Biomedical subjects

N J Sebire

Publications and source records attributed to N J Sebire.

At least 109 records · Page 6Linked to original sources

PubMed1997

Diagnosis of the Meckel-Gruber syndrome at eleven to fourteen weeks' gestation.

OBJECTIVE: Our purpose was to examine the feasibility of diagnosing the Meckel-Gruber syndrome at 11 to 14 weeks' gestation, both in high-risk pregnancies and during routine ultrasonographic screening for fetal chromosomal abnormalities. STUDY DESIGN: The high-risk population consisted of 9 pregnancies in 7 women with previous pregnancies affected by the Meckel-Gruber syndrome. At 11 to 14 weeks' gestation, systematic ultrasonographic examinations of the fetal skull, brain, kidneys, bladder, hands, and feet were undertaken in each case. The low-risk population consisted of 21,477 self-referred pregnancies undergoing first-trimester ultrasonographic screening for chromosomal defects at 11 to 14 weeks' gestation. RESULTS: The triad of fetal occipital encephalocele, bilateral polycystic kidneys, and postaxial polydactyly was detected by transabdominal ultrasonography and confirmed by transvaginal scanning in 4 of the 9 pregnancies in the high-risk group. The parents were counseled of the likely recurrence of the Meckel-Gruber syndrome, and all elected to terminate the pregnancy by transcervical evacuation at 12 to 13 weeks. In the low-risk population the only case of Meckel-Gruber syndrome was identified at 13 weeks; in the remaining screened pregnancies there were no other cases of termination of pregnancy or neonatal death with the diagnosis of Meckel-Gruber syndrome. CONCLUSION: This report demonstrates that the Meckel-Gruber syndrome can be confidently detected at the 11- to 14-week scan in both high- and low-risk populations.

Cerebellum↗

PubMed1997

Crown-chin length in normal and anencephalic fetuses at 10 to 14 weeks' gestation.

OBJECTIVE: Our goal was to establish a reference range for the fetal crown-chin length at 10 to 14 weeks' gestation and to determine its usefulness in the prenatal detection of anencephaly in the first trimester. STUDY DESIGN: Women attending our center for transabdominal ultrasonographic screening at 10 to 14 weeks' gestation were prospectively recruited for this study. The crown-chin length was measured in a sagittal view of the fetal head, which included the fetal profile, from the highest point of the head to the most anterior aspect of the jaw. Nomograms for the crown-chin length and the ratio of the crown-chin length to the crown-rump length according to gestational age were generated. Additionally, the crown-chin length and the ratio of the crown-chin length to crown-rump length were obtained from a subset of 13 anencephalic fetuses and plotted against the reference range. RESULTS: In normal fetuses the crown-chin length increased (Crown-chin length = 65.2 x Gestational age in days - 28.4; r = 0.74%, p <0.0001) and the ratio of the crown-chin length to the crown-rump length decreased (Ratio of crown-chin length to crown-rump length -17.2 x Gestational age in days + 60.5; r = 0.23, p <0.0001) with advancing gestation. In anencephalic fetuses crown-chin length measurements and the ratio of the crown-chin length to the crown-rump length were below the 5th percentile in 77% and 62% of the cases, respectively. The slope of change in the ratio of the crown-chin length to the crown-rump length with gestational age was significantly different in anencephalic fetuses compared with normal fetuses (t = 2.7, p <0.003). CONCLUSION: Measurement of the crown-chin length at 10 to 14 weeks' gestation provides a technique that can assist in the early recognition of anencephaly.

Anencephaly↗

PubMed1997

Evolution of the lambda or twin-chorionic peak sign in dichorionic twin pregnancies.

