Comparison of levonorgestrel level and creamatocrit in milk following immediate versus delayed postpartum placement of the levonorgestrel IUD.

BACKGROUND: Breastfeeding and postpartum contraception critically influence infant and maternal health outcomes. In this pilot study, we explore the effects of timing and duration of postpartum levonorgestrel exposure on milk lipid and levonorgestrel content to establish baseline data for future research. METHODS: This sub-study recruited a balanced convenience sample from 259 participants enrolled in a parent randomized controlled trial comparing immediate to delayed (4-8 weeks) postpartum levonorgestrel IUD placement. All planned to breastfeed, self-selected for sub-study participation, and provided the first sample at 4-8 weeks postpartum (before IUD placement for the delayed group) and the second four weeks later. We used the Wilcoxon rank sum (inter-group) and signed rank (intra-group) tests to compare milk lipid content (creamatocrit) and levonorgestrel levels between groups and time points. RESULTS: We recruited 15 participants from the immediate group and 17 from the delayed group with 10 and 12, respectively, providing both early and late samples. Initially, median levonorgestrel concentration of the immediate group (n = 10) (32.5 pg/mL, IQR: 24.8, 59.4) exceeded that of the delayed group (n = 12) (17.5 pg/mL, IQR: 0.0, 25.8) (p = 0.01). Four weeks later, the values aligned: 26.2 pg/mL (IQR: 20.3, 37.3) vs. 28.0 pg/mL (IQR: 25.2, 40.8). Creamatocrits were similar between both groups and timepoints. CONCLUSIONS: Immediate postpartum levonorgestrel IUD placement results in steady, low levels of levonorgestrel in milk without apparent effects on lipid content. These findings provide initial support for the safety of immediate postpartum levonorgestrel IUD initiation, though the study was not powered to detect noninferiority between groups. TRIAL REGISTRATION: This randomized controlled trial was registered with ClinicalTrials.gov (Registry No. NCT01990703) on November 21, 2013.

Nutritional status and human milk intake of exclusively breast-fed infants at high altitude in La Paz, Bolivia.

Breast-feeding habits are related to the nutritional status and the risk of illness and death in children under 2 years of age. For the first 6 months, infants should be exclusively breast-fed. This study aimed to evaluate the relationship between the infant's nutritional status and human milk intake by breast-fed infants at high altitude. A quantitative, descriptive, correlational study was conducted including mother/baby pairs of infants aged 2-6 months. The amount of human milk consumed by the infants was assessed by the deuterium oxide dose-to-mother technique. The lipid content of human milk was measured by creamatocrit, and anthropometric measurements were performed. A total of eighteen mother/baby pairs were assessed. The mean human milk intake was 888 (sd 149) g/d, and the intake of water from other sources was 24·3 (sd 29·8) g/d. The lipid content in human milk was 41 (sd 12) g/l. The infant's nutritional indicators were normal in all cases. A moderate positive correlation was found between milk volume and z scores weight-for-length r 0·58 (P=0·01), BMI-for-age r 0·56 (P=0·01) and weight-for-age r 0·45 (P=0·05). There was no correlation with length-for-age z score. The mean of breast milk intake in this study was similar to that found in other studies in the world. The lipid content is comparable to similar studies and was within the normal range. Children older than 3 months showed signs of stunting despite adequate volume and lipid content of breast milk.

Fat Content and Energy Calculation in Pasteurized Human Milk: Comparison Between Infrared Analysis and Creamatocrit Method.

Aims: This study aimed to analyze and compare the quantity of energy and fat using the infrared analysis and creamatocrit method in pasteurized human milk (HM) samples. Methods: This cross-sectional study analyzed 1,858 pasteurized human samples from 317 mothers at a single center. Infrared transmission spectrophotometry (Miris, Human Milk Analyser [HMA], Uppsala, Sweden) and the creamatocrit method were used to evaluate the quantity of energy and fat in pasteurized HM samples. Results: The average age of donor mothers was 29.7 ± 5.1 years, and the median duration of lactation was 22 days (interquartile range [IQ]: 7.7-59.2). Full-term births were observed in 196 (95.1%) of the women. The values of energy (difference: +8.96 kcal/dL, 95% CI: 8.52-9.44 kcal/dL; p < 0.001) and fat (difference: +0.40 g/dL, 95% CI: 0.35-0.45 g/dL; p < 0.001) in HM samples obtained by Miris were higher than those by the creamatocrit method. The energy calculated and the fat measured by Miris in the HM samples correlated moderately and directly with the obtained by creamatocrit (fat, r = 0.585; p < 0.001 and energy, r = 0.591; p < 0.01). The linear regression, adjusted for maternal age and lactation time, showed that the energy values calculated by creamatocrit were directly associated with those of Miris (energy kcal/dL = 38.43 + [0.516 × kcal/dL of creamatocrit]). Conclusion: The energy and fat quantity of pasteurized HM samples obtained by the creamatocrit and infrared methods were significantly correlated. However, the values calculated by the creamatocrit method were significantly lower than those by the infrared analyzer.

