Objective: Determine associations of cardiorespiratory fitness, exercise systolic blood pressure (SBP) and heart rate recovery (HRR) following a maximal exercise test performed years preceding pregnancy with odds of preterm birth (PTB; <37 weeks' gestation) and small for gestational age (SGA; birthweight <10 th percentile) delivery. Design: Prospective, longitudinal. Setting: Multi-site, observational cohort study initially consisting of 2787 black and white women aged 18–30 at baseline (1985–86) and followed for 25 years (Y25; 2010–2011). Population: 768 nulliparous women at baseline who reported ≥1 live birth by the Y25 exam. Methods: We used Poisson regression to determine associations of exposures with PTB/SGA. Main outcome measures: PTB and/or SGA births. Results: Women with PTB (n = 143) and/or SGA (n = 88) were younger, had completed fewer years of education and were more likely to be black versus women without PTB/SGA (n = 546). Women with PTB/SGA had lower fitness (501 ± 9 versus 535 ± 6 seconds, P < 0.002) and higher submaximal SBP than women without PTB/SGA (144 ± 1 versus 142 ± 1 mmHg, P < 0.04). After adjustment, no exercise test variables were associated with PTB/SGA, though the association with HRR and submaximal SBP approached significance in the subset of women who completed the exercise test <5 years before the index birth. Conclusions: Neither fitness nor haemodynamic responses to exercise a median of 5 years preceding pregnancy, were associated with PTB/SGA. These findings indicate excess likelihood of PTB/SGA is not detectable by low fitness or exercise haemodynamic responses 5 years preceding pregnancy, but exercise testing, especially HRR and submaximal SBP, may be more useful when conducted closer to the onset of pregnancy. Tweetable abstract: Exercise testing conducted >5 years before pregnancy may not detect women likely to have PTB/SGA.
|Original language||English (US)|
|Number of pages||8|
|Journal||BJOG: An International Journal of Obstetrics and Gynaecology|
|State||Published - Aug 2018|
Bibliographical noteFunding Information:
The Coronary Artery Risk Development in Young Adults Study (CARDIA) is supported by contracts HHSN2682013 00025C, HHSN268201300026C, HHSN268201300027C, HH SN268201300028C, HHSN268201300029C and HHSN268 200900041C from the National Heart, Lung, and Blood Institute (NHLBI), the Intramural Research Program of the National Institute on Aging (NIA), and an intra-agency agreement between NIA and NHLBI (AG0005). The analyses were supported by grants from R01 DK106201 (PI: Gunderson), R01 DK090047 (PI: Gunderson) and K01 DK059944 (PI: Gunderson) from the National Institute of Diabetes, Digestive and Kidney Diseases. ALC is funded by the American Heart Association’s Strategically Focused Research Network in Prevention 14SFRN20480260 (PI: Greenland).
© 2018 Royal College of Obstetricians and Gynaecologists
- Exercise test
- preterm birth
- small for gestational age