Judith S. Mercer

Variables Associated With Breastfeeding Duration

OBJECTIVE To identify the variables associated with breastfeeding duration. DATA SOURCES The health science reference databases of CINAHL, PubMed, and the Cochrane Database of Systematic Reviews. STUDY SELECTION Meta-analyses, Cochrane reviews, literature reviews, and quantitative and qualitative studies published in English from 1998 through 2008. DATA EXTRACTION Data included all variables, both positive and negative, that were found to influence the outcome of breastfeeding duration. DATA SYNTHESIS Demographic factors that influence breastfeeding duration are race, age, marital status, education, socioeconomics, and Special Supplemental Nutrition Program for Women, Infants, and Children status. Biological variables consisted of insufficient milk supply, infant health problems, maternal obesity, and the physical challenges of breastfeeding, maternal smoking, parity, and method of delivery. Social variables included paid work, family support, and professional support. Maternal intention, interest, and confidence in breastfeeding were psychological variables. CONCLUSION Human lactation is a complex phenomena and the duration of breastfeeding is influenced by many demographic, physical, social, and psychological variables.

Delayed cord clamping in very preterm infants reduces the incidence of intraventricular hemorrhage and late-onset sepsis: a randomized, controlled trial.

OBJECTIVE. This study compared the effects of immediate (ICC) and delayed (DCC) cord clamping on very low birth weight (VLBW) infants on 2 primary variables: bronchopulmonary dysplasia (BPD) and suspected necrotizing enterocolitis (SNEC). Other outcome variables were late-onset sepsis (LOS) and intraventricular hemorrhage (IVH). STUDY DESIGN. This was a randomized, controlled unmasked trial in which women in labor with singleton fetuses <32 weeks’ gestation were randomly assigned to ICC (cord clamped at 5–10 seconds) or DCC (30–45 seconds) groups. Women were excluded for the following reasons: their obstetrician refused to participate, major congenital anomalies, multiple gestations, intent to withhold care, severe maternal illnesses, placenta abruption or previa, or rapid delivery after admission. RESULTS. Seventy-two mother/infant pairs were randomized. Infants in the ICC and DCC groups weighed 1151 and 1175 g, and mean gestational ages were 28.2 and 28.3 weeks, respectively. Analyses revealed no difference in maternal and infant demographic, clinical, and safety variables. There were no differences in the incidence of our primary outcomes (BPD and suspected NEC). However, significant differences were found between the ICC and DCC groups in the rates of IVH and LOS. Two of the 23 male infants in the DCC group had IVH versus 8 of the 19 in the ICC group. No cases of sepsis occurred in the 23 boys in the DCC group, whereas 6 of the 19 boys in the ICC group had confirmed sepsis. There was a trend toward higher initial hematocrit in the infants in the DCC group. CONCLUSIONS. Delayed cord clamping seems to protect VLBW infants from IVH and LOS, especially for male infants.

CURRENT BEST EVIDENCE: A REVIEW OF THE LITERATURE ON UMBILICAL CORD CLAMPING

Immediate clamping of the umbilical cord can reduce the red blood cells an infant receives at birth by more than 50%, resulting in potential short-term and long-term neonatal problems. Cord clamping studies from 1980 to 2001 were reviewed. Five hundred thirty-one term infants in the nine identified randomized and nonrandomized studies experienced late clamping, ranging from 3 minutes to cessation of pulsations, without symptoms of polycythemia or significant hyperbilirubinemia. Higher red blood cell flow to vital organs in the first week was noted, and term infants had less anemia at 2 months and increased duration of early breastfeeding. In seven randomized trials of preterm infants, benefits associated with delayed clamping in these infants included higher hematocrit and hemoglobin levels, blood pressure, and blood volume, with better cardiopulmonary adaptation and fewer days of oxygen and ventilation and fewer transfusions needed. For both term and preterm infants, few, if any, risks were associated with delayed cord clamping. Longitudinal studies of infants with immediate and delayed cord clamping are needed.

Seven-month developmental outcomes of very low birth weight infants enrolled in a randomized controlled trial of delayed versus immediate cord clamping

Objective:The results from our previous trial revealed that infants with delayed cord clamping (DCC) had significantly lesser intraventricular hemorrhage (IVH) and late-onset sepsis (LOS) than infants with immediate cord clamping (ICC). A priori, we hypothesized that infants with DCC would have better motor function by 7 months corrected age.Study Design:Infants between 24 and 31 weeks were randomized to ICC or DCC and follow-up evaluation was completed at 7 months corrected age.Result:We found no differences in the Bayley Scales of Infant Development (BSID) scores between the DCC and ICC groups. However, a regression model of effects of DCC on motor scores controlling for gestational age, IVH, bronchopulmonary dysplasia, sepsis and male gender suggested higher motor scores of male infants with DCC.Conclusion:DCC at birth seems to be protective of very low birth weight male infants against motor disability at 7 months corrected age.

