Pregnancy Prevention and Exclusive Breastfeeding

by | September 6, 2018

A very common and immediate concern for people after they have given birth is the pregnancy prevention. While that sweet smell of a new baby can be addicting, most people want to wait sometime before expanding their family. 

In fact, the Department of Health and Human Services suggests that people wait at least twelve months between pregnancies. Contraception options vary and, depending on preferences, can provide adequate protection from unintended pregnancy if used correctly.


No period so no baby?

One of the sweet joys of pregnancy (apart from the baby, that is) is not having a menstrual cycle for nine full months.  What’s even better, is that a large majority of people that exclusively breastfeed their baby, will go through a prolonged period of not menstruating. Since ovulation and the menstrual cycle tend to go hand in hand, the lack of this cycle can give people a tool for pregnancy prevention. However, while some people are able to prevent pregnancy by exclusively breastfeeding, it is important to note that the human body is a complicated machine and this method is not without its flaws.


What is a feedback loop?

The human body is made up of many different feedback loop mechanisms. These loops help to control and regulate homeostasis, which is the body’s ability to maintain the relatively constant Breastfeeding Pregnancy Preventionconditions in which it functions at optimum performance despite input from internal and external sources. Everyone has a unique homeostasis level, which is why some people prefer different resting temperatures inside their home – their body prefers to function at a specific temperature and is happier that way! Picture, if you will, rising from your warm cozy bed and walking straight outside to a brisk winter day. Your body’s internal temperature will not simply drop to the temperature outside like your coffee will. Instead, through chemical messengers and hormonal changes, the body will work to maintain its internal temperature, something you will feel as shivers, goosebumps, and tingly skin.

Some of these feedback loops are considered positive feedback while other are considered negative feedback. Positive feedback loops are a process in which the presence of a material will cause the body to keep performing the action that creates that material. On the other hand, a negative feedback loop is one in which the presence of that material will cause the body to stop performing the action that creates that material. Your body’s hormone balances are regulated through feedback loops with hormones preventing and encouraging other hormones from being produced.


What does this have to do with menstruation?

The female menstrual cycle is one that is on different feedback loops. Throughout this generally 28-day cycle, levels of estrogen, progesterone, testosterone, luteinizing hormone (LH), gonadotropin-releasing hormone (GnRH) and follicle-stimulating hormone (FSH) fluctuate and are heavily dependent on the levels of the others. When an ovary is ready to release a mature follicle (egg), the ovary will first release estrogen, causing an estrogen spike. This spike causes the body to release luteinizing hormone and gonadotropin-releasing hormone. The presence of LH causes the ovary to release even more estrogen, inducing the positive feedback loop of LH and GnRH production. This rise also causes the release of FSH, which eventually leads to ovulation. If the released egg is not fertilized and implanted, all levels of these hormones dramatically decrease leading to menstruation and the beginning of the cycle all over again.


So what happens when a person gives birth and begins to breastfeed?

The placenta is a hormone-making machine, producing high levels of estrogen and progesterone. High levels of these two hormones prevent high levels of another hormone, prolactin, from being produced. Once the placenta leaves the body, estrogen and progesterone levels plunge, allowing the body to produce prolactin in much larger quantities. This hormone, known to contribute to over 300 biochemical mechanisms, is mainly responsible for breastmilk production in mammals. These high levels of prolactin not only suppress the production of estrogen, but also hinder FSH and LH from forming, suppressing the positive feedback loop of ovulation. Without the production of these hormones, not only does ovulation (usually) not occur, but the ovaries also don’t work to mature follicles. Yay for natural methods of birth control…maybe?


Why Do Some People Still Get Pregnant When Exclusively Breastfeeding?Breastfeeding Pregnancy Prevention

Once prolactin rises, regular, exclusive breastfeeding is required in order to keep it at high levels. Prolactin production is very sensitive to breastfeeding and simple variations in schedule can cause dramatic decreases in its production. Estrogen is hiding below the surface, just itching to be produced. One small dip in prolactin production can easily allow estrogen formation to begin. If allowed to continue, it will lead to increased levels of FSH, GnRH, and LH, promoting the positive feedback loop. So while the same hormones that make milk also suppress the release of reproductive hormones, there are very specific instructions that, if not followed, will greatly increase the chance of ovulation. These are the five main ‘rules’ that need to be followed in order to keep these levels up:

  1. Exclusively breastfeeding – no bottles, no pacifiers, no solid food
  2. Nursing on demand – no trying to get baby on a schedule (until at least 3 months)
  3. Nursing at least 6 times a day – keep feeding that baby
  4. Nursing at least 60 minutes per day – in total
  5. Nursing at night – no more than 4-5 hours between sessions


Sounds simple right?

For some people who exclusively breastfeed, it is that simple. There are parents who are able to go almost the entire duration of breastfeeding without the return of their cycle, some twelve months or more. For reasons not completely understood, their body’s homeostasis works quite happily within the changes in prolactin production and maintains the low levels of estrogen. On the other hand, some parents who have very small changes in prolactin production will immediately lead to estrogen production. Parents need to be honest with themselves about how perfectly they stick to the above rules. This is especially true once parents choose to start feeding their baby solid foods, since this will also lead to fluctuations in prolactin. In almost all cases, ovulation occurs prior to menstruation so counting on the arrival of it as your sign for more protection may be too little too late.


So how do I protect myself from pregnancy?

Considering that some forms of birth control can take up to three weeks to be effective, it is fairly important to consider your family planning choices and weigh them against the possible outcomes. It is important to understand that breastfeeding as birth control can (and does!) fail so understanding that outcome is necessary. If you want something more than that, your care team can advise you on the best methods of pregnancy prevention while still breastfeeding. Options that are available include both hormonal and non-hormonal.

While hormonal methods are considered to be more effective, many people have concerns about how hormones will affect not only their baby, but also their milk supply. It is generally agreed upon in the medical community that hormonal birth control is safe while breastfeeding. However, progestin-only contraception in the form of pills, shots or intrauterine devices has a very minimal effect on milk supply while estrogen-containing methods can have some effects due to its negative effect on prolactin.

However, if hormones are not for you, other options should be considered if you intend to prevent pregnancy. These options can include all barrier methods of pregnancy prevention such as condoms, spermicidal lotion, and a diaphragm. Additionally, copper intrauterine devices are also very effective and contain no hormones. Natural family planning is also an option, however, is not highly recommended postpartum since cycles are often not regular enough to be predicted and it can take some time to understand your body’s natural rhythm and cycle lengths.

Pregnancy can be quite stressful on the body so allowing it to heal properly will promote healthier subsequent pregnancies. If you have questions about your fertility and ability to prevent unintended pregnancy after giving birth, you should definitely have a discussion with your care team.



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