REVISIÓN

 

Effect of maternal obesity on lactation: systematic review

Efecto de la obesidad materna sobre la lactancia: revisión sistemática

 

 

M. Lepe, M. Bacardí Gascón, L. M. Castañeda-González, M.^a E. Pérez Morales and A. Jiménez Cruz

Universidad Autónoma de Baja California. Medical and Psychology School. Tijuana. Baja California. México.

Correspondence

 

 

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ABSTRACT

Objective: The short duration or lack of breastfeeding has been associated with maternal obesity. The purpose of this study was to systematically review prospective studies that assessed the effect of maternal obesity on lactation.
Methods: A search of studies was conducted in Pubmed, these included prospective studies on maternal obesity and initiation, intention and duration of breastfeeding: 653 articles were found, only seven were prospective studies. After adding other studies found by hand, a total of nine studies were analyzed.
Results: Three out of four papers observed a higher risk for delay lactogenesis among obese mothers, odds ratio ranging from 1.02 to 1.10. The study assessing the initiation of lactation showed that non-obese mothers initiated lactation sooner, OR: 0.39 (95% CI: 0.25-0.62). The overall risk for cessation of breastfeeding showed that obese mothers had higher risks of early cessation, HR: 1.50 (CI 95% 1.11-2.04). In one study it was observed that obese mothers were not more likely to never breastfeed, OR = 1.56 (95% CI: 0.97-1.50).
Conclusions: This review shows that in prospective studies, obese mothers are more likely to have delayed lactogenesis and reduced lactation. Therefore, weight control and breastfeeding promotion should be reinforced before and during pregnancy. In overweight and obese mothers, breastfeeding should be closely monitored after birth.

Key words: Maternal obesity. Lactogenesis. Breastfeed.

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RESUMEN

Objetivo: La falta de lactancia o su corta duración ha sido asociada con la obesidad materna. El propósito de este estudio fue realizar una revisión sistemática de estudios prospectivos que estudiaron el efecto de la obesidad materna sobre la lactancia.
Métodos: Se realizó una búsqueda en Pubmed, se incluyeron estudios prospectivos del efecto de la obesidad materna sobre la iniciación, la intención y la duración de la lactancia: se encontraron 653 artículos, y siete fueron estudios prospectivos. Después de agregar otros estudios seleccionados a mano, se analizaron nueve estudios.
Resultados: Tres de cuatro estudios observaron un mayor riesgo de retraso de la lactogénesis en madres obesas, OR: 1,02 a 1,10. El estudio que analizó la iniciación de la lactancia describió que las madres no obesas iniciaron la lactancia más temprano, OR: 0,39 (95% CI: 0,25-0,62). El riesgo de terminación temprana de la lactancia fue mayor en madres obesas, HR: 1,50 (CI 95% 1,11-2,04). En un estudio se observó que las madres obesas no tenían más probabilidades de no lactar, OR = 1,56 (95% CI: 0,97-1,50).
Conclusiones: Esta revisión realizada en estudios prospectivos indica que, es más probable que las madres obesas tengan lactogénesis atrasada o un periodo corto de lactancia. Por lo tanto, el control de peso y la promoción de la lactancia deben reforzarse antes y durante el embarazo. En madres con sobrepeso y obesidad, la lactancia debe de ser promovida y supervisada después de nacimiento.

Palabras clave: Obesidad materna. Lactogenesis. Lactancia.

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Introduction

Obesity is a public health problem worldwide that demands important attention.^1,4 It is considered a risk factor for the development of multiple chronic diseases such as hypertension, insulin resistance, diabetes and hyperlipidemia.⁵ Additionally, obesity has been associated with an increased risk for death.⁶

A recent study showed that the prevalence of obesity among pregnant women was 28.9%, a trend that continues to rise.⁷ Obesity during pregnancy has been associated with a number of complications during and after pregnancy, including gestational diabetes, preeclampsia, birth defects, and increased risk for thromboembolism and shoulder dystocia.^8,9 Furthermore, it has been suggested that maternal obesity could predispose the unborn child to a higher risk for coronary artery disease later in life.¹⁰

Conjointly, several studies have shown that maternal obesity has a negative effect on the duration of breastfeeding and delayed lactogenesis.^11-13 Rutishauser & Carlin reported a 50% risk of early termination of breastfeeding amongst mothers with BMI > 26 kg/m^{2. 11}

A recent systematic review¹⁴ analyzed the effects of maternal obesity on duration of breastfeeding, initiation and intention to breastfed. However, this systematic review incorporated prospective, retrospective, and other types of publications. Since prospective studies could identify a cause-effect association, the purpose of this study was to systematically review and evaluate only prospective studies that assessed the effect of maternal obesity on lactation.