The relationship between creamatocrit and cumulative percentage of total milk volume: a cross-sectional study in mothers of very preterm infants in Bangkok, Thailand.

BACKGROUND: Human hindmilk contains higher concentrations of fat than foremilk and is more desirable for growth in preterm infants who can tolerate limited volumes of breastmilk. There is currently no clear demarcation between foremilk and hindmilk. This study characterized the change in breastmilk's fat content from the start to end of milk flow and defined this demarcation. METHODS: Mothers of infants born at ≤ 32 weeks gestational age and ≥ 14 days after childbirth in a University hospital in Bangkok, Thailand between July, 2011, and April, 2012 were included in this cross-sectional study. Breastmilk samples were sequentially collected from the start to end of milk flow in 5-mL aliquots using breast pumps. The fat content of each aliquot from each breast was determined through creamatocrit. The average creamatocrit of foremilk and hindmilk were compared in predefined foremilk to hindmilk ratios of 20:80, 25:75, 33:67, and 50:50. Creamatocrit of the first and last aliquots were compared for mothers who expressed low- (≤ 25-mL per breast) and high-volumes (> 25-mL per breast) of breastmilk. RESULTS: Of the 25 mothers enrolled, one was excluded due to unsuccessful creamatocrit measurement. The last aliquot of breastmilk had a significantly higher creamatocrit than the first from the same breast (median [interquartile range] of 12.7% [8.9%, 15.3%] vs. 5.6% [4.3%, 7.7%]; test statistic 1128, p < 0.001). Mean creamatocrit in hindmilk portions (9.23%, 9.35%, 9.81%, and 10.62%, respectively) was significantly higher than foremilk portions (6.28%, 6.33%, 6.72%, and 7.17%, respectively) at all predefined ratios. Creamatocrit increased by 1% for every 10% incremental increase in expressed breastmilk volume until the breast was emptied. Low-volume mothers had a significantly higher creamatocrit in the first aliquot compared with high-volume mothers (U = 437, p = 0.002). No significant difference in breastmilk volume was observed between mothers with and without breastfeeding experience. CONCLUSIONS: Fat content in breastmilk increased on an incremental basis. More fluid definitions of foremilk and hindmilk should be adopted. Mothers should prepare their breastmilk into aliquots based on the required feeding volume of their infant. Hindmilk aliquots can be prioritized over foremilk aliquots to ensure infants obtain optimal caloric intake.

Reproducibility of the creamatocrit technique for the measurement of fat content in human milk.

Quantification of human milk (HM) fat is important for determining the energy intake of infants. The simplest and most rapid method is the creamatocrit method. However, the reliability of the creamatocrit has not been comprehensively investigated. The aims of this study were to test the inter- and-intra-rater reliability of: 1) HM sampling after hand- or-machine mixing methods and 2) HM fat measurement by the creamatocrit method. Inter-and-intra rater HM sampling after hand- or-machine mixing methods had high intraclass correlation coefficient (>0.91). Inter-rater reliability of measurement of HM with low fat (<2%) resulted in high variability (median coefficient of variations (CVs) > 15%). Intra- and inter-rater reliability of measurement of HM with higher fat (>3.5%) had low variability (median CVs < 10%). As the greatest variation in the creamatocrit method occurred during the measurement of HM samples with low fat, duplicate readings are necessary to reduce discrepancies in every HM fat determination.

Macronutrient Analysis of Modified-Fat Breast Milk Produced by 3 Methods of Fat Removal.

