Trans fatty acid intake tied to hypertensive disorders of pregnancy

Prepregnancy intakes of total fat, unsaturated fat, and monounsaturated fatty acid (MUFA) do not appear to contribute to hypertensive disorders of pregnancy (HDP), but trans fatty acid (TFA) shows a positive association with HDP, reports a study.

A team of investigators followed 11,535 women without chronic disease participating in the Nurses’ Health Study II from 1991 to 2009. A food frequency questionnaire was used to assess prepregnancy dietary fat. Intakes of total fat, saturated fat, TFA, MUFAs, polyunsaturated fatty acids (PUFAs), and fat subtypes (omega-3 and -6) were then categorized into quintiles of intake.

HDP was self-reported. The investigators estimated the risk ratios (RRs) of HDP using log-binomial generalized estimating equation regression models, with an exchangeable correlation matrix to account for repeated pregnancies while adjusting for potential confounders.

The mean age at pregnancy was 34.6 years. A total of 16,892 singleton pregnancies were recorded, of which 495 (2.9 percent) cases of pre-eclampsia and 561 (3.3 percent) cases of gestational hypertension occurred during 19 years of follow-up.

Only prepregnancy TFA was associated with an increased HDP risk (RR, 1.32, 95 percent confidence interval [CI], 1.05‒1.66), and only for pre-eclampsia (RR, 1.50, 95 percent CI, 1.07‒2.10) but not for gestational hypertension (RR, 1.21, 95 percent CI, 0.87‒1.70).

Among specific PUFA types, arachidonic acid intake significantly correlated with gestational hypertension (RR, 1.43, 95 percent CI, 1.00‒2.04) but not with pre-eclampsia (RR, 1.08, 95 percent CI, 0.75‒1.57).

Analyses restricted to pregnancies 1 year after the diet assessment revealed that women with the highest intake of long-chain omega-3 fatty acids had a 31-percent lower HDP risk (95 percent CI, 3‒51), which was driven by pre-eclampsia (RR, 0.55, 95 percent CI, 0.33‒0.92).

“These findings highlight the importance of ongoing efforts to eliminate TFA from the global food supply,” the investigators said.