Whoever said your dose should double is dangerous!
The usual first step that is advised is to increase dose by 25 micrograms of levothyroxine.
However, I know nothing of how best to manage anyone on a combination. Some doctors advise to stop taking T3 altogether (and increase levothyroxine to compensate). The basis seems to be they don't know what to do either - and that puts you closer to what they are more used to handling.
Thank you for your reply. I know when I read that I was like 🤣. I am definitely not keen to remove T3 at all it and LDN have been a literal lifeline for me and I think the reason I have tested positive. I understand T3 is fine to take throughout.
It is the combination as you say that is confusing for me re what the doctors who know about combo meds tend to advise. I recently moved to a new GP practice and I think when I go in and they see what I am on with their limited understanding of hashimotos, they will just want me to come off everything and I do think that will not be helpful for me.
So I’ve never been hypo and pregnant but have done a few deep dives research on the topic and will share a couple thoughts I’ve come across frequently.
Remember that the baby will rely on your thyroid hormones until mid-gestation (20 weeks) when the baby then develops their own functioning thyroid.
And the fetus needs sufficient maternal free T4 as early as right now for you, so definitely get that thyroid panel for your own peace of mind.
Now for some details. Below are articles - just sharing info that sums up a few things I’ve read - about quantifying Levo increases. For your consideration and to add to your own research and learning.
1) one is very old (2004) but is consistent with newer research. It explains clinical observations and analysis for how much addl Levo their group needed and how it was managed, ie 30% to 45-50% incrementally over time, starting immediately when pregnancy is confirmed: (ie 8 weeks) and noting the importance of testing starting at 4-5 weeks after that dose has settled and calibrate up from there.
Timing and Magnitude of Increases in Levothyroxine Requirements during Pregnancy in Women with Hypothyroidism
- Levothyroxine requirements increased in 85 percent of the cohort. In these subjects, a mean increase of 47 percent was necessary to maintain the thyrotropin concentration at a prepregnancy value. The required levothyroxine dose increased during the first 16 to 20 weeks of gestation but plateaued thereafter.
- The best-fit curve for the levothyroxine dose shows a rapid increase between 6 and 16 weeks of gestation and a subsequent plateau (Figure 1). At 10 weeks of gestation, the levothyroxine dose had increased by 29±25 percent as compared with the dose at baseline (P<0.001). At 20 weeks, the increase relative to baseline was 48 percent (P<0.001), but the dose remained stable thereafter (Table 2). …Within two weeks after delivery, all the subjects resumed taking their prepregnancy dose of levothyroxine.
- On the basis of our observations, we propose a practical solution: women who are currently being treated for hypothyroidism should be given written instructions to increase their current dose of levothyroxine by taking two extra daily doses during each week (i.e., to increase the dose by 29 percent) beginning the week pregnancy is confirmed and to continue doing so until they are able to undergo thyroid-function testing and obtain appropriate professional guidance.
- Thus, levothyroxine requirements increase early during pregnancy in most women with primary hypothyroidism, reaching a plateau after 16 to 20 weeks of gestation at a value about 47 percent higher than the prepregnancy value and persisting throughout pregnancy.
2) This second article is more recent -and the two together tell a similar story, with differences in details for their own clinical study set up. Note that both studies show about 85% of women conclusively needed the increase in Levo, and frequent testing and active management is essential.
Levothyroxine Dosage Requirement During Pregnancy in Well-Controlled Hypothyroid Women: A Longitudinal Study
- Conclusions According to the present study, most of well-controlled hypothyroid pregnant women needed increased dosage of thyroid hormone after pregnancy. The levothyroxine dosage was increased 50% in the first trimester and then needed to be added 5% every trimester thereafter. As some pregnant women did not need such adjustment and in some cases even the levothyroxine dosage was decreased, we recommend that the drug adjustment should be according to laboratory results if accessible.
- In addition to several reports regarding the requirement for adjustment of levothyroxine dose in hypothyroid pregnant women, there are various controversies surrounding the amount and timing of this dosage adjustment. Different studies stated that an increase in the levothyroxine dose is necessary in 50-85% of pregnancies to maintain the preconception serum TSH level (Abalovich et al., 2002; Alexander et al., 2004; Kaplan, 1996; Mandel, Larsen, Seely, & Brent, 1990) and the levothyroxine dose need to be increased 23-50% compared to the pre-pregnancy dosage and after parturition it could be decreased in most women (Alexander et al., 2004; Hallengren et al., 2009; Kaplan, 1992; Mandel, 2004; Mandel et al., 1990; Pekonen et al., 1984). It is recommended that hypothyroid women can increase levothyroxine dose by approximately 30% as pregnancy is confirmed (Alexander et al., 2004).
3) Lastly -the T4 vs T3 topic
Almost all clinical research on pregnant hypo women and outcomes focuses on Free T4 results. Consensus is that maternal FT4 needs to be sufficient for a healthy baby. I can’t recall the exact level but at a minimum middle of FT4 results or mid-upper range. So definitely give yourself peace of mind with a quick thyroid panel now.
You will also see studies focusing on managing to TSH, for better or worse.
On the other hand - in articles and other discussions that have been on this forum - the ambiguity around the role of FT3 should not be interpreted as there being any “evidence” about whether T3 is “good” or “bad”.
Rather, there simply isn’t much research at all. I think there are a few links you will come across but it’s very limited.
That being said - despite the lack of knowledge and research in T4/T3/NDT combo therapy or even t3 mono, what we do know is that there are obviously t3-mono moms that have healthy babies.
Thank you very much for sharing. This is exactly what I was looking for so I really appreciate the time it took to put this together. You have given me lots to think about and yes I will test asap.xo
Beware, lots of women do not need to change dose during pregnancy. So, even if there is some literature on increasing dose once pregnancy is confirmed, there is no actual consensus in this.
Have your thyroid hormones tests asap and adjust dose accordingly if required. There are pregnancy specific ranges for each trimester, and in the first trimester your aim is for a TSH under 2.5. As for FT4 and FT3 need to be interpreted accordingly also. Not too high, not too low.
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