Prenatal Diagnosis and Pregnancy Outcomes of Fetuses With Orofacial Cleft: A Retrospective Cohort Study in Two Centres in Hong Kong

OBJECTIVE

To evaluate the local incidence of orofacial cleft (OFC) encountered in fetal morphology scan and prenatal diagnosis, genetic etiology of fetuses with or without other structural abnormalities, and their pregnancy outcomes.

DESIGN

Retrospective cohort study.

SETTING

Two maternal fetal medicine units, tertiary hospitals, Hong Kong.

PARTICIPANTS

All pregnant women with antenatal diagnosis of fetal OFC between January 2016 and December 2020 (N = 66).

RESULTS

OFC has an incidence of 0.13% among pregnancies in Hong Kong and 28.8% (19/66) were syndromic cleft that exhibited other fetal structural anomalies. There were 55 cases (84.6%) who opted for invasive prenatal diagnostic testing. Genetic defects were identified in 25.8% (17/66) of this cohort, including 14 pathogenic variants. The detection rate in the syndromic cases is 68.4% (13/19) which was significantly higher than 8.5% (4/47) among non-syndromic cases. Aneuploidies would be the most common cause, accounting for 9.1% (6/66). Chromosomal microarray analysis (CMA) provided an incremental diagnostic yield of 6.1% compared to conventional karyotyping. A total of 29 live births including 3 cases of a variant of uncertain significance and 26 cases without genetic abnormalities detected have continued pregnancy to birth. There were 87.5% (21/24) without detectable pathogenic genetic abnormality reported good long-term outcomes. The chance of OFC fetuses having a good long-term outcome was significantly higher if no genomic variant was detected (P < .001).

CONCLUSIONS

Invasive prenatal tests with CMA should be offered to pregnancies with OFC regardless of the type. It has provided incremental diagnostic yield over conventional karyotyping and helped in prenatal and genetic counseling. A negative result in non-syndromic OFC favors couples to keep the pregnancy.

A critical evaluation of the external and internal maneuvers for resolution of shoulder dystocia

In the management of shoulder dystocia, it is often recommended to start with external maneuvers, such as the McRoberts maneuver and suprapubic pressure, followed by internal maneuvers including rotation and posterior arm delivery. However, this sequence is not based on scientific evidence of its success rates, the technical simplicity, or the related complication rates. Hence, this review critically evaluates the success rate, technique, and safety of different maneuvers. Retrospective reviews showed that posterior arm delivery has consistently higher success rates (86.1%) than rotational methods (62.4%) and external maneuvers (56.0%). McRoberts maneuver was thought to be a simple method, however, its mechanism is not clear. Furthermore, McRoberts position still requires subsequent traction on the fetal neck, which presents a risk for brachial plexus injury. The 2 internal maneuvers have anatomic rationales with the aim of rotating the shoulders to the wider oblique pelvic dimension or reducing the shoulder width. The techniques are not more sophisticated and requires the accoucher to insert the correct hand (according to fetal face direction) through the more spacious sacro-posterior region and deep enough to reach the fetal chest or posterior forearm. The performance of rotation and posterior arm delivery can also be integrated and performed using the same hand. Retrospective studies may give a biased view that the internal maneuvers are riskier. First, a less severely impacted shoulder dystocia is more likely to have been managed by external maneuvers, subjecting more difficult cases to internal maneuvers. Second, neonatal injuries were not necessarily caused by the internal maneuvers that led to delivery but could have been caused by the preceding unsuccessful external maneuvers. The procedural safety is not primarily related to the nature of the maneuvers, but to how properly these maneuvers are performed. When all these maneuvers have failed, it is important to consider the reasons for failure otherwise repetition of the maneuver cycle is just a random trial and error. If the posterior axilla is just above the pelvic outlet and reachable, posterior axilla traction using either the accoucher fingers or a sling is a feasible alternative. Its mechanism is not just outward traction but also rotation of the shoulders to the wider oblique pelvic dimension. If the posterior axilla is at a higher sacral level, a sling may be formed with the assistance of a long right-angle forceps, otherwise, more invasive methods such as Zavanelli maneuver, abdominal rescue, or symphysiotomy are the last resorts.

The use of bubble charts in analyzing second stage cesarean delivery rates

BACKGROUND

The incidence of second stage cesarean delivery has been rising globally because of the failure or the anticipated difficulty of performing instrumental delivery. Yet, the best way to interpret the figure and its optimal rate remain to be determined. This is because it is strongly influenced by the practice of other 2 modes of birth, namely cesarean delivery performed before reaching the second stage and assisted vaginal birth during the second stage. In this regard, a bubble chart that can display 3-dimensional data through its x-axis, y-axis, and the size of each plot (presented as a bubble) may be a suitable method to evaluate the relationship between the rates of these 3 modes of births.

OBJECTIVE

This study aimed to conduct an epidemiologic study on the incidence of second stage cesarean deliveries rates among >300,000 singleton term births in 10 years from 8 obstetrical units and to compare their second stage cesarean delivery rates in relation to their pre-second stage cesarean delivery rates and assisted vaginal birth rates using a bubble chart.

STUDY DESIGN

The territory-wide birth data collected between 2009 and 2018 from all 8 public obstetrical units (labelled as A to H) were reviewed. The inclusion criteria were all singleton pregnancies with cephalic presentation that were delivered at term (≥37 weeks' gestation). Pre-second stage cesarean delivery rate was defined as all elective cesarean deliveries and those emergency cesarean deliveries that occurred before full cervical dilatation was achieved as a proportion of the total number of births. The second stage cesarean delivery rate and assisted vaginal birth rate were calculated according to the respective mode of delivery as a proportion of the number of cases that reached full cervical dilatation. The rates of these 3 modes of births were compared among the parity groups and among the 8 units. Using a bubble chart, each unit's second stage cesarean delivery rate (y-axis) was plotted against its pre-second stage cesarean delivery rate (x-axis) as a bubble. Each unit's second stage cesarean delivery to assisted vaginal birth ratio was represented by the size of the bubble.

RESULTS

During the study period, a total of 353,434 singleton cephalic presenting term pregnancies were delivered in the 8 units, and 180,496 (51.1%) were from nulliparous mothers. When compared with the multiparous group, the nulliparous group had a significantly lower pre-second stage cesarean delivery rate (18.58% vs 21.26%; P<.001) but a higher second stage cesarean delivery rate (0.79% vs 0.22%; P<.001) and a higher assisted vaginal birth rate (17.61% vs 3.58%; P<.001). Using the bubble of their averages as a reference point in the bubble chart, the 8 units' bubbles were clustered into 5 regions indicating their differences in practice: unit B and unit H were close to the average in the center. Unit A and unit F were at the upper right corner with a higher pre-second stage cesarean delivery rate and second stage cesarean delivery rate. Unit D and unit E were at the opposite end. Unit C was at the upper left corner with a low pre-second stage cesarean delivery rate but a high second stage cesarean delivery rate, whereas unit G was at the opposite end. Unit C and unit G were also in the extremes in terms of pre-second stage cesarean delivery to assisted vaginal birth ratio (0.09 and 0.01, respectively). Although some units seemed to have very similar second stage cesarean delivery rates, their obstetrical practices were differentiated by the bubble chart.

CONCLUSION

The second stage cesarean delivery rate must be evaluated in the context of the rates of pre-second stage cesarean delivery and assisted vaginal birth. A bubble chart is a useful method for analyzing the relationship among these 3 variables to differentiate the obstetrical practice between different units.

Longitudinal evaluation of cervical length and shear wave elastography in women with spontaneous preterm birth

OBJECTIVES

To compare longitudinal changes in cervical length (CL) and mean cervical shear wave elastography (CSWE) scores between women with singleton and twin pregnancies who experience spontaneous preterm birth (sPTB) and those who have term births (TB).

METHODS

This was a prospective longitudinal study of 1264 unselected women with singleton (n=1143) and twin (n=121) pregnancy attending a dedicated research clinic for screening of sPTB at 4 timepoints during pregnancy including 11-15+6 (visit 1), 16-20+6 (visit 2), 21-24+6 (visit 3) and 28-32+6 (visit 4) weeks of gestation. At each visit, a transvaginal ultrasound scan was conducted to measure the CL and the CSWE scores from six regions of interest (ROI) (inner, middle, and external parts of anterior and posterior lips) in the cervix. The mean of CSWE scores from the six ROIs were calculated for data analysis. Log10 transformation was applied to make the data Gaussian prior to statistical analysis. A multilevel mixed-effects analysis was performed to compare CL and CSWE longitudinally between sPTB and TB groups.

