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Assisted Fertility and Breastfeeding

A Personal Account By Bláthnaid Buckley. Speech and Language Therapist, Breastfeeding Advocate.

As presented by Carol Smyth at La Leche League of Ireland Conference, 2024.

Carol Smyth, IBCLC and CBT Psychotherapist, presented on the topic of ‘Assisted Fertility and Breastfeeding’ at the 2024 La Leche League of Ireland Conference which took place in Sligo on 1-3rd March this year. Her presentation was both thought-provoking and highly informative. Carol provided insight into this significant but extremely under-researched area. She had disclosed that although she is not an endocrinologist or fertility expert, she has a personal interest in this area due to her own “lived experience which ignited a deep dive into the literature”. Her presentation covered: how lactation affects the menstrual cycle and fertility; fertility treatment whilst breastfeeding; and breastfeeding after fertility treatment. As a conference delegate, it was her personal experience that
really made this presentation special and as such I would like to share my report from it.

We were brought back to the reproductive cycle and the role of breastfeeding in this process. Carol zoned in on the key hormones that contribute to the menstrual cycle: progesterone, oestradiol, luteinising hormone (LH), follicle stimulating hormone (FSH) and gonadotrophin releasing hormone (GnRH). The latter being seen as a ‘master switch’ in the menstrual cycle as GnRH communicates with
the pituitary thus signalling release of the other key hormones.

As we know, all pregnant women will produce milk and lactation is the final step of the reproductive process, regardless of the woman’s choice to breastfeed or not. For women who choose to breastfeed, the process of lactation and stimulation of the breast through sucking will continue to suppress the woman’s fertility. We know that for some women, their periods may or may not return despite continuing to breastfeed. For women whose periods do return, fertility may continue to be suboptimal as breastfeeding impacts the pathway of GnRH. As such, once there is stimulation of the breast through the nursling’s suck, the pathway of GnRH is interrupted. This has a knock on effect on FSH and LH secretion, which in turn halts egg production. Carol supported this with reference to McNeilly (1993) from a journal article titled ‘Lactational Amenorrhea’,

“Thus, while suckling continues, any follicle that starts to develop and secrete estradiol will inhibit further LH release and therefore stop growing. When suckling declines, the pulsatile pattern of LH returns to normal, sensitivity to estrogen negative feedback declines, and follicle
growth can continue and ovulation will occur.”

Carol outlined the steps to trying to conceive: firstly the occurrence of ovulation and secondly having a healthy cycle with a mature egg. When a woman’s menstrual cycle returns post-partum in the presence of continuing to breastfeed, it is possible that she may not necessarily have ovulated or have had a mature egg that is capable of being fertilized. She made reference to McNeilly (2001),

“Often while women continue to breast-feed, the first few ovulations and menses are associated with inadequate corpus luteum function, which would probably not support a pregnancy. Eventually, normal menstrual cycles resume when suckling declines further. The duration of amenorrhea and subsequent period of inadequate luteal function varies greatly between mother-baby combinations, and in different societies.”

Carol presented some findings from a systematic review completed by Cox (2022). According to this systematic review and meta-analysis, 17.5% of individuals worldwide will experience infertility during their lifetime. This is infertility is equally divided between male-factor and female-factor infertility. Female related infertility can be related to: ovulation disorders (group 1 relating to issues with the pulsatile release system, group 2 relating to polycystic ovary syndrome); ovarian failure; tubal issues; uterine issues; and unexplained infertility. The latter issue may require the use of assisted reproductive technology (ART). With specific reference to breastfeeding support, it is not clear if ART (such as IVF and IUI) is an issue if there are breastfeeding difficulties present.

There is a lot that we do not understand about the impact of fertility treatments on breastfeeding. Many consultants may advise considering weaning from breastfeeding before commencing fertility treatments. There are many factors at play to consider such as the impact of breastfeeding on fertility, the effect of fertility medications on the nursling, and the effect of breastfeeding on the controlled menstrual cycle. As fertility treatments (specifically IVF) are focused on ‘control’, lactation can present as a barrier to successful ovulation. Amongst these factors, Carol highlighted the following areas that are important to consider when supporting breastfeeding families who are undergoing IVF: the effect
on the nursling; the emotional impact of weaning; success rates; and the emotional impact of previous losses. Each dyad needs to be approached individually when breastfeeding support is being provided. Carol left us with the following profound take home message:

“Meet the parent where they are”.

Bláthnaid Buckley.
Speech and Language Therapist, Breastfeeding Advocate.

Carol Smyth, IBCLC and CBT Psychotherapist. ‘Assisted Fertility and Breastfeeding’ as presented at La Leche League of Ireland Conference 2024.

Cox, C. M., Thoma, M. E., Tchangalova, N., Mburu, G., Bornstein, M. J., Johnson, C. L., & Kiarie, J. (2022). Infertility Prevalence and the Methods of Estimation from 1990 to 2021: A Systematic Review and Meta-analysis. Human Reproduction Open, 4.

McNeilly, A.S. (1993). Lactational Amenorrhea. Endocrinology and Metabolism Clinics of North America, 22(1), 59–73.

McNeilly, A.S. (2001). Neuroendocrine Changes and Fertility in Breast-feeding Women. Progress in Brain Research, 133, 207–214.

Complied by: Bláthnaid Buckley

Dated: 28th March 2024. 

Bláthnaid did not receive a bursary from ALCI for this report.

ALCI Council would like to thank you for this report.