Re: Two Yolk Sacs, one embryo
From: Dave Berck (djberck@yahoo.com)
Wed Jan 22 15:05:15 2003
OK OK OK. So maybe I'm wrong. BUT . . . . .
Once you have 2 yolk sacs, isn't the split early
enough and complete enough to make CONJOINED twins
impossible? (I bet no one has this answer since
conjoined twins are so rare)
--- Mário_Libardi <mariolibardi@uol.com.br> wrote:
> Dr.Moroder
> Your cases are so elucidatives for this
> discussion.Then my reply to Dr.Berck is a little bit
> different:
>
> Dr.Berck: You can be correct and I can be wrong!!!!
> :-))))))))
>
> Regards
> Mário Libardi
>> ----- Original Message -----
> From: Wolfgang Moroder, MD
> To: Multiple recipients of list ULTRASOUND
> Sent: Wednesday, January 22, 2003 5:27 PM
> Subject: Re: Two Yolk Sacs, one embryo
>
> Dear friends,
> Interesting discussion on the YS but what counts
> are facts (ha,ha..).
> On the OBGYN.net Image gallery
> http://www.obgyn.net/us/gallery/gallery.htm I have
> published one case of
> monoamniotic twins: here are the twins:
>
http://www.obgyn.net/us/gallery/OB_1_Normal_Monoamniotic_Twins.jpg
>
> and ...the evidence:
>
http://www.obgyn.net/us/gallery/OB_1_Normal_Monoamniotic_Twins_Yolk_Sacs.jpg
>
> I have observed other two monoamniotic twins early
> in pregnancy. Of a
> total of three observations two pairs had a double
> yolk sac and one pair
> a single yolk sac. I presume, when monoamniotic
> twins are generated
> between day 8 and day 13 post conception it
> depends on the time when the
> zigote splits into two embryos if one or two yolk
> sacs are formed.
>
> Best regards
> Wolfgang
>
> At Wed, 22 Jan 2003, Terry J. DuBose wrote:
> >
> >"How could this be conjoined twins?
> >Conjoined twins are by definition monochorionic
> >monoamniotic and have 1 yolk sac. If there are
> two
> >yolk sacs, it is mono / di. Am I wrong?"
> >
> >In thinking more about this, I wonder. Would not
> "normal" mono-mono twins each have a yolk sac? And
> if so, could not some variation that resulted in
> conjoined twins also possibly have two yolk sacs?
> It appears that there may be one or two yolk sacs
> depending upon the timing of the splitting of the
> zygote. I could not find anything on the number of
> yolk sacs for these twins in the new Fleischer,
> Manning, Jeanty & Romero textbook, but did find the
> following web sites that address the subject. It
> >does appear that if the zygote splits after the
> formation of the yolk sac, then monoamniotic
> twinning is the result. So you are correct... two
> yolk sacs should indicate no possibility of
> conjoined twins... if we can ever say "no
> possibility" of anything in medicine.
> >
>
>http://collection.nlc-bnc.ca/100/201/300/cdn_medical_association/carj/vol-47/0098.htm
>
>http://www.gen.umn.edu/faculty_staff/jensen/1135/example_student_projects/Sum2000/Twins/twins.html
> >
> >Peace, Terry J DuBose
> >
> >--
> >Terry J. DuBose writes:
> >>Dr. Libardi, I join you on this message...
> learning something every day here. Thanks, Terry J
> DuBose
> >>
> >>ultrasound@obgyn.net writes:
> >> Doctor Berck
> >>
> >>You are correct.I am wrong.The number of YS
> represents the number of amnions.It's impossible
> conjoined twins in this case.
> >>
> >>See this excerpt:
> >>
> >>"Especially in nonchorionic diamniotic or
> monoamniotic twins only after the 8th week of
> gestation, one can safely determine the amnionicity.