RESULTS

A total of 57 (4.99%) singleton pregnancies and 33 (27.27%) twin pregnancies were complicated with sPTB. Women with sPTB had shorter CL across gestation when controlling for history of cervical surgery, number of fetuses, gestational age at cervical assessment (GA), and the interaction between GA and sPTB. CL in the sPTB group was significantly lower than that of the TB group at 21-24+6 weeks (p=0.039) and 28-32+6 weeks (p<0.001). Twin pregnancies had significantly longer CL throughout pregnancy, compared to singleton pregnancies (coefficient=0.01864, p<0.001). Furthermore, after adjusting for maternal age, weight, height, body mass index (BMI), and GA, CSWE scores in sPTB group were significantly lower in the sPTB group across gestation, compared to the TB group (1.28265 vs 1.32832; p=0.013). However, in the individual visit analysis, CSWE scores in the sPTB group were significantly lower than that of the TB group only at 11-15+6 weeks (p=0.013). There was no difference in CSWE scores between singleton and twin pregnancies throughout pregnancy (coefficient=-0.00128, p=0.937).

CONCLUSION

Women with sPTB have shorter CL and softer cervix across gestation when compared to those with TB. In the individual visit analysis, the reduction in CL in the sPTB group occurs from late second trimester onwards, while the reduction in cervical stiffness in the sPTB group is observed primarily in the first trimester. Additionally, our study has found that CL is significantly shorter in singleton pregnancies compared to twin pregnancies, while cervical stiffness does not differ between the two types of pregnancy. Our findings indicate that the cervix tends to undergo a softening process prior to shortening in the sPTB cases This article is protected by copyright. All rights reserved.

The use of bubble charts in analyzing the global second-stage cesarean delivery rates: a systematic review

OBJECTIVE

This study aimed to systematically review the worldwide second-stage cesarean delivery rate concerning pre-second-stage cesarean delivery and assisted vaginal birth rates.

DATA SOURCES

PubMed, Medline Ovid, EBSCOhost, Embase, Scopus, and Google Scholar were queried from inception to February 2023, with the following terms: "full dilatation," "second stage," and "cesarean," with their word variations. Furthermore, an additional cohort of 353,434 cases from our recently published study was included.

STUDY ELIGIBILITY CRITERIA

Only original studies that provided sufficient information on the number of pre-second-stage cesarean deliveries, second-stage cesarean deliveries, and vaginal births were included for the calculation of different modes of delivery. Systemic reviews, meta-analyses, or case reports were excluded.

METHODS

Study identification and data extraction were independently performed by 2 authors. Selected studies were categorized on the basis of parity, study period, and geographic regions for comparison.

RESULTS

A total of 25 studies were included. The overall pre-second-stage cesarean delivery rate, the second-stage cesarean delivery rate, and the second-stage cesarean delivery-to-assisted vaginal birth ratio were 17.94%, 2.65%, and 0.19, respectively. Only 5 studies described singleton, term, cephalic presenting pregnancies of nulliparous women, and their second-stage cesarean delivery rates were significantly higher than those studies with cohorts of all parity groups (4.50% vs 0.83%; P<.05). In addition, the second-stage cesarean delivery rate showed a secular increase across 2009 (0.70% vs 1.05%; P<.05). Moreover, it was the highest among African studies (5.14%) but the lowest among studies from East Asia and South Asia (0.94%). The distributions of second-stage cesarean delivery rates of individual studies and subgroups were shown with that of pre-second-stage cesarean delivery and assisted vaginal birth using the bubble chart.

CONCLUSION

The overall worldwide pre-second-stage cesarean delivery rate was 17.94%, the second-stage cesarean delivery rate was 2.65%, and the second-stage cesarean delivery-to-assisted vaginal birth ratio was 0.19. The African studies had the highest second-stage cesarean delivery rate (5.14%) and second-stage cesarean delivery-to-assisted vaginal birth ratio (1.88), whereas the studies from East Asia and South Asia were opposite (0.94% and 0.11, respectively).

Long-term trends in the incidence and management of shoulder dystocia in a tertiary obstetric unit in Hong Kong

INTRODUCTION

Because there have been changes in the management of macrosomic pregnancies and shoulder dystocia in the past decade, this study was conducted to compare the incidences of shoulder dystocia and perinatal outcomes between the periods of 2000-2009 and 2010-2019.

METHODS

This retrospective study was conducted in a tertiary obstetric unit. All cases of shoulder dystocia were identified using the hospital's electronic database. The incidences, maternal and fetal characteristics, obstetric management methods, and perinatal outcomes were compared between the two study periods.

RESULTS

The overall incidence of shoulder dystocia decreased from 0.23% (134/58 326) in 2000-2009 to 0.16% (108/65 683) in 2010-2019 (P=0.009), mainly because of the overall decline in the proportion of babies with macrosomia (from 3.3% to 2.3%; P<0.001). The improved success rates of the McRoberts' manoeuvre (from 31.3% to 47.2%; P=0.012) and posterior arm extraction (from 52.9% to 92.3%; P=0.042) allowed a greater proportion of affected babies to be delivered within 2 minutes (from 59.0% to 79.6%; P=0.003). These changes led to a significant reduction in the proportion of fetuses with low Apgar scores: <5 at 1 minute of life (from 13.4% to 5.6%; P=0.042) and <7 at 5 minutes of life (from 11.9% to 4.6%; P=0.045).

CONCLUSION

More proactive management of macrosomic pregnancies and enhanced training in the acute management of shoulder dystocia led to significant improvements in shoulder dystocia incidence and perinatal outcomes from 2000-2009 to 2010-2019.

Low-Pass Genome Sequencing-Based Detection of Paternity: Validation in Clinical Cytogenetics

Submission of a non-biological parent together with a proband for genetic diagnosis would cause a misattributed parentage (MP), possibly leading to misinterpretation of the pathogenicity of genomic variants. Therefore, a rapid and cost-effective paternity/maternity test is warranted before genetic testing. Although low-pass genome sequencing (GS) has been widely used for the clinical diagnosis of germline structural variants, it is limited in paternity/maternity tests due to the inadequate read coverage for genotyping. Herein, we developed rapid paternity/maternity testing based on low-pass GS with trio-based and duo-based analytical modes provided. The optimal read-depth was determined as 1-fold per case regardless of sequencing read lengths, modes, and library construction methods by using 10 trios with confirmed genetic relationships. In addition, low-pass GS with different library construction methods and 1-fold read-depths were performed for 120 prenatal trios prospectively collected, and 1 trio was identified as non-maternity, providing a rate of MP of 0.83% (1/120). All results were further confirmed via quantitative florescent PCR. Overall, we developed a rapid, cost-effective, and sequencing platform-neutral paternity/maternity test based on low-pass GS and demonstrated the feasibility of its clinical use in confirming the parentage for genetic diagnosis.

Deficits in neural encoding of speech in preterm infants

Preterm children show developmental cognitive and language deficits that can be subtle and sometimes undetectable until later in life. Studies of brain development in children who are born preterm have largely focused on vascular and gross anatomical characteristics rather than pathophysiological processes that may contribute to these developmental deficits. Neural encoding of speech as reflected in EEG recordings is predictive of future language development and could provide insights into those pathophysiological processes. We recorded EEG from 45 preterm (≤ 34 weeks of gestation) and 45 term (≥ 38 weeks) Chinese-learning infants 0-12 months of (corrected) age during natural sleep. Each child listened to three speech stimuli that differed in lexically meaningful pitch (2 native and 1 non-native speech categories). EEG measures associated with synchronization and gross power of the frequency following response (FFR) were examined. ANCOVAs revealed no main effect of stimulus nativeness but main effects of age, consistent with earlier studies. A main effect of prematurity also emerged, with synchronization measures showing stronger group differences than power. By detailing differences in FFR measures related to synchronization and power, this study brings us closer to identifying the pathophysiological pathway to often subtle language problems experienced by preterm children.

