Poor Lactation Research Articles

Breastfeeding and Prolactin Levels in Lactating Women With a Family History of Alcoholism

Many motivated new mothers fail to reach public health goals for breastfeeding, highlighting the need to identify risk factors. Because having a family history of alcoholism is associated with blunted prolactin responses to an alcohol challenge in nonlactating individuals, this study aimed to identify associations in family history of alcoholism, prolactin, and breastfeeding behaviors in lactating women. This was a 2-day experimental study that used within-subject alcohol or control beverage consumption and between-subject family history of alcoholism factors. The participants were non-alcohol-dependent lactating women; 7 were family history-positive (FHP) for alcohol dependence, and 21 were family history-negative (FHN). Consumption of 0.4 g/kg alcohol or nonalcoholic beverage occurred in separate randomized sessions, followed by use of a breast pump. Basal and suckling-induced prolactin, blood alcohol concentrations, milk yield, self-reported drug effects, neophobia, and breastfeeding patterning were measured. Although no group differences in alcohol pharmacokinetics were detected, FHP women exhibited blunted prolactin to breast stimulation after drinking the control and alcohol beverage and felt more of the stimulant-like effects of alcohol than did FHN women. FHP women reported more frequent daily breastfeeding than did FHN women. This is the first evidence that family history of alcoholism is associated with a blunted magnitude, rapidity, and duration of the prolactin response to breast stimulation and an alcohol challenge in lactating women. More frequent breastfeeding by FHP women suggests behavioral compensation for perceived and/or actual poor lactation. Alcohol did not enhance lactational performance, further disputing the lore that alcohol is a galactagogue.

Increased Lactation Risk for Late Preterm Infants and Mothers: Evidence and Management Strategies to Protect Breastfeeding

Late preterm infants (34 0/7-36 6/7 weeks of gestation) are often cared for in general maternity units by clinicians who have limited experience with the specific needs of these newborns. Although the benefits of human milk are well documented, mothers and their late preterm infants are at risk for poor lactation outcomes. These include early breastfeeding cessation and lactation-associated morbidities, including poor growth, jaundice, and dehydration. Late preterm infants are more likely than term infants to develop temperature instability, hypoglycemia, respiratory distress, jaundice, feeding problems, and to require rehospitalization in the first 2 weeks postbirth. Breastfeeding can exacerbate these problems, because late preterm infants often lack the ability to consume an adequate volume of milk at breast, and their mothers are at risk for delayed lactogenesis. This article reviews strategies to protect breastfeeding for the late preterm infant and mother dyad by establishing and maintaining maternal milk volume while facilitating adequate infant intake.

Association of Maternal Obesity Before Conception with Poor Lactation Performance

The objective of this review is to evaluate the evidence for a link between maternal obesity and poor lactation performance. In nonhuman species, excess maternal fatness is deleterious for lactation and also for maternal health and survival. These effects occur during pregnancy and as milk production is beginning. They may result in poor growth and survival of the young. In women, there is a negative association between maternal obesity and the initiation as well as the continuation of breastfeeding. This appears to be derived from biological as well as sociocultural factors that are still poorly understood. Excessive gestational weight gain, complications of pregnancy and delivery, and the condition of the infant at birth may also contribute to this association. Given the increasingly high rates of obesity among women of reproductive age worldwide and the importance of breastfeeding for infant health, further study of this association is essential.

Risk factors for subclinical mastitis among HIV‐infected and uninfected women in Lusaka, Zambia

