Endocrinology of lactation

No Measurable Transfer of Oxytocin-Receptor Agonist Merotocin Detected in Human Breast Milk

Objective: The study aimed to assess the transfer of merotocin from systemic circulation to breast milk in early postpartum women and women with established lactation. Methods: This was a two-part, multicenter, open-label, parallel-group study. Merotocin was administered as a single 90-minute intravenous (iv) infusion mimicking the intranasal pharmacokinetic profile. In Part A, 12 early postpartum women received doses of either 4 μg (n = 6) or 16 μg (n = 6) of merotocin within 4 days of delivery. In Part B, six women with established lactation received 20 μg of merotocin. The total concentration of merotocin in plasma and breast milk and its metabolites excreted in breast milk were measured at various time points. Adverse events (AEs) were also assessed for both parts of the study. Results: In both early postpartum and established lactation groups (mean age, 26.3 years; 83.3% Caucasian), merotocin and its metabolites in breast milk were below the limit of quantification (25.0 pg/mL) at all time points. Sixteen treatment-emergent AEs occurred in early postpartum women only, including seven events of uterine spasm and three of breast engorgement. There was one moderate event, whereas all the other events were considered mild. Conclusion: Merotocin was undetectable in breast milk after single iv administration of up to 20 μg in early postpartum women and women with established lactation.

Characteristics of reproductive history, use of exogenous hormones and walking speed among women: Data from the CONSTANCES French Cohort Study

OBJECTIVE

To investigate the cross-sectional associations of reproductive history and use of exogenous hormones with fast walking speed (WS) in women.

STUDY DESIGN

Between 2012 and 2020, 33,892 French women aged 45 years or more, recruited at health centers, underwent physical function tests and self-reported information on reproductive history and use of exogenous hormones. Linear mixed models with the center as random intercept were used to estimate the association of exposures with WS.

MAIN OUTCOME MEASURES

Fast WS.

RESULTS

Mean WS was 172.2 cm/s. WS increased with age at menarche (β_+1y = 0.23, 95 % confidence interval = 0.05 to 0.40), age at first birth (β_+1y = 0.20, 95 % CI = 0.13 to 0.27) and duration of breastfeeding (β_{for ≥10 vs ≤5months} = 1.38; 95 % CI = 0.39 to 2.36). In addition, parity was quadratically associated with WS, with women with 3 children having the highest WS (p for U-shaped relationship < 0.01). Menopausal status had no impact on WS but age at menopause was positively associated with WS (β_+5y = 0.52, 95 % CI = 0.17 to 0.87) and partly explained the deleterious impact of artificial menopause on WS. WS increased with reproductive lifetime duration (β_+5y = 0.49, 95 % CI = 0.16 to 0.83) and decreased with time since onset of menopause (β_+5y = -0.65, 95 % CI = -0.99 to -0.31). By contrast, there was no association of WS with oral contraception and postmenopausal hormone therapy.

CONCLUSION

Our findings suggest that reproductive life characteristics may be associated with WS and timing of exposure could play a role.

Study protocol for the sheMATTERS study (iMproving cArdiovascular healTh in new moThERS): a randomized behavioral trial assessing the effect of a self-efficacy enhancing breastfeeding intervention on postpartum blood pressure and breastfeeding continuation in women with hypertensive disorders of pregnancy

BACKGROUND

Individuals with hypertensive disorders of pregnancy (HDP) have an elevated lifetime risk of chronic hypertension, metabolic syndrome, and premature cardiovascular disease. Because breastfeeding duration and exclusivity have been associated in observational studies with improved cardiovascular health, optimizing breastfeeding in those with HDP might be an unrealized cardio-prevention approach, in particular because individuals with HDP have more breastfeeding challenges. Breastfeeding supportive interventions targeting one's breastfeeding self-efficacy have been shown to improve breastfeeding rates.

METHODS

We designed an open-label, multi-center 1:1 randomized behavioral trial to test whether a previously validated self-efficacy enhancing breastfeeding intervention can improve breastfeeding duration and/or exclusivity, and lower postpartum blood pressure at 12 months. Randomization is computer-generated and stratified by site (four hospitals in Montreal, Quebec and one hospital in Kingston, Ontario; all in Canada). Included are breastfeeding participants with HDP (chronic/gestational hypertension or preeclampsia) who delivered a live singleton infant at > 34 weeks, speak English or French, and have no contraindications to breastfeeding. Informed and written consent is obtained at hospitalization for delivery or a re-admission with hypertension within 1 week of discharge. Participants assigned to the intervention group receive a breastfeeding self-efficacy-based intervention delivered by a trained lactation consultant in hospital, with continued reactive/proactive support by phone or text message for up to 6 months postpartum. Regardless of group assignment, participants are followed for self-reported outcomes, automated office blood pressure, and home blood pressure at several time points with end of follow-up at 12 months.

DISCUSSION

This study will assess whether an intensive nurse-led behavioral intervention can improve breastfeeding rates and, in turn, postpartum blood pressure - an early marker for atherosclerotic cardiovascular disease. If effective, this form of enhanced breastfeeding support, along with closer BP and metabolic surveillance, can be implemented broadly in individuals lactating after HDP.

TRIAL REGISTRATION

ClinicalTrials.gov, # NCT04580927 , registered on Oct 9, 2020.

Parity predicts allonursing in a cooperative breeder

In some mammals that breed cooperatively, nonbreeding female helpers nurse offspring born to the breeding female in their group, a process known as allonursing. Previous laboratory studies have suggested that primiparous and multiparous females (those that have successfully given birth once or more, respectively) are more likely to contribute to allonursing than nulliparous females (those that have not given birth). In contrast, few field studies have been able to demonstrate whether breeding experience, or parity, affects the likelihood or duration of allonursing. In this study, we investigated whether the likelihood and duration of allonursing by subordinate female meerkats (Suricata suricatta) were associated with variations in their parity (number of pregnancies reaching a viable gestational age) and their immediate pregnancy status. Comparisons showed that nonpregnant nulliparous females were less likely to allonurse than nonpregnant primiparous and multiparous females, although parity was not related to variation in allonursing duration. Parity may enhance the expression of maternal behavior when exposed to foster pups, especially since mammary gland development has been shown to be directly associated with parity in other mammals.