Mate-pair genome sequencing reveals structural variants for idiopathic male infertility

Currently, routine genetic investigation for male infertility includes karyotyping analysis and PCR for Y chromosomal microdeletions to provide prognostic information such as sperm retrieval success rate. However, over 85% of male infertility remain idiopathic. We assessed 101 male patients with primary infertility in a retrospective cohort analysis who have previously received negative results from standard-of-care tests. Mate-pair genome sequencing (large-insert size library), an alternative long-DNA sequencing method, was performed to detect clinically significant structural variants (SVs) and copy-number neutral absence of heterozygosity (AOH). Candidate SVs were filtered against our in-house cohort of 1077 fertile men. Genes disrupted by potentially clinically significant variants were correlated with single-cell gene expression profiles of human fetal and postnatal testicular developmental lineages and adult germ cells. Follow-up studies were conducted for each patient with clinically relevant finding(s). Molecular diagnoses were made in 11.1% (7/63) of patients with non-obstructive azoospermia and 13.2% (5/38) of patients with severe oligozoospermia. Among them, 12 clinically significant SVs were identified in 12 cases, including five known syndromes, one inversion, and six SVs with direct disruption of genes by intragenic rearrangements or complex insertions. Importantly, a genetic defect related to intracytoplasmic sperm injection (ICSI) failure was identified in a patient with non-obstructive azoospermia, illustrating the additional value of an etiologic diagnosis in addition to determining sperm retrieval rate. Our study reveals a landscape of various genomic variants in 101 males with idiopathic infertility, not only advancing understanding of the underlying mechanisms of male infertility, but also impacting clinical management.

Case report: prenatal recurrent microcephaly and corpus callosum abnormalities in a Chinese family with novel biallelic SASS6 mutations

INTRODUCTION

Primary microcephaly (MCPH) is not an uncommon disorder with multiple etiologies. There is a growing number of MCPH-related genes discovered due to the extensive application of whole-exome sequencing (WES) in clinical and research settings. Biallelic mutations in the SASS6 gene cause an extremely rare MCPH, type 14. To date, only two families with SASS6 gene-related microcephaly have been reported.

CASE DESCRIPTION

We report a case of recurrent congenital microcephaly in a Chinese family. The two affected fetuses presented with microcephaly early in the second trimester with agenesis of the corpus callosum. In the first affected fetus, trio WES detected two compound heterozygous candidate variants c.1139T>C(p.L380P) and c.1223C>G (p.T408S) in the SASS6 gene. Another affected fetus also inherited both variants, while the normal child carried neither variant through Sanger sequencing analysis. Both variants were classified as a variant of uncertain significance according to the current American College of Medical Genetics and Genomics guidelines.

CONCLUSION

We reported novel biallelic variants in the SASS6 gene, encoding the SAS6 centriolar assembly protein, associated with prenatal onset of autosomal recessive microcephaly. We postulate that the pathomechanism of the compound heterozygous variants in close proximity could potentiate the overall coiled instability leading to the phenotypic features of our case.

Neonatal outcome of infants with umbilical cord arterial pH less than 7

INTRODUCTION

Umbilical arterial pH of less than 7 is often used as the threshold below which the risks of neonatal death and adverse long-term neurological outcomes are considered to be higher. Yet within the group with pH <7, the risks have not been further stratified. Here, we aimed to investigate the predictors of adverse long-term outcomes of this group of infants.

MATERIAL AND METHODS

This was a retrospective study of 248 infants born after 34 weeks of gestation in a tertiary obstetric unit, between 2003 and 2017, with cord arterial pH <7 or base excess ≤-12 mmol/L at birth. The infants were categorized into two groups: (1) intact survivors, or (2) neonatal/infant deaths or cerebral palsy or developmental delay. The umbilical arterial pH and base excess levels, Apgar scores, mode of delivery, gestational age, small for gestational age, birth in the era before the implementation of neonatal hypothermic therapy, and the presence of a known sentinel event, were compared between the groups using univariate analysis followed by multivariate analysis.

RESULTS

Among the 248 infants, there were 222 intact survivors (89.5%) and 26 infants with poor outcomes (10.5%), including eight deaths (3.2%) and 18 (7.3%) with cerebral palsy and/or developmental delay. Univariate analysis showed that infants with adverse outcomes had significantly lower cord arterial pH (6.85 vs 6.95, with p < 0.001), lower cord arterial base excess (-19.95 vs -15.90 mmol/L, p < 0.001), a higher proportion of having AS at 5 min <7 (65.4% vs 13.1%, p < 0.001), and a higher proportion of having a sentinel event (34.6% vs 16.7%, p = 0.034). Multivariate analysis confirmed cord arterial pH of <6.9 and an Apgar score at 5 min <7 as independent prognostic factors (the adjusted odds ratios were 4.64 and 6.62, respectively). The risk of adverse outcome increased from 4.3% when the arterial pH was between 6.9 and <7, to 30% when the pH was <6.9.

CONCLUSIONS

Infants born with umbilical artery pH <7 still have a high chance of 89.5% to become intact survivors. A cord arterial pH of <6.9 and an Apgar score at 5 min <7 are independent prognostic factors for neonatal/infant death or adverse long-term neurological outcomes.

Neonatal mortality in singleton pregnancies: a 20-year retrospective study from a tertiary perinatal unit in Hong Kong

INTRODUCTION

The global neonatal death (NND) rate has been declining in recent decades, but there are no comprehensive data concerning the characteristics of NNDs in Hong Kong. This study investigated the trends and aetiologies of NNDs among singleton pregnancies in Hong Kong.

METHODS

This study included all cases of NND from singleton pregnancies in a tertiary hospital in Hong Kong between 2000 and 2019. The rates, clinical characteristics, and aetiologies of NND were compared between the first (2000-2009) and the second (2010-2019) decades.

RESULTS

The NND rate decreased from 1.66/1000 livebirths (97 cases) in the first decade to 1.32/1000 livebirths (87 cases) in the second decade. Congenital or genetic abnormalities (82 cases) caused 44.6% of all NNDs. There was a significant reduction from 0.82/1000 livebirths in the first decade to 0.52/1000 livebirths in the second decade (P=0.037). Other causes of NND were prematurity (69 cases; 37.5%), sepsis (16 cases; 8.7%), hypoxic-ischaemic encephalopathy (15 cases; 8.2%), and sudden infant death syndrome (2 cases; 1.1%). Gestational age-specific neonatal mortality for moderately preterm neonates (31-33 weeks of gestation) significantly decreased from 34.73/1000 in 2000-2009 to 8.63/1000 in 2010-2019 (P=0.001), but there were no significant changes in neonatal mortality for other gestations.

CONCLUSION

The NND rate in Hong Kong is among the lowest worldwide. Neonatal deaths in our centre declined over the past two decades, mainly because of improvements in the prenatal diagnosis and treatment of congenital or genetic abnormalities, as well as an improved survival rate among moderately preterm neonates.

The view of Hong Kong parents on secondary use of dried blood spots in newborn screening program

Background

Residual dried blood spots (rDBS) from newborn screening programmes represent a valuable resource for medical research, from basic sciences, through clinical to public health. In Hong Kong, there is no legislation for biobanking. Parents’ view on the retention and use of residual newborn blood samples could be cultural-specific and is important to consider for biobanking of rDBS.

Objective

To study the views and concerns on long-term storage and secondary use of rDBS from newborn screening programmes among Hong Kong Chinese parents.

Methods

A mixed-method approach was used to study the views and concerns on long-term storage and secondary use of rDBS from newborn screening programmes among Hong Kong Chinese parents of children 0–3 years or expecting parents through focus groups (8 groups; 33 participants) and a survey (n = 1012, 85% mothers) designed with insights obtained from the focus groups. We used framework analysis to summarise the themes as supportive factors, concerns and critical arguments for retention and secondary use of rDBS from focus group discussion. We used multiple logistic regression to assess factors associated with support for retention and secondary use of rDBS in the survey.

Results

Both in focus groups and survey, majority of parents were not aware of the potential secondary use of rDBS. Overall secondary use of rDBS in medical research was well accepted by a large proportion of Hong Kong parents, even if all potential future research could not be specified in a broad consent. However parents were concerned about potential risks of biobanking rDBS including leaking of data and mis-use of genetic information. Parents wanted to be asked for permission before rDBS are stored and mainly did not accept an “opt-out” approach. The survey showed that parents born in mainland China, compared to Hong Kong born parents, had lower awareness of newborn screening but higher support in biobanking rDBS. Higher education was associated with support in rDBS biobanking only among fathers.

Conclusion

Long-term storage and secondary use of rDBS from newborn screening for biomedical research and a broad consent for biobanking of rDBS are generally acceptable to Hong Kong parents given their autonomy is respected and their privacy is protected, highlighting the importance of an accountable governance and a transparent access policy for rDBS biobanks.

Perinatal mortality rate in multiple pregnancies: a 20-year retrospective study from a tertiary obstetric unit in Hong Kong

INTRODUCTION

Multiple pregnancies have become more common, but their perinatal mortality rate remains higher than the rate among singleton pregnancies. This retrospective study investigated the prevalence and causes of perinatal mortality among multiple pregnancies in Hong Kong.

