RESUMEN
BACKGROUND: Delayed onset of lactation is a key factor in the low rate of exclusive breast-feeding in 6 months after caesarean section. The mechanism of delayed onset of lactation is not clear. Milk production depends largely on mitochondrial adenosine triphosphate synthesis, and the neutrophil-lymphocyte ratio is closely related to mitochondrial deoxyribonucleic acid copy number and adenosine triphosphate production. Presently, it is unclear whether a difference in the neutrophil-lymphocyte ratio exists between those undergoing vaginal delivery and those undergoing caesarean delivery and, if so, whether the difference correlates to the time of onset of lactation. OBJECTIVES: To identify whether the neutrophil-lymphocyte ratio at 24 hours after delivery is different between mothers delivering by caesarean section and those giving birth vaginally and whether the neutrophil-lymphocyte ratio is related to the delayed onset of lactation. DESIGN: The study adopted a prospective cohort study design. SETTINGS: Maternity units of an Obstetrics & Gynecology Hospital. PARTICIPANTS: 327 mother-infant pairs who met inclusion/exclusion criteria and were followed up to the time of onset of lactation. METHODS: Mother-infant pairs were allocated to the vaginal birth group or the caesarean section group according to birth method. The neutrophil-lymphocyte ratio was calculated as the absolute value of neutrophils divided by the absolute value of lymphocytes based on full blood counts. Before delivery, full blood counts were obtained from medical records. After delivery, blood samples were drawn 24â¯hours postpartum, and blood cells were classified and counted. The onset of lactation was confirmed by the maternal perception of breast fullness. The neutrophil-lymphocyte ratio and its relationship with lactation onset were analyzed by multivariable regression. RESULTS: The neutrophil-lymphocyte ratios of both groups were elevated after delivery. Based on the covariance analysis, after adjusting for baseline full blood counts before delivery, the neutrophil-lymphocyte ratio in the caesarean group was higher than the ratio in the vaginal group after delivery (p = .000). In addition, after adjustment for confounding factors, multivariable regression analyses showed that an increased neutrophil-lymphocyte ratio was correlated with delayed onset of lactation (95% confidence interval 0.285-1.646). CONCLUSIONS: The neutrophil-lymphocyte ratio in the caesarean section group was higher than that in the vaginal delivery group and was related to a delayed onset of lactation. Given the decreased mitochondrial copy number in the elevated neutrophil-lymphocyte ratio and therefore the associated reduction in adenosine triphosphate synthesis, these findings may elucidate the mechanism for delayed onset of lactation in caesarean section births.
Asunto(s)
Lactancia , Linfocitos/citología , Neutrófilos/citología , Periodo Posparto , Adenosina Trifosfato/metabolismo , Femenino , Humanos , Mitocondrias/metabolismo , Embarazo , Estudios ProspectivosRESUMEN
BACKGROUND: While it is well established that very preterm birth (gestational age at birth <32 weeks) is related to increased attention problems, there is still considerable uncertainty of the effects of moderate or late preterm birth or smallness for gestational age (SGA) on attention regulation. AIMS: To investigate the impact of gestational age at birth and SGA, birth on child attention problems. STUDY DESIGN: Prospective longitudinal cohort study. SUBJECTS: A total of 1435 children sampled from the Bavarian Longitudinal Study (BLS). OUTCOME MEASURES: Main outcome variables were parent-reported attention problems and examiner-reported attention skills at 6 and 8 years. Predictors were linked to attention outcomes using hierarchical regression analyses. RESULTS: Gestational age at birth ranged from 25 weeks to 41 weeks. We found a quadratic effect of gestational age on attention problems (ß6 years=0.161, 95% CI=0.085; 0.236; ß8 years=0.211, 95% CI=0.135; 0.287), and attention skills at 6 and 8 years (ß6 years=-0.178, 95% CI=-0.252; -0.104; ß8 years=-0.169, 95% CI=-0.243; -0.094). Elective caesarean birth did not predict child attention. In adjusted models, SGA was an additional risk factor for attention problems (ß=0.080, 95% CI=0.026; 0.134), and attention skills (ß=-0.091, 95% CI=-0.143; -0.039) at 6 years but not at 8 years after adjusting for child sex and family SES. CONCLUSION: Adverse effects on attention are disproportionately higher at early gestations. In contrast, the impact of SGA status was found to be similar at all gestational ages but disappeared by 8 years.