OBJECTIVE: To study the sonographic evolutaion of the chorionic tissue projection at the intertwin membrane-placental junction, or lambda sign, or twin-chorionic peak sign, in dichorionic twin pregnancies and to determine the effect of placental location on its prevalence during the first half of pregnancy. METHODS: We prospectively recruited women with twin pregnancies undergoing sonographic screening for chromosomal abnormalities at 10-14 weeks' gestation for this study. The presence or absence of the lambda sign and the position of the placenta(s) were recorded in all cases. The presence of the lambda sign was evaluated prospectively at 16 and 20 weeks' gestation. RESULTS: There were 101 twin pregnancies with a lambda sign identified at 10-14 weeks' gestation, 67 with fused placentas and 34 with separate placentas. At 16 weeks, the lambda sign was present in all 67 pregnancies with fused placentas (100%) and in 31 of 34 (91%) pregnancies with separate placentas. At 20 weeks, the lambda sign was present in 25 of the 34 (74%) pregnancies with separate placentas and in 62 of the 67 (93%) with fused placentas. The lambda sign was identified subsequently in none of the 53 pregnancies in which it was absent at 10-14 weeks' gestation. CONCLUSIONS: At 10-14 weeks' gestation, twin pregnancies with the lambda sign can be classified as dichorionic and pregnancies with absent lambda sign can be classified as monochorionic and therefore monozygotic. At 16-20 weeks, the lambda sign is indicative of dichorionicity but its absence does not exclude dizygosity.

Adolescent↗

PubMed1997

Fetal nuchal translucency thickness at 10-14 weeks' gestation and congenital diaphragmatic hernia.

OBJECTIVE: To examine the possible association between increased fetal nuchal translucency thickness at 10-14 weeks and congenital diaphragmatic hernia. METHODS: This was a multicenter ultrasound screening study for chromosomal defects in singleton pregnancies by a combination of maternal age and fetal nuchal translucency at 10-14 weeks' gestation. The prevalence of diaphragmatic hernia diagnosed prenatally or postnatally was calculated in the chromosomally normal group and in those pregnancies resulting in live births with no dysmorphic features suggestive of a chromosomal abnormality. We calculated the sensitivity of nuchal translucency above the 95th centile of the normal range in the detection of diaphragmatic hernia and the possible prognostic value of increased nuchal translucency in the prediction of outcome. RESULTS: There were 78,639 pregnancies presumed to be normal chromosomally, including 19 with diaphragmatic hernia. In four cases, the parents opted for termination of the pregnancy. The other 15 pregnancies resulted in live births; nine infants survived after successful surgical repair of the hernia, but six neonates died because of pulmonary hypoplasia. At the 10- to 14-week scan, the fetal nuchal translucency was above the 95th centile for crown-rump length in seven (37%) cases of diaphragmatic hernia. The translucency was increased in five of the six cases that resulted in neonatal death, compared with two of the nine survivors (Z = 2.32, P < .05). CONCLUSION: The prevalence of diaphragmatic hernia in chromosomally normal fetuses is about one in 4000, and nearly 40% of affected fetuses have increased nuchal translucency at 10-14 weeks' gestation. Increased nuchal translucency may be a marker of intrathoracic compression-related pulmonary hypoplasia.

Adolescent↗

PubMed1997

Ultrasound screening for anencephaly at 10-14 weeks of gestation.

In an ongoing study involving seven hospitals in London and surrounding areas, 55,237 fetuses were examined by ultrasound at 10-14 weeks of gestation. There were 47 fetuses (1 in 1175) with anencephaly which presented with acrania with varying degrees of cerebral degeneration. The first audit of results was performed in April 1995. During the first phase of the study 34,830 fetuses were examined and in eight of the 31 with anencephaly the diagnosis was not made at the 10-14-week scan. Following the audit, 20,407 fetuses were examined and in all 16 with anencephaly the diagnosis was made at the 10-14-week scan (p = 0.03). These findings demonstrate that anencephaly can be reliably diagnosed at the routine 10-14-week ultrasound scan, provided a specific search is made for the sonographic features for this condition.

Anencephaly↗

PubMed1997

Lethal congenital arthrogryposis presents with increased nuchal translucency at 10-14 weeks of gestation.

This study examines the ultrasonographic features of congenital lethal arthrogryposis. In 27 cases of arthrogryposis diagnosed in the second and third trimesters there was severe bilateral talipes, fixed flexion deformities of the wrists and elbows and either fixed flexion or extension of the knees. In seven (26%) of the cases there was nuchal edema. In two fetuses with arthrogryposis that were examined at 13 weeks of gestation the nuchal translucency thickness was above the 99th centile of the normal range for crown-rump length. In three other women with previously affected pregnancies, ultrasound examination at 10-14 weeks demonstrated normal fetal nuchal translucency thickness and none of these fetuses were subsequently found to have arthrogryposis. These findings suggest that lethal arthrogryposis, which is usually diagnosed by the demonstration of multiple joint contractures during the second or third trimester of pregnancy, may present as increased nuchal translucency thickness at 10-14 weeks of gestation.

