27th August 2012 | by Dr. William Buckett
I’m still breastfeeding my 23 month old. I’ve been trying to get pregnant for months and months with no luck. I’m 34 and desperate to have another. Could it be the breastfeeding that’s stopping me?
Written by our medical expert William Buckett, M.D.
The quick answer is quite possibly!
Breastfeeding, and particularly exclusive breastfeeding during the first 6 months without any other substance other than breast-milk being fed to the baby, has long been associated with an absence of menstruation. This led to the publication of the Bellagio Consensus in 1988, where exclusive or near-exclusive breastfeeding and a lack of menstruation could be viewed as an effective form of contraception for this first 6 months [1]. The continued nipple stimulation through suckling causes an increase in the hormone prolactin, which inhibits normal ovulation and therefore pregnancy.
The timing of the return to normal ovarian function and menstruation (and therefore the ability to become pregnant) is highly variable. Although 80% women who continue to breastfeed will have a return to menstruation after 12 months, some women still remain without menses 24 months after delivery [2]. Until menstruation resumes, the likelihood of becoming pregnant remains very small.
Even after there is a return to menstruation, while continuing to breastfeed, there is a period of reduced fertility [3]. This occurs in two ways: firstly, prolactin disrupts normal ovarian function, leading to menstrual cycles without ovulation; secondly even after a normal ovulation the luteal phase – where a fertilized embryo typically implants in the uterus – can be disrupted, further reducing the likelihood of becoming pregnant.
In general there is a delay of a few months between the start of menstruation and the start of ovulation.
Usually after 24 months, provided there is a return to normal menstruation, most women who are still breastfeeding will be able to conceive. However, if this does not happen, it would be appropriate to consult a fertility specialist.
References:
1. Consensus Statement: Breastfeeding as a family planning method. Lancet 1988; 2 (8621): 1204-1205.
2. Short RV. Lactational infertility in family planning. Ann Med 1993; 25: 175-180.
3. McNeilly AS. Lactational control of reproduction. Reprod Fertil Dev 2001; 13: 583-590.
Thank you very much for this detailed answer.
Since I submitted this question my son weaned himself at 23 months and my periods stopped all together for 58 days. I’m hoping as my hormones regulate and get back to normal I will be able to get pregnant again.
Thanks again for a wonderful, informative service.