OBJECTIVES:: To study whether real-time three-dimensional (3D) ultrasound with live xPlane imaging, which enables the simultaneous display of two real-time high-quality image planes, can assist both FMF (Fetal Medicine Foundation of United Kingdom) and non-FMF certified operators in acquiring a true midsagittal plane. METHODS:: Eight sonographers, four of them FMF certified (FMF Group) and the other four not (non-FMF Group), were asked to acquire a fetal image they believed to represent the true midsagittal plane using real-time 3D ultrasound with live xPlane imaging as a guidance. Each sonographer was asked to obtain such an image from 5 patients, five times on each patient. A total of 200 images from forty patients were obtained and stored for subsequent analysis. All pregnancies were between 11+0 and 13+6 weeks of gestation. The angle between the falx cerebri and vertical axis (angle of deviation) was measured. True midsagittal section was defined as an angle of deviation equal to zero. The angle of deviation and the time taken for acquiring each image were compared between FMF and non-FMF groups using the Wilcoxon's sign rank test. RESULTS:: The median angle of deviation for each operator ranged from 1.2 degrees to 3.4 degrees . There was no significant difference in this angle between those who were FMF certified and non-FMF certified (2.0 degrees vs. 2.2 degrees , P=0.463). The inter-quartile range of the angle of deviation was also similar among the FMF and non-FMF certified operators. Although the time taken for image acquisition was longer among the non-FMF certified operators (median: 45.5s vs. 32.0s), this difference did not reach statistical significance (P=0.107). CONCLUSION:: The availability of live xPlane imaging can provide a tool to assist the acquisition of a true midsagittal plane and decide how true a midsagittal plane really is. Copyright (c) 2010 ISUOG. Published by John Wiley & Sons, Ltd.

OBJECTIVE:: To estimate whether fetal bradycardia-to-delivery interval or decision-to-delivery interval was related to cord arterial pH according to different causes of fetal distress. METHODS:: Women who delivered singleton neonates by urgent cesarean delivery because of intrapartum fetal bradycardia were retrospectively categorized into three groups according to the cause of fetal bradycardia: 1) Irreversible; 2) Potentially Reversible; and 3) Unknown (no identifiable cause). Comparisons were made between groups in regard to pH, bradycardia-to-delivery interval, and decision-to-delivery interval. Correlation analyses between pH and both intervals were then performed for different groups. RESULTS:: Of 235 cases, 39, 22, and 174 were respectively categorized into the Irreversible group, Potentially Reversible group, and Unknown group. The median pH was lower in the Irreversible group (7.094; interquartile range [IQR] 6.991-7.216) than in Potentially Reversible group (7.162; IQR 7.064-7.251) or Unknown group (7.210; IQR 7.161-7.255)(P<.001). The Irreversible group's median bradycardia-to-delivery interval was 5 minutes shorter than those of the other two groups (11 compared with 16.5 and 16 minutes, respectively; P<.001), whereas its median decision-to-delivery interval was 1 minute shorter (10 compared with 11.5 and 11 minutes, respectively; P=.001). In the Irreversible group, pH decreased with the bradycardia-to-delivery interval (Spearman's rho=-0.354; P=.027) at a rate of 0.011 per minute. Cord arterial pH did not correlate with the bradycardia-to-delivery interval in the Potentially Reversible and Unknown groups. In neither group did pH correlate with decision-to-delivery interval. CONCLUSION:: Cord arterial pH deteriorates with bradycardia-to-delivery interval when the underlying cause of fetal distress is irreversible, but not so otherwise. LEVEL OF EVIDENCE:: II.

OBJECTIVE: To determine the number of ultrasound examinations required to train sonographers to accurately measure the fetal frontomaxillary facial (FMF) angle at 11(+0) to 13(+6) weeks of gestation. METHODS: Eight sonographers accredited for nuchal translucency thickness (NT) measurement were trained to measure the fetal FMF angle using specially acquired three-dimensional (3D) volumes. Training was provided in cycles, and each cycle consisted of a training period on 20 randomly selected cases followed by an examination using 10 randomly selected cases. During training, the sonographer was informed of the "true FMF angle value" after each FMF angle measurement on a case by case basis. During examination, the difference between the measured and the true value of the FMF angle (i.e. the delta angle) was calculated. A measurement for a case was considered accurate if the delta angle was less than 5( masculine). The sonographer was considered to be competent and the training finished if all 10 examination cases satisfied this criteria. Otherwise, the sonographer would undergo further cycles of training-examination, until he became competent. RESULTS: The number of training cases required for a sonographer to be competent was 40 in two sonographres, 60 in one, 80 in one, 100 in two, 120 in one and 140 in one, with an average of 85. The median number of failed cases reduced from 2.5 (out of 10) at the first cycle to 0 by the 7th cycle. As training cycles increased, the mean angle deviation and measurement time required both reduced significantly. The average delta angle of the passing examination cycle was 2.06 degrees +/-1.40 degrees . The number of training cases required to be competent in FMF angle measurement was 40 for each of the two experienced trainees and 80, 120, and 140 for three less experienced trainees respectively. CONCLUSION: We have demonstrated that competence in FMF angle measurement was achieved after a median number of 90 cases with a range up to 140. The number required was substantially lower at 40 cases among those with extensive experience on NT measurement. Copyright (c) 2010 ISUOG. Published by John Wiley & Sons, Ltd.