METHODS

All multiple pregnancies in a university tertiary obstetric unit between 2000 and 2019 were reviewed, and the medical records of cases complicated by stillbirth and neonatal death were identified. The causes of perinatal mortality were determined based on clinical assessment and laboratory results, then compared between the first (2000-2009) and second (2010-2019) decades.

RESULTS

The prevalence of multiple pregnancies increased from 1.41% in the first decade to 1.91% in the second decade (P<0.001). Compared with the first decade, the second decade had a lower stillbirth rate (14.72 vs 7.68 [both per 1000 births]; P=0.026), late neonatal death rate (4.78 vs 1.16 [both per 1000 livebirths]; P=0.030), and total mortality rate (25.32 vs 13.82 [both per 1000 births]; P=0.006). The decline in stillbirth rate was related to improvements in antenatal care and treatment. The decline in the late neonatal death rate was related to a reduction in preterm birth before 34 weeks (18.5% vs 15.2%; P=0.006), as well as an improvement in the mortality rate in the subgroup of 31-33 weeks (19.23 vs 0 [both per 1000 livebirths]; P=0.035).

CONCLUSION

Although the prevalence of multiple pregnancies increased during the study period, the corresponding total perinatal mortality rate improved by 45.4%.

Impact of replacing or adding pregnancy-associated plasma protein-A at 11-13 weeks on screening for preterm pre-eclampsia

OBJECTIVE

To assess whether pregnancy-associated plasma protein-A (PAPP-A) alters or provides equivalent screening performance as placental growth factor (PlGF) when screening for preterm pre-eclampsia (PE) at 11-13 weeks of gestation.

METHODS

This was a secondary analysis of a non-intervention screening study of 6546 singleton pregnancies that were screened prospectively for preterm PE in the first trimester between December 2016 and June 2018. Patient-specific risks for preterm PE were estimated by maternal history, mean arterial pressure (MAP), uterine artery pulsatility index (UtA-PI), PlGF and PAPP-A. A competing-risks model with biomarkers expressed as multiples of the median was used. All women and clinicians were blinded to the risk for preterm PE. The performance of screening for preterm PE using PlGF vs PAPP-A vs both PAPP-A and PlGF was assessed by comparing areas under the receiver-operating-characteristics (AUC) curves. McNemar's test was used to compare detection rate at a fixed false-positive rate (FPR) of 10%.

RESULTS

PlGF and PAPP-A were measured in 6546 women, of whom 37 developed preterm PE. The AUC and detection rate at 10% FPR using PlGF in combination with maternal history, MAP and UtA-PI were 0.854 and 59.46%, respectively. The respective values were 0.813 and 51.35% when replacing PlGF with PAPP-A and 0.855 and 59.46% when using both PAPP-A and PlGF. Statistically non-significant differences were noted in AUC when replacing PlGF with PAPP-A (ΔAUC, 0.04; P = 0.095) and when using both PAPP-A and PlGF (ΔAUC, 0.002; P = 0.423). However, on an individual case basis, screening using PlGF in conjunction with maternal history, MAP and UtA-PI identified three (8.1%) additional pregnancies that developed preterm PE and that were not identified when replacing PlGF with PAPP-A. Screening using PAPP-A in addition to maternal history and other biomarkers did not identify any additional pregnancies.

CONCLUSION

On an individual case basis, adoption of a screening strategy that uses PAPP-A instead of PlGF results in reduced detection of preterm PE, consistent with previous literature. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

First trimester screening for gestational diabetes mellitus with maternal factors and biomarkers

Introduction: This study aimed to identify risk factors among maternal characteristics, obstetric history and first trimester preeclampsia-specific biomarkers that were associated with subsequent development of gestational diabetes mellitus (GDM) and evaluate the performance of the prediction models. Methods: Secondary analysis of a prospective cohort study. The performance of the prediction models was assessed by area under receiver operating characteristic curve (AUROC). Results: A total of 837 (8.9%) cases of GDM and 8535 (91.1%) unaffected cases were included. The AUROC of the prediction model combining maternal characteristics and obstetric history (0.735) was better than that of the model utilizing maternal characteristics (AUROC 0.708) and preeclampsia-specific biomarkers (AUROC 0.566). Amongst the preeclampsia-specific biomarkers, the mean arterial pressure (MAP) contributed to the increasing risk of GDM, however, its addition did not improve the AUROC of the model combining maternal characteristics and obstetric history (0.738). Conclusion: The first trimester prediction model for GDM with maternal characteristics and obstetric history achieves moderate predictability. The inclusion of MAP in the model combining maternal characteristics and obstetric history does not improve the screening performance for GDM. Future studies are needed to explore the effect of blood pressure control from early pregnancy on preventing GDM.

Case Report: Novel Biallelic Variants in the COL18A1 Gene in a Chinese Family With Knobloch Syndrome

Knobloch syndrome is a rare collagenopathy characterized by severe early onset myopia, retinal detachment, and occipital encephalocele with various additional manifestations due to biallelic changes in the COL18A1 gene. Here we reported a Chinese family with two affected siblings presented with antenatal occipital encephalocele, infantile onset retinal detachment, and pronounced high myopia at early childhood. Quartet whole exome sequencing was performed in this family and identified that both siblings carried novel compound heterozygous variants in the COL18A1 gene (NM_001379500.1): the maternally inherited variant c.1222-1G>A at the consensus acceptor splice site of intron 8, and the paternally inherited frameshift variant c.3931_3932delinsT p.(Gly1311Serfs^*25) in the last exon. Both patients had successful surgical treatment for the occipital encephalocele soon after birth. They had normal neurocognitive outcome and good general conditions examined at the age of 7 years old for the elder sister and 4 years old for the younger brother. The younger brother developed infantile onset retinal detachment at 7 months of age while the sister had high myopia without signs of retinal detachment until 7 years old. This report expands the phenotype and genotype spectrum of Knobloch syndrome with antenatal and postnatal findings.

Dynamic changes in maternal immune biomarkers during labor in nulliparous vs multiparous women

BACKGROUND

Immunomodulation is observed in human parturition. However, data from longitudinal studies for the prelabor phase and the active phase of labor are lacking, and no study had compared the immune responses during labor between nulliparous and multiparous women.

OBJECTIVE

This study aimed to investigate the temporal changes of immune biomarkers in maternal blood from the prelabor phase to the latent and active phases of labor and to compare the dynamic changes between nulliparous and multiparous women.

STUDY DESIGN

A prospective case-control study was conducted on women who had induction of labor at term followed by vaginal delivery. Maternal blood was serially collected at 3 consecutive time points: (1) before the onset of labor, (2) during the latent phase of labor, and (3) during the active phase of labor. Peripheral immune cells were measured by 4-color flow cytometry, and the plasma concentrations of cytokines and chemokines were measured by cytometric bead arrays. A longitudinal comparison was made to assess the dynamic changes in inflammatory parameters over 3 time points in nulliparous and multiparous women, respectively, and a cross-sectional comparison was made between nulliparous and multiparous women.

RESULTS

A total of 40 women, including 20 nulliparous and 20 multiparous, were included in the study. Prelabor circulating levels of macrophage inflammatory protein-1β, monokine induced by gamma interferon, and interferon gamma-induced protein-10 were higher in multiparous women than in nulliparous women. In the latent phase of labor, the innate immune system in both groups responded with increases in neutrophils and interleukin 6, and the nulliparous women showed a more pronounced response. During the active phase of labor, such innate immune response continued with both groups, with additional increases in natural killer cells, monocyte chemoattractant protein-1, interleukin 8, and interleukin 10. Conversely, the adaptive immune system in nulliparous women showed a reduction in both cytotoxic and helper T cells, whereas the adaptive immune system in multiparous women only had a reduction in helper T cells, showing a smaller reduction.

CONCLUSION

Innate and adaptive immune responses partake in immunomodulation during human parturition. Nulliparous and multiparous women showed different responses in their blood levels of immune cells and biomarkers during the different phases of labor.

The impact of antenatal massage practice on intrapartum massage application and their associations with the use of analgesics during labour : Sub-analysis of a randomised control trial

Background

Massage during labour is one form of intrapartum non-pharmacological pain relief but it is not known whether the frequency of practicing these massage techniques among couples during the antenatal period could enhance the effectiveness of intrapartum massage. This study was to evaluate the association between compliance of antenatal massage practice with intrapartum application and their impact on the use of analgesics during labour.