> Also, the number of yolk sacs imaged is correlated
> with the number of amnions, and the number of yolk
> sacs can be observed at least two weeks before the
> number of amnions."
> >>
> >>The First World Congress On: Controversies in
> Obstetrics, Gynecology & Infertility Prague, Czech
> Republic - 1999
> >>
> >>Can Ultrasound Determine Chorionicity and
> Amnionicity in Mutiple Pregnancy?
> >>
> >>I. Meizner
> >>
> >>Ultrasound Unit, Department of Obstetrics and
> Gynecology, Rabin Medical Center, Petah-Tikva and
> Sackler Faculty of Medicine, Tel-Aviv University,
> Tel-Aviv, Israel
> >>
> >>Regards
> >>Mário Libardi
> >>
>> >>>----- Original Message -----
> >>From: [ mailto:djberck@yahoo.com ]Dave Berck
> >>To: [ mailto:ultrasound@mail.medispecialty.com
> ]Multiple recipients of list
> >> ULTRASOUND
> >>Sent: Wednesday, January 22, 2003 1:19 PM
> >>Subject: Re: Two Yolk Sacs, one embryo
> >>
> >>How could this be conjoined twins?
> >>Conjoined twins are by definition monochorionic
> >>monoamniotic and have 1 yolk sac. If there are
> two
> >>yolk sacs, it is mono / di. Am I wrong?
> >>
> >>--- "Terry J. DuBose" <[
> mailto:duboseterryj@uams.edu ]duboseterryj@uams.edu>
> wrote:
> >>> With "
> >>> >LMP : 6 weeks and CRL 5 weks and 5 days.
> >>> " and an EHR of 119 B/M which calculates to
> 5.9
> >>> weeks or 5w6.7 days, the heart rate is
> absolutely
> >>> normal for the age. The follow-up on Jan 31
> will be
> >>> 7.3 weeks, and I will predict that the hear
> rate
> >>> will be near 151 at that time... and you will
> likely
> >>> find a second CRL and heart rate that will be
> >>> corresponding smaller and slower.
> >>>
> >>> Can't wait to here what happens. Terry
> >>>
> >>> [ mailto:ultrasound@obgyn.net
> ]ultrasound@obgyn.net writes:
> >>> > Terry and friends
> >>> >
> >>> >I'm worry about conjoined twins possibility
> in this
> >>> case.During scan I can't separate the two yolk
> >>> sacs.I agree that in some days the other
> embrio will
> >>> appear.Very interesting your article about EHR
> and
> >>> IG.In this case the EHR of the embrio is 119
> bpm.
> >>> >Dr.Corda, the YS diameters is 3.7mm(embrio)
> and
> >>> 3.5mm(non-embrio).
> >>> >The patient will return in January 31.I'll
> post the
> >>> follow up.
> >>> >
> >>> >Regards
> >>> >
> >>> >Mário
> >>> >
> >
>> >>>> >----- Original Message -----
> >>> >From: [ [ mailto:duboseterryj@uams.edu
> ]mailto:duboseterryj@uams.edu ]Terry J.
> >>> > DuBose
> >>> >To: [ [
> mailto:ultrasound@mail.medispecialty.com
> ]mailto:ultrasound@mail.medispecialty.com
> >>> ]Multiple recipients of list
> >>> > ULTRASOUND
> >>> >Sent: Tuesday, January 21, 2003 9:23 PM
> >>> >Subject: Re: Two Yolk Sacs, one embryo
> >>> >
> >>> >My first thought is that if you wait 3-4
> days, the
> >>> other twin will show up... I have seen cases
> where
> >>> one twin was larger than the other by up to 6
> >>> days... and their heart rates correlated with
> their
> >>> CRL sizes both in the acceleration and
> deceleration
> >>> phases. Our hypothesis was that when the cell
> mass
> >>> split, one twin got a larger mass of cells.
> Both
>
=== message truncated ===
=====
David J. Berck, MD, MPH