Adult↗

PubMed1997

Increased nuchal translucency thickness at 10-14 weeks of gestation as a predictor of severe twin-to-twin transfusion syndrome.

The study examines a possible association between increased nuchal translucency thickness at 10-14 weeks of gestation in monochorionic twin pregnancies and the subsequent development of severe twin-to-twin transfusion syndrome (TTS). In 132 monochorionic twin pregnancies, including 16 that developed severe TTS at 15-22 weeks of gestation and 116 that did not develop TTS, crown-rump length, nuchal translucency thickness and fetal heart rate were measured at 10-14 weeks. In those that developed severe TTS, the prevalence of nuchal translucency thickness above the 95th centile of the normal range and the intertwin difference in nuchal translucency thickness and fetal heart rate were significantly higher than in the non-TTS group; there were no significant differences between the groups in the inter-twin difference in crown-rump length. For fetal nuchal translucency above the 95th centile, the positive and negative predictive values for the development of TTS were 38% and 91%, respectively; the likelihood ratios of nuchal translucency above or below the 95th centile for the development of severe TTS were 4.4 (1.8-9.7) and 0.7 (0.4-0.9), respectively. These findings demonstrate that the underlying hemodynamic changes associated with TTS may manifest as increased fetal nuchal translucency thickness at 10-14 weeks of gestation.

Adult↗

PubMed1997

Prenatal diagnosis of trisomy 18 at the 10-14-week ultrasound scan.

A beneficial consequence of screening for trisomy 21 by a combination of maternal age and fetal nuchal translucency thickness (NT) at 10-14 weeks is the early diagnosis of trisomy 18. In a multicenter study of 91,091 singleton pregnancies there were 106 fetuses with trisomy 18 and 83% were identified by NT screening. Trisomy 18 was also associated with early onset intrauterine growth retardation, decreased fetal heart rate and the presence of exomphalos.

Adolescent↗

PubMed1997

Presence of the 'lemon' sign in fetuses with spina bifida at the 10-14-week scan.

In three cases of lumbosacral spina bifida diagnosed at 12, 13 and 14 weeks of gestation there was an associated lemon sign, or scalloping of the frontal bones, and in one case the fetal nuchal translucency was increased. In a multicenter ultrasound screening study at 10-14 weeks there were 61,972 singleton pregnancies including 29 cases of spina bifida, none of which was diagnosed at the routine first-trimester scan, but 28 of the 29 cases were detected by ultrasonography at 16-22 weeks; in one case the diagnosis was missed at the 20-week scan and the defect was identified at 32 weeks during a scan for localization of the placenta. The fetal nuchal translucency was above the 95th centile in only one of the cases (3.4%). It is possible that the majority of fetuses with spina bifida have a lemon sign in the first trimester, but the sensitivity of the 10-14-week scan in the diagnosis of spina bifida and the prevalence of the lemon sign at this gestation will only be established by further studies incorporating early systematic examination of the head and spine.

Female↗

PubMed1997

Body stalk anomaly at 10-14 weeks of gestation.

In a multicenter project of screening for chromosomal defects by fetal nuchal translucency thickness and maternal age at 10-14 weeks, 14 of 106,727 fetuses examined had body stalk anomaly. The ultrasonographic features were a major abdominal wall defect, severe kyphoscoliosis and a short umbilical cord. In all cases, the upper part of the fetal body was in the amniotic cavity, whereas the lower part was in the celomic cavity. The nuchal translucency thickness was above the 95th centile in ten (71.4%) of the cases, but the fetal karyotype was normal in all 12 fetuses evaluated. The findings suggest that early amnion rupture before obliteration of the celomic cavity is a possible cause of the syndrome.

Abdominal Muscles↗

PubMed1997

Preterm delivery and growth restriction in multifetal pregnancies reduced to twins.

