–This post is part of our 10-year anniversary series “Breastfeeding is…”—
Breastfeeding is an opportunity to learn. Although breastfeeding is an ancient practice, there is still so much to learn about the lactating breast, breast function and the process of breastfeeding, especially as our modern lives continue to change.
Many current textbook depictions of the anatomy of the lactating breast are largely based on research conducted over 150 years ago, Donna T. Geddess points out in The anatomy of the lactating breast: Latest research and clinical implications.
“…Few studies have actively investigated the anatomy of the lactating breast despite the obvious importance a clear understanding of the lactating mammary gland has to both mother and infant,” Geddess writes. “Perhaps this lack of information is a part of the greater reason why many women continue to experience breastfeeding problems.”
Katherine Lee writes in Katie Hinde Championing the Fun Side of Science Through Virtual Animal Games, Thunderdome Style about Hinde’s hope to change the perception about breastmilk and quotes her saying “‘Still to this day, there is no integration between breastfeeding and milk composition and volume,’ noted Hinde. ‘In Pubmed, there are more articles about tomatoes than human breast milk.’ When they listed the human microbiome project, they didn’t include breastmilk…”
This week we present several recent (in the last 5 years) publications that are helping to shape our understanding of infant feeding. We have also included studies that relate specifically to pregnancy as pregnancy, birth and breastfeeding are all part of a continuum.
It is important to note that research published in medical journals is not the only way to capture and develop an understanding of infant feeding experiences. For instance, Camie Jae Goldhammer, MSW, LICSW, IBCLC, (Sisseton-Wahpeton), founder of Hummingbird Indigenous Doula Services says that their program is proudly not rooted in “evidence”; instead, it’s a community designed program. Anecdotal evidence and indigenous knowledge and wisdom should be honored. Moreover, as with any research, we must always consider how the research is funded, who is or is not being represented, and how the research is presented. For more on equity in science, check out Increasing equity in data science and the work being done at the Urban Indian Health Institute.
Lactation duration and stroke risk
In February 2022, Ziyang Ren, MD, et al released Lactation Duration and the Risk of Subtypes of Stroke Among Parous Postmenopausal Women From the China Kadoorie Biobank.
Stroke is a growing global health problem. It is the third leading cause of disability adjusted–life years (DALYs) worldwide and the first leading cause of DALYs in China, Ren, et al point out. Stroke imposes a financial burden on patients, families, and society. The cohort study found that lactation duration significantly lowers the risk of stroke.
Up until now, most research has focused on the association between lactation and cardiovascular diseases (CVDs), but this piece lays out the association between lactation and stroke subtypes.
Specifically, the study found that parous postmenopausal women with lifetime lactation duration of at least 7 months had lower risks of ischemic stroke and intracerebral hemorrhage (ICH) compared with women who never lactated. For subarachnoid hemorrhage (SAH) though, such associations were found only in participants with lifetime lactation duration of longer than 24 months. In addition, the authors found that those with an average lactation duration per child or lactation duration for the first child of at least 7 months were less likely to develop stroke and its subtypes.
Marijuana exposure in utero
Birth Outcomes of Neonates Exposed to Marijuana in Utero: A Systematic Review and Meta-analysis by Greg Marchand, et al, the largest meta-analyses on prenatal cannabis use to date, the authors found significant increases in seven adverse neonatal outcomes among women who were exposed to marijuana during pregnancy versus those who were not exposed during pregnancy.
The systematic review and meta-analysis demonstrated higher rates of low birth weight (<2500 g) and small for gestational age (<fifth percentile), lower mean birth weight, preterm delivery (<37 weeks’ gestation), higher rate of admission to the neonatal intensive care unit, poorer Apgar scores at 1 minute, and smaller head circumference in those exposed to marijuana.
The prevalence of marijuana use during pregnancy is significant, and many people cite the belief that marijuana use is relatively safe during
pregnancy. This work may help to raise awareness and be used to educate patients about adverse outcomes with the hope of improving neonatal health.
With increased marijuana legalization in mind, Kara R. Skelton, PhD and Sara E. Benjamin-Neelon, PhD, JD, MPH in Reexamining Risks of Prenatal Cannabis Use—Mounting Evidence and a Call to Action urge states that have legalized and commercialized cannabis to retroactively prioritize protection of neonatal health.
