Breast-feeding During Pregnancy and the Risk of Miscarriage

Theory-based antecedents of breastfeeding among pregnant women in the United States

Background

Breastfeeding provides several positive health benefits for the newborn child, yet breastfeeding rates remain low in the United States (US). Theory-based approaches have the potential to improve breastfeeding promotion interventions. Hence, the study examined the correlates of intention to breastfeed among US pregnant women based on the multi-theory model (MTM) of health behavior change.

Methods

Using a cross-sectional design, a 36-item online survey was administered to a nationally representative sample of 315 pregnant women in the US. The instrument was psychometrically validated for face, content, and construct validity by a panel of six experts over two rounds. Further, construct validation was done by confirmatory factor analysis (CFA). Hierarchical regression modeling was employed to explain the intention to start breastfeeding and sustain exclusive breastfeeding for up to six months and with complementary foods for up to 24 months.

Results

Internal consistency using Cronbach's alpha was found to be acceptable. It was found that behavioral confidence and changes in the physical environment positively affected the initiation of breastfeeding (P<0.01; adjusted R2=0.478). All three constructs of MTM namely practice for change, emotional transformation, and changes in the social environment were significant predictors for the sustenance of breastfeeding at six months (P<0.01; adjusted R2=0.591) and at 24 months (P<0.01; adjusted R2=0.347).

Conclusion

Based on the findings of this study it is essential for educators and healthcare providers to design MTM-based interventions to promote breastfeeding among pregnant women in the US.

Maternal care in wild toque macaques (Macaca sinica) involves prolonged lactation and interbirth intervals as adaptations to reduce maternal depletion and infant mortality in harsh environments

Weaning age in primates has been challenging to measure and new methods, involving molecular biomarkers in feces, tissue, or teeth have contributed to a solution. Here, we used a direct approach by briefly anesthetizing 442 female toque macaques (Macaca sinica) of Sri Lanka (over a 17-year period) and manually testing their mammary tissue for the presence or absence of milk. Milk tests were related to known offspring ages and maternal care behaviors and indicated that older infants suckled milk well past the weaning age of 7 months that is often reported for food-provisioned primates. Mothers strongly rejected their infants' nursing attempts in two phases, the first at 7 months as an honest signal "giving notice" promoting a shift to greater independence from milk to solid food, and when "shutting down" at final weaning after 12-18 months. The shift to supplementary lactation coincided also with the cessation of mothers carrying their infants and a resumption of cycling. All infants up to 7.2 months suckled milk, 91% of them did up to 18 months, this continued for 42% of infants beyond 18 months, and normally none received milk after 22 months. Lactation extended into 2.2% of cycling and 10.7% of pregnant females (up to 50% of gestation). The interbirth interval was prolonged by factors predicted to draw on female metabolic energy reserves and included the duration of lactation, growth among primiparas, and dietary limitations. The last also increased menarche. Females offset the metabolic costs of lactation with increased foraging and catabolism, but infants died when lactation costs seemingly compromised maternal condition. The prolonged lactation and slowed reproduction are considered adaptations to promote infant survival and growth in an environment where the natural food supply limits population growth and competition for food and water impacts the mortality of the youngest the most.

Breastfeeding During Pregnancy: A Systematic Review of the Literature

Objectives: Breastfeeding during pregnancy has unintended repercussions that have yet to be determined. Previous research employed various approaches and reached varied outcomes, with some emphasizing on advantages and others focusing on hazards. With this study we aim at shedding light on the effects of breastfeeding during pregnancy on the outcome of pregnancy and the risk of miscarriage. Materials and methods: We conducted a systematic review of relevant papers which have been published in English between 2014 and 2022 by using the PubMed, Scopus and Google Scholar search engines. Databases identified 257 records, which were checked for their relatedness to the topic (title and abstract), and compliance with the selection criteria. Only 10 records met all requirements and were included in the present review. Results:The results revealed that breastfeeding during pregnancy appeared to be unrelated to pregnancy outcome and miscarriage risk, notwithstanding the need for caution in women at risk of preterm birth and high-risk pregnancies. Conclusion:All studies recognized the high nutritional requirements of lactating pregnant women as well as the importance of proper nutrition for a safe breastfeeding for both the mother and child (children). Further research, with larger samples and adequate methodology, is expected to lead to safer conclusions for breastfeeding during pregnancy.

Feto-Maternal Outcomes of Breastfeeding during Pregnancy: A Systematic Review and Meta-Analysis

BACKGROUND

Breastfeeding is beneficial to both mother and infant. However, overlap of lactation with pregnancy and short recuperative intervals may impact mothers nutritionally. We aimed to investigate the possible effects of pregnancy during breastfeeding.

METHODS

In October 2018, we searched systematically in nine electronic databases to investigate any association of breastfeeding during pregnancy with fetal and/or maternal outcomes. The study protocol was registered in PROSPERO (CRD41017056490). A meta-analysis was done to detect maternal and fetal outcomes and complications during pregnancy. Quality assessment was performed using the Australian Cancer Council bias tool for included studies.

RESULTS

With 1992 studies initially identified, eight were eligible for qualitative analysis and 12 for quantitative analysis. Our results showed no significant difference in different abortion subtypes between lactating and non-lactating ones. In delivery, no difference between two groups regarding the time of delivery in full-term healthy, preterm delivery and preterm labor. No significant difference was detected in rates of antepartum, postpartum hemorrhage and prolonged labor between two groups. The women with short reproductive intervals may have higher supplemental intake and greater reduction fat store. The present studies showed that breastfeeding during pregnancy does not lead to adverse outcomes in the mother and her fetus in normal low-risk pregnancy, although it may lead to the nutritional burden on the mother.

