Nutrition During Pregnancy and Lactation: Exploring New Evidence Day 2

Last week,  Cindy Turner-Maffei, MA, ALC, IBCLC shared a summary of what she learned at the Nutrition During Pregnancy and Lactation: Exploring New Evidence – A Workshop through her tweets. This week, she shares Day 2.

NASEM has made the videos from the workshop available here.

Cindy Turner-Maffei, MA, ALC, IBCLC at the academy.



Guest post by Cindy Turner-Maffei, MA, ALC, IBCLC

Dr. Thorlton

On January 30, 2020, the presentations on the impact of Nutrition during Pregnancy & Lactation continued at the National Academy of Sciences in Washington DC began with Janet Thorlton of University of Illinois-Chicago College of Nursing with an update on the impact of caffeine in this time frame:

  • Genetic variance determines whether we’re slow (SCM) or fast (FCM) caffeine metabolizers. If exposed to high doses of caffeine, SCMs may have increased risk of preterm birth, and FCMs of smaller babies.

Kjersti Aagaard of Baylor College of Medicine reported on the impact of maternal diet on the developing infant microbiome:

  • The diversity of vaginal microbes decreases in pregnancy. The neonate’s early biome looks very different than that of the vagina. 
  • The neonate’s microbiome may reflect the amount of fat in the mother’s diet. High fat diet (>35% of calories as fat) is more correlated with infant dysbiosis* than with maternal obesity. (This difference persists—it seems irreversible with dietary changes later.) [*dysbiosis=imbalance in the microbiome—a less than desirable microbial community]
  • We should stop focusing on treating obesity in pregnancy/lactation and focus instead on supporting dietary change. Within days of changing the diet (less added sugar and fat and more fiber), the mother’s metabolic markers and those in her milk change for the better. 
  • Similarly, “we must come to value nutrition over weight.” 
  • Encourage nutrient quality: “fresh from the source produce” is best. Address equity issues in access to fresh produce.
  • Today’s research does not show that giving probiotics in pregnancy protects mother or infant.
  • Fun fact: Did you know that “there are Pseudomonas species that can exist solely on caffeine”???!!!

    Dr. Aagaard

Michael Goran of Children’s Hospital of Los Angeles and the University of Southern California on fructose and oligosaccharides in breastmilk and the effects on infant body composition and cognitive outcomes:

  • Children who were BF >12 m were less likely to be obese at 4 y, even when regularly fed sugar sweetened beverages (SSB). Does human milk offers some protection against effects of SSB?
  • Maternal diet alters the type of human milk oligosaccharides (HMO) in milk. HMOs are also found in amniotic fluid by mid pregnancy. Is this part of how the baby comes to tolerate (and not attack) commensal microbes?


Dr. Allen

Lindsay Allen of U.S. Department of Agriculture on maternal micronutrient status and intake and their effect on milk composition:

  • Maternal status and intake has no effect on calcium, folate, iron, zinc and copper content of human milk
  • Many other micronutrients are lower in milk when status/intake is low.
  • Research is needed to determine specific micronutrient needs in these time frames.

Ellen Demerath of University of Minnesota on the implications of maternal weight and metabolic status for lactation and breastmilk composition:

  • Why are BF rates and duration shorter in obese folks? It’s complicated! There are biological, social, and emotional contributors. 
  • Some intriguing new insights, e.g., leptin is thought to suppress oxytocin, thus potentially decreasing milk release. Leptin levels are higher in obesity.
  • Those with higher pre-pregnancy BMI have more leptin and insulin in their milk. 
  • There may be even higher insulin in their milk when they have female infants. 
  • In diabetic individuals, insulin and glucose are higher in colostrum, but this normalizes in mature milk.
  • Focus on helping new moms improve nutrition and get more sleep, and work for paid parental leave, instead of focusing on weight loss. The diseases BF protects against are crucial to women’s health. Paid leave and more support would both increase BF success and thereby public health.
Lunch break Day 2, needed a brain expansion, appealed to this guy for some help. -CTM

