Pregnancy and Postpartum Cardiomyopathy
Most women who develop PPCM are told that they are not able to have any more babies. This is because the initial study on post PPCM pregnancies was done on 16 Haitian women, and the study did not distinguish between women who had normal heart function and those who didn't and of the 16, 8 experienced a worsening of heart function, one died and only one went on to make a full recovery.(1)
There was a more recent study in 2009 (2), that found no relapses in 9 women with post-PPCM pregnancies when there was adequate contractile reserve in their stress ECHO. All these women had an EF > 55%. Again the sample size was limited but the important part of this study was that it distinguished between women with a recovered heart function and those without. While there is always a risk in any pregnancy of developing PPCM, a number of women who recovered from PPCM have gone on to have successful pregnancies without relapse and women who did relapse, were diagnosed and treated early and generally recovered.
A study done on PPCM survivors have suggested that the risk of relapse in future pregnancies is minimized if the woman meets certain criteria prior to becoming pregnant.
The criteria include:
- LVEF ≥ 55 %. (There has
- Maintain LVEF after discontinuation of heart failure Rx (may be required to continue beta-blockade).
- Adequate contractile reserve as estimated from exercise stress echo and peak CO/O2 consumption on exercise ergonomics. (In a 1997 study from the University of Chicago Medical Center, indicated that women who had seemingly recovered from peripartum cardiomyopathy, that their hearts showed evidence of impaired contractile reserve. Passing a stress echo, rules out any impaired heart function)
- Normal LV size and shape
- No evidence of diastolic dysfunction
The risk of relapse of heart failure in a post-PPCM pregnancy is largely based on a study (2) where 20% of the participants in the study are from Haiti and the remaining from the US, with the total number of 56 women in the study and 61 pregnancies. There is a significant difference between PPCM in Haiti, where the incidence is 1 in 300 and in the US, where the incidence is approximately 1 in 2,000. Added to the complication of this study, all the participants from Haiti, had an EF of less than 50%, and if you were to conclude simply from the data about the incidence of relapse in a post-PPCM pregnancy, based on cumulative figures, you would conclude that 29.5% (18/61) of all pregnancies resulted in a relapse. Dividing the figures up into those who had an EF of less than 55%, 12/26 relapsed, giving you the figure of 46% and for those who have an initial EF greater than 55%, 6/35 or 17.1% relapsed.
All the Haitian mothers studied had an EF of less than 50%, of which 8 out of the 11 relapsed (73%) and one died (who had an initial EF of 25%) and by including the Haitian mothers in with the total pregnancies, we have a result that concludes a higher rate of post PPCM relapse in a future pregnancy, than we would have, if these women were excluded from the data.
Of all 18 pregnancies in which women relapsed, 10 of the pregnancies had an initial EF that was less than 50% and only 2 of those women went on to make a full recovery, where as the remaining 8 whose initial EF was greater than 50%, 7 or 87% of these women went on to make a full recovery. In this sample, all 8 of the women were from the US, so we could conclude based on this small sample that for initial EF greater than 50%, the majority will make a full recovery, even if a relapse occurs..
Of the 9 PPCM pregnancies from the US, who had a LVEF of 55 % before the post-PPCM pregnancy, and also had adequate contractile reserve as demonstrated by a stress echo, none relapsed. This leads to a 0% relapse rate on women whose heart function performed well under a stress echo.
In order to draw statistical inference from a set of data, the sample size of similar participants should be larger than what we have in this study. It is too small a study to make statistical inference about the risk of relapse in a post ppcm study but the figure of 17.1%, represents women from the US, of whom 35/49 had an initial EF greater than 55% and only 6 relapsed.