Subclinical mastitis, defined as raised milk sodium/potassium (Na/K) ratio, is associated with poor infant growth and, among HIV-infected women, with increased milk HIV viral load. We conducted a longitudinal cohort study in Lusaka, Zambia, in order to investigate the relative importance of several potential causes of subclinical mastitis: maternal infection, micronutrient deficiencies and poor lactation practice. Women (198 HIV-infected, 189 HIV-uninfected) were recruited at 34 weeks' gestation and followed up to 16 weeks postpartum for collection of information on their health, their infant's health, infant growth and infant feeding practices. Milk samples were collected from each breast at 11 postpartum visits and blood at recruitment and 6 weeks postpartum. The geometric mean milk Na/K ratio and the proportion of women with Na/K ratio > 1.0 in one or both breasts were significantly higher among HIV-infected than among uninfected women. Other factors associated with the higher mean Na/K ratio in univariable analyses were primiparity, high maternal alpha(1)-acid glycoprotein (AGP) at 6 weeks, maternal overall morbidity and specific breast symptoms, preterm delivery, low infant weight or length, infant thrush and non-exclusive breast feeding. In multivariable analyses, primiparity, preterm delivery, breast symptoms, HIV status and raised AGP were associated with the raised Na/K ratio. Thus the main factors associated with subclinical mastitis that are amenable to intervention are poor maternal overall health and breast health. The impact of improved postpartum health care, especially management of maternal infections and especially in primiparous women, on the prevalence of subclinical mastitis and its consequences requires investigation.

Is Maternal Obesity a Cause of Poor Lactation Performance?

Several investigators have reported a relationship between maternal obesity and low rates of initiation and duration of breast-feeding. Recent research findings suggest that poor infant feeding behavior and reduced hormonal responses in the early postpartum period result in delayed lactogenesis and early cessation of breast-feeding among overweight/obese women.

Is Maternal Obesity a Cause of Poor Lactation Performance?

Several investigators have reported a relationship between maternal obesity and low rates of initiation and duration of breast-feeding. Recent research findings suggest that poor infant feeding behavior and reduced hormonal responses in the early postpartum period result in delayed lactogenesis and early cessation of breast-feeding among overweight/obese women.

Risk Factors for Suboptimal Infant Breastfeeding Behavior, Delayed Onset of Lactation, and Excess Neonatal Weight Loss

Even mothers who strongly want to breast feed their infants could have difficulty getting started. This prospective community-based study was an attempt to identify risk factors other than sociocultural barriers that arerelated to poor lactation outcomes. Risk factors were sought for suboptimal infant breastfeeding behavior (SIBB), delayed lactation, and excessive neonatal weight loss. Participants gave birth to a healthy single infant at term and were willing to try breast feeding exclusively for at least 30 days. Trained lactation consultants provided guidance in such areas as correct positioning, demand feeding, and avoidance of supplements, and also evaluated infant breastfeeding behavior using the Infant Breast-feeding Assessment Tool. Weight loss exceeding 10% of birth weight on day 3 was considered excessive. The mean maternal age was 30.6 years and 56% of mothers were primiparous. Nearly 80% of subjects were non-Hispanic whites. The average educational level was high. These mothers expressed strongly positive attitudes toward breast feeding. SIBB was found in 49% of infants at baseline, 22% on day 3 and 14% on day 7. It correlated significantly with primiparity on days 0 and 3, with cesarean section (day 0 in multiparas), and with flat or inverted nipples. Other significant correlates of SIBB included using nonbreast milk fluids in the first 2 days of life, use of a pacifier, stage II labor lasting longer than 1 hour, and a maternal body mass index (BMI) greater than 27 kg/m 2 . Lactation was delayed in 22% of women, more frequently in primiparas, after cesarean section, and women having a prolonged second stage of labor, a high material BMI, flat or inverted nipples, or (in primiparas) a birth weight greater than 3600 g. Excessive weight loss was observed in 12% of neonates. It correlated with primiparity, a long labor, the use of labor medication (by multiparas), and infant status at birth. Excessive weight loss was 7.1-fold more likely if lactation was delayed and 2.6-fold more likely if SIBB was present on the first day of life.

High prepregnant body mass index is associated with poor lactation outcomes among white, rural women independent of psychosocial and demographic correlates.

To determine whether high prepregnant body mass index (BMI) is associated with later onset of lactogenesis II (LGII) and shorter duration of breastfeeding, we questioned 151 women about their demographic and psychosocial characteristics during pregnancy and about the onset of LGII during days 1 to 5 postpartum. Compared to women with earlier (< 72 hours) onset of LGII, those with later onset had a higher BMI (P < .05), a higher proportion of primiparity (P < .01), and a lower infant score on the Mother-Baby Assessment (P < .05). Prepregnant BMI (P < .04) and primiparity (P < .005) were each associated with later onset of LGII, but only primiparity remained significant when both factors were considered simultaneously. These results suggest that, in addition to those who have just delivered their first infant, those with higher prepregnant BMI values also warrant extra support to decrease their risk of early discontinuation of breastfeeding.

