Prenatal vs postnatal diagnosis of 22q11.2 deletion syndrome: cardiac and noncardiac outcomes through 1 year of age

BACKGROUND

The 22q11.2 deletion syndrome is the most common microdeletion syndrome and is frequently associated with congenital heart disease. Prenatal diagnosis of 22q11.2 deletion syndrome is increasingly offered. It is unknown whether there is a clinical benefit to prenatal detection as compared with postnatal diagnosis.

OBJECTIVE

This study aimed to determine differences in perinatal and infant outcomes between patients with prenatal and postnatal diagnosis of 22q11.2 deletion syndrome.

STUDY DESIGN

This was a retrospective cohort study across multiple international centers (30 sites, 4 continents) from 2006 to 2019. Participants were fetuses, neonates, or infants with a genetic diagnosis of 22q11.2 deletion syndrome by 1 year of age with or without congenital heart disease; those with prenatal diagnosis or suspicion (suggestive ultrasound findings and/or high-risk cell-free fetal DNA screen for 22q11.2 deletion syndrome with postnatal confirmation) were compared with those with postnatal diagnosis. Perinatal management, cardiac and noncardiac morbidity, and mortality by 1 year were assessed. Outcomes were adjusted for presence of critical congenital heart disease, gestational age at birth, and site.

RESULTS

A total of 625 fetuses, neonates, or infants with 22q11.2 deletion syndrome (53.4% male) were included: 259 fetuses were prenatally diagnosed (156 [60.2%] were live-born) and 122 neonates were prenatally suspected with postnatal confirmation, whereas 244 infants were postnatally diagnosed. In the live-born cohort (n=522), 1-year mortality was 5.9%, which did not differ between groups but differed by the presence of critical congenital heart disease (hazard ratio, 4.18; 95% confidence interval, 1.56-11.18; P<.001) and gestational age at birth (hazard ratio, 0.78 per week; 95% confidence interval, 0.69-0.89; P<.001). Adjusting for critical congenital heart disease and gestational age at birth, the prenatal cohort was less likely to deliver at a local community hospital (5.1% vs 38.2%; odds ratio, 0.11; 95% confidence interval, 0.06-0.23; P<.001), experience neonatal cardiac decompensation (1.3% vs 5.0%; odds ratio, 0.11; 95% confidence interval, 0.03-0.49; P=.004), or have failure to thrive by 1 year (43.4% vs 50.3%; odds ratio, 0.58; 95% confidence interval, 0.36-0.91; P=.019).

CONCLUSION

Prenatal detection of 22q11.2 deletion syndrome was associated with improved delivery management and less cardiac and noncardiac morbidity, but not mortality, compared with postnatal detection.

COVID-19 vaccination and transmission patterns among pregnant and postnatal women during the fifth wave of COVID-19 in a tertiary hospital in Hong Kong

INTRODUCTION

Vaccination is a key strategy to control the coronavirus disease 2019 (COVID-19) pandemic. Safety concerns strongly influence vaccine hesitancy. Disease transmission during pregnancy could exacerbate risks of preterm birth and perinatal mortality. This study examined patterns of vaccination and transmission among pregnant and postnatal women during the fifth wave of COVID-19 in Hong Kong.

METHODS

The Antenatal Record System and Clinical Management System of the Hospital Authority was used to retrieve information concerning the demographic characteristics, vaccination history, COVID-19 status, and obstetric outcomes of women who were booked for delivery at Queen Mary Hospital in Hong Kong and had attended the booking antenatal visit from 1 July 2021 to 30 June 2022.

RESULTS

Among 2396 women in the cohort, 2006 (83.7%), 1843 (76.9%), and 831 (34.7%) had received the first, second, and third doses of COVID-19 vaccine, respectively. Among 1012 women who had received the second dose, 684 (67.6%) women were overdue for their third dose. There were 265 (11.1%) reported COVID-19 cases. Women aged 20 to 29 years had a low vaccination rate but the highest disease rate (19.1%). The disease rate was more than tenfold higher in women who had no (20.3%) or incomplete (18.8%) vaccination, compared with women who had complete vaccination (2.1%; P<0.001).

CONCLUSION

Acceptance of COVID-19 vaccination was low in pregnant women. Urgent measures are needed to promote vaccination among pregnant women before the next wave of COVID-19.

Hemoglobin A1c in early pregnancy to identify preexisting diabetes mellitus and women at risk of hyperglycemic pregnancy complications

BACKGROUND

Unrecognized diabetes mellitus during pregnancy could pose serious maternal and neonatal complications. A hemoglobin A1c level of ≥6.5% was used to diagnose both diabetes mellitus in nonpregnant individuals and diabetes in pregnancy. As the hemoglobin A1c level could be influenced by maternal physiological changes, the optimal cutoff in early pregnancy to detect women with diabetes in pregnancy and associated complications remains unclear.

OBJECTIVE

This study aimed to evaluate the diagnostic performance of various hemoglobin A1c levels and the optimal hemoglobin A1c cutoff to identify mothers with diabetes in pregnancy diagnosed by the gold standard 75 g oral glucose tolerance test before 24 weeks of gestation. In addition, the pregnancy and neonatal outcomes were compared using the optimal hemoglobin A1c cutoff.