A U-shaped Association of Breastfeeding Duration with Cognitive Impairment in Chinese Postmenopausal Women

Breastfeeding is related to maternal health. However, the association of women’s breastfeeding duration with cognitive function in their later life is limited and inconsistent. The aim of this study was to accurately evaluate the association in Chinese postmenopausal women. We analyzed the data from Zhejiang Ageing and Health Cohort Study including 5487 postmenopausal women. Cognitive impairment was assessed via the Mini-Mental State Examination. Data on breastfeeding duration was collected in the reproductive history section within the questionnaire. Generalized additive models (GAMs) and logistic regression models, controlled for an extensive range of potential confounders, were generated to examine the associations. A U-shaped association was identified between breastfeeding duration and cognitive impairment based on GAM. The nadir with lowest odds of cognitive impairment was ascertained by quadratic model as 12 months. The logistic models showed that compared with women breastfeeding 12 months per child, the fully adjusted odds ratios (ORs) were 1.50 (95% Confidence Interval (CI): 1.20–1.88), 1.58 (95% CI: 1.29–1.93), 1.33 (95% CI: 1.06–1.68), 2.08 (95% CI: 1.64–2.65) for those averagely breastfeeding <6, 6-<12,>12–18,>18 months, respectively. Furthermore, we did not observe significant effect modification of the association. Future longitudinal studies are needed to confirm the association.

Role of Oxytocin/Vasopressin-Like Peptide and Its Receptor in Vitellogenesis of Mud Crab

Oxytocin (OT)/vasopressin (VP) signaling system is important to the regulation of metabolism, osmoregulation, social behaviours, learning, and memory, while the regulatory mechanism on ovarian development is still unclear in invertebrates. In this study, Spot/vp-like and its receptor (Spot/vpr-like) were identified in the mud crab Scylla paramamosain. Spot/vp-like transcripts were mainly expressed in the nervous tissues, midgut, gill, hepatopancreas, and ovary, while Spot/vpr-like were widespread in various tissues including the hepatopancreas, ovary, and hemocytes. In situ hybridisation revealed that Spot/vp-like mRNA was mainly detected in 6–9th clusters in the cerebral ganglion, and oocytes and follicular cells in the ovary, while Spot/vpr-like was found to localise in F-cells in the hepatopancreas and oocytes in the ovary. In vitro experiment showed that the mRNA expression level of Spvg in the hepatopancreas, Spvgr in the ovary, and 17β-estradiol (E₂) content in culture medium were significantly declined with the administration of synthetic SpOT/VP-like peptide. Besides, after the injection of SpOT/VP-like peptide, it led to the significantly reduced expression of Spvg in the hepatopancreas and subduced E₂ content in the haemolymph in the crabs. In brief, SpOT/VP signaling system might inhibit vitellogenesis through neuroendocrine and autocrine/paracrine modes, which may be realised by inhibiting the release of E₂.

Molecular cloning and distribution of oxytocin/vasopressin-like mRNA in the blue swimming crab, Portunus pelagicus, and its inhibitory effect on ovarian steroid release

This study was aimed to characterize the full length of mRNA of oxytocin/vasopressin (OT/VP)-like mRNA in female Portunus pelagicus (PpelOT/VP-like mRNA) using a partial PpelOT/VP-like sequence obtained previously in our transcriptome analysis (Saetan, 2014) to construct the primers. The PpelOT/VP-like mRNA was 626 bp long and it encoded the preprohormones containing 158 amino acids. This preprohormone consisted of a signal peptide, an active nonapeptide (CFITNCPPG) followed by the dibasic cleavage site (GKR), and the neurophysin domain. Sequence alignment of the PpelOT/VP-like peptide with those of other animals revealed strong molecular conservation. Phylogenetic analysis of encoded proteins revealed that the PpelOT/VP-like peptide was clustered within the group of crustacean OT/VP-like peptide. Analysis by RT-PCR revealed the expression of mRNA transcripts in the eyestalk, brain, ventral nerve cord (VNC), ovary, intestine and gill. The in situ hybridization demonstrated the cellular localizations of the transcripts in the central nervous system (CNS) and ovary tissues. In the eyestalk, the mRNA expression was observed in the neuronal clusters 1-5 but not in the sinus gland complex. In the brain and the VNC, the transcripts were detected in all neuronal clusters but not in the glial cell. In the ovary, the transcripts were found in all stages of oocytes (Oc1, Oc2, Oc3, and Oc4). In addition, synthetic PpelOT/VP-like peptide could inhibit steroid release from the ovary. The knowledge gained from this study will provide more understanding on neuro-endocrinological controls in this crab species.

Breastfeeding: A Review of Its Physiology and Galactogogue Plants in View of Traditional Persian Medicine

INTRODUCTION

The beneficial effects of breastfeeding for the infant and mother are well recognized. Many natural products are reputed to be galactogogue agents in major Traditional Persian Medicine (TPM) textbooks. The aim of this study is to review those medicinal plants that are reported to be effective in increasing breast milk in TPM and to compare the data from TPM texts with the findings of modern pharmacological and clinical research.

MATERIALS AND METHODS

Data on the medicinal plants used to increase breast milk were obtained from major TPM textbooks. A detailed search in PubMed, Science Direct, Scopus, Google Scholar, and Web of Science databases was performed to confirm the effects of medicinal plants mentioned in TPM on lactation in view of the identified pharmacological actions.

RESULTS

Foeniculum vulgare, Anethum graveolens, Pimpinella anisum, Nigella sativa, and Vitex agnus-castus are among the most effective galactogogue TPM plants. Many pharmacologically relevant activities have been reported for these herbs.

CONCLUSION

The use of traditional knowledge can pave the way toward finding effective phytopharmaceuticals for increasing breast milk.

Intestinal transepithelial permeability of oxytocin into the blood is dependent on the receptor for advanced glycation end products in mice

Plasma oxytocin (OT) originates from secretion from the pituitary gland into the circulation and from absorption of OT in mother's milk into the blood via intestinal permeability. However, the molecular mechanism underlying the absorption of OT remains unclear. Here, we report that plasma OT concentrations increased within 10 min after oral delivery in postnatal day 1-7 mice. However, in Receptors for Advanced Glycation End Products (RAGE) knockout mice after postnatal day 3, an identical OT increase was not observed. In adult mice, plasma OT was also increased in a RAGE-dependent manner after oral delivery or direct administration into the intestinal tract. Mass spectrometry evaluated that OT was absorbed intact. RAGE was abundant in the intestinal epithelial cells in both suckling pups and adults. These data highlight that OT is transmitted via a receptor-mediated process with RAGE and suggest that oral OT supplementation may be advantageous in OT drug development.

