Nishmat's Women’s Health and HalachaIn memory of Chaya Mirel bat R' Avraham

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Pre-pregnancy veset kavua on pill

29 May, 2006


In a response to another question you write:
“Only a woman with a veset kavua prior to conception carries over her calculations after pregnancy.”

Does this also apply to a hormonal “veset kavua“? We conceived the first month I was off the pill. So I had a veset based on the interval between the time I took my last pill each month and the onset of my flow. I have gone back on to birth control; the mini-pill. Would I assume that my period would arrive at the same interval as on the other one?


When switching between formulations of two similar pills, one can argue for carrying over a veset kavua until or unless it has been uprooted.  In this case, however, the progesterone-only pill is significantly different from the combination estrogen-progesterone pills you took before conceiving.  For example, your prior veset kavua was based on days from cessation of the pill until onset of bleeding.  The progesterone-only pill is taken continuously without a break.

In short, in this case, your veset kavua does not carry over.  If, at some point in the future, you plan to switch to combination pills, please get back to us with exact details of your previous veset so we can advise you further

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