Objective. This randomised trial was designed to study the psychological status and morbidity during and after delivery among women with a previous cesarean section (CS) who were randomised to planned vaginal birth (VBAC) or planned CS. Methods. Two hundred and ninety-eight women with one previous lower segment CS were randomised to either planned VBAC or planned CS. Women were asked to complete psychometric scales during their pregnancy till 6 months after confinement. The primary outcome studied was the differences in psychometric scores between the two study groups. Results. There were no differences in anxiety, depression, psychological well-being or satisfaction scores between the two groups. Significantly more women in planned VBAC (27/123) requested to change to elective CS, compared to those who were randomised to planned CS (15/135) initially requested to change to planned VBAC (OR: 2.25; 95% CI: 1.13-4.47). Subgroup analyses showed that women who changed from planned CS to VBAC had lower satisfaction at delivery [Client Satisfaction Score: 24.0 (23.0-24.3), 23.0 (22.0-24.0); p = 0.009] compared to women who did not change their plan for elective CS. Conclusions. The planned mode of delivery, either elective CS or VBAC, in pregnant women who had one previous CS did not influence the psychological dynamic during the course of or after the pregnancy. VBAC was not associated with higher psychological morbidity and therefore should be encouraged.

Maternal rubella status was compared between local residents with non-residents who delivered in our hospital during 1998-2008. Among the 60,822 women, non-immunity was more common in the non-residents (19.9% versus 8.1%, P<0.001). Significant difference and positive correlation with age and parity were found for both groups, but a significant inverse correlation with year-of-birth was found only in the residents. Regression analysis confirmed that birth after 1970 was associated with reduced odds of non-immunity, which indicated that the rubella vaccination programme, introduced since 1978, has succeeded in reducing the incidence of non-immunity to <5% in the youngest generation.

OBJECTIVE:: To assess the relative performance of a multi-stage first trimester screening protocol for fetal Down syndrome. METHODS:: 10,767 women whom underwent combined ultrasound and biochemistry (BC) screening in the first trimester were re-analysed using a contingent model approach. Amongst the 10,854 fetuses with known outcome, 32 had Down syndrome and 10,590 were unaffected. pregnancy. Nuchal Transluceny (NT), BC and combined (NT+BC) gestational age specific risks were calculated for each individual using the Fetal Medicine Foundation risk calculation algorithms (Mixture Model and Biochemistry). Individual patients were categorised as either 'Low','High' or 'Intermediate' risk according to one of the following three strategies. In 'Strategy-NTBC' initial screening was performed using both the NT and BC. In 'Strategy-BC' initial screening was undertaken using maternal serum markers followed by NT assessment in those with an 'Intermediate' risk (1:51< Risk </= 1:1000) whereas in 'Strategy-NT' initial screening was undertaken using NT followed by serum marker assessment in those with an 'Intermediate' risk (1:51< Risk </= 1:1000). The nasal bone (NB) was assessed in those with an 'Intermediate' risk as the final stage in each of the three strategies. Those with an adjusted risk of 1 in 100 or higher after nasal bone assessment were reclassified as 'High' risk. Detection rate (DR) and false positive rates (FPR) were compared between differing strategies in our local population as well as England and Wales age standardised population. RESULTS:: In our local population the DR for a 5% FPR using a combined screening policy (NT+BC) was 88%(95% CI 75.3% to 98.9%) and 2.3% had an absent nasal bone. The respective DR and FPR of the three multistage screening strategies were:'Strategy-NTBC': 87.5% and 2.5%;'Strategy-BC': 87.5% and 5%;'Strategy-NT': 84.4% and 2.9%. In the contingent 'Strategy-BC' only 29% of those initially screened using serum markers required an NT scan. If the model is applied to a hypothetical obstetric population standardised to the maternal age distribution in the England and Wales the DR and FPR of the same three screening strategies were:'Strategy-NTBC': 86.2% and 1.9%;'Strategy-BC': 82.8% and 4%;'Strategy- NT': 75.8% and 2.3 %. CONCLUSION:: First trimester contingent screening provides DR and FPR comparable to those achieved using combined screening but could be used to significantly reduce the number of scans performed. Copyright (c) 2009 ISUOG. Published by John Wiley & Sons, Ltd.