Effect of Lactation on myocardial vulnerability to ischemic insult in rats

Background

Cardiovascular diseases are the leading cause of mortality and long-term disability worldwide. Various studies have suggested a protective effect of lactation in reducing the risk of cardiovascular diseases.

Objective

This study was designed to assess the effects of pregnancy and lactation on the vulnerability of the myocardium to an ischemic insult.

Methods

Eighteen female rats were randomly divided into three groups: ischemia-reperfusion (IR), in which the hearts of virgin rats underwent IR (n = 6); lactating, in which the rats nursed their pups for 3 weeks and the maternal hearts were then submitted to IR (n = 6); and non-lactating, in which the pups were separated after birth and the maternal hearts were submitted to IR (n = 6). Outcome measures included heart rate (HR), left ventricular developed pressure (LVDP), rate pressure product (RPP), ratio of the infarct size to the area at risk (IS/AAR %), and ventricular arrhythmias - premature ventricular contraction (PVC) and ventricular tachycardia (VT).

Results

The IS/AAR was markedly decreased in the lactating group when compared with the non-lactating group (13.2 ± 2.5 versus 39.7 ± 3.5, p < 0.001) and the IR group (13.2 ± 2.5 versus 34.0 ± 4.7, p < 0.05). The evaluation of IR-induced ventricular arrhythmias indicated that the number of compound PVCs during ischemia, and the number and duration of VTs during ischemia and in the first 5 minutes of reperfusion in the non-lactating group were significantly (p < 0.05) higher than those in the lactating and IR groups.

Conclusion

Lactation induced early-onset cardioprotective effects, while rats that were not allowed to nurse their pups were more susceptible to myocardial IR injury.

Oxytocin Mediates a Calming Effect on Postpartum Mood in Primiparous Mothers

OBJECTIVES

The current study sought to characterize changes in salivary oxytocin (OT) secretion patterns across the breastfeeding cycle, and to evaluate whether breastfeeding has a positive effect on mood disturbances related to postpartum depression, via endogenous OT release.

MATERIALS AND METHODS

Twenty-four primiparous mothers who delivered vaginally at term and were exclusively breastfeeding were examined 4-5 days postpartum. Salivary OT was measured using enzyme immunoassays at 30 minutes before breastfeeding (baseline), during breastfeeding (feeding), and 30 minutes after completing breastfeeding (postfeeding). In addition, maternal mood changes were evaluated at baseline and postfeeding using the Profile of Mood States (POMS) questionnaire.

RESULTS

OT levels rose significantly during feeding (p_corr < .05) and postfeeding (p_corr < 0.05), compared with baseline. POMS scores for Tension-Anxiety were decreased postfeeding compared with baseline (p < 0.001). This decrease was significantly associated with increased OT (feeding minus baseline: r = -0.52, r_part = -0.51, postfeeding minus baseline: r = -0.53, r_part = -0.52, ps < 0.05). POMS scores for Fatigue and Confusion also decreased, while Vigor significantly increased. Significant correlations were found between Fatigue decreases and OT increases (feeding minus baseline: r = -0.48, r_part = -0.53, postfeeding minus baseline: r_part = -0.60, ps < 0.05). This result partially contradicted with the finding of no correlation between increased Vigor and increased OT.

CONCLUSIONS

OT is released across the breastfeeding cycle and can be detected with salivary measurement. This OT release exhibited a temporary anxiolytic-like calming effect on postpartum maternal mood disturbances.

Are Prolactin Levels Linked to Suction Pressure?

BACKGROUND

Suction pressure has been reported to be a key driving force of lactation. An infant's sucking at its mother's breasts is the major stimulus to post-natal prolactin (PRL) secretion, and PRL is the essential hormone for lactation and milk production. It is unknown what role suction pressure has in PRL secretion and milk supply postnatally.

OBJECTIVES

To explore the relationship between the suction pressure, PRL level, lactation, and milk supply in breastfeeding mother-infant dyads.

METHODS

Healthy women with normal full-term infants were enrolled (n = 122). Data collection included suction pressure, PRL level, and the mother's perception of both the onset of her lactation and her milk supply at 1 month. Suction pressure was measured with a pressure sensor connected to a tube placed alongside the nipple. The chemiluminescence method was used to quantify maternal serum PRL level both before and after a breastfeed to explore the effect of suckling on PRL increment. The mother's perception of the onset of her lactation was evaluated by the mother's sense of fullness in her breast. The mother's perception of milk supply was evaluated by using the H&H Lactation Scale.

RESULTS

Data from 117 participants were included in this analysis. Low suction pressure, a shorter gestational age, a high pre-gestational body mass index (BMI), and high infant birth weight were associated with a smaller than average PRL increment. High suction pressure, longer sucking duration, and a low gestational weight gain were related to a mother's perception of an earlier onset of her lactation. However, low suction pressure, a high frequency of giving formula, a small PRL increment, and the mother's perception of a later onset of her lactation were correlated with her perception of an insufficient milk supply.

CONCLUSIONS

Suction pressure varied directly with the post-natal PRL increment. Suction pressure was associated with the timing of the mother's perception of her lactation. Strong suction pressure by the infant is likely to enhance the mother's confidence in her lactation. Additionally, sucking duration, frequency of giving formula, maternal BMI, and infant birth weight played a role in early breastfeeding success.

Migraine and reproductive life

Migraine is prevalent in women during the fertile age. Indeed, both neuroendocrine events related to reproductive stages (menarche, pregnancy, and menopause) and menstrual cyclicity and the use of exogenous sex hormones, such as hormonal contraception and replacement therapy, may cause significant changes in the clinical pattern of migraine. Menstrual migraine may be more severe, long-lasting, and refractory to both acute and prophylactic treatment and, therefore, requires tailored strategies. The use of headache diaries, which makes it possible to record prospectively the characteristics of every attack, is of paramount importance for evaluating the time pattern of headache and for identifying a clear link with menstrual cycle-related features. Estrogen variations are highly implicated in modulating the threshold to challenges by altering neuronal excitability, cerebral vasoactivity, pain sensitivity, and neuroendocrine axes throughout the menstrual cycle and not only at the time of menstruation. On the other hand, estrogen withdrawal may really constitute a triggering factor for migraine in women with peculiar characteristics of vulnerability with menstruation or following the discontinuation of exogenous estrogen, as happens with hormonal contraception during the fertile age or with hormone therapy at menopause. In addition, exogenous estrogen may contribute to the occurrence of neurological symptoms, such as aura. When aura occurs, hormonal treatment should be discontinued.