BACKGROUND: Infants with chylothorax after congenital heart disease surgery are commonly treated using modified-fat breast milk. The effect of fat removal on breast milk macronutrients remains unclear. We compared macronutrient content of breast milk with breast milk skimmed using 3 methods, including a novel device, a cream separator. METHODS: Thawed frozen breast milk samples from 30 women were defatted using refrigerated centrifuge, cream separator, and manual separation after refrigeration. We used standard assays to measure energy, protein, and fat content of breast milk samples. RESULTS: All fat removal methods yielded skimmed breast milk with substantially lower fat and energy content. Mean energy content in breast milk skimmed by centrifuge (36.7 [SD 3.6] kcal/100 mL) was similar to that from cream separator (38.8 [3.5] kcal/100 mL). Both centrifuge and cream separator methods removed almost all fat and substantially more fat than the manual fat removal method. For unprocessed milk, energy and fat content estimated by creamatocrit was similar to reference method measurements; in skimmed milk, the creamatocrit significantly overestimated fat content. Mean protein content of skimmed breast milk was similar to unprocessed breast milk (mean 1.25 [0.31] g/100 mL). CONCLUSION: Breast milk fat removal did not significantly alter protein levels. In skimmed breast milk, the overestimation of fat content using creamatocrit method suggests a need for more accurate bedside methods to assess macronutrient content. The similar macronutrient composition of breast milk skimmed by cream separator and centrifuge suggests the potential for cream separator use as a new, portable defatting method for hospitals and families.

Comparison of gravimetric, creamatocrit and esterified fatty acid methods for determination of total fat content in human milk.

The gravimetric method is considered the gold standard for measuring the fat content of human milk. However, it is labor intensive and requires large volumes of human milk. Other methods, such as creamatocrit and esterified fatty acid assay (EFA), have also been used widely in fat analysis. However, these methods have not been compared concurrently with the gravimetric method. Comparison of the three methods was conducted with human milk of varying fat content. Correlations between these methods were high (r(2)=0.99). Statistical differences (P<0.001) were observed in the overall fat measurements and within each group (low, medium and high fat milk) using the three methods. Overall, stronger correlation with lower mean (4.73g/L) and percentage differences (5.16%) was observed with the creamatocrit than the EFA method when compared to the gravimetric method. Furthermore, the ease of operation and real-time analysis make the creamatocrit method preferable.

Analysis of the Storage Methods for Raw Human Milk from Mothers with Infants Admitted to a Neonatal Intensive Care Unit, According to Brazilian Regulations.

BACKGROUND: Milk safety is an important concern in neonatal units and human milk banks. Therefore, evidence-based recommendations regarding raw milk handling and storage are needed to safely promote supplying hospitalized infants with their mother's own milk. OBJECTIVES: To evaluate raw human milk storage methods according to Brazilian milk management regulations by investigating the effects of refrigeration (5°C) for 12 hours and freezing (-20°C) for 15 days on the acidity and energy content in a large number of raw milk samples. METHODS: Expressed milk samples from 100 distinct donors were collected in glass bottles. Each sample was separated into 3 equal portions that were analyzed at room temperature and after either 12 hours of refrigeration or 15 days of freezing. Milk acidity and energy content were determined by Dornic titration and creamatocrit technique, respectively. RESULTS: All samples showed Dornic acidity values within the established acceptable limit (≤ 8°D), as required by Brazilian regulations. In addition, energy content did not significantly differ among fresh, refrigerated and frozen milk samples (median of ~50 kcal/100 mL for each). CONCLUSION: Most samples tested (> 80%) were considered top quality milk (< 4°D) based on acidity values, and milk energy content was preserved after storage. We conclude that the storage methods required by Brazilian regulations are suitable to ensure milk safety and energy content of stored milk when supplied to neonates.

Is there a difference in breast milk fatty acid composition of mothers of preterm and term infants?

OBJECTIVE: Arachidonic acid (ARA) (c20:4 w6) and docosahexanoic acid (DHA) (c22:6 w3) are of major importance for neural maturation and retinal function in infancy. Requirements in preterm infants are increased due to accelerated growth and limited body stores. Data regarding human milk fatty acid composition after preterm and full-term delivery is inconsistent. This study compared fatty acid composition in breast milk from full-term and preterm infants. Findings were correlated with maternal dietary intake. METHODS: Human milk was obtained 4-5 days after full-term delivery (20 infants) and 4-5, 10-11 and 14-15 days after preterm delivery (21 infants, of whom 6 were born before 30 weeks). For fatty acid analysis, lipids were extracted, transesterified and separated by gas liquid chromatography. RESULTS: Total fat content was similar in the two groups. FA composition including LCPUFA and specifically ARA & DHA were similar in full-term and preterm infants and in the sub-set born before 30 weeks. In preterm infants, postnatal age did not influence LCPUFA content. CONCLUSIONS: This study did not detect any effect of gestational age or postnatal age on milk LCPUFA content. Accordingly, the increased demand for LCPUFA and specifically DHA in preterm infants need to be met by other supplementation.

