Shorter exclusive breastfeeding periods for women with a higher BMI compared to those with lower obesity classifications

By Pooja Toshniwal PahariaReviewed by Danielle Ellis, B.Sc.Jul 31 2024

In a recent study published in the International Journal of Obesity, researchers examined nursing behaviors and their relationships with maternal anthropometric factors and the serological metabolome six months after birth in ethnically diverse obese mothers.

Background

The World Health Organization advises exclusive breastfeeding for optimum child growth and development; however, rates remain low in the United Kingdom after discharge from hospitals and six to eight weeks postpartum. Studies report that maternal adiposity is related to a lower breastfeeding prevalence, intention, beginning, and duration. Fear of discomfort, shame, and inadequate milk are among the most common hurdles.

Obese women encounter extra challenges such as low prolactin, delayed lactogenesis, and negative body image. The influence breastfeeding has on the metabolic health of mothers is unknown; however, studying metabolomic changes in nursing women may reveal further information about physiological changes during lactogenesis.

About the study

In the present study, researchers investigated breastfeeding behaviors, anthropometry, postpartum weight retention, and the effect of breastfeeding on serological metabolomes among obese mothers at six months postpartum. They also evaluated the impact of ethnicity on nursing behaviors.

The researchers recruited 715 females from the United Kingdom Pregnancies Better Eating and Activity Trial (UPBEAT) with a body mass index (BMI) of 30.0 kg/m2 or above at 15 to 18 weeks of gestation between 2009 and 2014 from Glasgow, London, Sunderland, Newcastle, Manchester, and Bradford. They randomized participants to regular antenatal care practices or a lifestyle-enhancing intervention to reduce dietary glycemic load and increase physical exercise, superimposed on regular antenatal services.

The researchers examined breastfeeding practices among moms, concentrating on women who planned to breastfeed, started nursing, continued exclusive breastfeeding, and breastfed at six months postpartum. Secondary maternal outcomes examined the association between breastfeeding and obesity class (I: BMI 30 to 34.9 kg/m2, II: 35 to 39.9 kg/m2, III: 40 kg/m2), ethnicity, birth mode, gestational diabetes, and child weight. They investigated maternal postnatal weight retention and anthropometry concerning breastfeeding start and duration.

The researchers collected maternal data during early pregnancy, including sociodemographic characteristics, anthropometry, and BMI. After six months of delivery, they recorded breastfeeding behaviors, anthropometry, and maternal metabolic measures from blood samples. At birth, they recorded pregnancy-related outcomes and feeding mode. After six months of birth, they obtained data concerning feeding intentions, breastfeeding at childbirth, and total duration. They also recorded data on infant weaning and feeding selections.

At six months postpartum, the researchers measured maternal weight and skin thicknesses in the neck, mid-upper arm, wrist, waist, and hip. They measured biceps, triceps, subscapular, and suprailiac skinfold thickness using Harpenden calipers and used multivariable linear regressions adjusted for age, body mass index, ethnicity, and parity.

Results

The median participant BMI was 35 kg/m2. Among the participants, 354 had class I BMI, 225 class II, and 136 class III. Eighty-two percent (591 of 715) initiated breastfeeding, and at six months postpartum, 40% (283 of 715) breastfed partially or exclusively. Class I women exclusively breastfed for 90 days compared to 75 days by class II and 74 days by class III women. Compared to class I obesity, differences in the mean values for class II were 16 days, and for class III were 17 days.

Breastfeeding at six months after delivery was related to lower triglyceride, low-density lipoprotein (LDL), apolipoprotein A-1/apolipoprotein B ratio, monounsaturated fat, and glycoprotein acetyl, with higher high-density lipoprotein (HDL), polyunsaturated fat, acetate, glycine, and alanine levels. Women who breastfed at six months postpartum also showed lower weight retention by 1.8 kg and decreased anthropometric measures, including neck, mid-arm, wrist, and hip circumferences. However, the team did not observe anthropometric breastfeeding-related changes among Black women.

Women with higher educational attainment, advanced age, and cohabitation were more likely to breastfeed six months after delivery. In contrast, those who smoked and belonged to the White ethnicity showed a lower likelihood. Breastfeeding discontinuation among women before their child reached six months of age was primarily due to a reported low milk supply (23%), discomfort (7%), and convenience (5%). Other reasons included infant tongue tie, difficulty latching on, work necessity, and a desire to feed the child.

Conclusion

The study showed that women with a higher body mass index had shorter exclusive breastfeeding periods than those with lower obesity classifications. The study emphasizes the need for allowing obese women to breastfeed for at least six months to improve maternal health.

Healthcare practitioners should encourage increasing nursing periods for postpartum weight reduction, while social interventions such as family support, healthcare professionals, and government action may improve breastfeeding length and metabolic health. Further research is required to explain the absence of anthropometric changes associated with breastfeeding in black women.