Using LAM (Lactational Amenorrhea Method) for NFP while Breastfeeding

Breastfeeding, Fertility, and NFP: Choosing between Marquette and LAM

by | Marquette while Breastfeeding

This article is for new moms everywhere, breastfeeding (maybe even breastfeeding right now) and looking for reliable information on natural family planning options for breastfeeding moms. I’m a Marquette Method instructor, and I’m here to lay out—in depth—the similarities and differences between two family planning options that might apply to you—the Lactational Amenorrhea Method (LAM) and the Marquette Method of NFP Breastfeeding Protocols.

I’ve chosen to compare these two methods because they are significantly different approaches to tracking your fertility during the breastfeeding transition, but they are equally effective. The Marquette Method of NFP in the breastfeeding transition is 98% effective with perfect use, and the LAM method is 98% effective in the first 6 months of baby’s life (Rogers, 1997; Tommaselli, Guida, Palomba, Barbato, & Nappi, 2000; World Health Organization, 1998).

I want to give you the information you need to make an informed choice about which of these two options might be good fit for you, right now, at this point in your life. In order to make an educated choice, you’ll first need to know about how the methods work, and how to figure out which one is a good choice for your specific circumstances!

Breastfeeding and Fertility

Let’s start with the basics. Breastfeeding affects your fertility. How? When your baby nurses, your body produces prolactin. The primary function of prolactin is to prompt your body to produce more breastmilk. Elevated prolactin doesn’t just affect your milk supply—it also has an effect on your brain. Breastfeeding women with sufficient levels of prolactin circulating in their body will experience a delayed return to fertility. This happens because prolactin suppresses the production of gonadotropin-releasing hormone (GnRH) which in turn suppresses follicle stimulating hormone (FSH) and luteinzing hormone (LH). The result is that no follicle is stimulated to pick up an immature egg, which means that no egg will develop, which means that ovulation will not occur.

The chain reaction of prolactin, GnRH and FSH is fascinating (I wrote a chapter about it in my Marquette Method Breastfeeding Manual), but if you’re an overtired mom reading this article, it’s enough to know that the presence of prolactin will most likely suppress the regular, cyclical functioning of your reproductive system—at least for a time. For as long as prolactin continues to suppress egg development, breastfeeding mothers remain naturally infertile. Breastfeeding is nature’s way of ensuring that mothers can space out their pregnancies enough to be able to care for and nourish their babies before their next pregnancy.

TLDR: Most breastfeeding mothers usually experience a delayed return to fertility. How long? It depends on a lot of factors, but principally it’s related to how much you breastfeed, and how often. Every woman is different. Breastfeeding women might experience only a couple of months of infertility before their fertility returns, or they might experience a much longer phase of infertility—some women experience longer than 24 months of lactational amenorrhea. (Lactational amenorrhea is the medical term for the time in which breastfeeding suppresses menstruation—lactational means “breastfeeding,” and amenorrhea means “the absence of menstruation.”)

Lactational Amenorrhea: A Natural Way to Avoid Pregnancy

Researchers continue to study the complex relationship between breastfeeding and fertility. There is great interest in how the different hormones behave during a woman’s breastfeeding journey, and how these hormones impact her return to fertility. What the research continues to find is that women who are exclusively breastfeeding their baby generally see a return to fertility at around the 6 month mark.

I’m going explore one particular method here, LAM, because it has a lot of evidence-based research to back it up. My goal is not to teach you how to practice LAM, but to teach you the basic approach of the method, point you in the direction of reliable resources on it, and then to compare LAM’s approach to breastfeeding and fertility with the Marquette Method’s approach to the breastfeeding transition, which is significantly different.

Lactational Amenorrhea Method (LAM)

The Lactational Amenorrhea Method of natural family planning is relatively simple. A woman simply needs to be able to answer “yes” to each of the following three criteria:

  1. After lochia dries up, the woman must not have had any sort of vaginal bleeding.
  2. The woman must exclusively breastfeed her baby. The baby must nurse on demand, day and night, with no lapses longer than 4-6 hours between nursing sessions. The baby must derive all his or her nutrition from breast milk, and so cannot be fed formula or solid food.
  3. The baby must be less than 6 months old.

For as long as the answer remains “yes” to all three of these criteria, a breastfeeding woman can expect the LAM method to be 98% effective in avoiding pregnancy. No abstinence is required.