Breastfeeding and pelvic girdle pain: a follow-up study of 10,603 women 18 months after delivery

OBJECTIVE

To study the associations of patterns and duration of breastfeeding with the persistence of pelvic girdle pain 18 months after delivery.

DESIGN

Longitudinal population study.

SETTING

Norway, for the period 1999-2011.

POPULATION

A follow-up of 10 603 women with singleton deliveries in the Norwegian Mother and Child Cohort Study who reported pelvic girdle pain at 0-3 months postpartum.

METHODS

Data were obtained by four self-administered questionnaires and linked to the Medical Birth Registry of Norway.

MAIN OUTCOME MEASURE

Pelvic girdle pain, defined as combined anterior and bilateral posterior pelvic pain, 18 months after delivery.

RESULTS

Eighteen months after delivery, 7.8% of respondents (829/10,603) reported pelvic girdle pain. Breastfeeding patterns at 5 months after delivery were not associated with persistence of pelvic girdle pain. The proportion of women with pelvic girdle pain 18 months after delivery increased as the duration of breastfeeding decreased (test for trend, P < 0.001). The estimated associations attenuated after adjustment for educational level, smoking status, and body mass index, but remained statistically significant for the association between 0 and 2 months of breastfeeding and persistent pelvic girdle pain (adjusted odds ratio 1.34; 95% confidence interval 1.03-1.75). The association of short breastfeeding duration with persistent pelvic girdle pain was only present in women with body mass index ≥25 kg/m(2) .

CONCLUSIONS

Breastfeeding was associated with a small beneficial effect on the recovery process of pelvic girdle pain in women with a body mass index ≥25 kg/m(2) . Among women with pelvic girdle pain, breastfeeding should be encouraged in accordance with the existing child-feeding recommendations.

The effect of maternal stress activation on the offspring during lactation in light of vasopressin

Although it is obvious that preconceptional effects as well as stressors during pregnancy profoundly influence the progeny, the lactation period seems to be at least as important. Here we summarize how maternal stressors during the lactation period affect the offspring. As vasopressin is one of the crucial components both for stress adaptation and social behavior, special emphasis was given to this neuropeptide. We can conclude that stressing the mother does not have the same acute effect on the hypothalamo-pituitary-adrenocortical axis (as the main target of stress adaptation) of the pups as stressing the pups, but later endocrine and behavioral consequences can be similar. Vasopressin plays a role in acute and later consequences of perinatal stressor applied either to the mother or to the offspring, thereby contributing to transmitting the mothers' stress to the progeny. This mother-infant interaction does not necessarily mean a direct transmission of molecules, but rather is the result of programming the brain development through changes in maternal behavior. Thus, there is a time lag between maternal stress and stress-related changes in the offspring. The interactions are bidirectional as not only stress in the dam but also stress in the progeny has an effect on nursing.

Estrogen in the fetus

Estradiol and other estrogens are important modulators of fetal and maternal physiology in pregnancy. Much is known about the biosynthesis of estrogens in fetus and mother, and much is known about the role that estrogen plays in labor and delivery. However, much less is known about the regulation of estrogen biosynthesis throughout the latter half of gestation, and the role that estrogen plays in homeostatic and neuroendocrine control in the fetus. This review focuses on the biosynthesis and actions of estrogen in the fetal circulation, the role that it plays in the development of the fetus in the latter half of gestation, and the role that is played by the estrogen milieu in the control of the timing of birth. Estrogen circulates in fetal blood in both unconjugated and conjugated molecular forms, with the conjugated steroids far more abundant than the unconjugated steroids. This review therefore also addresses the biological significance of the variety of molecular forms of estrogen circulating in fetal and maternal blood.

Serotonin and dopamine in the hypothalamus of control and malnourished mother rats during pregnancy and lactation and body composition of their offspring

OBJECTIVE

To determine concentrations of serotonin and dopamine in the hypothalamus of undernourished rats and controls during pregnancy and lactation and body composition of their offspring.

METHODS

Malnourished rats along with control rats were used during pregnancy and lactation. At birth of their offspring, control mothers nursed their young and malnourished rats and the undernourished mothers nursed their offspring and control pups. On days 5, 10, 15, and 21 of lactation (at the beginning and end of a feeding), L-tryptophan (L-Trp)-free, bound and total, plasma prolactin (PRL) and milk composition were determined. Serotonin and dopamine were measured in the hypothalamus. Body composition of offspring was determined.

RESULTS

Increase of free L-Trp was confirmed in undernourished mothers. Furthermore, hypothalamic serotonin was elevated at the start of suckling and decreased at termination. There was also a decrease in dopamine in the hypothalamus at the beginning and end of suckling followed by an increase of plasma PRL that was greater in control mothers who breastfed malnourished offspring. Interestingly, undernourished offspring consumed more milk and showed a clear recovery of body composition with accumulation of body fat.

DISCUSSION

Changes observed in hypothalamic neurotransmitters appear to be closely related to nutritional status and to the response and control of PRL production, possibly to adapt the offspring to the metabolic changes. It was also confirmed that on-demand feeding of undernourished offspring is the main factor involved in nutritional recovery and a predisposition to overweight in the recovered undernourished animals.

The effect of low-to-moderate-dose ethanol consumption on rat mammary gland structure and function and early postnatal growth of offspring

High levels of alcohol consumption during pregnancy can lead to growth deficits in early postnatal life. However, the effects of low-to-moderate alcohol consumption during pregnancy are less clearly defined. The aim of this study was to determine whether low-to-moderate ethanol (EtOH) consumption throughout pregnancy in the rat alters maternal mammary gland morphology and milk protein levels, thereby affecting lactation and the growth of pups after birth. Sprague-Dawley rats were fed an ad libitum liquid diet ± 6% vol/vol EtOH throughout pregnancy. Mammary glands from dams were collected at embryonic day (E) 20 or postnatal day (PN) 1, and expression of milk proteins (α-lactalbumin, β-casein, and whey acidic protein) was examined. In addition, relative amounts of alveoli, lactiferous ducts, adipose tissue, and blood vessels were determined at PN1. A subset of rats gave birth, and offspring growth and milk intake were recorded. Mammary gland weight was unaltered by EtOH, and stereological analysis showed no differences in gland structure compared with control. Although there were no significant changes in mammary gland gene expression at the RNA level, protein levels of α-lactalbumin were increased and whey acidic protein were decreased by EtOH. Offspring of EtOH-fed dams consumed less milk than controls in the lactational period; however, this did not alter their early postnatal growth. Overall, it appears that low-to-moderate-dose prenatal EtOH exposure does not significantly alter mammary gland development but may alter the composition of the various proteins found within the milk in a manner that maintains overall pup growth.

