Women with high triglyceride levels in early pregnancy are more likely to experience preterm delivery than women with normal triglyceride levels, independent of early pregnancy BMI, according to an analysis of hospital medical records in China.
“Abnormal maternal lipids have been demonstrated to be associated with preeclampsia and large-for-gestational-age birth,” Xian-hua Lin, PhD, of the International Peace Maternity and Child Health Hospital in Shanghai, and colleagues wrote in the study background. “Therefore, it is reasonable to suspect that high levels of [triglycerides] in early pregnancy is also a risk factor for preterm delivery. Nevertheless, elucidating whether higher levels of [triglycerides], independent of BMI in early pregnancy, is associated with increased risk of preterm delivery remains a challenge.”
In a retrospective study, Lin and colleagues analyzed data from 49,612 women with a singleton pregnancy between 2013 and June 2016 who underwent fasting lipid screenings during early pregnancy (between 9 and 14 weeks’ gestation). Mean age of women was 30 years; 82% were nulliparous and 74.8% lived in Shanghai. Maternal triglyceride levels were stratified by low (below the 10th percentile), normal (between the 10th and 90th percentile) and high (above the 90th percentile). Researchers used logistic regression analysis to estimate ORs for preterm delivery in relation to maternal triglyceride levels in early pregnancy.
Within the cohort, 81.72% of women were normal weight, 7.61% were underweight and 10.67% had overweight or obesity. Among normal-weight women, 12.71% had low triglycerides, 79.59% had normal triglycerides and 7.71% had high triglycerides. Among women with overweight or obesity, 6.81% had low triglycerides, 78.02% had normal triglycerides and 15.17% had high triglycerides.
During the study period, researchers observed 2,494 (5.03%) preterm births.
To determine whether the increased risk for preterm delivery was related to high maternal triglyceride levels, researchers presented the distribution of maternal triglyceride levels according to preterm category. They found that the percentage of women with high triglyceride levels (> 2.04 mM) was higher among preterm births vs. term births (14.31% vs. 9.78%), and higher in early preterm delivery vs. late preterm delivery (18.05% vs. 13.52%). Additionally, researchers found that each per-unit increase in maternal triglycerides is associated with increased odds of total preterm delivery vs. women with normal triglyceride levels (adjusted OR = 1.35; 95% CI, 1.18-1.54), as well as increased odds for early preterm delivery (aOR = 1.72; 95% CI, 1.3-2.29) and late preterm delivery (aOR = 1.26; 95% CI, 1.09-1.46).
In sensitivity analyses accounting for different BMI subgroups in early pregnancy, researchers found that, after excluding pregnancy complications, high maternal triglyceride levels were associated with increased risks for total, preterm delivery, especially early preterm delivery, among women with normal BMI and overweight or obesity.
“Our results suggest that elevated maternal [triglyceride] levels in early pregnancy are related to the occurrence of preterm delivery, not only in women with [overweight or obesity], but in women with normal early pregnancy BMI,” the researchers wrote. “A lipid screening during early pregnancy should be considered in women in the normal BMI region, and not only in those who are overweight or obese.” – by Regina Schaffer
Disclosures: The authors report no relevant financial disclosures.