LAM is a great option for many women, and by all means get in touch if you don’t quite know how to answer any one of these criteria (human fertility can be complicated, and sometimes what seem like easy questions don’t have easy answers). As a Marquette Method instructor, I’m well-versed in the research surrounding LAM, and I can help you discern whether or not LAM is currently an option for you.

One of the biggest benefits of LAM, obviously, is that there is no abstinence required. If you practiced another form of NFP before becoming pregnant, LAM can be a nice break from urine testing, checking symptoms, and charting. It’s very effective, too … as long as you fit the criteria, you can engage in intercourse on any day and still only have a 2% chance of becoming pregnant.

Alas, all good things must come to an end. At some point all women will need to transition from LAM to another method if they want to continue avoiding pregnancy. Once you no longer fit all three criteria, the LAM method will no longer be a good fit for you. Some situations that may cause you to fall out of the LAM criteria are:

  • If your baby ever goes longer than 6 hours without nursing (even just once), you’re no longer eligible for LAM.
  • Women who experience any bleeding after 56 days postpartum will need to find an alternative method (even if the bleed you experienced wasn’t a menstrual bleed)
  • And finally, the method applies only up until 6 months postpartum, so when your baby reaches his or her half-birthday, you’ll need to switch to another method of pregnancy avoidance, if you’re still planning to avoid pregnancy.

If you go back to work before your baby is 6 months old, or if you are pumping rather than nursing, you may still qualify to continue using the LAM method—there are additional considerations to follow, and the method effectiveness drops to 94.8% (Valdés, Labbok, Pugin, & Perez, 2000). Please reach out if you want to know more about LAM and your specific life circumstances!

LAM—Practical or Not?

Most women who are breastfeeding aren’t doing it in order to avoid pregnancy for the first 6 months of their baby’s life—they’re doing it because it’s a practical way to feed their baby, and it’s a nice opportunity to bond with their baby! For some women, it’s an economical choice; babies have to eat, and formula is expensive! To breastfeed or not is very much a personal choice, and it’s not one that anyone can make except you. (And perhaps your baby. They have their own preferences … for proof of this, ask my third child! She wasn’t a fan.)

Many women love LAM and practice it successfully with each of their children. For many women the style of breastfeeding that LAM requires perfectly matches the type of breastfeeding relationship they always wanted to have with their baby, and the fertility-suppressing side effect of exclusive breastfeeding is just a happy and convenient side effect. Adding a new baby to the mix can complicate things and if breastfeeding is coming easily for you, then LAM can really simplify the NFP aspect of your life.

That said, not all women find breastfeeding easy. You might intend to practice LAM, only to find out that breastfeeding got off to a rough start, and your baby didn’t cooperate as planned. In these cases, most women still want to breastfeed their baby, but perhaps not as intensively or frequently as required make them eligible for LAM. Some babies tend to sleep long stretches through the night, and not a lot of mothers want to wake their sleeping baby just to ensure they continue to fit the LAM criteria!

Breastfeeding, but Not Exclusively? Let Me Tell You about Marquette.

A lot of breastfeeding women, for a wide variety of reasons, just don’t (or can’t) breastfeed in the way that LAM prescribes. For these women, the Marquette Method Breastfeeding Protocols can be a great choice.

The biggest difference between LAM and the Marquette Method is that in order to qualify for the Marquette Method Breastfeeding Protocols you simply need to be breastfeeding. All lactating mothers welcome! Once a day, twice a day, all-day-long … any kind of breastfeeding means you’re still eligible to follow Marquette’s protocols (and can expect them to be just as effective), regardless of what your breastfeeding habits are. The Marquette Method Breastfeeding Protocols work if you’re pumping some of the time, or all of the time, or not pumping at all. It works if your baby is sleeping through the night, or if your baby wakes you up all night long to nurse. It works if your baby has been fed some formula once or twice, gets formula regularly, and or has started solids. Have you experienced a bleed since your lochia has dried up? No problem! Your Marquette instructor can help you to figure out what phase of fertility you’re in and can teach you the appropriate protocol to follow!

What is this magic? Well, unlike LAM, the Marquette Method of NFP is not based on the likelihood of your fertility staying away. Instead, it’s based on direct, daily monitoring of your body’s actual hormone levels. At some point, no matter how much you breastfeed, the fertility-suppressing effect of prolactin wanes, and your GnRH levels will begin to rise. This rise in GnRH will begin a chain reaction of hormone production, which eventually results in your body returning to fertility.