STUDY DESIGN

A retrospective cohort study was conducted between 2004 and 2019. Women with at least 1 risk factor of gestational diabetes mellitus received an oral glucose tolerance test before 24 weeks of gestation. Terminology of hyperglycemia first detected during pregnancy by oral glucose tolerance test was classified as either diabetes in pregnancy or gestational diabetes mellitus following the World Health Organization's recommendation. Women who met the diagnostic criteria of diabetes in pregnancy and early-onset gestational diabetes mellitus (ie, before 24 weeks of gestation) and had a paired hemoglobin A1c measurement within 4 weeks of their early oral glucose tolerance test were studied. Sensitivity, specificity, and positive and negative predictive values at various hemoglobin A1c cutoffs were calculated for the detection of diabetes in pregnancy. The optimal hemoglobin A1c level was identified from the constructed receiver operating characteristic curves. Multivariate binary logistic regression analyses were performed to calculate the unadjusted and adjusted odds ratios for pregnancy complications.

RESULTS

There were 63,111 deliveries, and 22,949 women underwent an oral glucose tolerance test before 24 weeks of gestation. A total of 157 and 3210 women met the diagnostic criteria of diabetes in pregnancy and early-onset gestational diabetes mellitus using an oral glucose tolerance test, respectively. Only 346 participants had a paired hemoglobin A1c and oral glucose tolerance test measurement (82 cases with diabetes in pregnancy and 264 cases with early-onset gestational diabetes mellitus). The receiver operating characteristic curve identified an optimal hemoglobin A1c cutoff of 5.7% to diagnose diabetes in pregnancy, with a sensitivity of 64.6%, specificity of 81.1%, positive predictive value of 51.5%, and negative predictive value of 88.1%. A hemoglobin A1c cutoff of either 5.9% or 6.5% could miss 47.6% or 73.2% of women with diabetes in pregnancy. In multivariate logistic regression analysis, a hemoglobin A1c level of ≥5.7% increased the risk of maternal insulin use (adjusted odds ratio, 6.69; 95% confidence interval, 3.44-12.99), macrosomia (adjusted odds ratio, 7.43; 95% confidence interval, 1.90-29.00), and shoulder dystocia (adjusted odds ratio, 6.56; 95% confidence interval, 1.161-37.03).

CONCLUSION

The optimal hemoglobin A1c cutoff to detect diabetes in pregnancy diagnosed using an oral glucose tolerance test before 24 weeks of gestation was 5.7%, but this cutoff could not reliably identify diabetes in pregnancy owing to the low sensitivity. However, an early hemoglobin A1c level of ≥5.7% indicated increased risks of pregnancy and neonatal complications.

Prenatal diagnosis of Myhre syndrome with a heterozygous pathogenic variant in SMAD4 gene presented with thick nuchal translucency and cardiac abnormalities

Prenatal testing was performed in a 39-year-old Chinese pregnant woman referred for increased nuchal translucency measuring 5.7 mm. Non-invasive prenatal testing and SNP array study on amniotic fluid samples were normal. Whole exome sequencing (WES) was initiated further as the fetus had pericardial effusion of 1.2 mm, thickened myocardium over the right ventricular lateral wall and aberrant right subclavian artery. A detailed fetal echocardiogram also revealed persistent left superior vena cava and dilated coronary sinus at 20 weeks. From whole exome sequencing of the trio, a de novo heterozygous variant NM_005359.5(SMAD4): c.1499T>C (p.Ile500Thr) was detected. This pathogenic variant has been reported in the postnatal case cohort of Myhre syndrome. This condition is characterized by facial dysmorphism, intellectual disability, hearing loss, skeletal abnormalities and potential life threatening respiratory or cardiovascular manifestations. Termination of pregnancy was performed at 23 weeks. Small chins, pre-axial polydactyly, brachydactyly and clinodactyly were noted in the abortus. Ultrasound findings of increased nuchal translucency, thickened myocardium and pericardial effusion prompted further genetic evaluation for the prenatal diagnosis of Myhre syndrome by whole exome sequencing.

Impact of COVID-19 pandemic on preterm delivery

OBJECTIVE

Controversies exist on whether the pandemic lockdown has resulted in a lower rate of preterm deliveries. A higher stillbirth rate was also reported. This retrospective observational study aimed to examine the rate of preterm delivery and stillbirth in a tertiary hospital in Hong Kong during COVID-19 pandemic.

METHODS

Data from 8787 singleton pregnancies at Queen Mary Hospital between April 2018 to September 2021 were retrieved from the clinical management system and obstetric database. Rates of preterm delivery (<37 weeks), low birth weight infants (<2500 g), and stillbirth in the pre-pandemic (April 2018 to September 2019) and pandemic (April 2020 to September 2021) periods were compared.

