appropriate weight for their gestational age. Women born preterm also were significantly more likely than women born at term to have a diagnosis of chronic hypertension or type 2 diabetes. The study authors also found that chronic hypertension, type 1 or type 2 diabetes, and small for gestational age were all significant risk factors for pregnancy complications.

The authors suggest that these data, taken together, support the postulate that preterm birth itself has an effect on the development of conditions related to metabolic syndrome in adults. For clinical practice, the study authors suggest that the status of preterm birth be established and considered in the prenatal care of pregnant patients.

Pertinent Points:
- Women born before 32 weeks of gestation were 1.95 times more likely and women born between 32 and 36 weeks were 1.14 times more likely than women born at term to have pregnancy complications.
- Women with the lowest gestational age at birth had the greatest risk for pregnancy complications later in life.

References:

1. Boivin A, Zhong-Cheng L, Audibert F, et al. Pregnancy complications among women born preterm. CMAJ. 2012;184:1777-1784.
2. Hoffman PL, Regan F, Jackson WE, et al. Premature birth and later insulin resistance. N Engl J Med. 2004;351:2179-2186.
3. Hovi P, Andersson S, Eriksson JF, et al. Glucose regulation in young adults with very low birth weight. N Engl J Med. 2007;356:2053-2063.
4. Irving RJ, Belton NR, Elton RA, et al. Adult cardiovascular risk factors in premature babies. Lancet. 2000;355:2135-2136.