The basic concept of the Marquette Method for breastfeeding women is that the Clearblue fertility monitor (which the Marquette Method uses as a tool to measure your hormone levels) tracks your hormone levels on an almost-daily basis. By measuring your hormone levels regularly, you can begin to identify hormone patterns, and you will have a heads-up that your body is returning to fertility. Ah, the power of science!

Choosing between LAM and Marquette

Breastfeeding women, you have options. It does not have to be an either/or. You can do both. Many women choose to rely on LAM for as long as they qualify. It’s effective, it’s (relatively) easy, and it’s free. For as long as it works for your life and your baby cooperates, it’s a great option for new moms. Some women start practicing the Marquette Method of NFP only once they no longer qualify for LAM. The effectiveness rates for LAM and Marquette are basically the same, so choosing between them is really just making a decision about what’s going to be the most comfortable method for you. LAM requires no abstinence (as long as you fit the criteria), and the Marquette Method may or may not require periods of abstinence, depending on your hormone readings.

Some women like the added assurance (and control) that testing with the Marquette Method gives them and choose to use the Marquette Method’s Breastfeeding Protocols right from the get-go. Marquette has an excellent protocol for women who haven’t yet returned to fertility after the birth of their baby, and as the woman returns to fertility, Marquette has a separate protocol to cover them until their hormones regulate to a “normal” balance.

There’s no “right” or “wrong” answer about which method is the best—couples need to make this choice themselves. Now that the information has been clearly laid out for you … the decision is yours!

Still have questions? I’m always here to help. I’m a Marquette Method Instructor, and I am also well-versed in the Lactational Amenorrhea Method of pregnancy avoidance. The Marquette Method of NFP is a very popular option for breastfeeding mothers —approximately 90% of my clients switch to Marquette during a breastfeeding transition, some of them with brand-new babies, and others switching from another method of NFP that became unexpectedly confusing in the postpartum phase. I offer free consultations and would be glad to talk to you—either over email or in person—to help you decide which method of family planning is likely to be a good fit for you, taking into consideration your specific fertility situation!


Rogers, I. S. (1997). Lactation and fertility. Early Human Development, 49, S185–S190.
Tommaselli, G. A., Guida, M., Palomba, S., Barbato, M., & Nappi, C. (2000). Using complete breastfeeding and lactational amenorrhoea as birth spacing methods. Contraception, 61(4), 253–257.
Valdés, V., Labbok, M. H., Pugin, E., & Perez, A. (2000). The efficacy of the lactational amenorrhea method (LAM) among working women. Contraception, 62(5), 217–219.
World Health Organization. (1998). The World Health Organization multinational study of breast-feeding and lactational amenorrhea. II. Factors associated with the length of amenorrhea. Fertility and Sterility, 70(3), 461–471.


Louise Boychuk, RN

Marquette Method NFP Instructor
Vitae Fertility Education

I teach the Marquette Method of NFP online in one-on-one, personalized sessions to couples all over the world. I wrote two books on the Marquette Method of NFP, and now I blog regularly about the Marquette Method and natural family planning research.

Are you considering making a switch to Marquette? You probably have questions. Fill out a free, no-obligation consultation and I’ll answer all your questions, privately and professionally.

More About Marquette

Is This My Period? A Guide to Navigating Postpartum Bleeding

Is This My Period? A Guide to Navigating Postpartum Bleeding

You’ve got a new baby in your house. Congratulations! Maybe you’re snuggling a newborn, or maybe your baby is on the move and you’re chasing a crawler. But then, seemingly out of nowhere, you’re bleeding again. What’s up? You may be feeling confused and wondering what...

read more
5 Tips for Airplane Travel with The Marquette Method of NFP

5 Tips for Airplane Travel with The Marquette Method of NFP

Recently, my husband and I thought it would be fun to take our six-week-old newborn and three other small children to Hawaii. My mom came too. I was excited to dip my toes in the warm sand and drink a few Mai Tais. I use (and teach) the Marquette Method of NFP, so 6...

read more

Free Marquette Method Consultation

Have questions about the Marquette Method?


I’d be glad to answer any questions you have about the method or about Vitae Fertility's training packages.


Click below to start your free, no-obligation consultation with me.


Get A Free Consultation