The Association Between Pregnancy Complications and Long-term Maternal Cardiometabolic Health in the MIREC Cohort Study

Abstract

Context: During pregnancy, women who experience certain pregnancy complications show elevations in biomarkers of inflammation and insulin resistance; however, few studies have examined these cardiometabolic biomarkers in the decade following pregnancy.

Objective: To examine the association between pregnancy complications and cardiometabolic biomarkers 9 years postpartum including blood pressure, blood lipids, body fat percentage, insulin resistance [glucose, insulin, proinsulin, C-peptide, Homeostasis Model Assessment of Insulin Resistance (HOMA-IR), glycated hemoglobin (HbA1c), leptin, adiponectin], and inflammation (high-sensitivity-C-reactive protein).

Methods: Using data from the Maternal-Infant Research on Environmental Chemicals cohort study (2008-2021), we determined 3 groups of pregnancy complications: (1) hypertensive disorders of pregnancy (HDP) (n = 35); (2) any pregnancy complication in the index pregnancy, defined as preterm birth, HDP, impaired glucose tolerance or gestational diabetes mellitus (n = 55); and (3) self-reported recurrence of 1 of these pregnancy complications (n = 19). Our comparison group included 186 women with uncomplicated pregnancies.

Results: In our adjusted linear regression results, all pregnancy complication groups showed significantly higher systolic and diastolic blood pressure 9 years later. HOMA-IR was 23% [95% confidence interval (CI): -4.4%, 57%], 26% (95% CI: 2.0%, 55%), and 51% (95% CI: 12%, 104%) higher at follow-up in participants who had experienced a prior HDP, an index pregnancy complication, or a recurrent pregnancy complication, respectively. Elevations were also seen with HbA1c, insulin, C-peptide, and leptin, especially among those with recurrent complications.

Conclusion: This study contributes to the body of evidence that women with a history of certain pregnancy complications merit special attention in the prevention of cardiovascular disease. We recommend further exploration into these associations in larger cohorts.

Keywords: cardiometabolic health; hypertensive disorders; pregnancy; recurrence.

Figure 1.

VENN diagram of pregnancy complications in the MIREC index pregnancy (2008-2011). During the MIREC index pregnancy (2008-2011) 55 women had “any” pregnancy complication in the MIREC index pregnancy. There were 14 women who had gestational diabetes or impaired glucose tolerance, 16 preterm births, and 35 women experienced a HDP. Abbreviations: GDM, gestational diabetes mellitus; HDP, hypertensive disorders of pregnancy; IGT, impaired glucose tolerance; MIREC, Maternal-Infant Research on Environmental Chemicals.

Figure 2.

VENN diagram of recurrent pregnancy complications. Because women gave information on their obstetrical history in the MIREC ENDO follow-up visit approximately 9 years postpartum, we obtained self-reported information on all of their pregnancies. A total of 95 (36 + 14 + 26 + 11 + 4 + 4 = 95) participants had a pregnancy complication with their MIREC index child, previous to the MIREC index child (past pregnancy) or after the MIREC index child (future pregnancy). Nineteen women reported recurring pregnancy complications: 11 women had a complication in a past pregnancy and the MIREC index pregnancy, 4 had a pregnancy complication in MIREC and then again in the future, and another 4 women had a pregnancy complication in a past pregnancy, the MIREC index pregnancy, and a future pregnancy. Abbreviations: MIREC, Maternal-Infant Research on Environmental Chemicals.

Figure 3.

MIREC-ENDO clinic visit participation. Note that 49 participants were excluded from the “Uncomplicated Pregnancies” group because they had self-reported a pregnancy complication prior to (n = 26) or after (n = 14) the MIREC index pregnancy but not in the MIREC index pregnancy (see Fig. 2) or they were missing pregnancy complication information in the MIREC index pregnancy (n = 2) or were diagnosed with chronic HTN during the MIREC index pregnancy (n = 7). 186 (uncomplicated) + 55 (pregnancy complications) + 49 (described earlier) = 290. Abbreviations: BP, blood pressure; GDM, gestational diabetes mellitus; HTN, hypertension; MIREC, Maternal-Infant Research on Environmental Chemicals.