Gestation at delivery, birthweight and pregnancy outcome of surviving fetuses from 127 multifetal pregnancies undergoing embryo reduction to twins were compared to 354 chromosomally normal non-reduced dichorionic twin pregnancies. First-trimester embryo reduction was carried out by intracardiac injection of KCl. In 16 (12.6%) of the 127 multifetal pregnancies reduced to twins, there was miscarriage of both fetuses before 24 weeks of gestation. The median interval between reduction and fetal loss was 5 weeks (range 1-12). In livebirths, the median gestation at delivery was 36 weeks (range 24-41) and the median difference in birthweight from the appropriate mean was -0.94 SD (range -3.89-1.73 SD). Both fetal loss before 24 weeks and the interval between embryo reduction and delivery were significantly associated with the gestation at reduction (r = 0.40, P < 0.001 and r = -0.57, P < 0.001 respectively). In the pregnancies reduced to twins compared to the non-reduced twins, the percentage of miscarriages was higher (12.6 compared to 2.5%; chi 2 = 19.2, P < 0.001), the median gestation at delivery was lower (36 compared to 37 weeks; t = -1.74, P < 0.05), and the median birthweight deficit was greater (-0.94 compared to -0.65 SD: t = -4.1, P < 0.001).

Abortion, Spontaneous↗

PubMed1997

Effects of embryo reduction from trichorionic triplets to twins.

Sixty-six trichorionic triplet pregnancies reduced to twins were compared with 47 triplet pregnancies that were not reduced. The miscarriage rate was higher (7.6% compared with 2.6%) but the number delivering between 24 and 32 weeks was lower (8.2% compared with 24.0%). Since severe preterm delivery is associated with risks of neonatal death and severe handicap, embryo reduction of triplets to twins may not improve the chance of survival but may reduce the rate of handicap.

Abortion, Spontaneous↗

PubMed1997

The hidden mortality of monochorionic twin pregnancies.

In an ultrasound screening study at 10 to 14 weeks of gestation for measurement of fetal nuchal translucency thickness there were 102 monochorionic and 365 dichorionic twin pregnancies. In the monochorionic compared with the dichorionic pregnancies there was a higher rate of fetal loss before 24 weeks of gestation (12.2% versus 1.8%), perinatal mortality (2.8% versus 1.6%), prevalence of delivery before 32 weeks (9.2% versus 5.5%), and prevalence of birthweight below the 5th centile in both twins (7.5% versus 1.7%). However, the proportion of pregnancies with a birthweight discordancy of more than 25% was similar in the two groups (11.3% versus 12.1%).

Abortion, Spontaneous↗

PubMed1997

Fetal heart rate at 10 to 14 weeks and birthweight.

In 6644 singleton pregnancies resulting in live births, the fetal heart rate was measured at 10 to 14 weeks of gestation (median 12). There was no significant association between fetal heart rate and birthweight. These findings demonstrate that if there is an association between fetal heart rate, birthweight and subsequent development of cardiovascular disease the responsible intrauterine insult and/or the adaptive fetal response are not present at 10 to 14 weeks of gestation.

Birth Weight↗

PubMed1997

Increased fetal nuchal translucency thickness at 10-14 weeks: is screening for maternal-fetal infection necessary?

OBJECTIVE: To investigate the relation between increased fetal nuchal translucency thickness at 10-14 weeks of gestation and maternal-fetal infection. DESIGN: Prospective study. SETTING: Harris Birthright Research Centre for Fetal Medicine. POPULATION: Four hundred and twenty-six chromosomally normal pregnancies with increased fetal nuchal translucency thickness at 10-14 weeks of gestation and 63 with 'unexplained' second or third trimester fetal nuchal oedema or hydrops. METHODS: Maternal serum infection screening and investigations for fetal infection in those with evidence of recent maternal infection. MAIN OUTCOME MEASURES: Maternal and fetal infection. RESULTS: Evidence of recent maternal infection was present in six of the 426 pregnancies (1.4%) with increased fetal nuchal translucency thickness at 10-14 weeks, but in all cases a healthy infant was born with no evidence of infection. In contrast, 'unexplained' second or third-trimester fetal hydrops was associated with maternal infection in six of the pregnancies (9.5%) and in all cases there was evidence of fetal infection. CONCLUSIONS: Maternal-fetal infection is one of the causes of second or third trimester nuchal oedema or fetal hydrops. In contrast, the presence of increased nuchal translucency in the first trimester is not a marker of either maternal or fetal infection.