Methods

This was a sub-analysis of a childbirth massage programme which was carried out in two public hospitals with total births of around 8000 per year. Data from women who were randomized to the massage group were further analysed. After attending the pre-birth training class on massage at 36 weeks gestation, couples would be encouraged to practice at home. Their compliance with massage at home was classified as good if they had practiced for at least 15 minutes for three or more days in a week, or as poor if the three-day threshold had not been reached. Application of intrapartum massage was quantified by the duration of practice divided by the total duration of the first stage of labour. Women’s application of intrapartum massage were then divided into above and below median levels according to percentage of practice. Logistic regression was used to assess the use of epidural analgesia or pethidine, adjusted for duration of labour and gestational age when attending the massage class.

Results

Among the 212 women included, 103 women (48.6%) achieved good home massage compliance. No significant difference in the maternal characteristics or birth outcomes was observed between the good and poor compliance groups. The intrapartum massage application (median 21.1%) was inversely associated with duration of first stage of labour and positively associated with better home massage practice compliance (p = 0.04). Lower use of pethidine or epidural analgesia (OR 0.33 95% CI 0.12, 0.90) was associated with above median intrapartum massage application but not antenatal massage compliance, adjusted for duration of first stage of labour.

Conclusions

More frequent practice of massage techniques among couples during antenatal period could enhance the intrapartum massage application, which may reduce the use of pethidine and epidural analgesia.

Trial registration

(CCRBCTR) Unique Trial Number CUHK_ CCRB00525.

Mentoring a surgical team towards procedural competence in the early learning curve for selective fetoscopic laser photocoagulation

INTRODUCTION

Selective fetoscopic laser photocoagulation (SFLP) for twin-to-twin transfusion syndrome (TTTS) is challenging for new surgeons at the start of their learning curve. We described an approach utilising telementoring and team-based training to facilitate rapid attainment of the skills required for safe and efficient practice with a limited caseload.

METHODS

We conducted a prospective observational study of SFLP performed by the novice primary surgical team in three stages: under direct on-site supervision from an expert mentor (Group 1), with remote tele-guidance from that mentor (Group 2) and independently (Group 3), at an academic tertiary hospital in Singapore. The primary team undertook regular training on high-fidelity tissue models to accelerate skills acquisition and complement the surgical performance.

RESULTS

9 patients diagnosed with Stage 2 TTTS were assessed for procedural characteristics, surgical outcomes and perinatal survival following SFLP. There were no significant differences in operative duration, anastomoses ablated, gestational age or birth weight at delivery. The complications observed were: recurrent TTTS (22.2% of pregnancies), twin anaemia polycythaemia sequence (33.3%), preterm prelabour membrane rupture (22.2%) and delivery at < 32 weeks (44.4%). ≥ 1 twin was live-born in 88.9% of cases, while postnatal survival to six months of ≥ 1 twin occurred in 77.8% of cases.

CONCLUSION

Systematic mentoring and specialised skills training are useful in aiding new surgeons to negotiate the steep learning curve and achieve good outcomes at the start of a new practice, particularly in the setting of low patient numbers. This is best paired with dedicated model training to achieve and maintain surgical dexterity for this complex procedure.

Screening for spontaneous preterm birth by cervical length and shear-wave elastography in the first trimester of pregnancy

BACKGROUND

First-trimester cervical length for the prediction of spontaneous preterm delivery remains controversial. A better method for the measurement of the first-trimester cervical length and additional cervical ultrasound parameters for the identification of women at high risk for spontaneous preterm delivery are needed.

OBJECTIVE

This study aimed to compare the predictive value of cervical length measured by 2 different methods in the first trimester of pregnancy to predict spontaneous preterm delivery and to explore the potential value of first-trimester cervical shear-wave elastography for the prediction of spontaneous preterm delivery.

STUDY DESIGN

This was a prospective study in unselected singleton pregnancies at 11⁺⁰ to 13⁺⁶ weeks' gestation. Cervical length was measured by the following 2 methods in the base-cohort population: (1) a linear distance between the 2 ends of the glandular area around the endocervical canal (single-line method: cervical length-s) and (2) a sum of the linear distance from the internal os to the greatest cervical curvature and the linear distance from this point to the external os (2-line method: cervical length-t). In a substudy, cervical shear-wave elastography scores for 9 regions of interest (inner, middle, and external parts of anterior lip, endocervical canal, and posterior lip) in midsagittal plane were also obtained by transvaginal ultrasonography. The screening performance of the first-trimester cervical length measured by the 2 different methods for the prediction of spontaneous preterm delivery was assessed by receiver operating characteristics curve analysis. The areas under the curves were compared using a DeLong test. The predictive performance of a soft cervix (mean elastography scores with multiple of median <5th, 10th, 15th, 20th, and 25th percentile) for spontaneous preterm delivery was also determined.

RESULTS

Among a total of 2316 included pregnancies, spontaneous delivery at <37 and <34 weeks' gestation occurred in 111 cases (4.8%) and 20 cases (0.9%), respectively. In the total study population, when compared with the term delivery group, the median cervical length-t was shorter in women with spontaneous delivery at <34 weeks' gestation (36.9 mm vs 35.1 mm; P=.015), but there was no clear correlation for cervical length-s. Receiver operating characteristics curves demonstrated that cervical length-t achieved better performance in predicting spontaneous delivery at <34 weeks' gestation (area under the curve, 0.658 vs 0.573; P<.01) than cervical length-s. The best combined model to predict spontaneous delivery at <34 weeks' gestation was provided by cervical length-t and history of preterm delivery (area under the curve, 0.692). In the substudy, a soft cervix with a mean elastography scores multiple of median <10th percentile had a relative risk of 7.8 (95% confidence interval, 2.1-28.6) for spontaneous delivery at <34 weeks' gestation; the detection rate was 44.4% at a false-positive rate of 9.0%.

CONCLUSION

The 2-line approach provides a better estimate of the actual first-trimester cervical length and achieves better performance as a screening tool for spontaneous preterm delivery at <34 weeks' gestation than the conventional measurement. A soft cervix as determined by shear-wave elastograpthy in the first trimester is associated with an increased risk for subsequent spontaneous preterm delivery.

Non-visualisation of fetal gallbladder in a Chinese cohort

INTRODUCTION

Non-visualisation of fetal gallbladder (NVFGB) is associated with chromosomal abnormalities, biliary atresia, cystic fibrosis, and gallbladder agenesis in Caucasian fetuses. We investigated the outcomes of fetuses with NVFGB in a Chinese cohort.

METHODS

This retrospective analysis included cases of NVFGB among Chinese pregnant women at five public fetal medicine clinics in Hong Kong from 2012 to 2019. We compared the incidences of subsequent gallbladder visualisation, chromosomal abnormalities, biliary atresia, cystic fibrosis, and gallbladder agenesis between cases of isolated NVFGB and cases of non-isolated NVFGB.

RESULTS

Among 19 cases of NVFGB detected at a median gestational age of 21.3 weeks (interquartile range, 20.0-22.3 weeks), 10 (52.6%) were isolated and nine (47.4%) were non-isolated. Eleven (58.0%) cases had transient non-visualisation, four (21.0%) had gallbladder agenesis, three (15.8%) had chromosomal abnormalities (trisomy 18, trisomy 21, and 22q11.2 microduplication), one (5.2%) had biliary atresia, and none had cystic fibrosis. The incidence of serious conditions was significantly higher in the non-isolated group than in the isolated group (44.4% vs 0%; P=0.029); all three cases with chromosomal abnormalities and the only case of biliary atresia were in the non-isolated group, while all four cases with gallbladder agenesis were in the isolated group. The incidences of transient non-visualisation were similar (55.6% vs 60.0%; P=1.000).

CONCLUSION

Isolated NVFGB is often transient or related to gallbladder agenesis. While investigations for chromosomal abnormalities and biliary atresia are reasonable in cases of NVFGB, testing for cystic fibrosis may be unnecessary in Chinese fetuses unless the NVFGB is associated with consistent ultrasound features, significant family history, or consanguinity.

Exploring the diagnostic utility of genome sequencing for fetal congenital heart defects

OBJECTIVE

The diagnostic yield for congenital heart defects (CHD) with routine genetic testing is around 10-20% when considering the pathogenic CNVs or aneuploidies as positive findings. This is a pilot study to investigate the utility of genome sequencing (GS) for prenatal diagnosis of CHD.

METHODS

Genome sequencing (GS, 30X) was performed on 13 trios with CHD for which karyotyping and/or chromosomal microarray results were non-diagnostic.