RESULTS

Total numbers of singleton deliveries during the pre-pandemic and pandemic periods were 5064 and 3723, respectively. Background demographics were comparable, except 3 were higher rates of cesarean sections (30.7% vs. 25.8%; p < 0.05) and hypertensive disorders (1.4% vs. 0.7%; p < 0.05) in the pandemic cohort. Moreover, more women with a spontaneous onset of labor had a history of preterm delivery (3.5% vs. 2.4%; p < 0.05) during the pandemic. Rates of low birth weight infants (8.7% vs. 7.4%; p = 0.03) and spontaneous preterm deliveries (2.6% vs. 1.7%; p = 0.01), particularly spontaneous moderate-to-late preterm delivery (32-36 weeks) (1.9% vs. 1.2%; p = 0.01) were significantly higher during COVID-19. However, no statistical difference was found in stillbirth rates (0.2% vs. 0.4%; p = 0.17).

CONCLUSIONS

Rates of spontaneous preterm delivery and low birth weight babies increased significantly during the COVID-19 pandemic. This could be related to an increase in maternal stress, or a change in behavioral patterns for pregnant women.

Behavioural adaptations and responses to obstetric care among pregnant women during an early stage of the COVID-19 pandemic in Hong Kong: a cross-sectional survey

INTRODUCTION

This study evaluated behavioural adaptations and responses to obstetric care among pregnant women during an early stage of the coronavirus disease 2019 (COVID-19) pandemic.

METHODS

This cross-sectional survey included pregnant women who received obstetric care from 27 May 2020 to 16 June 2020 in a university-affiliated hospital in Hong Kong. Responses were collected with respect to obstetric appointment scheduling, workplace changes, mask-wearing practices, travel and quarantine experiences, obstetric service adjustments, and visiting arrangements. Regression analysis was used to compare the effects of patient characteristics on their responses.

RESULTS

In total, 1000 surveys were distributed; 733 pregnant women provided complete survey responses. Among obstetric-related appointments in public hospitals, 16% were postponed or cancelled by pregnant women; such changes were most frequent among women beyond 24 weeks of gestation, women who had previous deliveries, and women who had a history of mental illness. The practice of working from home imposed psychological stress and negatively impacted the pregnancy experience in 4.5% of women. Childbirth companionship was regarded as an important service by 88.1% of women; only 4.2% agreed with its suspension. Obstetric service adjustments had the greatest impact on Chinese women and nulliparous women.

CONCLUSIONS

The findings provide an overview of how pregnant women adapted during an early stage of the COVID-19 pandemic. Women adjusted obstetric service attendance, began working from home, and wore masks. Women's expectations did not match changes in childbirth companionship and peripartum services. Hospital administrators should consider psychological impacts on pregnant women when implementing service adjustments.

Effect of COVID-19 on delivery plans and postnatal depression scores of pregnant women

INTRODUCTION

Owing to the coronavirus disease 2019 outbreak Hong Kong hospitals have suspended visiting periods and made mask wearing mandatory. In obstetrics, companionship during childbirth has been suspended and prenatal exercises, antenatal talks, hospital tours, and postnatal classes have been cancelled. The aim of the present study was to investigate the effects of these restrictive measures on delivery plans and risks of postpartum depression.

METHODS

We compared pregnancy data and the Edinburgh Postpartum Depression Scale (EPDS) scores of women who delivered between the pre-alert period (1 Jan 2019 to 4 Jan 2020) and post-alert period (5 Jan 2020 to 30 Apr 2020) in a tertiary university public hospital in Hong Kong. Screening for postpartum depression was performed routinely using the EPDS questionnaire 1 day and within 1 week after delivery.

RESULTS

There was a 13.1% reduction in the number of deliveries between 1 January and 30 April from 1144 in 2019 to 994 in 2020. The EPDS scores were available for 4357 out of 4531 deliveries (96.2%). A significantly higher proportion of women had EPDS scores of ≥10 1 day after delivery in the post-alert group than the pre-alert group (14.4% vs 11.9%; P<0.05). More women used pethidine (6.2% vs 4.6%) and fewer used a birthing ball (8.5% vs 12.4%) for pain relief during labour in the post-alert group.

CONCLUSIONS

Pregnant women reported more depressive symptoms in the postpartum period following the alert announcement regarding coronavirus infection in Hong Kong. This was coupled with a drop in the delivery rate at our public hospital. Suspension of childbirth companionship might have altered the methods of intrapartum pain relief and the overall pregnancy experience.

Acceptance of antiviral treatment and enhanced service model for pregnant patients carrying hepatitis B

INTRODUCTION

A service model was established for pregnant women with positive screening results for hepatitis B surface antigen (HBsAg) at Queen Mary Hospital in Hong Kong. All women were offered a blood test for hepatitis B virus (HBV) DNA level during the first antenatal visit. Women with HBV DNA levels of ≥200 000 IU/mL received counselling from hepatologists regarding treatment with antenatal tenofovir disoproxil fumarate (TDF) 300 mg daily.

METHODS

This retrospective review included women attending our antenatal clinic who exhibited positive HBsAg screening results from 15 May 2017 to 31 December 2019. The proportions of women with positive HBsAg, DNA test acceptance, hepatological review, and TDF acceptance during pregnancy were reviewed.

