Serum YKL-40 and uterine artery Doppler -- a prospective cohort study, with focus on preeclampsia and small-for-gestational-age

Abstract

Objective: To test if serum YKL-40 is increased in women developing preeclampsia or small-for-gestational age fetuses. We also assessed the association between uterine artery pulsatility index, notching and serum YKL-40 levels.

Design: Prospective cohort study.

Setting: A primary referral unit for obstetric ultrasound.

Population: A total of 1214 unselected pregnant women enrolled at nuchal translucency examination between 11(+3) and 13(+6) weeks of gestation.

Methods: All women had ultrasound and blood sample collection at the nuchal translucency scan, a 20-week malformation scan and 25-week and 32-week fetal growth examinations. Uterine artery Doppler was assessed and outcome was registered from medical records.

Main outcome measures: Preeclampsia, hypertension, small-for-gestational age.

Results: Serum YKL-40 was associated with increasing maternal age (p < 0.0001), body mass index (p = 0.0002), primiparity (p = 0.0003), and hypertension (p = 0.015). Serum YKL-40 increased from 12 to 20 weeks and decreased from 20-25 and 25-32 weeks of gestation. No association was found between preeclampsia and serum YKL-40. Small-for-gestational-age at birth was significantly associated with a 5.4% increase in serum YKL-40 at 32 weeks of gestation (95% CI 1.5-9.3, p = 0.005). An association was found between uterine artery pulsatility index at 32 weeks and small-for-gestational age (p = 0.0015) but not between YKL-40 and uterine artery notching (p = 0.83).

Conclusions: Serum YKL-40 was not associated with preeclampsia. Increasing serum YKL-40 was related to maternal age, body mass index and small-for-gestational age and may reflect an exaggerated inflammatory response.

Trial registration: ClinicalTrials.gov NCT00836524.

Keywords: Biomarker; YKL-40; preeclampsia; pregnancy; small-for-gestational age.

© 2014 Nordic Federation of Societies of Obstetrics and Gynecology.