The effects of early pacifier use on breastfeeding: A randomised controlled trial

BACKGROUND

The majority of observational studies have found associations between pacifier use and shorter breastfeeding duration. Results from four randomised controlled trials did not reveal any difference in breastfeeding outcomes. The relationship between early pacifier use and breastfeeding outcomes remains unclear.

AIM

To investigate whether a recommendation of early pacifier use affects the proportion of breastfeeding at six months compared to a recommendation to avoid pacifier use during the first two weeks.

METHODS

An open, randomised controlled trial with parallel group design; 239 primiparous mothers and their term infants were randomly assigned to an intervention group or a control group. The primary outcome was the proportion of breastfeeding at six months. Secondary outcomes were the proportions of breastfeeding and breastfeeding problems at two and four months. To investigate factors which may influence breastfeeding, a multivariate logistic regressions analysis was performed.

FINDINGS

A total of 209 participants (87.5%) completed the study. There were no significant differences between the groups with respect to breastfeeding at six months. No negative association for breastfeeding between early versus late introduction of pacifier was found. Factors significantly associated with cessation of breastfeeding at six months were: use of nipple shield, intention to breastfeed, severe breastfeeding problems at two weeks, pacifier use at two months and lower educational level.

CONCLUSION

Early versus late recommendation of pacifier introduction did not affect the proportion of breastfeeding at six months. However, the compliance to the randomised group was insufficient. No negative association was found in the observational analysis.

Precision of MRI-based body composition measurements of postmenopausal women

OBJECTIVES

To determine precision of magnetic resonance imaging (MRI) based fat and muscle quantification in a group of postmenopausal women. Furthermore, to extend the method to individual muscles relevant to upper-body exercise.

MATERIALS AND METHODS

This was a sub-study to a randomized control trial investigating effects of resistance training to decrease hot flushes in postmenopausal women. Thirty-six women were included, mean age 56 ± 6 years. Each subject was scanned twice with a 3.0T MR-scanner using a whole-body Dixon protocol. Water and fat images were calculated using a 6-peak lipid model including R2*-correction. Body composition analyses were performed to measure visceral and subcutaneous fat volumes, lean volumes and muscle fat infiltration (MFI) of the muscle groups' thigh muscles, lower leg muscles, and abdominal muscles, as well as the three individual muscles pectoralis, latissimus, and rhomboideus. Analysis was performed using a multi-atlas, calibrated water-fat separated quantification method. Liver-fat was measured as average proton density fat-fraction (PDFF) of three regions-of-interest. Precision was determined with Bland-Altman analysis, repeatability, and coefficient of variation.

RESULTS

All of the 36 included women were successfully scanned and analysed. The coefficient of variation was 1.1% to 1.5% for abdominal fat compartments (visceral and subcutaneous), 0.8% to 1.9% for volumes of muscle groups (thigh, lower leg, and abdomen), and 2.3% to 7.0% for individual muscle volumes (pectoralis, latissimus, and rhomboideus). Limits of agreement for MFI was within ± 2.06% for muscle groups and within ± 5.13% for individual muscles. The limits of agreement for liver PDFF was within ± 1.9%.

CONCLUSION

Whole-body Dixon MRI could characterize a range of different fat and muscle compartments with high precision, including individual muscles, in the study-group of postmenopausal women. The inclusion of individual muscles, calculated from the same scan, enables analysis for specific intervention programs and studies.