Re: Two Yolk Sacs, one embryo
From: Terry J. DuBose (duboseterryj@uams.edu)
Wed Jan 22 10:50:53 2003
"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
>> were normal, but remained about a week different in
>> size until delivery. Check out this article:
>> >
>> >[
>>
>[ http://www.obgyn.net/english/pubs/features/dubose/ehr-age.htm ]http://www.obgyn.net/english/pubs/features/dubose/ehr-age.htm
>>
>]http://www.obgyn.net/english/pubs/features/dubose/ehr-age.htm
>> >particularly this image:
>> >[
>>
>[ http://www.obgyn.net/english/pubs/features/dubose/Image16.gif ]http://www.obgyn.net/english/pubs/features/dubose/Image16.gif
>>
>]http://www.obgyn.net/english/pubs/features/dubose/Image16.gif
>> >
>> >I also described this set of twins in detail in
>> FETAL SONOGRAPHY, p. 151-154.
>> >
>> >Or you may need to watch for conjoined twins later.
>> >
>> >Either way, please follow this one, give us feed
>> back... and get accurate measurement on the CRL and
>> EHR over the next month. Interesting case.
>> >
>> >Good luck. Terry J DuBose.
>> >
>> >[ [ mailto:ultrasound@obgyn.net ]mailto:ultrasound@obgyn.net ]ultrasound@obgyn.net
>> writes:
>> >> Patient with 25 years old, G2P1A0, LMP : 6 weeks
>> and CRL 5 weks and 5 days .
>> >>
>> >>US findings:
>> >>Two yolk sacs side by side, but only one embryo
>> identified.
>> >>
>> >>Opinions ?? Suggestions ???
>> >>
>> >>Regards
>> >>Mário Libardi, M.D.
>> >>Multimagem Ultra-sonografia
>> >>Botucatu - Sao Paulo
>> >>Brazil
>> >
>> >Peace, Terry J. DuBose, M.S., RDMS
>> >Assistant Professor & Director, Diagnostic Medical
>> Sonography Program
>> >University of Arkansas for Medical Sciences, CHRP
>> >4301 West Markham St. Mail Slot #563
>> >Little Rock, Arkansas, 72205 USA
>> >501-686-6510
>> >[ [ mailto:DuBoseTerryJ@UAMS.edu ]mailto:DuBoseTerryJ@UAMS.edu
>> ]DuBoseTerryJ@UAMS.edu
>> >[ [ http://www.io.com/~dubose/ ]http://www.io.com/~dubose/
>> ]http://www.io.com/~dubose/
>> >[ [ http://www.uams.edu/CHRP/dmshome.htm ]http://www.uams.edu/CHRP/dmshome.htm
>> ]http://www.uams.edu/CHRP/dmshome.htm
>> >[ [ http://www.obgyn.net/us/panel/panel.htm ]http://www.obgyn.net/us/panel/panel.htm
>> ]http://www.obgyn.net/us/panel/panel.htm
>> >
>>
>> Peace, Terry J. DuBose, M.S., RDMS
>> Assistant Professor & Director, Diagnostic Medical
>> Sonography Program
>> University of Arkansas for Medical Sciences, CHRP
>> 4301 West Markham St. Mail Slot #563
>> Little Rock, Arkansas, 72205 USA
>> 501-686-6510
>> [ mailto:DuBoseTerryJ@UAMS.edu ]DuBoseTerryJ@UAMS.edu
>> [ http://www.io.com/~dubose/ ]http://www.io.com/~dubose/
>> [ http://www.uams.edu/CHRP/dmshome.htm ]http://www.uams.edu/CHRP/dmshome.htm
>> [ http://www.obgyn.net/us/panel/panel.htm ]http://www.obgyn.net/us/panel/panel.htm
>>
>
>=====
>David J. Berck, MD, MPH
>
>Peace, Terry J. DuBose, M.S., RDMS
>Assistant Professor & Director, Diagnostic Medical Sonography Program
>University of Arkansas for Medical Sciences, CHRP
>4301 West Markham St. Mail Slot #563
>Little Rock, Arkansas, 72205 USA
>501-686-6510
>DuBoseTerryJ@UAMS.edu
>http://www.io.com/~dubose/
>http://www.uams.edu/CHRP/dmshome.htm
>http://www.obgyn.net/us/panel/panel.htm
>
Peace, Terry J. DuBose, M.S., RDMS
Assistant Professor & Director, Diagnostic Medical Sonography Program
University of Arkansas for Medical Sciences, CHRP
4301 West Markham St. Mail Slot #563
Little Rock, Arkansas, 72205 USA
501-686-6510
DuBoseTerryJ@UAMS.edu
http://www.io.com/~dubose/
http://www.uams.edu/CHRP/dmshome.htm
http://www.obgyn.net/us/panel/panel.htm