Cytomegalovirus Infections↗

PubMed1997

Management of twin pregnancies discordant for anencephaly.

OBJECTIVE: To examine options of management and outcome of twin pregnancies discordant for anencephaly. DESIGN: Retrospective study. SETTING: Research Centre for Fetal Medicine. POPULATION: Twenty-four twin pregnancies discordant for anencephaly. METHODS: A computer search was made of our database for twin pregnancies discordant for anencephaly. The data were reviewed for gestation at presentation, chorionicity, management and pregnancy outcome. MAIN OUTCOME MEASURES: Pregnancy outcome in relation to chorionicity and management. RESULTS: There were 13 dichorionic and 11 monochorionic twin pregnancies discordant for anencephaly. In the dichorionic group five pregnancies had selective fetocide at 17 to 21 weeks; one pregnancy resulted in spontaneous abortion but in the others a healthy infant was born at a median gestation of 37 weeks. The other eight dichorionic pregnancies were managed expectantly, but three developed polyhydramios at 26 to 30 weeks; in one case amniodrainage was performed and in another selective fetocide was carried out. In this group the median gestation at delivery was 35 weeks. All 11 monochorionic pregnancies were managed expectantly and in three there was intrauterine death of both fetuses. In the other eight cases the normal twin was liveborn at a median gestation of 34 weeks; in four of these pregnancies polyhydramnios developed and two were managed by amniodrainage. CONCLUSIONS: In monochorionic pregnancies, expectant management is associated with a high rate of intrauterine lethality of the normal twin. In dichorionic pregnancies selective fetocide in the second trimester prevents the development of polyhydramnios and is associated with a lower risk of preterm delivery but can cause miscarriage.

Anencephaly↗

PubMed1997

Management of twin pregnancies with fetal trisomies.

OBJECTIVE: To examine options of management and outcome of twin pregnancies affected by fetal trisomies. DESIGN: Retrospective study. SETTING: Research Centre for Fetal Medicine. POPULATION: Twenty-seven twin pregnancies affected by fetal trisomy. METHODS: A computer search was made of our database for twin pregnancies concordant or discordant for trisomies. The data were reviewed for gestation at diagnosis of the chromosomal abnormality, management and pregnancy outcome. MAIN OUTCOME MEASURES: Pregnancy management and outcome in relation to type and gestation at diagnosis of the trisomies. RESULTS: There were seven cases where both fetuses were trisomies and in these the parents opted for termination of pregnancy; termination was also performed in another pregnancy where one fetus had trisomy 18 and the chromosomally normal co-twin had a major facial cleft. In 19 cases one fetus had either trisomy 21 (n = 14) or trisomy 18 (n = 5) and the other was normal. Selective fetocide was carried out in 13 of 14 pregnancies discordant for trisomy 21 and in one of the five with trisomy 18. In the four cases discordant for trisomy 18 that were managed expectantly, the trisomic baby died in utero or in the neonatal period, whereas the normal co-twin was liveborn at 33 to 40 weeks (median 37). In the 14 cases of selective fetocide, the chromosomally normal co-twin was live born at 24 to 41 weeks of gestation (median 38), and there was a nonsignificant inverse correlation between the gestation at fetocide and gestation at delivery. CONCLUSIONS: In twin pregnancies discordant for fetal trisomies the main determinant in deciding whether to perform selective fetocide or adopt expectant management is the degree of lethality of the chromosomal defect.

Abortion, Induced↗

PubMed1997

The prevalence and consequences of missed abortion in twin pregnancies at 10 to 14 weeks of gestation.

In singleton pregnancies at 10 to 14 weeks of gestation the prevalence of missed abortion is about 2%. In an ultrasound screening study at 10 to 14 weeks of gestation involving 492 twin pregnancies the prevalence of missed abortion was about twice as high as in singletons. The risk of subsequent miscarriage in twin pregnancies with one missed abortion was about ten times higher than in normal twin pregnancies. These findings may have important implications both in terms of counselling and for future research into the causes of miscarriage.

Abortion, Missed↗