RESULTS

In total, 375 (2.9%) of 13 082 pregnant women had positive HBsAg screening results. Blood tests for HBV DNA and hepatological reviews were offered to 273 women who had not undergone hepatological review prior to pregnancy; the acceptance rate was 97.8%. Sixty (22.6%) pregnant women were hepatitis B carriers with high viral loads of ≥200 000 IU/mL. Among 58 women with high viral loads, 57 received antenatal counselling regarding TDF and 56 (96.6%) agreed to take the drug; 92.9% of these 56 women had commenced TDF at or before 32 weeks of gestation.

CONCLUSIONS

This study indicated broad acceptance of HBV DNA tests by pregnant women. Triage allowed early review and commencement of antiviral medication. This service model serves as a framework for enhanced antenatal service to prevent mother-to-child-transmission in public maternity units.

Application of transcervical hysterofetoscopy and cord blood collection at first trimester termination of pregnancy for fetal abnormalities

OBJECTIVE

To examine the applicability of hysterofetoscopy and cord blood collection at first trimester termination of pregnancy for fetal abnormalities.

METHODS

From 2004 to 2007, transcervical hysterofetoscopy was performed in seven patients at the same operation setting of surgical termination of pregnancy. The findings were compared with prenatal diagnosis. Feasibility of cord blood collection was also examined.

RESULTS

Out of these seven patients, six of them had prenatal ultrasound diagnosis of cystic hygroma. All of them had chromosomal abnormalities. Subcutaneous oedema was confirmed by hysterofetoscopy with good view. Another pregnancy was complicated by homozygous alpha thalassaemia and the diagnosis was confirmed by electrophoresis of fetal haemoglobin collected from umbilical cord vessel. Cord blood collection was also attempted in two other patients yielding fetal blood with minimal maternal contamination.

CONCLUSION

Transcervical hysterofetoscopy is a feasible tool in confirming external fetal structural abnormalities before surgical termination of pregnancy. It can be performed under either general anaesthesia or conscious sedation. Umbilical cord blood collection can facilitate confirmation of genetic diseases. It may also allow the potential of isolating fetal mesenchymal stem cell in first trimester.

Fetus in fetu--from prenatal ultrasound and MRI diagnosis to postnatal confirmation

We report a case of fetus in fetu presented as a complex intra-abdominal heterogeneous cystic lesion during ultrasound examination of the fetus at 25 weeks of gestation. Progressive growth of this mass was noted in the prenatal period. Fetal magnetic resonance imaging provided additional information to aid in the prenatal diagnosis. This allows proper counselling for the parents and helps to plan the postnatal management. Surgical excision was carried out in the early neonatal period and the diagnosis of fetus in fetu was confirmed.

Nuchal translucency in pregnancies conceived after assisted reproduction technology

PURPOSE OF REVIEW

Nuchal translucency is one of the important markers in the first trimester during antenatal screening for fetal Down's syndrome. With the observation of alterations in biochemical markers in pregnancies conceived after assisted reproduction, this review presents current information related to the thickness of nuchal translucency in these pregnancies.

RECENT FINDINGS

Early small studies did not demonstrate any discrepancy in the thickness of nuchal translucency in fetuses from assisted reproduction and from spontaneous pregnancies, but there has been recent evidence to suggest an increased level of nuchal translucency in singletons from various modes of assisted-reproduction technology. Nuchal translucency in twins following assisted reproduction did not, however, show a similar increase. Although the effect of chorionicity was not specifically addressed, nuchal translucency thickness in twins born after assisted reproduction was reported to be comparable to that in spontaneous singletons. It is possible that singletons and twins after assisted reproduction exhibit different antenatal behavior and pregnancy courses.

SUMMARY

Similar to other biochemical markers of fetal Down's syndrome, nuchal translucency is increased in singletons after assisted-reproduction technology. Further studies on twin pregnancies, in particular dichorionic twins, are necessary before conclusive evidence can be drawn for multiple pregnancies.

Nuchal translucency in dichorionic twins conceived after assisted reproduction

OBJECTIVES

As opposed to biochemical markers of Down syndrome, nuchal translucency (NT) was once thought to be a more reliable screening marker for high order multiple pregnancies and pregnancies conceived after assisted conception. Recent data suggested that NT in singleton fetuses from assisted reproduction technology (ART) was thicker than those from singleton pregnancies. The present study compared the thickness of NT in dichorionic twins from natural conception and assisted reproduction.

METHODS

A retrospective analysis for comparison of NT thickness on 3319 spontaneous singletons, 19 pairs of spontaneous twins and 27 pairs of assisted reproduction twins was performed.

RESULTS

The median NT multiple of median (MoM) of spontaneous singletons was 1.00. For twins, the median NT MoM for pregnancies after assisted reproduction and natural conception were 1.02 and 1.07 respectively. There was no statistical difference in the NT thickness among the three pregnancy groups.

CONCLUSION

Contrary to the observed increase in NT in singleton pregnancies from assisted reproduction, the NT in dichorionic twins was comparable to the spontaneous ones. The mode of conception appears to impose differential influence on singletons and twins.