RESULTS

Trio GS provided a diagnosis for 4/13 (30.8%) fetuses with complex CHDs and other structural anomalies. Findings included pathogenic or likely pathogenic variants in DNAH5, COL4A1, PTPN11, and KRAS. Of nine cases without a possibly genetic etiology by GS, we had follow-up on eight. For five of them (60%), the parents chose to keep the pregnancy. A balanced translocation [46,XX,t(14;22)(q32.33;q13.31)mat] was detected in a trio with biallelic DNAH5 mutations, which together explained the recurrent fetal situs inversus and dextrocardia that was presumably due to de novo Phelan-McDermid syndrome. A secondary finding of a BRCA2 variant and carrier status of HBB, USH2A, HBA1/HBA2 were detected in the trio.

CONCLUSIONS

GS expands the diagnostic scope of mutation types over conventional testing, revealing the genetic etiology for fetal heart anomalies. Patients without a known genetic abnormality indicated by GS likely opted to keep pregnancy especially if the heart issue could be repaired. We provide evidence to support the application of GS for fetuses with CHD. This article is protected by copyright. All rights reserved.

Investigation of Chromosomal Structural Abnormalities in Patients With Undiagnosed Neurodevelopmental Disorders

Background: Structural variations (SVs) are various types of the genomic rearrangements encompassing at least 50 nucleotides. These include unbalanced gains or losses of DNA segments (copy number changes, CNVs), balanced rearrangements (such as inversion or translocations), and complex combinations of several distinct rearrangements. SVs are known to play a significant role in contributing to human genomic disorders by disrupting the protein-coding genes or the interaction(s) with cis-regulatory elements. Recently, different types of genome sequencing-based tests have been introduced in detecting various types of SVs other than CNVs and regions with absence of heterozygosity (AOH) with clinical significance.

Method: In this study, we applied the mate-pair low pass (∼4X) genome sequencing with large DNA-insert (∼5 kb) in a cohort of 100 patients with neurodevelopmental disorders who did not receive informative results from a routine CNV investigation. Read-depth-based CNV analysis and chimeric-read-pairs analysis were used for CNV and SV analyses. The region of AOH was indicated by a simultaneous decrease in the rate of heterozygous SNVs and increase in the rate of homozygous SNVs.

Results: First, we reexamined the 25 previously reported CNVs among 24 cases in this cohort. The boundaries of these twenty-five CNVs including 15 duplications and 10 deletions detected were consistent with the ones indicated by the chimeric-read-pairs analysis, while the location and orientation were determined in 80% of duplications (12/15). Particularly, one duplication was involved in complex rearrangements. In addition, among all the 100 cases, 10% of them were detected with rare or complex SVs (&gt;10 Kb), and 3% were with multiple AOH (≥5 Mb) locating in imprinting chromosomes identified. In particular, one patient with an overall value of 214.5 Mb of AOH identified on 13 autosomal chromosomes suspected parental consanguinity.

Conclusion: In this study, mate-pair low-pass GS resolved a significant proportion of CNVs with inconclusive significance, and detected additional SVs and regions of AOH in patients with undiagnostic neurodevelopmental disorders. This approach complements the first-tier CNV analysis for NDDs, not only by increasing the resolution of CNV detection but also by enhancing the characterization of SVs and the discovery of potential causative regions (or genes) contributory to could be complex in composition NDDs.

Determining chorionicity and amnionicity in twin pregnancies: Pitfalls

Although the accuracy of chorioamnionicity determination in multiple pregnancy is nearly 100%, some pitfalls do exist. These pitfalls may arise from some confusing sonographic appearance or because of certain rare variations of twinning going against the general principles. Pitfalls in chorionicity determination include (1) the disappearance of the twin peak sign with the regression of chorion frondosum and thinning of the intertwin membrane with advancing gestation; (2) fake twin peak sign because of other structures creeping into the intertwin membrane-placental junction; (3) intrauterine septum or synechia being mistaken as a thick intertwin membrane; (4) bipartite placenta in monochorionic twin being misinterpreted as two separate placentas of dichorionic twin; (5) erroneous fetal sex determination in sex chromosome mosaicism, monogenic disorders, and malformed genitalia in one fetus; and (6) rare twinning types such as dizygotic monochorionic twin and sesquizygotic twin. Pitfalls in amnionicity determination are (1) the lack of correlation between the number of yolk sacs and amnionicity and (2) failure to visualize the intertwin membrane because of technical issues.

Early Development of Neural Speech Encoding Depends on Age but Not Native Language Status: Evidence From Lexical Tone

We investigated the development of early-latency and long-latency brain responses to native and non-native speech to shed light on the neurophysiological underpinnings of perceptual narrowing and early language development. Specifically, we postulated a two-level process to explain the decrease in sensitivity to non-native phonemes toward the end of infancy. Neurons at the earlier stages of the ascending auditory pathway mature rapidly during infancy facilitating the encoding of both native and non-native sounds. This growth enables neurons at the later stages of the auditory pathway to assign phonological status to speech according to the infant's native language environment. To test this hypothesis, we collected early-latency and long-latency neural responses to native and non-native lexical tones from 85 Cantonese-learning children aged between 23 days and 24 months, 16 days. As expected, a broad range of presumably subcortical early-latency neural encoding measures grew rapidly and substantially during the first two years for both native and non-native tones. By contrast, long-latency cortical electrophysiological changes occurred on a much slower scale and showed sensitivity to nativeness at around six months. Our study provided a comprehensive understanding of early language development by revealing the complementary roles of earlier and later stages of speech processing in the developing brain.

Chromosomal abnormalities and neurological outcomes in fetal cerebral ventriculomegaly: a retrospective cohort analysis

INTRODUCTION

This study investigated the incidences of chromosomal abnormalities and the neurological outcomes according to the degree of fetal cerebral ventriculomegaly.

METHODS

All women with antenatal ultrasound diagnosis of fetal cerebral ventriculomegaly were retrospectively identified from two maternal-fetal medicine units in Hong Kong from January 2014 to December 2018. Degrees of fetal ventriculomegaly were classified as mild (10-11.9 mm), moderate (12-14.9 mm), or severe (≥15 mm). Genetic investigation results were reviewed, including conventional karyotyping and chromosomal microarray analysis (CMA); correlations between chromosomal abnormalities and the degree of fetal ventriculomegaly were explored. The neurological outcomes of subsequent live births were analysed to identify factors associated with developmental delay.

RESULTS

Of 84 cases (ie, pregnant women and their fetuses) included, 46 (54.8%) exhibited isolated fetal ventriculomegaly, 55 (65.5%) had mild cerebral ventriculomegaly, and 29 (34.5%) had moderate or severe cerebral ventriculomegaly. Overall, 20% (14/70) of cases had chromosomal abnormalities. Moreover, 12% (3/25) of mild isolated ventriculomegaly cases had abnormal karyotype or CMA results. The CMA provided an incremental diagnostic yield of 8.6% (6/70), compared with conventional karyotyping; 4.3% exhibited pathogenic variants and 4.3% exhibited variants of uncertain significance. Among the 53 live births in the cohort, fewer cases of mild isolated ventriculomegaly were associated with developmental delay than more severe isolated ventriculomegaly (9.7% vs 41.7%, P<0.03).

CONCLUSIONS

Chromosomal microarray analysis testing should be offered to all women with fetal cerebral ventriculomegaly, including women with isolated mild ventriculomegaly. The incidence of developmental delay after birth increases with the degree of prenatal cerebral ventriculomegaly.

Effectiveness of a childbirth massage programme for labour pain relief in nulliparous pregnant women at term: a randomised controlled trial

INTRODUCTION

The effect of massage for pain relief during labour has been controversial. This study investigated the efficacy of a programme combining intrapartum massage, controlled breathing, and visualisation for non-pharmacological pain relief during labour.

METHODS

This randomised controlled trial was conducted in two public hospitals in Hong Kong. Participants were healthy low-risk nulliparous Chinese women ≥18 years old whose partners were available to learn massage technique. Recruitment was performed at 32 to 36 weeks of gestation; women were randomised to attend a 2-hour childbirth massage class at 36 weeks of gestation or to receive usual care. The primary outcome variable was the intrapartum use of epidural analgesia or intramuscular pethidine injection.

RESULTS

In total, 233 and 246 women were randomised to the massage and control groups, respectively. The use of epidural analgesia or pethidine did not differ between the massage and control groups (12.0% vs 15.9%; P=0.226). Linear-by-linear analysis demonstrated a trend whereby fewer women used strong pharmacological pain relief in the massage group, and a greater proportion of women had analgesic-free labour (29.2% vs 21.5%; P=0.041). Cervical dilatation at the time of pethidine/epidural analgesia request was significantly greater in the massage group (3.8 ± 1.7 cm vs 2.3 ± 1.0 cm; P<0.001).

CONCLUSION

The use of a massage programme appeared to modulate pain perception in labouring women, such that fewer women requested epidural analgesia and a shift was observed towards the use of weaker pain relief modalities; in particular, more women in the massage group were analgesic-free during labour.