Erica Gunderson of Kaiser Permanente Northern California on lactation and the future risk of cardiometabolic diseases in women: 

  • Pregnancy and lactation are a metabolic continuum. Pregnancy requires adaptations that would be considered pathological in any other state (e.g. suppressed immunity, inflammation)
  • Complicated pregnancy, preterm birth, and preexisting conditions such as hypertension and diabetes increase risk for metabolic disease in the future. Lactation may reset maternal metabolism (higher HDL levels, lower blood glucose and insulin, etc.)
  • BF is associated with 7% risk hypertension overall over maternal lifetime. More protection (12% reduction) for BF >12 mo. 
  • Cardiovascular mortality risk also decreases with increased BF duration. But most studies do not explore preexisting conditions that impact risk.
  • Ongoing SWIFT study is following ~1,000 women with gestational diabetes (GDM) for10 years, watching for conversion to Type 2 Diabetes (T2DM). So far, longer duration of BF is showing 50% reduction in risk of T2DM. Similar to findings of CARDIA study.
Drs. Goran, Aagaard & Myatt

Leslie Myatt of Oregon Health & Sciences University spoke on the role of the placenta in delivering nutrients and in developmental programming of the fetus:

  • The placenta’s metabolic activity is ~5X greater than the fetus’s! It’s not a passive portal. 
  • The placenta consumes about 1/3 of energy transferred from mother to make peptides and grow—it’s called a “selfish organ” for this reason.
  • The placenta adapts to nutrient shortages.
  • At term, its’ surface area is the size of a parking spot
  • The placenta functions differently for male vs female fetuses, supporting sexual dimorphism.

Angela Odoms-Young launched the final session examining community solutions to improve nutrition access and equity in pregnancy and lactation.

Rafael Peréz-Escamilla on systems changes for improving maternal nutrition during pregnancy/lactation:

  • Social justice issues and inequities in access to and quality of lactation care are profound. 
  • The breastfeeding gear model identifies key partners for creating equity and systems change. 
    • [CTM Note: Check out the breastfeeding gear model here.]

      The Gear Model

Kate Keenan of University of Chicago on using nutrition science to reduce perinatal health disparities:

  • “Poverty=Stress=Health Disparities.” 
  • A pilot RCT of DHA supplementation of black pregnant women of low income status found a reduction in perceived stress among mothers, and higher birthweight and APGAR scores in their babies.

Barbara Laraia of University of California, Berkeley on food insecurity and stress as common challenges to optimal nutrition during pregnancy:

  • Her recent study provided mindfulness training and support, finding decreased stress, but no effect on % with high gestational weight gain (GWG). Some women had low GWG and lower scores on oral glucose tolerance tests. 
  • San Francisco is giving $40/month in additional vouchers for vegetables to WIC participants in pregnancy through 3 mo. postpartum. Preliminary data shows reduction in preterm birth and high utilization of the vouchers.

Darlena Birch of the National WIC Association (NWA) on the role of WIC in supports nutrition during pregnancy and lactation:

  • NWA is employing a health equity framework to address disparities in care experienced by WIC participants. 
  • WIC’s BF Peer Counseling program is a powerful tool in closing gaps in communities of color.

Patsy Brannon of Cornell University tackled the unenviable task of summarizing the entire two days of the meeting in 20 minutes:

Planning Committee chair Anna Siega-Riz of University of Massachusetts at Amherst graciously closed the workshop.

My reflections:

As I left the meeting, my brain felt incredibly full. I felt such gratitude to the Committee, the Planning Committee, the truly amazing presenters and the National Academy of Science for a fabulous crash course on the state of nutrition knowledge regarding pregnancy and lactation.

On my way home, I jotted this note synthesizing a few overarching threads:

Changemakers are prone to singling out and manipulating individual entities (nutrients, people, etc.) rather than examining the complex webs they inhabit. A needed shift is to understand the webs (systems) first.

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