Nuchal translucency in pregnancies conceived after assisted reproduction technology

OBJECTIVES

Levels of maternal serum markers of fetal Down syndrome in pregnancies conceived after assisted reproduction are different from those of normal spontaneous pregnancies. The present study examined the effects of conventional in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI) and embryo cryopreservation on nuchal translucency (NT) thickness.

METHODS

A retrospective analysis on 16 673 spontaneous pregnancies, 119 pregnancies with fresh embryos from IVF, 62 pregnancies with frozen-thawed embryos from IVF, 81 pregnancies with fresh embryos from ICSI and 39 frozen-thawed embryos from ICSI was performed. All were singletons with known normal outcomes. Multiples of the median (MoM) of NT were compared.

RESULTS

The median NT MoM of spontaneous pregnancies was 1.01. In the assisted reproduction pregnancies, the median NT MoM were significantly increased to 1.07 (P = 0.003), 1.09 (P = 0.009) and 1.09 (P = 0.001) in pregnancies conceived with fresh embryos from IVF, frozen-thawed embryos from IVF and fresh embryos from ICSI, respectively. A non-significant increase in median NT MoM (1.04; P = 0.489) was also observed in pregnancies with frozen-thawed embryos from ICSI.

CONCLUSIONS

Increased NT in assisted reproduction pregnancies is postulated to be due to some delay in fetal development. Another possible reason might be related to adverse antenatal course in these pregnancies.

Maternal serum pregnancy-associated plasma protein-A and free β-human chorionic gonadotrophin in pregnancies conceived with fresh and frozen-thawed embryos fromin vitro fertilization and intracytoplasmic sperm injection

OBJECTIVE

Maternal serum pregnancy-associated plasma protein-A (PAPP-A) and free beta-human chorionic gonadotrophin (beta-hCG) are useful markers in the screening of Down syndrome in the first trimester. We investigated the effect of intracytoplasmic sperm injection (ICSI), freezing and thawing of embryos on the levels of these two analytes in assisted reproduction pregnancies.

METHODS

We recruited 149 women who conceived after assisted reproduction with fresh embryos (92 from conventional IVF and 57 from ICSI), 85 women who conceived with frozen-thawed embryos (54 from conventional IVF and 31 from ICSI) and 401 women with spontaneous conceptions as controls. The concentrations of PAPP-A and free beta-hCG were measured between 10 and 14 weeks and were converted to multiples of medians (MoM) for comparisons.

RESULTS

Median PAPP-A MoMs were significantly reduced in ICSI pregnancies in the fresh and frozen-thawed embryo subgroups (0.70 and 0.66 MoM respectively) and in the IVF fresh embryo subgroups (0.83 MoM), as compared to controls (1.00 MoM). Free beta-hCG MoM was significantly reduced in the IVF fresh embryos subgroup (0.87 MoM), but not in the other three subgroups.

CONCLUSION

Further studies for exploring the underlying pathophysiology and adjustment in the marker levels for screening of Down syndrome are warranted in pregnancies conceived after assisted reproduction.

Pilot study on the midsecond trimester examination of fetal nasal bone in the Chinese population

OBJECTIVES

Hypoplasia of the nasal bone of fetuses affected by trisomy 21 and other aneuploidies could be detected by prenatal ultrasound examination and was an important new marker in the detection of Down syndrome in the second trimester. Racial differences in fetal nasal bone length have been reported. However, there was no reference range for the fetal nasal bone length (NBL) in the Chinese population. We conducted a pilot study to investigate the reproducibility of the measurement of fetal NBL in the mid second trimester and to determine whether there is any difference in NBL between the Chinese and the Caucasian population.

METHODS

From June 2002 to February 2003, 198 Chinese women were examined. Ultrasound measurements of NBL were performed on a strictly midsagittal plane in normal singleton fetuses at 15 to 23 weeks' gestation.

RESULTS

The mean difference in the NBL between the two investigators was small (mean = 0.043 mm; 95% CI, -0.033 to 0.12), and there was substantial agreement between the measurements for each observer. Limits of agreement were -0.48 to 0.35 and -0.29 to 0.22 mm in the two investigators respectively. It was found that the median length of the nasal bones increased from 3.5 mm at 15 weeks to 6.7 mm at 23 weeks' gestation. There was a linear relationship between the length of the nasal bone and the gestational age.

CONCLUSION

It was demonstrated that the measurement of nasal bone length was feasible and reproducible in the second trimester. The fetal nasal bone length in Chinese population appeared shorter than that of Caucasian and African-Americans. There is a need to establish a reference range of fetal NBL for the Chinese population.

Amniotic fluid human chorionic gonadotrophin and alpha-fetoprotein levels in pregnancies conceived after assisted reproduction

OBJECTIVES

To study the alteration in the second-trimester maternal serum levels of human chorionic gonadotrophin (hCG) and alpha-fetoprotein (AFP) in pregnancies conceived after assisted reproduction.

