Breastfeeding DOES affect conception.
Breastfeeding induces a state called lactational amenorrhea that can prevent conception under certain circumstances. This effect of breastfeeding was once thought to be an artifact of nutritional needs. Modern research shows that lactational amenorrhea, which is the delayed return of the period due to lactation, occurs regardless of the mother’s nutritional profile.
How Does Breastfeeding Interrupt the Monthly Cycle?
Regular nursing stops ovulation by inhibiting the release of hormones responsible for the monthly cycle. Researchers believe this effect is due to elevated levels of prolactin. The duration of this effect depends on the frequency of nursing and physiology of the individual. Women nursing according to the tenets of ecological breastfeeding show the longest duration of lactational amenorrhea. Ecological breastfeeding requires the baby breastfeed exclusively for six months without a schedule or the use of pacifiers/bottles. Even minor interruption of exclusive breastfeeding allows the release of hormones responsible for ovulation and fertility. This includes baby sleeping for six hours at night or using a pacifier instead of non-nutritive sucking at the breast.
Is Breastfeeding a Dependable Contraceptive?
A woman can become fertile before the return of the monthly period. This is possible, though highly unlikely, in the first six months even with exclusive breastfeeding. It becomes less unlikely over greater periods of time. Some mothers have prevented the return of the period as long as 32 months, yet others just as dedicated to breastfeeding have seen the return of menses after less than six months. The age of the woman, overall health, and unknown factors are all likely to influence the effect of breastfeeding on ovulation. For breastfeeding to serve as a dependable contraception, women can track the bodily changes that indicate fertility, such as basal body temperature, spotting blood, amount of cervical mucus, and other changes to the cervix.
“LLLI | Breastfeeding and Fertility.” La Leche League. N.p., n.d. Web. 25 Nov. 2012. http://www.lalecheleague.org/nb/nbsepoct06p196.html
“The effect of lactation on ovulation and fert… [Clin Perinatol. 1987] – PubMed – NCBI.” National Center for Biotechnology Information. N.p., n.d. Web. 25 Nov. 2012. http://www.ncbi.nlm.nih.gov/pubmed/3549114