Longitudinal monitoring of fetal behavior in twins when one is anencephalic

,lnalyGs of the RhD genotype in tetuses at risk for RhD hemolytic dis?,lbe. Obstet Gynecol lYY5;85:296-8. Arcc M4. Thompson ES, Wagner 5, Coynr KE, Ferdman BA, L.ubm DM. Molecul~~r clr,ning of RhD cDNA derived from a gene prtasmt in RhD-positive, but not RhD-negative individuals. Blood 1Oc)3;82:fcY I-S.

LONGITUDINAL FETAL ONE

MONITORING

BEHAVIOR

IN

TWINS

a rare case of twins in which one anencephalic. The anencephalic fetus’ behavior monitored serially by real-time ultrasound scan. behavioral patterns of the twins were analyzed compared with morphologic findings after birth. encountered

OF WHEN

IS ANENCEPHALIC

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Case Report

To our knowledge, there has been no report on longitudinal monitoring of fetal behavior in the anencephalic fetus. Casr: A 30-year-old woman was diagnosed with a twin pregnancy at 8 weeks’ gestation; at week 20, one of the twins was identified as anencephalic. From 25-36 weeks’ gestation, the behavioral patterns of each fetus were recorded weekly on videotape for 60 minutes, then compared with morphologic findings after birth. Conclusiorr: Our data comparing normal and anencephalic fetuses indicate that the development of the central nervous system above the medulla oblongata plays an important role in the elimination of fetal movements, such as startle, jumping, and writhing, and in the commencement of breathing movements. (Ohstct C!/rrc,col 7W;d6:67?-1) Backgromd:

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A X-year-old ~‘oman, gravida 0, became pregnant by in vitro tertilization. At 8 weeks’ gestation, ultrasound examination showed a twin pregnancy and a dichorionic-diamniotic placenta. At \veek 20, une of the twins was diagnosed as anencephalic. The patient WAS admitted to Nagoya University Hospital at 25 weeks’ gestation because of premature labor, and cerl,lcal cerclage was performed. After surgery, ritodrine was administered intravenously throughout pregnancy. The behavioral patterns of each fetus were recorded weekly on Gdeotape for 60 minutes, visualizing the fetuses in the nucl- or parasagittal section using a linear or sector U-sonic IIT-HOUO transducer (Yokogawa Medical Systems Co., Tokyo, Japan). We compared the patterns using the unaffected fetus as ‘1 control after informed consent was obtained from the parents. Fetal movements were defined as follows: 1) flexion, the forward bending of the head and hip; 2) stretching, a complex motor pattern consisting of overextension of the spine, retrotlexion of the head, external rotation, and elevation of the arms; 3) rolling, a rotation occurring along the longitudinal axih or the transverse axis of the fetal body; 4) startle, a quick, generalized movement that always starts in the limbs and often spreads to the trunk and neck; 5) jumping, a quick 5trctch of the legs and the trunk; 6) writhing, an indeterminate sequence of arm, leg, neck, and trunk movement; 7) hiccupping, a phasic contraction of the diaphragm, often repetitive at rquhr intervals; and 8) breathing, every contraction of the

diaphragm causing an inMan mo\~cment of the thorax and <3 simultaneous outward movement ot the ahdomrn. As Visser et al’ described prc\?cw~ly, general movement\ such as flexion, stretching, rolling, star&‘, jumping, and writb ing started abruptlv and indc~pendently of each other and ceased suddmlv in the anencephalic fetus, in contrast M.ith the normal fetus. In addition, the anenccphalic fetus continut4 to demonstrate a high frequency of startle, jumping, and writhing, even at late gcsbtion (Figure 1A). Rest-activitl cycles, in which the periods ot complete quiescence lait h minutes or more, emerged around 74 weeks and ctmtlnut~d to increase near term, and the pt>riod of quiesctmcc prcjgressively increased in the n~wnal fctub. In the anenzephalic fetus, these cycle5 did not Increase s\-ith gestation and the period rarely exceeded h minutes In the normal fetus, there was n marked increase in breathing tno\ rments around 75 weeks, with a continuing, up\\ard trend until ?h lqccks I hca frequency of hiccupping w’as maximal at the beginning ot recording and decreased thewaftcr (Figures 1 B and 1Ci. In the anenccphnlic fetus, these mo\-tmcnts rvt’re observed OCGI~IOIIally at 28-X Iveeks, although the trcquencv of thew rno\~c‘merits was much less than in the normal fetus (Figurtx 1K and 10. From 30 ueeks’ gestation. thta antwcephalic fctui ~h~~\vc~cI polyhydraiiii~il)~, g~~neralized t>dtm,l. pleural effusion, ,~nd ascites. Ech<>cnrdiographv re\,caled ION, c;lrdiac output and pericardial t+fusion. Consrqutwtl\., it\ mo\,ements decrclaf the CNS of the? anencephalic fetus were carried out b\ autopsy. WC tound an intact spinal cord with a dvsplastic medulla oblongata and hypoplastic lung, malrotation, and cr\,ptorchidism. Histologicallv, in the rrgion of the mrJull,~ ohlongata, a IILICIC~LII ambiguus-like structure was ohwr\ ed, hut the medulla oblongata was not formed clearly. The spIna cord \vas con%tructt’d normally. The mother and the normal Infant tvere di
Our case revealed that startle, jumping, and writhing decreased gradually in frequency in the normal fetus, whereas they remained high in the anencephalic fetus until week 32. Considering the findings from autopsy, this observation suggests that such movements are due to spinal cord stimulation and that the brain abc,ve the level of medulla oblongata is in\.c>l\red in their control and elimination during fetal de\,elopment. ln contrast, breathing movements, the frtxquency of which increased

