All of the below is true and Dr. Steingarber is correct its not as simple as
I implied. And while I was aware of most of the info given, I stand by the
spirit of my response.   Consider that, irrespective of the effects of
oxytocin released from orgasm vs nursing there is only one effect that an OB
or midwife is concerned about.  That effect is an increase in preterm labor,
this has not been demonstrated to be increased in low risk mothers who
continue to breastfeed.  Furthermore,  a high risk mother is routinely
instructed to avoid all causes of oxytocin release lending credence to my
assertion that "oxytocin is oxytocin" at least when discussing whether or not
it is OK to continue breastfeeding while having a normal pregnancy.
By the way the physicians I work with having been informing women they
deliver over the last 4 years that it is OK to continue breastfeeding  while
and I am not aware of any adverse effects.  Christine Betzold NP IBCLC

 In a message dated 3/12/02 12:02:48 PM Pacific Standard Time,
[log in to unmask] writes:


> Sometimes deductive logic can get us in trouble.  I suspect it's not
> as simple as Christine suggests. While oxytocin does play a role in
> female organism, it does so in tandem with other factors and chemical
> signals.  We don't know if orgasm-released oxytocin has the same
> effect on the uterus than milk let-down oxytocin.  Certainly,
> research on other hormones, such as estrogen, shows us that the
> impact of a hormone can be mitigated or potentiated by the presence
> of other chemical signals, by whether or not the hormone is bound to
> a blood protein or is traveling through the bloodstream in its free,
> unbound state, and by the pathway through which it is metabolized by
> liver enzymes.
>
> I did choose to wean my 2 year old during my last trimester because
> nursing her triggered such intense Braxton Hicks contractions that I
> could scarcely breathe or walk.  (She started nursing again after her
> brother was born, as you all know from a previous post of mine.)
> Orgasms and nipple stimulation by my husband had no such effect.
>
> Remember that milk let-down oxytocin is demonstrated to make the
> uterus contract, probably an evolutionary mechanism for decreasing
> blood loss after childbirth.  Orgasm-released oxytocin has no
> demonstrated function but is thought by some to induce REVERSE
> contractions in the uterus to move the sperm upstream to the egg.
> (Other researchers dispute this hypothesis.)
>
> The body is amazing in the ways it can use the same chemical
> substance for very different ends.  Thus, in the absence of more
> data, I'd be careful before drawing conclusions based on logic.  I'd
> put more weight on observational evidence here.
>
>
> warmly,
>
> Sandra Steingraber
>
>

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