 

Materials and methods

A systematic review was conducted from articles registered in Pubmed with the following search data: "obesity," "maternal obesity, "lactation" and "breastfeeding," and published in English. For the purpose of this review, we included only prospective studies up to June 2010. Research studies were also identified from the reference lists of other articles, and the authors' literature collection was hand-searched. Six hundred and fifty-three articles were found, only 14 of which were considered relevant.

After removing duplicates, eight articles remained and three additional papers that were duplicates from previous studies were also eliminated. Four studies reported in other papers were also included. After careful selection, we excluded all studies based on data from previous trials, a total of nine studies remained relevant and they were analyzed in this systematic review.

Quality evaluation

The prospective studies were evaluated according to the following criteria: 1. Type of measurement (objective vs subjective) of delayed lactogenesis. 2. Measurement of duration of lactation. 3. Objective or reported weight and height for the calculation of BMI. 4. Use of Analysis of Relative Risk Ratio (RR), Odds Ratio (OR), or Hazard Ratio (HR). Each criterion was assigned cero points if it was not described and/or measured subjectively; one point was given if the criterion was described and measured objectively. The highest score a study could potentially achieve was four points, those studies with such score were considered of great quality.

 

Results

Most studies utilized the WHO definition of obesity: underweight < 18.50 kg/m², normal range 18.50-24.99 kg/m², overweight ≥ 25.00 kg/m², and obese ≥ 30.00 kg/m².15 A few studies used the United States Institute of Medicine definition of obesity: underweight/normal weight BMI < 26.1 kg/m², overweight BMI 26.1-29.0 kg/m², obese BMI > 29.0 kg/m^{2 16}.

Table I shows the association between obesity and lactogenesis. The OR reported ranged from 1.1 to 6.1.^17-20 One study measured prolactin concentrations immediately after lactation and after suckling. The normal weight mother had a higher concentration of prolactin in both circumstances.²¹ Another study evaluating delayed lactogenesis in obese mothers at 72 hrs. postpartum and seven days postpartum found that obese women had an OR of 2.11 and 2.58 respectively.¹⁹ Table II presents the association between obesity and duration of lactation. All the studies revealed that obese mothers have a shorter period of lactation than normal weight mothers. The study conducted by Oddly et al.,¹² concluded that obese mothers who never breastfed had 1.56 odds of never breastfeeding, 1.98 odds of breastfeeding for less than two months, 1.97 odds of breastfeeding for less than four months and 1.68 odds of breastfeeding for less than six months.¹² The study conducted by Baker et al.,²² determined that the relative risk of early termination of lactation ranged from 1.12 for overweight mothers to 1.39 for type III obese women.

 

Discussion

Delayed lactogenesis

In this review we observed a consistent pattern of delayed lactogenesis in mothers with overweight or obesity. Although the results are consistent with those found in previous reviews¹⁴ and in studies conducted on obese women with diabetes,²³ this study adds to the literature by only including prospective studies and showing that the highest quality score studies demonstrate a higher risk of delayed lactogenesis among women with obesity.

The results could be explained by the lower prolactin concentration showed in obese mothers at rest and after suckling.²¹ Progesterone withdrawal, which occurs postpartum, is one of the factors responsible in preparing the mammary gland.^24,25 Progesterone is stored in adipose tissue leading to a constant hormonal level that albeit very low might also be responsible for inhibiting lactogenesis.^26,27 Another factor which could indirectly cause a perceived delay in lactogenesis could be associated with anatomical characteristics such as adipose tissue between ducts that prevents proper milk flow.¹⁹ The effects of psychological or physical problems of obese mothers regarding lactation need to be explored.