METHODS

We compared the amniotic fluid hCG and AFP concentrations of 45 pregnancies with fresh embryo transfer and 25 pregnancies with frozen-thawed embryo transfer with 269 spontaneous pregnancies. Wilcoxon rank-sum test was used for analysis.

RESULTS

The median amniotic fluid hCG MoM in pregnancies conceived after frozen-thawed embryo transfer was significantly increased to 1.41 compared to 1.00 (p = 0.01) in naturally occurring pregnancies and 0.96 (p = 0.049) in pregnancies after fresh embryo transfer. Further analysis showed that this was only observed in frozen embryos fertilized by conventional insemination with MoM of 1.59. The AFP MoMs were similar among the groups.

CONCLUSIONS

The observed raised amniotic fluid hCG level in IVF-FET pregnancies may reflect the elevated maternal serum level in these pregnancies. Further studies should be directed towards exploring the underlying pathophysiology.

Maternal serum hCG and alpha-fetoprotein levels in pregnancies conceived after IVF or ICSI with fresh and frozen-thawed embryos

BACKGROUND

Studies have shown that levels of serum markers of Down's syndrome were altered in pregnancies conceived after IVF, though the reason for this remains unknown.

METHODS

Second-trimester maternal serum levels of hCG and alpha-fetoprotein (AFP) in pregnancies conceived with fresh and frozen-thawed embryos after assisted reproduction were compared with those conceived spontaneously.

RESULTS

There were 203 pregnancies with fresh embryo transfers (130 IVF cases, 73 ICSI cases) and 98 pregnancies with frozen-thawed embryo transfers (61 IVF cases, 37 ICSI cases). The controls consisted of 17 145 spontaneous pregnancies. The median hCG multiples of the median (MoM) was significantly increased to 1.24 in 98 pregnancies conceived after frozen embryo transfer. This elevation was observed only in the IVF-frozen embryo transfer subgroup (P < 0.001), but not in the ICSI-frozen embryo transfer subgroup. The median AFP MoM for 203 pregnancies after fresh embryo transfer was 0.90. Among the subgroups, the median AFP MoM was significantly reduced to 0.90 and 0.86 in IVF-embryo transfer (P = 0.04) and ICSI-embryo transfer (P = 0.001) pregnancies respectively, and significantly raised to 1.20 in the IVF-frozen embryo transfer subgroup.

CONCLUSIONS

The degree of alterations in maternal serum hCG and AFP levels varied between fresh and frozen-thawed embryos, and also between the mode of fertilization. Pregnancies resulting from ICSI or frozen embryo transfer should be regarded as distinct entities from those of IVF-embryo transfer.

Sonographic features of ileal duplication cyst at 12 weeks

Enteric duplication cyst is a congenital abnormality that is believed to arise from abnormal recanalization of the bowel during embryogenesis. Previous reports suggest that the condition may be suspected prenatally by sonographic demonstration of an intra-abdominal cystic mass in the second and third trimesters. We present the sonographic features of a fetus with ileal duplication cyst at 12 weeks of gestation, which show that the condition may present in the first trimester of pregnancy.

Attitude of at-risk subjects towards preimplantation genetic diagnosis of alpha- and beta-thalassaemias in Hong Kong

OBJECTIVES

The aim of the study was to assess whether preimplantation genetic diagnosis (PGD) was an acceptable alternative to prenatal diagnosis in couples at risk of giving birth to a child with alpha- or beta-thalassaemia in an Asian population.

METHODS

An information leaflet was distributed to the women at risk. They were asked to complete a questionnaire after having an interview with a designated investigator.

RESULTS

A total of 141 valid questionnaires were analysed; 82.3% of the women considered PGD either the same or better than conventional prenatal diagnosis. Women with an affected child or a subfertility problem were more willing to accept PGD and to undergo this procedure in their future pregnancies. Their main concern about PGD was damage to the embryo during the PGD procedure. The most important perceived advantage of PGD was avoidance of termination of an affected pregnancy.

CONCLUSIONS

PGD is an acceptable alternative to conventional prenatal diagnosis in women at risk of giving birth to a child with alpha- or beta-thalassaemia in an Asian population. This is particularly true in women with a subfertility problem and in women who already have an affected child.

Fluid conductance of cancellous bone graft as a predictor for graft-host interface healing

The aim of this study is to test the hypothesis that the fluid conductance of cancellous bone graft is a deciding factor in graft-host union. Cylindrical cancellous bone specimens were trephined from fresh porcine femoral heads in a direction either parallel or perpendicular to the femoral neck axes. The graft after a defatting and freeze-drying process was placed in a perfusion apparatus. The pressure drop across the bone graft and the induced flow were measured and the conductance to fluid flow was calculated as the slope of the flow-pressure relation. Grafts of different flow conductance were transplanted into 35 rabbits to replace segments of tibiae. Nine weeks after grafting, 29 rabbits which had completed the follow-up without incidents were sacrificed. The decalcified sections of the grafts and the adjacent tibiae were examined microscopically for histological events during graft-host interface healing. Perfusion data indicated that fluid conductance ranged from 0.05 x 10(-10) to 13.4 x 10(-10) m3 s-1 Pa-1 and was higher in the direction parallel to the femoral neck axis, inversely proportional to the length of the graft and directly proportional to the square of porosity. Data from rabbit model supported the hypothesis stated above. A threshold conductance was found to be 1.5 x 10(-10) m3 s-1 Pa-1, below which revascularisation and the formations of osteoblasts and fibrous tissues could not be attained. How the low conductance led to non-union at the graft-host interface was briefly discussed.