A systematic review of early postpartum medroxyprogesterone receipt and early breastfeeding cessation: evaluating the methodological rigor of the evidence

BACKGROUND

Breastfeeding has numerous maternal and infant benefits. Progesterone contraception after birth is frequently recommended, but because a decrease in progesterone is required to initiate lactation, early postpartum progesterone contraception use could inhibit lactation. The purpose of this article is to critically evaluate the scientific basis for conflicting clinical recommendations related to postpartum medroxyprogesterone use among breastfeeding women.

METHODS

Relevant peer-reviewed literature was identified through a comprehensive search of PubMed through December 2010. The search was restricted to clinical trials, randomized clinical trials, or comparative studies written in English and conducted among humans. The studies included in this review addressed the effect of medroxyprogesterone administration at <6 weeks postpartum on breastfeeding exclusivity and/or duration and measured breastfeeding outcomes at ≥ 6 weeks postpartum.

RESULTS

Of the 20 articles identified, only three studies satisfied the inclusion criteria. However, all three studies were of low-quality methodological rigor, and none accounted for potential confounders.

CONCLUSION

Current evidence is methodologically weak and provides an inadequate basis for inference about a possible causal relationship between early postpartum medroxyprogesterone use and poor breastfeeding outcomes. However, given the presence of a strong biological model describing the potential deleterious effect of postpartum medroxyprogesterone use on lactation, further research that improves on current literature is warranted. Meanwhile, we recommend that potential breastfeeding risks associated with early (<6 weeks) postpartum medroxyprogesterone use be disclosed to allow for a fully informed consent and decision-making process.

Effects of domperidone on augmentation of lactation following cesarean delivery at full term

OBJECTIVE

To evaluate the effects of domperidone on breast milk production in women who underwent cesarean at full term.

METHODS

Women who underwent uncomplicated full-term cesarean were randomly assigned to receive domperidone or placebo for 4 consecutive days post partum. Breast milk was collected twice daily via electric breast pump. Baseline milk production was determined by measuring the volume of milk collected on the 1st postpartum day, before initiation of study medication (day 0). The daily volume of milk collected was compared between groups. Adverse treatment-related effects were recorded.

RESULTS

The study was completed by 22 women in the domperidone group and 23 in the placebo group. Compared with day 0, mean increases in milk volume per participant collected on days 1, 2, 3, and 4 were significantly higher in the domperidone (13.6 ± 23.2 mL, 68.5 ± 71.9 mL, 144.5 ± 122.3 mL, and 191.3 ± 136.1 mL) than in the placebo (2.5 ± 4.6 mL, 24.5 ± 26.5 mL, 72.1 ± 55.6 mL, and 91.4 ± 60.3 mL) group. Minor adverse effects were reported by 7 women in the domperidone group.

CONCLUSION

Postpartum treatment with domperidone can augment breast milk production after full-term cesarean, with minimal adverse effects.

Data supporting a new physiological role for brain apelin in the regulation of hypothalamic oxytocin neurons in lactating rats

Apelin is a bioactive peptide identified as the endogenous ligand of the human orphan G protein-coupled receptor APJ in 1998. The present data show that apelin modulates the activity of magnocellular and parvocellular oxytocin (OXY) neurons in the lactating rat. A combination of in situ hybridization and immunohistochemistry demonstrated the presence of apelin receptor mRNA in hypothalamic OXY neurons. Double immunofluorescence labeling then revealed the colocalization of apelin with OXY in about 20% of the hypothalamic OXY-positive neurons. Intracerebroventricular apelin administration inhibited the activity of magnocellular and parvocellular OXY neurons, as shown by measuring the c-fos expression in OXY neurons or by direct electrophysiological measurements of the electrical activity of these neurons. This effect was correlated with a decrease in the amount of milk ejected. Thus, apelin inhibits the activity of OXY neurons through a direct action on apelin receptors expressed by these neurons in an autocrine and paracrine manner. In conclusion, these findings highlight the inhibitory role of apelin as an autocrine/paracrine peptide acting on OXY neurons during breastfeeding.

Effects of pregnancy and lactation on warfarin-induced changes in blood coagulation-related parameters in rats

Effects of pregnancy and lactation on warfarin-induced changes in blood coagulation-related parameters were examined in rats. Warfarin (0.5 mg/kg/day) was given orally to pregnant and non-pregnant rats for 3 days from gestation day (GD) 17 to 19 or to lactating and non-pregnant rats for 3 days from post partum day (PPD) 10 to 12. Blood samples were collected from the rats on the day following the last administration (GD 20 or PPD 13) to measure prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (FIB), thrombotest (TBT), factor VII and X activities and anti-thrombin III concentration (ATIII). Administration of warfarin to non-pregnant rats resulted in significant prolongation of APTT and TBT and significant decreases in factor VII and X activities. On the other hand, similar but not significant changes were observed in pregnant rats and similar significant but less prominent changes were observed in lactating rats. The reduction of the anticoagulant effects of warfarin may partially be related to high plasma 17beta-estradiol concentration in pregnant rats and to high plasma prolactin concentration in lactating rats, respectively.