Increased rubella susceptibility has been shown in subjects from the Asian-Pacific region where chronic hepatitis B virus (HBV) infection is endemic. This study was performed to explore the relationship between chronic HBV infection and rubella susceptibility in the obstetric population. We conducted a retrospective cohort study on 50556 pregnant women delivered in a university obstetric unit from January 1998 to June 2008. The incidence of rubella susceptibility according to maternal HBV carrier status was examined. HBV infection and rubella susceptibility were found in 5105 (10.1%) and 6102 (12.1%) women, respectively. Rubella susceptibility was more common in women with HBV (13.1%vs 12.0%, P = 0.017), even after adjusting for other confounding factors (odds ratio 1.11, 95% confidence interval 1.01-1.21). Advancing age was associated with progressively decreasing odds of rubella susceptibility, from 0.48 at age 20-24 years to 0.34 at age >/=40 years in women without HBV infection, but had no effect in women with hepatitis B. In conclusion, our study is the first to demonstrate an association between chronic HBV infection with rubella susceptibility. Further studies are warranted to confirm whether chronic HBV infection, especially that acquired by vertical transmission, may impair the immune response to rubella vaccine or natural infection throughout the reproductive age.

OBJECTIVES. To determine the background, qualifications, and certification status of specialists currently performing first trimester screening in Hong Kong, the extent of their participation (and the laboratories they use) in quality assurance programmes, and their willingness to provide follow-up data for auditing purposes. DESIGN. Questionnaire survey. SETTING. Hong Kong. PARTICIPANTS. A survey was mailed to all registered Hong Kong specialist obstetricians. Results were reported using descriptive statistics. RESULTS. The response rate was 32%(106/331). Overall, 73% offered universal screening to all pregnant women. The majority (72%) most commonly performed first trimester screening for their patients. Sixty-six (62%) of the respondents performed nuchal translucency scanning; only 30 (45%) were accredited by a recognised body to perform such scans. Only 33% of the relevant laboratories used by specialists participated in external quality assurance programmes specific to Down's syndrome screening undertaken by a third party organisation. CONCLUSIONS. According to our data, first trimester screening has become one of the most common screening strategies for Down's syndrome in Hong Kong, but there is a need to assess the quality of such prenatal screening for aneuploidy to ensure its efficacy.

OBJECTIVE: To assess whether the policy of restrictive episiotomy could be safely implemented in Chinese population, and whether perineal length was related to risk of perineal tear during spontaneous vaginal delivery. METHODS: A prospective observational study was conducted between November 2007 and February 2008. A restrictive approach of episiotomy was implemented in those Chinese women who carried an uncomplicated singleton cephalic presenting pregnancy in labour. Perineal length (PL) was measured at three time points:(A) at early first stage of labour;(B) at the beginning of the second stage;(C) at crowning. Women with and without perineal tears were compared with reference to PL measured at different stages and its stretching performance (defined by the change in PL between different stages). RESULTS: Among the 429 women recruited, mean PL at point A, B and C was 38.8 mm (+/-7.9), 49.4 mm (+/-8.1) and 59.4 mm (+/-9.4), respectively, which were similar to those reported in other countries. Episiotomy rate reduced from 73.3 to 26.8%. Among the non-episiotomy group, 13.7% had no perineal tear, 86.3% had minor (first or second degree) tears but none had major tears, whilst 3.5% and 0.9% of episiotomy group had minor and major tears, respectively. PL was not associated with the risk of perineal tear. CONCLUSIONS: Restrictive episiotomy reduces the episiotomy rate without compromising the perineal safety. Chinese women's PL is not shorter than other races, or is predictive of perineal tears.

OBJECTIVE: We investigated the application of microarray-based comparative genomic hybridization (array CGH) on a fetus showing hemivertebrae and intra-abdominal mass at 15 weeks. METHODS: Conventional karyotyping and high-resolution array CGH techniques using 244K CGH microarray were performed to investigate the possibility of genomic imbalance on the opted chorionic villus sample. RESULTS: G-banded fetal chromosome analysis showed 46,XY,der(6)t(6;7)(q26;q31.2)pat. Whole genome scan by array CGH fine mapped the origin of the aberrant chromosomes to be a partial single copy gain of 42.5 Mb from chromosome region 7:116266547 --> qter and concurrent partial single copy loss of 8.1 Mb from chromosome region 6:162756975 --> qter. Pathological examination of the abortus showed gastrointestinal malformations, hemivertebrae with scoliosis, clinodactyly and club feet. CONCLUSIONS: Prenatal and perinatal findings of concurrent trisomy 7q and monosomy 6q were unique. This study demonstrated array CGH can interrogate the entire genome at a resolution and rapidity unattainable by conventional cytogenetic techniques and may have wide application in prenatal diagnosis.