History of breast feeding and risk of incident endometriosis: prospective cohort studyBMJ 2017; 358 doi: https://doi.org/10.1136/bmj.j3778 (Published 29 August 2017) Cite this as: BMJ 2017;358:j3778
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In their questionnaire based cohort study involving 72,394 women from USA, Farland et al (1) suggested an association of prolonged breastfeeding with a reduction in the rate of subsequent development of endometriosis. This is an observation of considerable significance for modifiable maternal health from the direct and indirect benefits attributable to the duration of breastfeeding.
What about extrapolating the reproducibility of this interesting observation to Irish population? Irish breastfeeding initiation rate is just 48-56% (2,3) and the exclusive sustenance rate at 6 months is just 6% (4)- lowest in the developed world for decades. If the positive long-term maternal effect through modifiable exclusive breastfeeding behaviour during the entire infancy of the offspring could be reproduced based on the incidence and prevalence of endometriosis in Ireland, it would be a worthwhile real world verification for Farland et al. With the annual Irish births at 64,000 (unfortunately only 3,840 women exclusively breastfeeding at 6 months in the whole country!), previously reported rate of endometriosis from Ireland (5) interestingly is comparable to that reported elsewhere in Europe with very high breastfeeding rates for over six months(3,6).
For the 'field test' of the suggested hypothesis to the developing regions of the world, perhaps Sudan could be considered with the one of the lowest reported breastfeeding rates (7) in the African continent. The prevalence of endometriosis in Sudan from published literature could not be determined, perhaps a detailed analysis of the available data from Government health services might give an insight.
While we should be cognisant of the other potential confounders including genetic, immunological, environmental, dietary and infective causative factors; if prospectively collated epidemiological data on endometriosis rate from countries of very low exclusive breastfeeding rates could show a significant increase of incident endometriosis against the 'best breastfeeding champion nations' then it would be yet another reaffirmation that 'breast is best' -not just for the baby.
1. Farland LV, Eliassen AH, Tamimi RM, Spingelman D, Michels KB, Missmer SA Rate of breastfeeding and risk of incident endometriosis: prospective cohort study. BMJ doi: 10.1136/bmj.j3778 | BMJ 2017;358:j3778
2. Gallagher L, Begley C, Clarke M. Determinants of breastfeeding initiation in Ireland. Ir J Med Sci. 2016 Aug;185(3):663-8. doi: 10.1007/s11845-015-1333-2.
3. Bernard JY, Cohen E, Kramer MS. Breastfeeding initiation rates across Western countries: does religion matter? An ecological study. BMJ Glob Health. 2016 Dec 6;1(4):e000151. doi: 10.1136/bmjgh-2016-000151.
4. Ward M, Sheridan A, Howell F, Hegarty I, O'Farrell A. Infant feeding: factors affecting initiation, exclusivity and duration. Ir Med J. 2004 Jul-Aug;97(7):197-9.
5. Horne AW, Saunders PTK, Abokhrais IM, Hogg L; Endometriosis Priority Setting Partnership Steering Group (appendix). Top 10 endometriosis research priorities in the UK and Ireland. Lancet. 2017 Jun 3;389(10085):2191-2192. doi: 10.1016/S0140-6736(17)31344-2.
6. Bruun S, Wedderkopp N, Mølgaard C, Kyhl HB, Zachariassen G, Husby S.
Using text messaging to obtain weekly data on infant feeding in a Danish birth cohort resulted in high participation rate. Acta Paediatr. 2016 Jun;105(6):648-54. doi: 10.1111/apa.13382. Epub 2016 Apr 13.
7. el Bushra SM, Salih Ma, Satti SA, Ahmed Mel F, Kamil IA. Infant- feeding practices in urban and rural communities of the Sudan. Trop Geogr Med 1994; 46(5): 309-12.
Competing interests: No competing interests
Prolactin is associated with the production of breast milk and is a hormone that also plays a role in fertility by inhibiting follicle stimulating hormone (FSH) and gonadotropin-releasing hormone (GnRH), the hormones that trigger ovulation and allow eggs to develop and mature. Endometriosis is estrogen dependent disease and is related to ovulation, thus inhibition of ovulation by prolactin will prevent/ inhibit endometriosis.
Competing interests: No competing interests