Maternal obesity and breast-feeding practices

Maternal obesity has been associated with poor lactation in animal models, but the results of related research in humans are inconclusive. We tested the hypothesis that women who are obese before pregnancy or who gain excessive weight during pregnancy are less likely to initiate and maintain breast-feeding than are their normal-weight counterparts. We analyzed 124 151 mother-infant pairs from the Pediatric Nutrition Surveillance System and the Pregnancy Nutrition Surveillance System. Body mass index (BMI) before pregnancy and gestational weight gain were categorized according to guidelines from the Institute of Medicine. Multiple logistic regression was used to identify the association between maternal obesity and breast-feeding initiation (n = 51 329), and multiple linear regression was used to examine the effect of maternal obesity on breast-feeding duration among women who initiated breast-feeding (n = 13 234). Regardless of gestational weight gain, obese women were less likely to initiate breast-feeding than were women with a normal BMI before pregnancy who also gained the recommended weight during pregnancy. Maternal BMI before pregnancy and gestational weight gain were each independently associated with duration of breast-feeding. Women who were obese before pregnancy breast-fed approximately 2 wk less than did their normal-weight counterparts, and women who either failed to reach or exceeded the recommended gestational weight gain breast-fed approximately 1 wk less than did those who gained the recommended gestational weight. Both obesity before pregnancy and inadequate weight gain during pregnancy have a negative effect on breast-feeding practice. Women who are obese before pregnancy or who gain inadequate weight during pregnancy need extra support for breast-feeding.

Patterns of parturition and mortality in weaned greater cane rats (Thryonomys swinderianus, Temminck).

The patterns of parturition and mortality were studied in a colony of weaned captive greater cane rats, Thryonomys swinderianus, Temminck, from January to December 2000 at the Grasscutter Domestication Centre, Pokoase Research Station, Animal Research Institute, Ghana. The most important finding from the study was that it is practical to wean greater cane rats at 4 weeks of age with proper post-weaning management. Mortality ranged between 0 and 3.9% with an average of 1.4% for animals weaned at 4 weeks. Among the factors contributing to mortality in the weaned greater cane rats may be the number of animals per unit space. The mortality in this study was a marked improvement compared to that of 11% reported elsewhere for animals weaned at 6 weeks. The animals were, however, smaller at weaning compared to those in reports from elsewhere, probably owing to poor lactation by the mothers. Peak parturition occurred in October with captive breeding having no influence on the parturition pattern.

Differences in mammary gland weight and litter performance between Large White sows selected for different traits

Genetic selection has increased pig lean tissue growth rate, the most extreme animals comprising the ‘sire’ lines of breeding stock. However such improvement has not been without cost in other areas of production. Sire line sows are characterised by smaller litters with poorer pre-weaning growth rates than dam line sows of the same breed. The aim of this experiment was to determine whether reduced pre-weaning growth rate of sire line piglets was due to poor lactation performance of the sow or reduced vitality of sire line piglets.

Maternal smoking and reduced duration of breastfeeding: a review of possible mechanisms.

To systematically review the possible mechanisms by which maternal smoking affects lactation. Databases (Medline, CINAHL, Current Contents, Psychinfo, Sociological Abstracts and the Cochrane Library) were searched for smoking and breastfeeding or infant feeding. The Journal of Human Lactation and Birth were hand-searched, searches were also conducted at NMAA's Lactation Resource Centre and references cited were located where appropriate. Articles were divided into the various ways that smoking could affect breastfeeding and were tabulated. Most studies were conducted on small samples of animals or humans; the majority were prior to 1985. Most animal studies exposed the animals to much greater levels of nicotine than those to which humans are exposed. Most studies did not examine if breastfeeding behaviour was similar in smokers and non-smokers, and did not consider that any physiological difference found could be the result of poor lactation practices, rather than the cause of poor lactation in smokers. The definition of breastfeeding infants was also problematic in many studies. The effect of smoking on oxytocin in women was only examined in one study, and no effect was found, yet a negative effect of smoking on oxytocin release is reported in the breastfeeding literature. Although there is consistent evidence that women who smoke breastfeed their infants for a shorter duration than non-smokers, the evidence for a physiological mechanism is not strong.