Antiestrogenic constituents of the Thai medicinal plants Capparis flavicans and Vitex glabrata

Antiestrogenic compounds were investigated from Thai indigenous plants for galactogogues since estrogen is reported to suppress lactation in breastfeeding women. The aerial parts of the Thai medicinal plant Capparis flavicans, which has traditionally been used to promote lactation, gave the new compound capparoside A (1), along with 28 known compounds. The leaves of Vitex glabrata belong to the same genus as the chaste tree (Vitex agnus-castus), which is used traditionally to support lactation, and afforded the new compounds khainaoside A (14), khainaoside B (15), and khainaoside C (16), together with six known compounds. The isolates were tested for their biological activity using the estrogen-responsive human breast cancer cell lines MCF-7 and T47D. Syringaresinol (3) and principin (6), from C. flavicans, and khainaoside A (14) showed the most potent inhibitory effects on estrogen-enhanced cell proliferation among all compounds isolated. These results suggest that the lactation-promoting properties of C. flavicans might be related to the inhibitory effect on excess estrogen of women who experience insufficient breastfeeding and highlight the possibility of using V. glabrata leaves for their antiestrogenic properties.

Medications in pregnancy and lactation: part 1. Teratology

One of the least-developed areas of clinical pharmacology and drug research is the use of medication during pregnancy and lactation. This article is the first in a two-part series designed to familiarize physicians with many aspects of the drugs they commonly prescribe for pregnant and breast-feeding women. Almost every pregnant woman is exposed to some type of medication during pregnancy. Although the majority of pregnant and breast-feeding women consume clinically indicated or over-the-counter drug preparation regularly, only few medications have specifically been tested for safety and efficacy during pregnancy. There is scant information on the effect of common pregnancy complications on drug clearance and efficacy. Often, the safety of a drug for mothers, their fetuses, and nursing infants cannot be determined until it has been widely used. Absent this crucial information, many women are either refused medically important agents or experience potentially harmful delays in receiving drug treatment. Conversely, many drugs deemed "safe" are prescribed despite evidence of possible teratogenicity. Novel research and diagnostic applications evolving from the opportunities presented by the advances in genomics and proteomics are now beginning to affect clinical diagnosis, vaccine development, drug discovery, and unique therapies in a modern diagnostic-therapeutic framework-part of the new scientific field of theranostics. This review critically explores a number of recently raised issues in regard to the use of several classes of medications during gestation and seeks to provide a general and concise resource on drugs commonly used during pregnancy and lactation. It also seeks to make clinicians more aware of the controversies surrounding some drugs in an effort to encourage safer prescribing practices through consultation with a maternal-fetal medicine specialist and through references and Web sites that list up-to-date information.

Structure and function of a new class of human prolactin antagonists

Delta 41-52 hPRL (human prolactin with residues 41-52 removed) is a lead compound for a new class of hPRL antagonists. The deleted sequence contains residues that functionally couple sites 1 and 2, the two hormone surfaces that each bind receptors. Delta 41-52 hPRL retains 0.03% agonist activity in FDC-1 cell bioassays, a 3054-fold reduction in activity, and displays approximately 100-fold less agonist activity than G129R hPRL, an antagonist that reduces the binding of hPRL receptor at site 2 during the formation of the heterotrimeric hormone/receptor complex. Replacement of various numbers and types of residues into the gap created by the deletion of residues 41 through 52 created hPRLs with varying agonist activities, suggested that manipulation of the sequence connecting the C-terminal of helix 1 with the disulfide bond (cysteines 58 with 174) linking helices 1 and 4 modulates articulation of these helices and influences agonist activity. We have compared the antagonist activities of G129R and Delta 41-52 hPRLs to induce apoptosis in Jurkat cells, a human lymphoid cell line displaying an autocrine/paracrine hPRL/receptor system. Delta 41-52 hPRL induces apoptosis in a time and dose-dependent fashion. Under these same conditions G129R hPRL fails to induce apoptosis. We conclude Delta 41-52 hPRL is a lead compound of a new class of hPRL antagonists capable at low concentrations of inducing apoptosis in human cells expressing an autocrine/paracrine hPRL/receptor system.

Do placental genes affect maternal breast cancer? Association between offspring's CGB5 and CSH1 gene variants and maternal breast cancer risk

The protective effect of full-term pregnancy against breast cancer is thought to be induced by two placental hormones: human chorionic gonadotropin and human chorionic somatotropin hormone (CSH) produced by the placental trophoblastic cells. We hypothesized that variants in placental genes encoding these hormones may alter maternal breast cancer risk subsequent to pregnancy. We conducted a case-control study to examine the association between polymorphisms in a woman's placental (i.e., her offspring's) homologous chorionic gonadotrophin beta5 (CGB5) and CSH1 genes and her post-pregnancy breast cancer risk. A total of 293 breast cancer cases and 240 controls with at least one offspring with available DNA were selected from the New York site of the Breast Cancer Family Registry. Three single nucleotide polymorphisms (SNP) in CGB5 and CSH1 genes were genotyped for 844 offspring of the cases and controls. Overall, maternal breast cancer risk did not significantly differ by the offspring's carrier status of the three SNPs. Among women with an earlier age at childbirth (younger than the median age of 26 years), those with a child carrying the variant C allele of CGB5 rs726002 SNP had an elevated breast cancer risk [odds ratio (OR), 2.09; 95% confidence interval (95% CI), 1.17-3.73]. Among women with a later age at childbirth, breast cancer risk did not differ by offspring's carrier status of CGB5 rs726002 SNP (OR, 0.90; 95% CI, 0.53-1.51; P for interaction=0.04). The findings suggest that placental CGB5 genotype may be predictive of maternal post-pregnancy breast cancer risk among women who give birth early in life.

Clinical practice guideline for hypotalamic-pituitary disturbances in pregnancy and the postpartum period

During pregnancy, the body undergoes a major adaptation process as a result of the interaction between mother, placenta and fetus. Major anatomical and histological changes are produced in the pituitary, with an increase of up to 40% in the size of the gland. There are wide variations in the function of the hypothalamus-pituitary-thyroid axis that effect iodine balance, the overall activity of the gland, as well as transport of thyroid hormones in plasma and peripheral metabolism of thyroid hormones. The incidence of goiter and thyroid nodules increases throughout pregnancy. The management of differentiated thyroid carcinoma should be individually tailored according to tumoral type and pregnancy stage. Given the effects of hypothyroidism on fetal development, both the diagnosis and appropriate therapeutic management of thyroid hypofunction are essential. The most important modification to the hypothalamus-pituitary-adrenal axis during pregnancy is the rise in serum cortisol levels due to an increase in cortisol-binding proteins. Although Cushing's syndrome during pregnancy is infrequent, both diagnosis and treatment of this disorder are especially difficult. Adrenal insufficiency during pregnancy does not substantially differ from that occurring outside pregnancy. However, postpartum pituitary necrosis (Sheehan's syndrome) is a well-known complication that occurs after delivery and, together with lymphocytic hypophysitis, constitutes the most frequent cause of adrenal insufficiency. The management of prolactinoma during pregnancy requires suppression of dopaminergic agonists and their reintroduction if there is tumoral growth. Notable among the neuropituitary disorders that can occur throughout pregnancy is diabetes insipidus, which occurs as a consequence of increased vasopressinase activity.