Assessment of embryo morphology following perinatal exposure to aspirin, ibuprofen and paracetamol using whole embryo culture system

BACKGROUND

Recent evidence from a meta-analysis indicates that maternal prenatal exposure, single or repeated, to non-steroidal anti-inflammatory drugs (NSAIDs) or non-opioid painkillers, is associated with increased risk of cerebral palsy and cognitive-behavioral disorders in offspring. One potential route of action is interference with the neurulation process and hence early brain development.

OBJECTIVE

To examine the effect of prenatal exposure to common NSAIDs and non-opioid drugs on neurulation using an in vitro whole embryo culture system.

METHODS

Mouse embryos from in-bred Institute of Cancer Research albino strain mice were exteriorized on embryonic day 7.5 and cultured for 48 h in either 1 mL heat-inactivated rat serum + 0.1% dimethyl sulfoxide ("Control") or 1 mL of rat serum supplemented with six increasing concentrations of laboratory-grade aspirin, paracetamol, and ibuprofen ("Experimental"). After culture, embryo morphological and developmental parameters were documented using standardized scoring systems at each dosage concentration. The assessed concentration in rat serum culture ranged from 1.23 to 13.57 mg/mL for aspirin and 0.06-4.93 mg/mL for paracetamol and ibuprofen. The equivalent respective human dosages were 600-6600 mg and 30-2400 mg.

RESULTS

Between-group comparisons ("Control" vs "Experimental") and post-hoc pair-wise tests, adjusted for multiple comparisons, indicating no statistically significant effect on crown-rump length (p > .21), head length (p > .28), somite number (p > .25), incidence of absent hindlimb buds (p > .18), yolk sac circulation score (p > .07) and posterior neuropore closure (p > .35) in the aspirin, paracetamol and ibuprofen experiments. All embryos had forelimb buds, closed anterior neuropores and none had neural tube defects.

CONCLUSION

This study has demonstrated that there are no safety concerns regarding high-dose aspirin, ibuprofen, and paracetamol on mice's embryonic development.

Trio-Based Low-Pass Genome Sequencing Reveals Characteristics and Significance of Rare Copy Number Variants in Prenatal Diagnosis

Background: Low-pass genome sequencing (GS) detects clinically significant copy number variants (CNVs) in prenatal diagnosis. However, detection at improved resolutions leads to an increase in the number of CNVs identified, increasing the difficulty of clinical interpretation and management.

Methods: Trio-based low-pass GS was performed in 315 pregnancies undergoing invasive testing. Rare CNVs detected in the fetuses were investigated. The characteristics of rare CNVs were described and compared to curated CNVs in other studies.

Results: A total of 603 rare CNVs, namely, 597 constitutional and 6 mosaic CNVs, were detected in 272 fetuses (272/315, 86.3%), providing 1.9 rare CNVs per fetus (603/315). Most CNVs were smaller than 1 Mb (562/603, 93.2%), while 1% (6/603) were mosaic. Forty-six de novo (7.6%, 46/603) CNVs were detected in 11.4% (36/315) of the cases. Eighty-four CNVs (74 fetuses, 23.5%) involved disease-causing genes of which the mode of inheritance was crucial for interpretation and assessment of recurrence risk. Overall, 31 pathogenic/likely pathogenic CNVs were detected, among which 25.8% (8/31) were small (<100 kb; n = 3) or mosaic CNVs (n = 5).

Conclusion: We examined the landscape of rare CNVs with parental inheritance assignment and demonstrated that they occur frequently in prenatal diagnosis. This information has clinical implications regarding genetic counseling and consideration for trio-based CNV analysis.

Intrauterine fetal death followed by shoulder dystocia and birth by modified posterior axillary sling method: a case report

Background

Various manoeuvres such as McRoberts position, suprapubic pressure, rotational methods, posterior arm extraction and all-four position (HELPERR) have been proposed for relieving shoulder dystocia with variable success. Posterior axillary sling method using a rubber catheter was proposed in 2009 but has not been widely used. We modified this method using ribbon gauzes and a long right-angle forceps and report a successful case.

Case presentation

A 44 years old parity one Chinese woman with a history of a caesarean delivery and poorly controlled type 2 diabetes mellitus was admitted to the Accident and Emergency Department for advanced stage of labour at term. Upon arrival, intrauterine fetal demise was diagnosed with severe asynclitism causing obstruction at the perineum. Episiotomy resulted in birth of the fetal head. The fetal posterior right shoulder, however, remained very high up in the pelvis and HELPERR methods failed to extract the shoulders. We then tied two long ribbon gauzes together, and guided its knot to the anterior aspect of the posterior axilla. By using a long right-angle forceps (24 cm long) to grasp the knot on the posterior side of the axilla and pulling it through, a sling was formed. Traction was then applied through the sling to simultaneously pull and rotate the posterior shoulder. A stillbirth of 3488 g was finally extracted.

Conclusions

We modified the sling method by using two ribbon gauzes, tied together and a right-angle forceps with several advantages. Compared to a rubber catheter, ribbon gauze with a knot can be easily held between the fingers for easy guidance past the fetal axilla. It is also thin, non-elastic and stiff enough to ensure a good grip for traction. The long and slim design of the right-angle forceps makes it easy to pass through a narrow space and reach the axilla high up in the pelvis. We emphasize simultaneous traction and rotation, so that the shoulders are delivered through the wider oblique pelvic outlet dimension.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04126-4.

Umbilical cord prolapse: revisiting its definition and management

Umbilical cord prolapse is an unpredictable obstetrical emergency with an incidence ranging from 1 to 6 per 1000 pregnancies. It is associated with high perinatal mortality, ranging from 23% to 27% in low-income countries to 6% to 10% in high-income countries. In this review, we specifically addressed 3 issues. First, its definition is not consistent in the current literature, and "occult cord prolapse" is a misnomer because the cord is still above the cervix. We proposed that cord prolapse, cord presentation, and compound cord presentation should be classified according to the positional relationship among the cord, the fetal presenting part, and the cervix. All of them may occur with either ruptured or intact membranes. The fetal risk is highest in cord prolapse, followed by cord presentation, and lastly by compound cord presentation, which replaces the misnomer "occult cord prolapse." Second, the mainstay of treatment of cord prolapse is urgent delivery, which means cesarean delivery in most cases, unless vaginal delivery is imminent. The urgency depends on the fetal heart rate pattern, which can be bradycardia, recurrent decelerations, or normal. It is most urgent in cases with bradycardia, because a recent study showed that cord arterial pH declines significantly with the bradycardia-to-delivery interval at a rate of 0.009 per minute (95% confident interval, 0.0003-0.0180), and this may indicate an irreversible pathology such as vasospasm or persistent cord compression. However, cord arterial pH does not correlate with either deceleration-to-delivery interval or decision-to-delivery interval, indicating that intermittent cord compression causing decelerations is reversible and less risk. Third, while cesarean delivery is being arranged, different maneuvers should be adopted to relieve cord compression by elevating the fetal presenting part and to prevent further cord prolapse beyond the vagina. A recent study showed that the knee-chest position provides the greatest elevation effect, followed by filling of the maternal urinary bladder with 500 mL of fluid, and then the Trendelenburg position (15°) and other maneuvers. However, each maneuver has its own advantages and limitations; thus, they should be applied wisely and with great caution, depending on the actual clinical situation. Therefore, we have proposed an algorithm to guide this acute management.

Transperineal ultrasound assessment of fetal head elevation by maneuvers used for managing umbilical cord prolapse

OBJECTIVE

To assess objectively the degree of fetal head elevation achieved by different maneuvers commonly used for managing umbilical cord prolapse.

METHODS

This was a prospective observational study of pregnant women at term before elective Cesarean delivery. A baseline assessment of fetal head station was performed with the woman in the supine position, using transperineal ultrasound for measuring the parasagittal angle of progression (psAOP), head-symphysis distance (HSD) and head-perineum distance (HPD). The ultrasonographic measurements of fetal head station were repeated during different maneuvers, including elevation of the maternal buttocks using a wedge, knee-chest position, Trendelenburg position with a 15° tilt and filling the maternal urinary bladder with 100 mL, 300 mL and 500 mL of normal saline. The measurements obtained during the maneuvers were compared with the baseline measurements.