Translation of the radius as a predictor of outcome in distal radial fractures of children

We conducted a retrospective analysis of 94 children with fractures of the distal third of the radius, with or without ulnar fractures, treated by primary closed reduction and plaster. The overall failure rate of 29% was due mainly to irreducibility, inability to maintain reduction and eventual limitation of forearm rotation. Age, sex and severity of angulation were not significant, but the direction of angulation and the degree of translation at either the radial or the ulnar fracture sites were significant risk factors. Translation of the radius was the single most reliable predictor of outcome (83% correct). The risk of failure in fractures with translation of the radius of more than half the diameter of the bone was 60%, compared with 8% for fractures with less translation.

Partial weight bearing after operations for hip fractures in elderly patients

Factors affecting a patient's ability to carry out partial weight bearing after operation for hip fracture were studied in 100 patients. Seventy-six were able to do so. Significant factors included the muscle power of the good limbs and the mental state, whereas age, body-weight and type of operation were not significant. Logistical regression analysis showed that it was possible to predict a patient's partial weight bearing potential by simply testing the left hand grip and the 'Set' test score.

Gamma nails and dynamic hip screws for peritrochanteric fractures. A randomised prospective study in elderly patients

The Gamma nail was introduced for the treatment of peritrochanteric fractures with the theoretical advantage of a load-sharing femoral component which could be implanted by a closed procedure. We report a randomised prospective study of 186 fractures treated by either the Gamma nail or a dynamic hip screw. Gamma nails were implanted with significantly shorter screening times, smaller incisions, and less intraoperative bleeding. The Gamma nail group had a shorter convalescence and earlier full weight-bearing, but there was no significant difference in mortality within six months, postoperative mobility, or hip function at review. More intra-operative complications were recorded in the Gamma nail group, mainly due to the mismatching of the femoral component of the nail to the small femurs of Chinese people. Use of a smaller modified nail reduced these complications. We conclude that with careful surgical technique and the modified femoral component, the Gamma nail is an advance in the treatment of peritrochanteric fractures.

Joint laxity in children

Joint laxity was measured clinically in 2,360 normal Chinese children aged 3-13 years with equal sex distribution using the Carter Wilkinson five tests and scoring system. Results showed minimal differences due to gender. The degree of joint laxity diminished with age. The knee extension and ankle extension tests were more sensitive than other tests. Chinese children were far more lax throughout the age range, with 100% "laxity" at age 3, 67% laxity at age 6, and 28% laxity at age 12, in contrast to 50, 5, and 1% laxity in the same age group respectively, in large series of Caucasian children.

Angular and rotational profile of the lower limb in 2,630 Chinese children

Angular and rotational profile of the lower limbs of 2,630 normal Chinese children from newborn to age 12 years were compiled using tibiofemoral angle, intercondylar, intermalleolar distance, medial and lateral rotation of the hip, and thigh-foot angle. Children with clinical tibiofemoral angles, intercondylar or intermalleolar distances tended to be bowlegged at birth, maximally knock-kneed at age 3 and to have normal lower limbs by age 8. Medial hip rotation increased steadily from birth to a maximum of 56 degrees at age 9, and lateral hip rotation decreased from birth to a minimum of 30 degrees at age 9. Significant differences between Chinese children and children of other races were highlighted.

Effect of premedication on arterial blood gases prior to cardiac surgery

The effect of premedication on arterial blood gas tensions was studied in thirty adult surgical patients with valvular disease. They were divided into three groups, each group having a different premedication regimen. Blood gas tensions were compared in these patients when awake on the night before surgery, asleep, after premedication and just prior to induction of anaesthesia. Samples were taken while the patient breathed air and each patient acted as his/her own control. The patients were randomised into one of three premedication regimens: 1. intramuscular lorazepam, 2. intramuscular morphine and hyoscine (scopolamine) and 3. oral lorazepam plus intramuscular morphine and hyoscine. There was a statistically significant though not clinically significant rise in PaCO2 and fall in pH following premedication with lorazepam, morphine and hyoscine. There was also a significant fall in PaO2 associated with morphine and hyoscine premedication which was greater than that which occurred with unsedated sleep. Patients who are to undergo cardiac valvular surgery should receive supplementary oxygen following premedication and during transfer to the operating room.