Usefulness of recombinant human prolactin for treatment of poor puerperal lactation in a rat model.

Recombinant human prolactin (r-hPRL) was produced by a line of murine C127 cells transfected with human PRL gene. To assess the biological efficacy of r-hPRL in vivo, we studied its influence on milk secretion using a rat model in which lactation was reduced by bromocriptine treatment. Puerperal rats were injected daily for 9 days after delivery with bromocriptine or bromocriptine plus r-hPRL, and lactational performance was assessed by weighing the pups. The concentrations of rat and human PRL in rat serum were measured by specific radioimmunoassays and the mammary glands were examined on postpartum day 10. Daily injection of bromocriptine (0.1 mg/rat) significantly reduced the endogenous level of rat PRL and impaired the weight gain of the pups. Administration of r-hPRL increased the serum level of human PRL. Daily injections of r-hPRL (50 micrograms/rat, twice a day) restored lactational performance and significantly increased the weight of the pups. The detrimental effect of bromocriptine on the mammary glands, assessed by both weight and histological appearance, was reversed by administration of r-hPRL. These results demonstrate that r-hPRL is biologically active in vivo and replacement therapy of r-hPRL is effective in improving the lactational performance in bromocriptine-treated rats, and also that r-hPRL may be useful for the treatment of women with poor lactation.

The effect of energy and protein intake of sows on their longevity: a review

The characterization of the effects of protein and energy intake of sows on their longevity requires long-term experiments involving large numbers of females. Results from the studies available show that sows are culled mainly for reasons involving reproductive failure, locomotion problems or poor lactation performance. Energy under-feeding during gestation is associated with lower body fat reserves at farrowing or at weaning and generally return to oestrus is delayed and conception rate is lower. On the contrary, over-feeding during gestation increases weight and condition of the sow at the end of pregnancy and this can affect the occurrence of farrowing and lactation problems and culling for poor lactation performance or locomotion problems. During lactation, it seems that there are critical levels for energy and for protein below which weaning to oestrus interval, rate of return to oestrus and pregnancy rate are affected, especially in primiparous sows. This is the main reason for early culling of sows. The mechanisms are not yet elucidated, but the metabolic status or the status of body reserves of the sows at weaning seem to be involved. It is thus necessary to apply a feeding strategy adapted to each sow, in relation to its own level of production, its behaviour and the housing conditions, in order to maintain body reserves within an optimal zone all along the reproductive life and to maximize its longevity.

Evaluation of a health education programme in China to increase breast-feeding rates

Researchers compared data on 106 pregnant women who participated in the health education program A Friend of Pregnant Women which promoted breast feeding with data on pregnant women who did not participate in this program to determine whether the program is effective at increasing breast feeding rates. All the women were from HuiHai neighborhood in Luwan District in Shanghai China. The cases were registered at the Maternal and Child Health Center. Their expected delivery dates fell between December 1990 and June 1991. Those of the controls fell between May and December 1989. Most mothers (94% and 91% respectively) wanted to breast feed and knew that breast feeding would not be difficult. Fewer cases correctly answered knowledge items in the pretest than in the posttest (44% vs. 60%). At 4 months postpartum women in the program group were significantly more likely to be breast feeding than those in the control group (44% vs. 21%). The leading reason for women not breast feeding was insufficient breast milk (76.1% of non-breast feeding mothers). Reasons for poor lactation included delayed first feed (80% within 48 hours) low frequency of breast feeding (53% less than 4 times/day) and Cesarean section which reduces lactation (50%). Many breast feeding mixed-feeding and bottle-feeding mothers (35% 42% and 44% respectively) had husbands and mothers-in-law who did not support breast feeding. Even though most mothers (92%) claimed that their physicians supported breast feeding the support did not influence the feeding chosen by mothers. Hospital policy contributed to reduced breast feeding. The hospital staff placed mothers and babies in different wards. They gave most newborns sugar feeds before their first breast feeding. The hospital accepted artificial milk products. The nurses heavy workload did not allow them time to educate mothers about breast feeding. After changing the hospital policy the breast feeding rate at time of discharge is now more than 90%.