Proteolysis of Milk Fat Globule Membrane Proteins in Preterm Milk: A Transient Phenomenon with a Possible Biological Role?

Milk fat globule membrane (MFGM) proteins constitute a milk fraction currently of great interest, as they appear to significantly contribute to milk protective role. We investigated these proteins in human preterm colostrum and milk. For the former we found a peculiar 2-DE pattern, with a spot concentration at low molecular weight, which mass spectrometry analysis showed to be fragments belonging to some MFGM proteins with a well-known biological and especially immunological role: lactadherin, membrane-associated lactoferrin, butyrophilin, clusterin and heavy-chain immunoglobulin. Since we were able to rule out protease activity after specimen collection, we hypothesize the localization of the proteolytic enzymes in the alveolar cell membranes of the mammary gland. This mechanism is probably under hormonal control and the unexpected advent of preterm delivery would not allow hormonal conditions typical of lactation to occur immediately, causing a delay in enzymatic inhibition. This hypothesis is supported by some of our results, picturing a peculiar transient phenomenon of adaptation of the mammary-gland-membrane proteins after preterm delivery. Further studies will be required to verify whether the presence of protein fragments exerts a specific biological and immuno-defensive role in preterm infants, thus adding evidence to the outstanding biological role and benefits of mother's own milk in feeding preterm infants.

Interferência do controle glicêmico na transição entre as fases I e II da lactogênese em pacientes com diabetes melito tipo 1

A lactogênese é constituída pelas fases designadas como I e II. A transição entre essas fases é caracterizada pelo aumento da concentração de lactose no colostro. Este estudo teve como objetivo analisar a interferência do diabetes melito tipo 1 (DM1) na transição entre as fases da lactogênese. A concentração de lactose foi determinada em amostras de colostro de 11 puérperas portadoras de DM1 e de 19 puérperas sem a doença, durante os cinco primeiros dias do puerpério. A determinação da concentração da lactose foi feita pela reação com ácido pícrico. Em ambos os grupos houve aumento progressivo da concentração da lactose em função do tempo; entretanto, o aumento foi significativamente menor no terceiro e no quinto dia no grupo das portadoras de diabetes. A análise da transição de fases da lactogênese revelou que as puérperas portadoras de diabetes melito com controle glicêmico inadequado apresentaram atraso de 18 horas para alcançar a fase II da lactogênese, dificultando o estabelecimento do aleitamento materno.

What can we learn from rodents about prolactin in humans?

Prolactin (PRL) is a 23-kDa protein hormone that binds to a single-span membrane receptor, a member of the cytokine receptor superfamily, and exerts its action via several interacting signaling pathways. PRL is a multifunctional hormone that affects multiple reproductive and metabolic functions and is also involved in tumorigenicity. In addition to being a classical pituitary hormone, PRL in humans is produced by many tissues throughout the body where it acts as a cytokine. The objective of this review is to compare and contrast multiple aspects of PRL, from structure to regulation, and from physiology to pathology in rats, mice, and humans. At each juncture, questions are raised whether, or to what extent, data from rodents are relevant to PRL homeostasis in humans. Most current knowledge on PRL has been obtained from studies with rats and, more recently, from the use of transgenic mice. Although this information is indispensable for understanding PRL in human health and disease, there is sufficient disparity in the control of the production, distribution, and physiological functions of PRL among these species to warrant careful and judicial extrapolation to humans.

A critical review of pharmaceutical galactagogues

Use of plant and drug products to enhance lactation is widespread, and numerous papers have been published in the medical literature claiming efficacy for various products. This paper will review and evaluate the published literature on the most widely used pharmaceuticals that are used as galactagogues. Breastfeeding physiology is reviewed with the aim of creating a framework for understanding galactagogue pharmacology. Published articles were selected and evaluated using the principles of evidence-based medicine, and were also evaluated using the principles of good lactation management. Only three studies on oxytocin and seven studies on dopamine antagonists were found to be useful. Oxytocin is probably not useful as a galactagogue, except possibly in rare circumstances of tetraplegic mothers. Dopamine antagonists appear not to enhance milk supply if mothers are given good lactation support and employ these practices. The safety of the dopamine antagonists has not been adequately evaluated, so their use should be avoided unless other measures have failed.

Breast-feeding after breast cancer in childbearing women

According to the American Cancer Society in 2007, about 178,000 women are diagnosed with breast cancer each year in the United States. Of these, 25% have tumors in their childbearing years and may desire future opportunities for pregnancy and lactation. Although there is a multitude of options related to preserving fertility, little is known about the residual effects of breast cancer treatment and the ability to breast-feed afterward. This article describes the epidemiological relationship between breast cancer and pregnancy and lactation. Basic types of treatment for breast cancer including surgery, chemotherapy, and radiation are reviewed. Practical information on how to support breast-feeding after breast cancer is included.

Replacement of connexin43 by connexin26 in transgenic mice leads to dysfunctional reproductive organs and slowed ventricular conduction in the heart

Background

In order to further distinguish unique from general functions of connexin43, we have generated mice in which the coding region of connexin43 was replaced by that of connexin26.

Results

Heterozygous mothers showed impaired mammary gland development responsible for decreased lactation and early postnatal death of the pups which could be partially rescued by wild type foster mothers. Only about 17% of the homozygous connexin43 knock-in connexin26 mice instead of 25% expected according to Mendelian inheritance, were born and only 6% survived to day 21 post partum and longer. Neonatal and adult connexin43 knock-in connexin26 mice exhibited slowed ventricular conduction in their hearts, i.e. similar but delayed electrophysiological abnormalities as connexin43 deficient mice. Furthermore, connexin43 knock-in connexin26 male and female mice were infertile and exhibited hypotrophic gonads. In testes, tubuli seminiferi were developed and spermatogonia as well as some primary spermatocytes were present, but further differentiated stages of spermatogenesis were absent. Ovaries of female connexin43 knock-in connexin26 mice revealed only few follicles and the maturation of follicles was completely impaired.