Prognostic factors and progress for ambulation in elderly patients after hip fracture

A longitudinal study of the ambulation progress was done on 102 patients in the first 9 wk after an operation for repair of hip fractures. The time taken to achieve a stable walking pattern from frame to a cane was recorded for every patient. Results showed that 82.2% of the patients were able to walk with a cane at 4 wk postoperatively. Of the remaining 17.8% of the patients, 7.7% were able to walk with a cane at 6 wk whereas 10.1% were not able to walk with a cane at 6 wk. Several factors including the age, sex, mental state, the type of operation and the preoperative ambulation level of the patients were studied to predict the ambulation progress of the patients. The most important factors affecting the ambulation progress were the age and the preoperative ambulation level of the patient. Because of the general trend in the aging of the population, an increase in the number of hip fractures is expected. The result of this study may help in predicting the prognosis and provide guidance for restoring the function of the patients.

Left ventricular function in beta thalassaemia major

The left ventricular dimension and posterior wall dynamics were studied by computer assisted analysis of M mode echocardiography in 25 normal children (group 1) and 32 transfusion dependent children with beta thalassaemia major who had no evidence of heart failure (group 2). Twenty seven of those in group 2 remained well but five died of cardiac decompensation within 12 months. Compared with group 1, the left ventricular fractional shortening and ejection fraction were normal in those in group 2 who survived but diminished in those who died. Evaluation of left ventricular dimension and posterior wall dynamics during systole (peak shortening rate, peak velocity of circumferential fibre shortening, and peak posterior wall thickening rate) showed similar findings in that only the group who died had abnormal values. The left ventricular dimension and posterior wall diastolic dynamics (peak relaxation rate, normalised peak relaxation, peak wall thinning, and normalised peak wall thinning rate), however, showed progressively slower rates in all the children in group 2. The findings suggest that left ventricular diastolic dysfunction occurs early in myocardial impairment in patients with beta thalassaemia major. When there are abnormalities in both diastole and systole, the myocardial impairment is advanced and the prognosis is poor.

Echocardiographic assessment of neonates with pulmonary atresia and intact ventricular septum

In this prospective study, 27 consecutive neonates suspected to be suffering from pulmonary atresia and intact ventricular septum underwent detailed two-dimensional echocardiographic examination before cardiac catheterization. Of the 27 neonates 25 had pulmonary atresia and intact ventricular septum and the remaining 2 had "functional pulmonary atresia" secondary to severe Ebstein's anomaly of the tricuspid valve. In all 25 neonates with pulmonary atresia and intact ventricular septum, the diagnosis and right ventricular morphology based on the tripartite approach were correctly established by echocardiography. The associated Ebstein's anomaly in two babies with pulmonary atresia and intact ventricular septum was also correctly identified by echocardiography. Among the five babies who had a sinusoidal-coronary artery communication, echocardiography demonstrated the fistula in one and provided clues for its diagnosis in two others. In the 25 neonates with pulmonary atresia and intact ventricular septum, the echocardiographic dimensions of their tricuspid anulus, right ventricular infundibulum and main pulmonary artery correlated well with the angiocardiographic measurements (r greater than 0.8). The results of this study suggest that, in the management of neonates with pulmonary atresia and intact ventricular septum, preoperative evaluation by echocardiography is usually sufficient and cardiac catheterization should be reserved for selected cases.

Cross-sectional and pulsed Doppler echocardiography of the atrioventricular junction of hearts with univentricular atrioventricular connexion

The atrioventricular junction of 52 consecutive patients with univentricular atrioventricular connexion was examined by cross-sectional and pulsed Doppler echocardiography. The echocardiographic features were then compared with catheterisation and cineangiographic findings. In the diagnosis of the mode of atrioventricular connexion, cross-sectional echocardiography was superior to cineangiography in differentiating single inlet with absence of one atrioventricular connexion from double inlet with a common atrioventricular valve. Straddling atrioventricular valves were diagnosed by echocardiography alone. Using pulsed Doppler echocardiography, the diagnostic sensitivity of atrioventricular valvar regurgitation was 92.6% and the specificity 100%. By mapping the regurgitant jet with pulsed Doppler echocardiography, an index was derived to evaluate the severity of atrioventricular valvar regurgitation. The indices obtained correlated well with cineangiographic grading on a three-point scale (Spearman rank correlation coefficient: rs = 0.9). Thus, cross-sectional echocardiography coupled with a range-gated Doppler system provide accurate anatomical details of the atrioventricular junction and reliable assessment of atrioventricular valvar regurgitation in patients with univentricular atrioventricular connexion.

Frequency analysis of the first and second heart sounds of humans

Each sound signal of the first and the second heart sounds of humans was divided into three equal segments. The frequency spectrum of each segment was analyzed using the fast-Fourier-transform technique. Theory predicts that if the first and second heart sounds are caused principally by the respective vibrations of the atrioventricular and semilunar valves, then the frequency of these sounds should increase with an increase in the pressure difference across these valves. In other words, the frequency of the heart sounds should increase with time, as the pressure difference across these valves increases with time for most of the duration of the sounds. Our frequency analysis, however, showed that there is no systematic relation between the predominant frequency of successive segments of the sound signals. This therefore appears to indicate that it is quite unlikely that the vibrations of the heart valves are the principal contributor to the origin of the first and second heart sounds.

Trigger finger following partial flexor tendon laceration

An uncommon cause of trigger finger, caused by partial laceration of superficialis flexor tendon is illustrated in two patients.