Duration of lactation

This review showed a consistent pattern of reduced lactation among mothers with overweight or obesity. The four prospective studies, including the two with the highest qualitative scores, show that obese mothers breastfed for a shorter period of time when compared to non-obese mothers.¹² Obesity poses several socio-cultural aspects that have been observed and associated with shorter lactation periods. ^{8,12,13,17,27} It has been suggested that obese women might be part of social groups that are linked with higher risk of shorter lactation time,²⁸ and they also have negative attitudes towards breastfeeding.²⁹ This may be due to problems with self-image³⁰ and with being uncomfortable with breastfeeding in public.³¹ Additionally, post-partum depression is more common among obese mothers, which is also associated with reduced lactation.

When comparing these results with the findings of Amir et al., we observed the mix of various types of studies included in their tables, which could potentially hinder or bias the results stated therein. Yet, the prospective studies that they analyzed show that there are statistically significant findings, suggesting a link between a higher BMI and lower duration of breastfeeding and a delay in lactogenesis.

In conclusion, this review shows that, in prospective studies, maternal obesity is consistently associated to delayed lactogenesis and reduced lactation and thus, reinforcing the fact that weight control before, during, and after pregnancy should be an objective of prenatal control. Additionally, these results also indicate the importance of emphasizing the promotion of breastfeeding among obese women during pregnancy.

 

References

1. Medina Blanco RI, Jiménez Cruz A, Pérez Morales ME, Armendariz Anguiano AL, Bacardí Gascón M. Programas de intervención para la promoción de actividad física en niños escolares: revisión sistemática. Nutr Hosp 2011; 26 (2): 263-268.         [ Links ]

2. Bacardí Gascón M, Reveles Rojas C, Jiménez Cruz A, Woodward López G, Crawford PB. Evaluation of the activity questionnaire applied to mothers and caregivers of preschool children. Nutr Hosp 2011; 26 (1): 258-259.         [ Links ]

3. Velasco Martínez RM, Jiménez Cruz A, Higuera Domínguez F, Domínguez de la Piedra E, Bacardí Gascón M. Obesidad y resistencia a la insulina en adolescentes de Chiapas. Nutr Hosp 2009; 24 (2): 151-156.         [ Links ]

4. Bin Zaal AA, Musaiger AO, D'Souza RD. Dietary habits associated with obesity among adolescents in Dubai, United Arab Emirates. Nutr Hosp 2009; 24 (4): 437-444.         [ Links ]

5. WHO. Physical status: the use and interpretation of anthropometry. Geneva 1995.         [ Links ]

6. Adams KF, Schatzkin A, Harris TB, Kipnis V, Mouw T, Ballard-Barbash R et al. Overweight, Obesity, and Mortality in a Large Prospective Cohort of Persons 50 to 71 Years Old. New England Journal of Medicine 2006; 355 (8): 763-78.         [ Links ]

7. Herring SJ, Platek DN, Elliott P, Riley LE, Stuebe AM, Oken E. Addressing Obesity in Pregnancy: What Do Obstetric Providers Recommend? Journal of Women's Health: Mary Ann Liebert, Inc.; 2010, pp. 65-70.         [ Links ]

8. Huda SS, Brodie LE, Sattar N. Obesity in pregnancy: prevalence and metabolic consequences. Seminars in Fetal and Neonatal Medicine 2010; 15 (2): 70-6.         [ Links ]

9. Watkins ML, Rasmussen SA, Honein MA, Botto LD, Moore CA. Maternal Obesity and Risk for Birth Defects. Pediatrics 2003; 111 (5): 1152-8.         [ Links ]

10. Forsén T, Eriksson JG, Tuomilehto J, Teramo K, Osmond C, Barker DJP. Mother's weight in pregnancy and coronary heart disease in a cohort of finnish men: follow up study. BMJ 1997; 315 (7112): 837-40.         [ Links ]

11. Rutishauser IH, Carlin JB. Body mass index and duration of breast feeding: a survival analysis during the first six months of life. Journal of Epidemiology and Community Health 1992; 46 (6): 559-65.         [ Links ]

12. Oddy WH, Li J, Landsborough L, Kendall GE, Henderson S, Downie J. The association of maternal overweight and obesity with breastfeeding duration. The Journal of Pediatrics 2006; 149 (2): 185-91.         [ Links ]

13. Li R, Jewell S, Grummer-Strawn L. Maternal obesity and breast-feeding practices. Am J Clin Nutr 2003; 77 (4): 931-6.         [ Links ]