Growth patterns of breast-fed infants in affluent (United States) and poor (Peru) communities: implications for timing of complementary feeding

We compared growth, dietary intake, and morbidity of infants breast-fed for > or = 12 mo from two populations: Davis, CA (n = 46) and Huascar, Peru (n = 52). When compared against WHO reference data (based primarily on formula-fed infants), Huascar infants appeared to falter as early as 3-4 mo, but when compared with Davis breast-fed infants, the curves for weight and length were very similar in girls until 10-12 mo and in boys until 6-9 mo. Thereafter, Huascar infants grew less rapidly than did Davis infants. Breast milk intake was very similar between groups, but in Huascar the amount and nutrient density of complementary foods consumed after 6 mo were lower and morbidity rates were much higher than in Davis. These results indicate that growth faltering of Huascar infants, when judged against breast-fed infants in the United States, occurs primarily after the first 6 mo of life and is not due to poor lactation performance.

Effects of far-infrared radiation on lactation.

Massage and warm compresses to the breast have been commonly used for stimulating and/or increasing blood flow to the breasts, and for enhancing lactation consequently. However, more effective and easier remedies seem to be necessary. The vasodilating and warming effects of ceramics far-infrared radiation were studied. Based on the results obtained, the effect of a ceramic disc on lactation, attached to the breast skin, was evaluated in 27 puerperal women who had had poor lactation previously and in 36 with currently poor lactation monthly until weaning. Approximately 3/4 of these puerperal women enhanced lactation significantly one month after attachment and 1/2 of the women were able to breast-feed until weaning. Thus, we found that ceramics far-infrared radiation may be an effective remedy for enhancing lactation.

A DOSE RESPONSE RELATION BETWEEN IMPROVED LACTATION AND METOCLOPRAMIDE

In a placebo-controlled, cross-over study, thirty-seven puerperal women with inadequate production of breast-milk were treated with 5, 10, or 15 mg of metoclopramide three times a day for 2 weeks. Doses of 10 or 15 mg significantly raised maternal serum prolactin; they also increased breast-milk secretion by 42.5±34.7 (SD) ml and 50.0+35.9 ml per feed, respectively. This effect was unrelated to the phase of the puerperium during which treatment was started. The increase in milk secretion was associated with a decreased need for supplementary feeds, and 33% ofthe infants ofthese mothers needed no supplementary feeds during treatment. 5 mg doses did not stimulate prolactin or milk secretion. Although placebo had no objective effect on the milk yield, 24% of the women judged its effect to be good, and 89% of women on metoclopramide reported a good effect. Seven women on metoclopramide and three women on the placebo complained of slight side-effects. No adverse effects upon the infants were observed. Metoclopramide therapy may be useful for improving poor lactation.

Metoclopramide increases prolactin release and milk secretion in puerperium without stimulating the secretion of thyrotropin and thyroid hormones.

To explore the effect of metoclopramide (MC) on the secretion of PRL, TSH, and thyroid hormones (T3 and T4) and on defective lactation, 17 mothers with poor lactation were treated with oral MC (10 mg. three times daily) for 3 weeks starting 18-141 days post partum. After a pause of 1 week, the medication was given for a further 2 weeks. The breast milk yield was monitored objectively before and during the trial. Furthermore, iv stimulation tests with MC (10 mg) and TRH (200 microgram) were done before and at the end of oral MC therapies. Oral MC increased the mean (+/-SEM) plasma PRL level from 36.6 +/- 9.2 to 90.6 +/- 7.5 ng/ml (P less than 0.001) after 1 week, and the PRL level remained elevated for as long as MC was administered. During the pause, the PRL level decreased to 19.5 +/- 7.5 ng/ml, but increased once again during the second MC treatment to 85.5 +/- 16.0 ng/ml (P less than 0.01). Plasma TSH, T3, and T4 did not change. The PRL level rose significantly after TRH and MC injections before and during oral treatments with MC, whereas the TSH concentrations were elevated only after TRH stimulation. The PRL response to iv MC or TRH and the TSH response to iv TRH were not affected by oral MC treatment. The mean daily milk volume increased from 433 +/- 55 to 626 +/- 75 ml (P less than 0.001) during the first treatment and from 390 +/- 73 to 606 +/- 56 ml (P less than 0.01) during the second oral MC treatment. Correspondingly, the volume of daily supplemental alimentation decreased from 348 +/- 61 to 280 +/- 59 ml (P less than 0.05) and from 526 +/- 68 to 363 +/- 66 ml (P less than 0.01), respectively. MC caused no significant side effects.