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rcmarkoblv around week 30 in the normal fetus, were \‘crv limited, if at all present, in the anencephalic fetus. Phi; indicates that at least an intact medulla oblongata and pans are required for such preparatory movements to occur. To our knowledge, this is the first study to document longitudinal monitoring of fetal behavior in an anencephalic fetus. Visser et al’ reported qualitative and quantitative modifications of fetal movements in anencephalic fetuses proportional to the severity of morphologic abnormalities. However, the fetuses in their study \vere aborted after the diagnosis, and serial observation \I’JS not carried out during pregnancy. The present obscr\,atinns clearly proved that tetal behavior is regulated in proportion to the development of the fetal CNS. In addition, our data comparing normal and anencephalic fetuses show that development of the CNS above the medulla oblongata plays an important role in the elimination of fetal movements, such as startle, jumping, and w.rithing, and in the appearance of breathing movements.

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UMBILICAL

ARTERY

WAVEFORMS

IN

TWINS

CORD

WITH

FLOW

VELOCITY

MONOAMNIOTIC ENTANGLEMENT

Background: Monoamniotic twins with ultrasonographic evidence of umbilical cord entanglement present a management challenge in the antepartum period. Cases: We report two pregnancies with monoamniotic twins and ultrasonographic evidence of cord entanglement in which longitudinal Doppler flow velocity waveforms ot the umbilical and middle cerebral arteries were obtained. A notch in the umbilical artery velocity waveform was noted in one twin member at 33 weeks’ gestation and in both twin members of the other pregnancy at 31 weeks’ gestation. Worsening of the umbilical artery velocity waveform notch with advancing gestation was noted in one fetus. Conchsion: The presence of a notch in the umbilical artery velocity waveform may reflect hemodynamic alterations in the fetal-placental circulation secondary to narrowing of the umbilical vessels involved in cord entanglement. This Doppler finding may be useful in the antepartum management of these pregnancies. (Obstct Gr/rrccol 199.5;86:67$-7)

Monoamniotic twinning, occurring in onlv O.l-2.3% ot all twin pregnancies, ’ is associated with an increased risk of perinatal morbiditv and mortality.’ This high

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risk for perinatnl complications in monoamniotic twins is thought to result from cord accidents caused by entanglement of the two umbilical cords.‘,’ Although the exact incidence of cord entanglement in monoamnic)tic twins is not known at present, two reports’,’ suggest that cord entanglement is a common finding in monoamniotic twins. Although the need for intensive fetal surveillance is \vell established in pregnancies with monoamniotic twins, controversy exists regarding the specific antenatal fetal surveillance test that should be used, the schedule of fetal testing, and timing of delivery. It is :;entrallv accepted that currently available fetal surveillance t&s do not predict cord accidents, which are helit~ved to contribute significantly to the poor perinatal outcome in pregnancies with monoamniotic twins. We present our experience with two cord-entangled cases of monoamniotic twins in whom Doppler flow velocimetrv studies of the umbilical artery were used to ,Issist in ,>ntepartuni management.

Case 1 ;4 i I -\ car-old yeoman, gravida 2, pam 1, with monoamniotic t\~~ns diaq~sed by ultrasound examination in the second trinic>5tttr ot pregnancy, was referred to the perinatal unit at Eastern L’irginia Medical School for pregnancy management. LYechlv ultrasound examinations, including Doppler studies ot the umbilical and middle cerebral arteries, and nonstress tests CYST) gi\,en two times per week, were initiated at 28 \vetlks’ gt~station. A 25 % weight discordance was noted at 29 Lyet,ks. Doppler flow studies of the umbilical and middle c-crtbral arteries and NSTs x,verereassuring in both fetuses. All Doppler tlo\v studies of the umbilical artery were obtained from thcs abdominal cord insertion. At 33 weeks’ gestation,