[Effect of freezing on the "creamatocrit" measurement of the lipid content of human donor milk]. / Medida por crematocrito del contenido calórico de la leche materna donada congelada.

OBJECTIVE: To determine, by the creamatocrit measurement, the effect on the fat content of raw and pasteurized donor milk of freezing during 3 months at -20 °C. METHODS: The evolution of the creamatocrit measurement (following Lucas technique) on frozen (-20 °C), raw and pasteurized human milk, was analyzed during 3 months. RESULTS: The fat content of raw milk (n=44) was 3.19 g/dl at the beginning and 2.86 g/dl after 3 months frozen (p=0.02). In pasteurized milk (n=36) fat content at the first determination was 2.59 g/dl and 2.20 g/dl after 1 month frozen (p=0.01). Afterwards there were no significant changes up to 3 months frozen. Variability was observed in the intermediate values. CONCLUSIONS: A reduction on the fat content measurement of raw and pasteurized donor human milk after freezing was observed. Freezing does not inactivate the milk lipase but does destroy the fat globule. Creamatocrit measurement may not be the best method to determine the fat content of processed human milk.

Efeito da semente de linhaça no crematócrito do leite de ratas e sua contribuição no crescimento corporal dos filhotes / Effects of flaxseed on rat milk creamatocrit and its contribution to offspring body growth

OBJETIVOS: Avaliar o efeito da semente de linhaça no crematócrito do leite de ratas e crescimento corporal dos filhotes durante a lactação. MÉTODOS: Utilizou-se 22 ratas Lister Hooded divididas em dois grupos: controle (GC, n = 11), que recebeu ração caseína com 17 por cento de proteína; e linhaça (GL, n = 11), que recebeu ração com 25 por cento de linhaça acrescida de 14 por cento de caseína, totalizando 17 por cento de proteína. Controlou-se o consumo de ração das ratas por gaiola individual, número de crias, e avaliou-se o crematócrito do leite materno e variação ponderal dos filhotes até idade de desmame. RESULTADOS: O GL foi semelhante ao GC no consumo de ração das ratas (GL = 76,46±31,87 g; GC = 76,7±33,36 g; p = 0,9613) e equivalente ao GC no número de crias (GL = 4,94±2,34; GC = 5,5±3,19; p = 0,435). O mesmo foi verificado no teor de gordura do leite materno (GL = 18,4±4,76; GC = 15,3±6,03; p = 0,204) e valor energético total (GL = 212,92±46,4; GC = 181,1±60; p = 0,1964). O GL assemelhou-se ao GC tanto no peso corporal dos filhotes ao desmame (GL = 37±6,96 g; GC = 32,6±7,5 g; p = 0,1817) quanto na evolução ponderal (GL = 31,8±7,0 g; GC = 27,7±7,5 g; p = 0,2104). CONCLUSÃO: Um total de 25 por cento de linhaça promoveu um crescimento adequado aos filhotes.

OBJECTIVES: To assess the effect of flaxseed on rat milk creamatocrit and its contribution to offspring weight gain during lactation. METHODS: The study was conducted with 22 Lister Hooded rats divided into two groups: Control Group (CG, n = 11), which received a casein-based diet with 17 percent protein, and Flaxseed Group (FG, n = 11), which received a 25 percent flaxseed diet supplemented with 14 percent casein, totaling 17 percent protein. Food consumption was controlled per individual cage and litter size. Maternal milk creamatocrit and offspring weight variation until weaning age were also evaluated. RESULTS: FG was similar to CG concerning food intake (FG = 76.46±31.87 g; CG = 76.7±33.36 g; p = 0.9613) and equivalent to CG concerning litter size (FG = 4.94±2.34; CG = 5.5±3.19; p = 0.435). The same was found for milk fat content (FG = 18.4±4.76; CG = 15.3±6.03; p = 0.204) and total energy value (FG = 212.92±46.4; CG = 181.1±60; p = 0.1964). FG was similar to CG both in offspring body weight at weaning (FG = 37±6.96 g; CG = 32.6±7.5 g; p = 0.1817) and in weight gain (FG = 31.8±7.0 g; CG = 27.7±7.5 g; p = 0.2104). CONCLUSION: A total of 25 percent flaxseed promoted an adequate offspring growth.