Growth hormone, prolactin and chorionic somatomammotropin in normal, molar pregnancy and puerperium (author's transl)

In order to know the secretory behaviors of human growth hormone (hGH), human prolactin (hPRL), and chorionic somatomammotropin (hCS) in normal and molar pregnancy or puerperium, and after evacuation of hydatidiform mole, the following studies were undertaken.Forty five normal pregnant women of every period of gestation, 40 women of postpartum (good or poor lactation), 20 patients with molar pregnancy between the 13th and 19th gestational week, 25 patients with good prognosis after the evacuation of hydatidiform mole, 20 patients with destructive mole, and five nonpregnant subjects volunteered for this study.All studies were started at 0800h after an overnight fast. The subjects reported to the endocrine research facility and were placed at bed rest in a quiet room for about one hour. A#18 Medicut was placed in an antecubital vein and kept patent with a slow drip of normal saline. Two baseline blood samples were drawn 15 min. apart and the results were averaged. Immediately after the second sampling, 30g of arginine was administered intravenously over 30 min. Blood samples were collected at 30, 45, 60, 90 and 120 min. after the initiation of the infusion.Serum was immediately separated from the blood samples by centrifugation of 3000 rpm for 10 min. and stored for assay at-20°C. HGH levels were measured by a radioimmunoassay kit (Dinabot, Tokyo, Japan). Serum hPRL was determined by a double antibody radioimmunoassay system using hPRL supplied by NIH-NIAMDD, U.S.A. HCS level was measured by the hCS-Kobe double antibody radioimmunoassay system. Immunological crossreaction was not observed between these radioimmunoassay systems within the assay ranges. Serum 17β-estradiol and progesterone were measured by a CIS(CEA-IRE-SORIN, France)'s radioimmunoassay kit for each of the steroid hormones. Statistical analysis was carried out using a Student's t test.1. The secretions of serum hGH, hPRL and hCS during normal pregnancy were as follows : The baseline level of hGH remained almost unchanged throughout the course of pregnancy, but that of hPRL and hCS increased with the progress of pregnancy.The hGH response to arginine infusion decreased (p=n.s. in first trimester, P<0.01 in second trimester, P<0.001 in third trimester), but the hPRL response increased along with the progress of pregnancy (p=n.s. in first trimester, PC0.001 in second and third trimester).During arginine infusion, the hCS concentration did not change.2. The secretions of serum hGH and hPRL in puerperium were as follows : The baseline level of hGH did not change as compared to that of nonpregnant or pregnant women.The hGH response to arginine infusion was suppressed at the first postpartum week (P<0.01), then recovered to the nonpregnant level at the fifth postpartum week.Basal and response hPRL maintained a high level from the first to third postpartum week, and decreased at the fifth postpartum week (P<0.001-0.01, respectively).No significant difference was seen in basal and response hPRL among the subjects with good or poor lactation.3. The secretions of serum hGH, hPRL, hCS and steroid hormones in molar pregnancy were as follows : The baseline level of hGH did not change as compared to that of nonpregnant or pregnant women.The hGH response to arginine infusion in molar pregnancy was greater than that in normal pregnancy (P<0.01).Basal and response hPRL were higher than that of normal pregnant women in the same gestational week (P<0.01).On an average, hCS concentration in molar pregnancy was 0.22/μg/ml and significantly low compared to that in normal pregnancy (P<0.001).The mean value of 1713-estradiol was lower in molar pregnancy than in normal pregnancy (P<0.01), but no significant difference existed regarding the levels of progesterone.4. The secretions of serum hGH,