How long will my cycles be?

Have you just had your first period party? The utter thrill when you are working to recover from hypothalamic amenorrhea (HA) and you see blood in your underwear is indescribable. I got my first bleed when I was on vacation. It had been really tough because my sister was announcing to our family in South Africa that she was pregnant; we were supposed to be pregnant together but I hadn’t even gotten a period yet, and here she was – Kate and 2/9 as my Uncle put it. I went upstairs to the bathroom and there was my first glorious period. I felt like a million bucks, I had *done* it!!!!  I could finally start trying to get pregnant myself!

After that celebration, though, comes another wait. This one is so tantalizing; you got a period, you hope that if you just to keep up what you’ve been doing you will  ovulate again and get another… or if you’re trying to get pregnant, you’ll get that oh so magical positive test instead. But for many women newly recovered from HA, cycle day 14 (when ovulation happens in a “normal” menstrual cycle) comes and goes, with nary a fertile sign. This can feel incredibly defeating (I know – in my case I randomly had an ultrasound scheduled on CD13 of my next cycle and we saw a nice juicy 13mm follicle which had my heart soaring, until I went back two days later and it hadn’t grown, and my doctor told me we’d need to do injections…).

But it is extremely common in women with HA for it to take a few cycles for the length to normalize, and this is one reason we say in No Period. Now What? to wait at least three cycle before making any changes in terms of eating, exercise, or stress.

I think that it is helpful to know exactly how common longer cycles are, and how long it typically takes for them to normalize, so I graphed the cycle length data I had from the surveys I did for NPNW. I took the data from each person who had at least one natural cycle, and ended up creating four graphs, split by number of cycles to get pregnant (most of the women who took the survey were trying to get pregnant).

Occasionally a woman will get pregnant on her very first ovulation–before getting her first period–in which case I do not have cycle length data (this happened in about 5% of women who ovulated naturally prior to any treatment). Other than that, in the data from my survey respondents, it took between one additional cycle to up to 12 to get pregnant the first time (in the women who provided cycle length data), so I split the graphs into one cycle to get pregnant (so these are women who had one period then got pregnant on their next ovulation), between 2-4 additional cycles, 5-7 cycles, and 8-12 cycles.

Here’s the first one – those women who took only one additional cycle to get pregnant. You can see that the cycle day of ovulation ranged from CD13 to CD63. (These were natural cycles as my requirement for using data for these graphs was that there was at least one natural cycle; there were certainly people who got pregnant on their first oral med, inject, or IVF cycle, but I will leave that for another day.)

The next graph shows those for whom pregnancy took 2-4 cycles… oh, but first here’s the figure from the book that shows the cumulative pregnancy rate by cycle so you have an idea of how long it is likely to take (if you desire pregnancy at the moment). Not everyone supplied cycle length data, so the numbers on these cycle length graphs don’t give a good sense of how long it took on average. Of my survey respondents, 56% achieved pregnancy within the first three cycles, and 84% within the first six. This is very similar to other studies of similar nature.

Back to those who took 2-4 additional cycles after their first period to get pregnant. This graph is a little more complicated, but if you just look at the first versus second cycle you can see a significant decrease in time to ovulation for those who had long initial cycles. The one case where cycle length increased, the woman in question decided to increase her exercise amount. You can see why we suggest not doing that right away, her cycle length increased from 45 to 60 days. This graph also includes some information about cycle lengths for those who used either oral medications (i.e. Femara or Clomid), or injectables. Some started with treatment but then after failed cycles got pregnant naturally (like the one woman who had ovulation on CD12 with injects, red triangle, on her first cycle, also used injects for cycles 2 and 3, but then got pregnant naturally cycle #4). Others had a natural cycle but then moved to treatment, like the woman whose first post-period ovulation was on CD70, reduced to CD24 with Clomid (and pregnant, filled blue square). Another example of this is the woman whose first post-period ovulation was at CD45, increased exercise and up to CD60, decreased exercise again and ovulated CD45, then used Clomid, ovulated CD18 and was pregnant.

The next graph shows those for whom pregnancy took between 5-7 additional cycles after their first period. Again you can see the commonality of a marked decrease in cycle length for those who had long initial cycles, and also a trend toward shorter cycles when oral meds were used. In this group were seven women who initially used Femara or Clomid to ovulate, but then after failed cycles stopped taking the meds and cycled naturally. Note that the filled red triangle indicates a pregnancy achieved on an injectable cycle (adding the legends to the graphs was taking me too much time).

Finally, those for whom it took between 8-12 cycles to achieve pregnancy. In this case the bump down to “CD 0” indicates no ovulation on that particular cycle. Here you see somewhat of an anomaly, with one woman whose first post-period ovulation was on CD63, which didn’t decrease until she started on oral meds, and another whose subsequent cycles were longer than her initial one. However, as you can see from the other graphs, this pattern is definitely not the norm. In either of these cases I probably would recommend oral meds (assuming that eating and exercise were not more restrictive). And again, filled red triangle indicates pregnancy achieved through injectables, black triangle shows a miscarriage on an injectable cycle.

I know that this is a lot of information, kudos if you’ve made it this far 🙂 I am happy to answer questions, please leave a comment if there’s anything unclear or another way you’d like me to analyze the data.

<3 Nico

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