Conclusion

The impaired gametogenesis of homozygous males and females can explain their infertility.

Maternal distress and intended breastfeeding duration

AIM

To evaluate the associations between maternal psychological status and intended breastfeeding duration.

METHODS

A total of 852 pregnant women who attended antenatal care between September 1997 and August 2000 in 12 health units and five hospitals in Jundiaí city, Brazil, were included in the study. Psychological measures (stress and distress) were obtained at a gestational age from 30 to 36 weeks, using standardized scales, questionnaires and inventories. Psychological factors specifically related to breastfeeding assessed their worries, concerns, and support when breastfeeding. Multiple linear regression analysis identified the associations between the outcome "intended duration of breastfeeding" and psychological status of the mothers, controlling for toxic exposure, socioeconomic, demographic, obstetric and nutritional factors.

RESULTS

There were negative associations between the outcome and distress, "concerned about body's changes", and work outside home, and a positive association between the outcome and marital status (p < or = 0.03).

CONCLUSION

Early identification of distress in pregnant women and a more attentive encouragement to breastfeed is probably one of the steps to improve intended breastfeeding duration.

Effect of Prolactin and Bromocriptine on the Population of Prostate Neuroendocrine Cells from Intact and Cyproterone Acetate-Treated Rats: Stereological and Immunohistochemical Study

This work deals with the quantification of serotonin-immunoreactive prostate neuroendocrine cells (NECs) in rats exposed to prolactin in normal, cyproterone acetate-exposed, and bromocriptine-exposed animals to establish the possible influence of prolactin with or without androgenic blockade on this cell population. Thirty male peripubertal Sprague-Dawley rats were grouped as controls (CT) and those treated with cyproterone acetate (CA), cyproterone acetate plus prolactin, cyproterone acetate plus bromocriptine, prolactin (PL), and bromocriptine (BC). The volume of ductal epithelium (Vep) and total number (NSER) of the NECs serotonin-immunoreactive were measured. NECs were detected in the periurethral ducts. Compared to CT, Vep was increased in PL and BC and NSER was decreased in CA and increased in the prolactin or bromocriptine groups. The androgenic blockade decreases NSER in rat prostate; PL induces in normal and cyproterone acetate-treated rats the increase of NSER; and BC exerts a local effect over the prostate similar to that described for PL.

Oligosaccharides in colostrum of Italian and Burkinabe women

Human milk contains a large number of compounds to provide nutrition and defense for the newborn. Among these, oligosaccharides are present in concentrations up to 12 g/L, and their composition varies during lactation. Colostrum from 53 Burkinabe women were collected at the maternity department of St Camille Medical Centre in Ouagadougou (Burkina Faso, West Africa). Colostrum from 50 Italian women were collected at the maternity department of St Bambino Hospital in Catania (Catania, East Sicily, Italy). All mothers spontaneously delivered at term. Italian mothers received an injection of the ergot derivative ergotamine after delivery. Ergotamine, notoriously, delays breastfeeding initiation up to 2 to 3 days. Chromatographic separation of colostrum from both Burkinabe and Italian women showed a progressive appearance of oligosaccharides in the first 3 days. Burkinabe women showed high concentrations of 2-fucosyllactose and lower concentrations of lacto-N-fucopentaose I. By contrast, Italian women showed inverted behaviour. A comparable percentage of the secretor genotype for the Lewis blood group phenotype in both Burkinabe and Italian women was found. According to the different ethnicity, different milk oligosaccharide profiles were documented in the present study. 2-Fucosyllactose in milk should be biologically significant for Burkinabe infants because of the high levels found in their mothers' colostrum after the second day of lactation.

Cocaine- and amphetamine-regulated transcript is localized in pituitary lactotropes and is regulated during lactation

Cocaine- and amphetamine-regulated transcript (CART) is a highly expressed peptide implicated in the regulation of feeding, reward and reinforcement, and stress-related behaviors. CART has been localized to discrete cell populations in the brain, gut, adrenal gland, and pancreas. In contrast, CART-producing cell types in the pituitary gland remain ill defined. In the present study, double-label immunohistochemistry, employing a high-affinity antiserum we generated against CART-(62-102), was used to identify CART-producing cells in the pituitary gland. In the anterior pituitary, the majority of CART immunoreactivity (-ir) was localized in lactotropes; minor populations of CART-ir cells were identified as somatotropes and corticotropes. In the posterior pituitary, CART-ir extensively colocalized with oxytocin-containing fibers; in contrast, only a few vasopressin fibers contained CART-ir. As expected, CART colocalized with oxytocin in magnocellular neurons of the supraoptic nucleus. The effects of bromocriptine, a potent dopamine receptor agonist, were examined to determine whether CART mRNA expression and protein release are regulated in a similar fashion as prolactin. Similar to prolactin, CART mRNA expression and protein release were significantly decreased after bromocriptine treatment of dispersed rat anterior pituitary cells in culture. To explore the putative physiological role of pituitary CART, we compared levels of CART mRNA expression in lactating and nonlactating female rats. CART mRNA levels were significantly increased in the anterior pituitary and supraoptic nucleus of lactating rats. Furthermore, levels of CART in the systemic circulation were significantly elevated at the onset of lactation, peaked on d 10 of lactation and returned to baseline values 10 d after pups were weaned. The current study describes the cellular localization and regulation of CART expression and protein release from the rat pituitary gland. These findings suggest a putative role for CART in lactation.

Clinical lactation practice: 20 years of evidence

Lactation consultants depend on a vast multidisciplinary knowledge base to support their practices. To coincide with the 20-year anniversary of the International Lactation Consultant Association, the authors sought to highlight the knowledge base to demonstrate how practice has been affected. Using standard databases, they extracted English-language scientific literature related to breastfeeding and maternal and infant health outcomes; factors associated with breastfeeding initiation, exclusivity, and duration; lactation physiology; common breastfeeding challenges; breastfeeding practices within vulnerable populations; health professional support of breastfeeding; and breastfeeding practices in developing countries of Africa. Summaries of research are provided to demonstrate scientific method and knowledge evolution. As the knowledge of the biological, behavioral, and environmental factors that affect breastfeeding continues to grow, researchers and lactation consultants will identify additional research areas. Thus, the cycle of describing and explaining phenomena, testing interventions to improve practice, and ultimately improving breastfeeding outcomes worldwide will continue.