In another study, involving 44 women who had had PPCM and a total of 60 subsequent pregnancies—28 with normal left ventricular function (group 1) and 16 with ventricular dysfunction (group 2). The ejection fraction decreased slightly in group 1, but not significantly in group 2. However, group 2 had the following complications respective to group 1: heart failure symptoms (44% vs 21%) and mortality (19% vs 0%). Therapeutic abortions were performed more often in group 2 (25% vs 4%).(Source, http://emedicine.medscape.com/article/153153-overview#aw2aab6c18 )
Based on this study, the following recommendations were made;
Before a subsequent pregnancy, the following recommendations are appropriate:
Women should undergo echocardiography and, if findings are normal, dobutamine stress echocardiography
Pregnancy should not be recommended to women with persistent left ventricular dysfunction
Patients with normal findings upon echocardiography but decreased contractile reserve should be warned that they might not tolerate the increased hemodynamic stresses of pregnancy
Patients with full recovery should be told that although a chance of recurrence exists, the mortality is low and the majority of such women have normal pregnancies
We envisage that with more research and awareness, management of subsequent pregnancies for women who have recovered EF will be no different to management of other high risk pregnancies.. It is due to the lack of research, that doctors are wary to recommend future pregnancies. Women can go through a post PPCM pregnancy, with an EF of 40% or less and not relapse (some of whom make a full recovery after a post ppcm pregnancy), while others may die. The answers are not cut and dry and the research is limited.
A stress ECHO determines if a woman has adequate contractile reserve to cope with the increased blood flow that comes with pregnancy. http://emedicine.medscape.com/article/153153-overview#aw2aab6c18 contains more information about PPCM and future pregnancies.
The link to the study is Risk of heart failure relapse in subsequent pregnancy among PPCM mothers, can be found http://www.ijgo.org/article/S0020-7292(09)00604-3/abstract . As far as we are aware, this is the study most quoted from
There is a possibility that a precipitating factor for PPCM could be transferred in surrogacy warranting further investigation, Peripartum cardiomyopathy (PPCM) in both surrogate and biological mother
Monitoring a PPCM Pregnancy
Guidelines for monitoring a post PPCM pregnancy are as follows but may vary from hospital to hospital. It is important to bear in mind that the greatest risk of relapse occurs between 36 to 40 weeks, at delivery, and in the 2 weeks post-partum and a woman should be mindful of any signs of heart failure, which include swelling, rapid weight gain, unexplained cough, extreme tiredness, difficulty lying flat during the pregnancy.
- Echocardiogram each trimester and postpartum
- Plasma BNP each trimester and postpartum (rising levels hours to days before clinical heart failure)
- Plasma hsCRP each trimester and postpartum (rising levels days to weeks before clinical heart failure when there is an inflammatory cardiomyopathy, as seen often in PPCM.)
- Physical exam for signs and symptoms each trimester and postpartum
- Self-test for pregnancy-associated heart failure each trimester and postpartum
The beginning of recovery in case of a relapse is to safely complete the pregnancy. There are many pathological changes in early relapse that will be silent so far as signs and symptoms of heart failure until enough cardiomyocytes have been damaged. That is why the plasma BNP can be helpful, showing a rise hours to days before any signs and symptoms of heart failure. If there is an inflammatory component, which there often is, the plasma high sensitivity C-Reactive Protein also rises beyond 10 mg/liter. Compare it to flood waters flowing into a reservoir behind a dam: a certain amount has to collect before any water overflows the dam, and floods the areas below the dam." (Source Dr. James Fett)
BNP tests during pregnancy provide information about any possible inflammatory process that may be a sign of relapse. Since the best outcomes for recovery occur when PPCM is diagnosed early, a PPCM pregnancy needs to be carefully monitored, so decisions about early delivery and treatment can be made. It is essential that any woman contemplating a PPCM pregnancy be monitored by a cardiologist who is familiar with the latest research on managing PPCM pregnancies and be fully informed as to the signs and symptoms of heart failure, in order to know when to seek help.
"Safely completing the pregnancy also means removing another source of potential hormones that can be metabolized to do harm--referring to prolactin metabolites from the placenta--may help to prevent or minimize relapse."
(1) Fett JD, Christie LG, Murphy JG. Brief communication: Outcomes of subsequent pregnancy after peripartum cardiomyopathy: a case series from Haiti. Ann Intern Med. Jul 4 2006;145(1):30-4
(2) Fett JD, Fristoe KL, Welsh SN. Risk of heart failure relapse in subsequent pregnancy among peripartum cardiomyopathy mothers. Int J Gynaecol Obstet. Nov 28 2009;[Medline].
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