More on cannabis during the perinatal period here.
The authors of Childhood Obesity and Breastfeeding Rates in Pennsylvania Counties-Spatial Analysis of the Lactation Support Landscape examined the relationship between childhood obesity and breastfeeding rates in Pennsylvania (PA) counties, the relationship between geographic access to professional lactation support providers (LSPs) in PA counties and breastfeeding rates, and the relationship between geographic access to professional LSPs and childhood obesity in PA counties. They found a significant, inverse relationship between breastfeeding rates and childhood obesity prevalence at the county level and a significant, inverse relationship between the number of CLCs and the number of all professional LSPs and childhood obesity rates at the county level. Thus, the authors conclude, the availability of breastfeeding support is significantly related to breastfeeding rates and inversely related to childhood obesity rates across Pennsylvania.
Measuring optimal skin-to-skin practice
The authors of Mapping, Measuring, and Analyzing the Process of Skin-to-Skin Contact and Early Breastfeeding in the First Hour After Birth show how process mapping of optimal skin-to-skin practice in the first hour after birth using the algorithm, HCP-S2S-IA, produced an accurate and useful measurement, illuminating how work is conducted and providing patterns for analysis and opportunities for improvement with targeted interventions.
More specifically, the algorithm provides a tool to help reduce delays or decrease interruptions during skin-to-skin contact (SSC). The authors note, “Not suckling in the first hour after birth places newborns at higher risk for neonatal morbidities and mortality. Examining patterns and developing strategies for change optimizes patient outcomes.”
Acknowledging the social determinants of health
Pregnancy and the origins of illness (2022) by Anne Drapkin Lyerly begins by acknowledging that the COVID-19 pandemic has induced a collective trauma that is expected to be felt for generations after the virus is contained. The study of epigenetics has shown that children gestated or born during times of great tragedy, carry a genetically coded and inherited imprint of their mother’s experience with lifelong consequences to their health.
Recognizing the “maternal-fetal interface” as the “nexus of inter-generational trauma” raises the question of how we should think about this implication of maternal bodies, especially in light of the current pandemic.
The author explores the growing field of developmental origins of health and disease (DOHaD) and its use of epigenetics. Thinking about the tools of history, philosophy, and gender studies of science, the author advises we proceed with caution as we consider maternal effect science which raises several concerns that can impact practice and the well-being of mothers and consequently their children.
Namely, there may be a tendency to ascribe blame on pregnant people for the health outcomes of their offspring that are well beyond their control. This approach doesn’t adequately weigh the effects of paternal, postanal, and other social and environmental factors that also influence the long-term health of children.
Analyzing epigenetics can eventually contribute to the erasure of the mother as a person, and further, characterizing the maternal body as an environment may excuse women from being appropriately considered in public health policies, clinical care and health research.
The author considers DOHaD research a corrective approach to near-sighted fetal origins science and urges that we expand our understanding of the gestational environment from not simply the womb, but to the broader environment in which a person gestates, marking the importance of acknowledging the social determinants of health. To best direct our efforts during the current pandemic, the author suggests shifting the focus off of maternal behavior and choices and instead focus on limiting the harm of climate change, racism, and other structural inequities.
Can’t get enough?
Check out the Breastfeeding Medicine Podcat’s episode Review of a Potpourri of Research Topics with co Hosts Anne Eglash MD, IBCLC and Karen Bodnar MD, IBCLC. You can find a full list of their podcast episodes here.
Subscribe to SPLASH! Milk Science Update
Check out The International Society for Research in Human Milk and Lactation
As part of our celebration, we are giving away an online learning module with contact hours each week. Here’s how to enter into the drawings:
Email email@example.com with your name and “OMW is 10” in the subject line.
This week, in the body of the email, tell us: What fascinates you about breastfeeding and/or what do you wonder about breastfeeding?
Subsequent weeks will have a different prompt in the blog post.
We will conduct a new drawing each week over the 10-week period. Please email separately each week to be entered in the drawing. You may only win once. If your name is drawn, we will email a link with access to the learning module. The winner of the final week will score a grand finale swag bag.