Hemodynamic Effects of Delayed Cord Clamping in Premature Infants

BACKGROUND AND OBJECTIVE: Delayed cord clamping (DCC) has been advocated during preterm delivery to improve hemodynamic stability during the early neonatal period. The hemodynamic effects of DCC in premature infants after birth have not been previously examined. Our objective was to compare the hemodynamic differences between premature infants randomized to either DCC or immediate cord clamping (ICC). METHODS: This prospective study was conducted on a subset of infants who were enrolled in a randomized controlled trial to evaluate the effects of DCC versus ICC. Entry criteria included gestational ages of 240 to 316 weeks. Twins and infants of mothers with substance abuse were excluded. Serial Doppler studies were performed at 6 ± 2, 24 ± 4, 48 ± 6, and 108 ± 12 hours of life. Measurements included superior vena cava blood flow, right ventricle output, middle cerebral artery blood flow velocity (BFV), superior mesenteric artery BFV, left ventricle shortening fraction, and presence of a persistent ductus arteriosus. RESULTS: Twenty-five infants were enrolled in the DCC group and 26 in the ICC group. Gestational age, birth weight, and male gender were similar. Admission laboratory and clinical events were also similar. DCC resulted in significantly higher superior vena cava blood flow over the study period, as well as greater right ventricle output and right ventricular stroke volumes at 48 hours. No differences were noted in middle cerebral artery BFV, mean superior mesenteric artery BFV, shortening fraction, or the incidence of a persistent ductus arteriosus. CONCLUSIONS: DCC in premature infants is associated with potentially beneficial hemodynamic changes over the first days of life.

Immediate and Delayed Cord Clamping in Infants Born Between 24 and 32 Weeks: A Pilot Randomized Controlled Trial

OBJECTIVE: This pilot studys aim was to establish feasibility of a protocol for delayed cord clamping (DCC) versus immediate cord clamping (ICC) at preterm birth and to examine its effects on initial blood pressure and other outcomes.STUDY DESIGN: A randomized controlled trial recruited 32 infants between 24 and 32 weeks. Immediately before delivery, mothers were randomized to ICC (cord clamped at 5 to 10 seconds) or DCC (30- to 45-second delay in cord clamping) groups.RESULTS: Intention-to-treat analyses revealed that the DCC group were more likely to have higher initial mean blood pressures (adjusted OR 3.4) and less likely to be discharged on oxygen (adjusted OR 8.6). DCC group infants had higher initial glucose levels (ICC=36 mg/dl, DCC=73.1 mg/dl; p=0.02).CONCLUSION: The research design is feasible. The immediate benefit of improved blood pressure was confirmed and other findings deserve consideration for further study.

Effects of placental transfusion in extremely low birthweight infants: meta-analysis of long- and short-term outcomes.

Risks and benefits of increasing placental transfusion in extremely preterm infants (extremely low birthweight [ELBW], <1000 g) are ill defined. We performed a meta‐analysis to compare long‐ and short‐term outcomes of ELBW infants in trials of enhanced placental transfusion regimens.

Neonatal Transitional Physiology: A New Paradigm

Early clamping of the umbilical cord at birth, a practice developed without adequate evidence, causes neonatal blood volume to vary 25% to 40. Such a massive change occurs at no other time in ones life without serious consequences, even death. Early cord clamping may impede a successful transition and contribute to hypovolemic and hypoxic damage in vulnerable newborns. The authors present a model for neonatal transition based on and driven by adequate blood volume rather than by respiratory effort to demonstrate how neonatal transition most likely occurs at a normal physiologic birth.

Umbilical cord milking in term infants delivered by cesarean section: a randomized controlled trial

Objective:The studys objective was to compare hematocrit (Hct) levels at 36 to 48 h of age in term infants delivered by cesarean section exposed to immediate cord clamping or umbilical cord milking (UCM).Study Design:In this randomized controlled trial, 24 women scheduled for elective cesarean section were randomized to either immediate clamping (<10 s) or UCM (milked × 5 by the obstetrical provider) at birth.Result:All subjects received their allocated intervention. The milking group had a smaller placental residual blood volume (13.2±5.6 vs 19.2±5.4 ml kg–1, P=0.01) and higher Hct levels at 36 to 48 h (57.5±6.6 vs 50.0±6.4 %, P=0.01). Five infants (42%) in the immediate group had a Hct of ⩽47%, indicative of anemia.Conclusion:UCM results in placental transfusion in term infants at the time of elective cesarean section with higher Hct levels at 36 to 48 h of age.

Umbilical cord clamping: beliefs and practices of American nurse-midwives.

The optimal time for umbilical cord clamping after birth remains a critical unknown fact that has implications for the infant, the mother, and science. A national survey was conducted using a randomized sample (n = 303) of the active membership of the ACNM to determine cord clamping practices and beliefs of American nurse-midwives. The response rate was 56%. The respondents fell into three cord clamping categories: early (EC) or before 1 minute (26%); intermediate (IC) or 1 to 3 minutes (35%); and late (LC) or after pulsations cease (33%). The EC group believes that early clamping facilitates management of the newborn. The IC group believes that a moderate delay of clamping allows for a gradual transition to extrauterine circulation, although many think that the timing of cord clamping is not significant. The LC group have strongly held beliefs that late clamping supports physiologic birth processes. The majority of CNMs (87%) place the baby on the mothers abdomen immediately after birth and 96% avoid clamping a nuchal cord whenever possible. Although Varneys Midwifery was cited most frequently as a reference, 78% of the respondents listed no references reflecting, in part, the absence of evidence-based recommendations for cord clamping practices.