Placental telomere length shortening is not associated with preeclampsia but the gestational age

STRUCTURED ABSTRACTO_ST_ABSBackgroundC_ST_ABSPreeclampsia is a severe pregnancy complication that affects about 2-8% of pregnant women globally and is one of the leading causes of maternal and fetal mortality and morbidity. Telomere length change has been associated with aging, environmental stress, and various diseases. Studying the telomere length change in preeclampsia complicated placentas may shed light on the pathophysiology of preeclampsia. ObjectivesIn this study, we aimed to explore if associations exist between placental telomere length and preeclampsia, gestational age, and other demographic, clinical and physiological factors related to pregnancy. Study DesignWe collected placentas samples from 120 severe preeclamptic deliveries and 129 healthy full-term deliveries in Hawaii between year 2006 and 2013 and measured the average absolute placental telomeres with quantitative polymerase chain reaction (qPCR). We retrieved their pre-recorded demographic, clinical and physiological data and conducted multiple linear regressions to associate placental telomeres with preeclampsia and other variables. ResultsPlacental telomere length of severe preeclampsia cases showed no significant difference (P=0.20) from healthy controls after controlling for gestational age difference. Instead, we identified that placental telomere length consistently decreases as gestation progresses (P=6.10e-05). Male babies have shorter placental telomere than female babies in the early trimester (p = 0.024), but the placentas of male babies have a reduced rate of telomere shortening along pregnancies, compared to those of female babies (p = 0.029). Latino mothers show longer placenta telomeres than other ethnicities (P=0.012), whereas mothers of blood type O have shorter placenta telomeres than those of other blood types (P=0.039). ConclusionsUsing the largest multiethnic cohort to date, we showed the lack of association between preeclampsia and placental telomere length. Rather, gestational age is the most dominant variable associated with placental telomere shortening. CondensationPlacental telomere length shows no significant association with preeclampsia but significantly shortens with the progressing gestational age at different rates for male and female babies. AJOG At A GlanceA. Why was this study conducted?O_LIUnderstanding the TL change in healthy and preeclampsia complicated placenta may help us better understand the physio-pathological impact of preeclampsia. C_LI B. What are the key findings?O_LIWe found no significant association between severe preeclampsia and placental TL in the largest multi-ethnic cohort to date. C_LIO_LIPlacental TL shortens consistently largely due to gestational age increase. C_LIO_LIPlacentas of male babies have shorter TLs at the early third trimester but slower TL shortening compared to those of female babies. C_LIO_LILatino mothers have longer placental TL compared to non-Latino mothers. C_LIO_LIMothers of blood type O have shorter placenta TL than others. C_LI C. What does this study add to what is already known?O_LIWe showed that placental telomere length shortening is not associated with preeclampsia but the gestational age in a large multi-ethnical cohort. C_LI