CONCLUSION

The present studies showed that breastfeeding during pregnancy did not lead to the adverse outcomes in the mother and her fetus.

Breastfeeding While Pregnant: A Country-Wide Population Study

Background: There are no national data on the prevalence of breastfeeding during pregnancy (BDP) in the world. Also, there is no consensus for the BDP. Aim: The purpose was to determine the prevalence of breastfeeding status in pregnant mothers having children younger than 24 months of age and to evaluate the associated sociodemographic factors and characteristics of the last-born child and current pregnancy through two consecutive national health survey. Methods: Data from the 2012 and 2017 Jordan Family Health and Population Survey were merged. Individual, household, and community-level factors associated with BDP were analyzed by using complex sample multivariate logistic regression. Results: Two surveys enrolled 6,858 women having at least one child younger than 24 months and 8.8% (weighted count: 603) of them got pregnant also. Of the pregnant women, 8.9% continued breastfeeding their last-born children. Being younger than 12 months positively affected breastfeeding compared to last-born child aged 12-23 months. Multivariate analysis revealed that BDP was associated positively with wealth index (richest vs. poorest) and postnatal care for the last-born child within 2 months (presence vs. absence), whereas negatively with bottle use (presence vs. absence), traditional contraceptive methods (abstinence/withdrawn vs. modern, lactational amenorrhea vs. modern), short interpregnancy interval (months), and current pregnancy duration (months) in Jordan. Conclusions: The prevalence for BDP differs according to some maternal, last-born infant, and current pregnancy characteristics. Prospective cohort studies are necessary to evaluate the impact of BDP on "mother, last-child, and future-child," and to detect the duration and prevalence of BDP in different countries.

A hierarchical procedure to select intrauterine and extrauterine factors for methodological validation of preterm birth risk estimation

Background

Etiopathogenesis of preterm birth (PTB) is multifactorial, with a universe of risk factors interplaying between the mother and the environment. It is of utmost importance to identify the most informative factors in order to estimate the degree of PTB risk and trace an individualized profile. The aims of the present study were: 1) to identify all acknowledged risk factors for PTB and to select the most informative ones for defining an accurate model of risk prediction; 2) to verify predictive accuracy of the model and 3) to identify group profiles according to the degree of PTB risk based on the most informative factors.

Methods

The Maternal Frailty Inventory (MaFra) was created based on a systematic review of the literature including 174 identified intrauterine (IU) and extrauterine (EU) factors. A sample of 111 pregnant women previously categorized in low or high risk for PTB below 37 weeks, according to ACOG guidelines, underwent the MaFra Inventory. First, univariate logistic regression enabled p-value ordering and the Akaike Information Criterion (AIC) selected the model including the most informative MaFra factors. Second, random forest classifier verified the overall predictive accuracy of the model. Third, fuzzy c-means clustering assigned group membership based on the most informative MaFra factors.

Results

The most informative and parsimonious model selected through AIC included Placenta Previa, Pregnancy Induced Hypertension, Antibiotics, Cervix Length, Physical Exercise, Fetal Growth, Maternal Anxiety, Preeclampsia, Antihypertensives. The random forest classifier including only the most informative IU and EU factors achieved an overall accuracy of 81.08% and an AUC of 0.8122. The cluster analysis identified three groups of typical pregnant women, profiled on the basis of the most informative IU and EU risk factors from a lower to a higher degree of PTB risk, which paralleled time of birth delivery.

Conclusions

This study establishes a generalized methodology for building-up an evidence-based holistic risk assessment for PTB to be used in clinical practice. Relevant and essential factors were selected and were able to provide an accurate estimation of degree of PTB risk based on the most informative constellation of IU and EU factors.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12884-021-03654-3).

Higher early life mortality with lower infant body mass in a free-ranging primate

Traits that reflect the amount of energy allocated to offspring by mothers, such as infant body mass, are predicted to have long-lasting effects on offspring fitness. In very long-lived species, such as anthropoid primates, where long-lasting and obligate parental care is required for successful recruitment of offspring, there are few studies on the fitness implications of low body mass among infants. Using body mass data collected from 253 free-ranging rhesus macaque Macaca mulatta infants on Cayo Santiago, Puerto Rico, we examined if lower infant body mass predicts lower chance of survival through to reproductive maturation (4th year of life). We also used data on inter-birth intervals and suckling behaviours to determine whether the duration of maternal care was adjusted to infant body mass. Rhesus macaque infants experienced on average 5% reduced hazard of death for an increase in body mass of 0.1 SD (~100 g) above the mean within their age-sex class. The positive association between body mass and early life survival was most pronounced in the 1st year of life. Infant body mass tended to be lower if mothers were young or old, but the link between infant body mass and early life survival remained after controlling for maternal age. This finding suggests that maternal effects on early life survival such as maternal age may act through their influence on infant body mass. Mothers of heavier infants were less likely to be delayed in subsequent reproduction, but the estimated association slightly overlapped with zero. The timing of the last week of suckling did not differ by infant body mass. Using infant body mass data that has been rarely available from free-ranging primates, our study provides comparative evidence to strengthen the existing body of literature on the fitness implications of variation in infant body mass.