14. Amir L, Donath S. A systematic review of maternal obesity and breastfeeding intention, initiation and duration. BMC Pregnancy and Childbirth 2007; 7 (1): 9.         [ Links ]

15. WHO. BMI Classification. 2006; Available from: http://apps.who.int/bmi/index.jsp?introPage=intro_3.html.         [ Links ]

16. IOM. Nutrition During Pregnancy. Washington, DC: National Academy Press; 1990.         [ Links ]

17. Nommsen-Rivers LA, Chantry CJ, Peerson JM, Cohen RJ, Dewey KG. Delayed onset of lactogenesis among first-time mothers is related to maternal obesity and factors associated with ineffective breastfeeding. Am J Clin Nutr 2010; 92 (3): 574-84.         [ Links ]

18. Hilson JA, Rasmussen KM, Kjolhede CL. High Prepregnant Body Mass Index is Associated With Poor Lactation Outcomes Among White, Rural Women Independent of Psychosocial and Demographic Correlates. Journal of Human Lactation 2004; 20 (1): 18-29.         [ Links ]

19. Dewey KG, Nommsen-Rivers LA, Heinig MJ, Cohen RJ. Risk Factors for Suboptimal Infant Breastfeeding Behavior, Delayed Onset of Lactation, and Excess Neonatal Weight Loss. Pediatrics 2003; 112 (3): 607-19.         [ Links ]

20. Chapman DJ, Perez-Escamilla R. Maternal Perception of the Onset of Lactation Is a Valid, Public Health Indicator of Lactogenesis Stage II. J Nutr 2000; 130 (12): 2972-80.         [ Links ]

21. Rasmussen KM, Kjolhede CL. Prepregnant Overweight and Obesity Diminish the Prolactin Response to Suckling in the First Week Postpartum. Pediatrics 2004; 113 (5): e465-71.         [ Links ]

22. Baker JL, Michaelsen KF, Sorensen TI, Rasmussen KM. High prepregnant body mass index is associated with early termination of full and any breastfeeding in Danish women. Am J Clin Nutr 2007; 86 (2): 404-11.         [ Links ]

23. Neubauer S, Ferris A, Chase C, Fanelli J, Thompson C, Lammi-Keefe C et al. Delayed lactogenesis in women with insulindependent diabetes mellitus. The American Journal of Clinical Nutrition 1993; 58 (1): 54-60.         [ Links ]

24. Neville MC, Morton J, Umemura S. Lactogenesis: The Transition from Pregnancy to Lactation. Pediatric Clinics of North America 2001; 48 (1): 35-52.         [ Links ]

25. Kuhn N. Progesterone withdrawal as the lactogenic trigger in the rat. Journal of Mammary Gland Biology and Neoplasia 2009; 14 (3): 327-42.         [ Links ]

26. Akre J. Infant feeding, the physiological basis. Ceylon Medical Journal 1994; 39 (3): 144.         [ Links ]

27. Chapman D, Perez-Escamilla R. Identification of risk factors for delayed onset of lactation. J Am Diet Assoc 1999; 99: 450-4.         [ Links ]

28. Wadden T, Brownell K, Foster G. Obesity: responding to the global epidemic. J Consult Clin Psychol 2002; 70 (3): 510-25.         [ Links ]

29. Riva E, Banderali G, Agostoni C, Silano M, Radaelli G, Giovannini M. Factors associated with initiation and duration of breastfeeding in Italy. Acta Paediatr 1999; 88: 411-5.         [ Links ]

30. Sarwer D, Wadden T, Foster G. Assessment of body image dissatisfaction in obese women: specificity, severity, and clinical significance. J Consult Clin Psychol 1998; 66 (4): 651-4.         [ Links ]

31. Barnes J, Stein A, Smith T, Pollock J, Team AS. Extreme attitudes to body shape, social and psychological factors and a reluctance to breast feed. JR Soc Med 1997; 90: 551-9.         [ Links ]

 

 

Correspondence:
Arturo Jiménez Cruz.
Maestría y Doctorado (Ciencias de la Salud) en Nutrición.
Facultad de Medicina y Psicología.
Universidad Autónoma de Baja California.
Calzada Universidad 14418. Mesa de Otay.
22390 Tijuana. Baja California. México.
E-mail: ajimenez@uabc.edu.mx

Recibido: 8-VII-2011.
Aceptado: 18-VII-2011.