RESULTS

Twenty pregnant women scheduled for elective Cesarean section at term were included in the study. When compared with baseline (median psAOP, 103.6°), the knee-chest position gave the strongest elevation effect, with the greatest reduction in psAOP (psAOP, 80.7°; P < 0.001), followed by filling the bladder with 500 mL (psAOP, 89.9°; P < 0.001) and 300 mL (psAOP, 94.4°; P < 0.001) of normal saline. Filling the maternal bladder with 100 mL of normal saline (psAOP, 96.1°; P = 0.001), the Trendelenburg position (psAOP, 96.8°; P = 0.014) and elevating the maternal buttocks (psAOP, 98.3°; P = 0.033) gave modest elevation effects. Similar findings were reported for HSD and HPD. The fetal head elevation effects of the knee-chest position, Trendelenburg position and elevation of the maternal buttocks were independent of the initial fetal head station, but that of bladder filling was greater when the initial head station was low.

CONCLUSIONS

To elevate the fetal presenting part, the knee-chest position provides the best effect, followed by filling the maternal urinary bladder with 500 mL then 300 mL of fluid, respectively. Filling the bladder with 100 mL of fluid, the Trendelenburg position and elevation of the maternal buttocks have modest effects. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Molecular Mechanism and Pathways of Normal Human Parturition in Different Gestational Tissues: A Systematic Review of Transcriptome Studies

Objective: Genome-wide transcriptomic studies on gestational tissues in labor provide molecular insights in mechanism of normal parturition. This systematic review aimed to summarize the important genes in various gestational tissues around labor onset, and to dissect the underlying molecular regulations and pathways that trigger the labor in term pregnancies.

Data sources: PubMed and Web of Science were searched from inception to January 2021.

Study Eligibility Criteria: Untargeted genome-wide transcriptomic studies comparing the gene expression of various gestational tissues in normal term pregnant women with and without labor were included.

Methods: Every differentially expressed gene was retrieved. Consistently expressed genes with same direction in different studies were identified, then gene ontology and KEGG analysis were conducted to understand molecular pathways and functions. Gene-gene association analysis was performed to determine the key regulatory gene(s) in labor onset.

Results: A total of 15 studies, including 266 subjects, were included. 136, 26, 15, 7, and 3 genes were significantly changed during labor in the myometrium (seven studies, n = 108), uterine cervix (four studies, n = 64), decidua (two studies, n = 42), amnion (two studies, n = 44) and placenta (two studies, n = 41), respectively. These genes were overrepresented in annotation terms related to inflammatory and immune responses. TNF and NOD-like receptor signaling pathways were overrepresented in all mentioned tissues, except the placenta. IL6 was the only gene included in both pathways, the most common reported gene in all included studies, and also the gene in the central hub of molecular regulatory network.

Conclusions: This systematic review identified that genes involved in immunological and inflammatory regulations are expressed in specific gestational tissues in labor. We put forward the hypothesis that IL6 might be the key gene triggering specific mechanism in different gestational tissues, eventually leading to labor onset through inducing uterine contraction, wakening fetal membranes and stimulating cervical ripening.

Systematic Review Registration: Identifier [CRD42020187975].

P-064 Application of an artificial intelligence model for morphologic prediction of fertilization-competent human spermatozoa

Study question

What is the role of artificial intelligence in selecting fertilization-competent human spermatozoa according to their morphological characteristics? 

Summary answer

The established AI model in this study can be potentially used to select semen samples with superior fertilization potential in clinical settings.

What is known already

Defective spermatozoa-zona pellucida (ZP) interaction causes subfertility and is a major cause of low IVF fertilization rates. While ICSI benefits patients with defective spermatozoa-ZP binding, a standard method to identify such patients prior to conventional IVF is lacking. The application of artificial intelligence to sperm morphology analysis has become a topic of growing interest owing to the fact that the conventional assessment is highly subjective and time-consuming. Deep-learning, a core element of artificial intelligence (AI), incorporates the convolutional neural networks (CNN) to process all the data composing a digital image through successive layers to identify the underlying pattern.

Study design, size, duration

The fertilization-competent spermatozoa were isolated according to their binding ability to the ZP. The ZP-bound and -unbound spermatozoa were collected for functional assays and to establish an AI model for morphologic prediction of sperm fertilization potential. Human spermatozoa (n = 289) were isolated from normozoospermic samples. Human oocytes (n = 562) were collected from an assisted reproduction program in Hong Kong. Sample collection has been ongoing and will continue until the end of this study in November 2021.

Participants/materials, setting, methods

Sperm-ZP binding assay was employed to collect ZP-bound and -unbound spermatozoa. The fertilization potential and genetic quality of the collected spermatozoa were evaluated by our established protocols. Diff-Quik- stained images of ZP-bound and -unbound spermatozoa were collected respectively for the establishment of an AI model. A novel algorithm for sperm image transformation and segmentation was developed to pre-process the images. CNN architecture was then applied on these pre-processed images for feature extraction and model training.

Main results and the role of chance

Our result showed that the sperm-ZP binding assay had no detrimental effect on sperm viability when compared with the raw samples and unbound-sperm subpopulations. ZP-bound spermatozoa were found with statistically higher acrosome reaction rates, improved DNA integrity, better morphology, lower protamine deficiency and higher methylation level when compared with the unbound spermatozoa. A deep-learning model was trained and validated by analyzing a total of 1,334 and 885 of ZP-bound/unbound spermatozoa to evaluate the predictive power of sperm morphology for ZP binding ability. Our newly trained AI-based model showed initial success in classifying the ZP-bound/ unbound spermatozoa according to their morphological characteristics with high accuracy of 85% and low computational complexity.

Limitations, reasons for caution

This sperm selection method requires micromanipulation and relatively long processing time to recover ZP-bound spermatozoa. In addition to limited availability, the use of human materials may result in interassay variations affecting the reproducibility of this method among laboratories.

Wider implications of the findings

In light of current findings, AI-based sperm selection method may provide high predictive values of sperm fertilization potential for clinical purposes. This method is particularly applicable to patients who had poor fertilization outcomes after conventional IVF treatments or those with high degree of defective sperm-ZP binding ability. 

Trial registration number

not applicable

P–064 Application of an artificial intelligence model for morphologic prediction of fertilization-competent human spermatozoa

Study question

What is the role of artificial intelligence in selecting fertilization-competent human spermatozoa according to their morphological characteristics? Summary answer: The established AI model in this study can be potentially used to select semen samples with superior fertilization potential in clinical settings.

What is known already

Defective spermatozoa-zona pellucida (ZP) interaction causes subfertility and is a major cause of low IVF fertilization rates. While ICSI benefits patients with defective spermatozoa-ZP binding, a standard method to identify such patients prior to conventional IVF is lacking. The application of artificial intelligence to sperm morphology analysis has become a topic of growing interest owing to the fact that the conventional assessment is highly subjective and time-consuming. Deep-learning, a core element of artificial intelligence (AI), incorporates the convolutional neural networks (CNN) to process all the data composing a digital image through successive layers to identify the underlying pattern.

Study design, size, duration

The fertilization-competent spermatozoa were isolated according to their binding ability to the ZP. The ZP-bound and -unbound spermatozoa were collected for functional assays and to establish an AI model for morphologic prediction of sperm fertilization potential. Human spermatozoa (n = 289) were isolated from normozoospermic samples. Human oocytes (n = 562) were collected from an assisted reproduction program in Hong Kong. Sample collection has been ongoing and will continue until the end of this study in November 2021.

Participants/materials, setting, methods

Sperm-ZP binding assay was employed to collect ZP-bound and -unbound spermatozoa. The fertilization potential and genetic quality of the collected spermatozoa were evaluated by our established protocols. Diff-Quik- stained images of ZP-bound and -unbound spermatozoa were collected respectively for the establishment of an AI model. A novel algorithm for sperm image transformation and segmentation was developed to pre-process the images. CNN architecture was then applied on these pre-processed images for feature extraction and model training.

Main results and the role of chance

Our result showed that the sperm-ZP binding assay had no detrimental effect on sperm viability when compared with the raw samples and unbound-sperm subpopulations. ZP-bound spermatozoa were found with statistically higher acrosome reaction rates, improved DNA integrity, better morphology, lower protamine deficiency and higher methylation level when compared with the unbound spermatozoa. A deep-learning model was trained and validated by analyzing a total of 1,334 and 885 of ZP-bound/unbound spermatozoa to evaluate the predictive power of sperm morphology for ZP binding ability. Our newly trained AI-based model showed initial success in classifying the ZP-bound/ unbound spermatozoa according to their morphological characteristics with high accuracy of 85% and low computational complexity.

Limitations, reasons for caution

This sperm selection method requires micromanipulation and relatively long processing time to recover ZP-bound spermatozoa. In addition to limited availability, the use of human materials may result in interassay variations affecting the reproducibility of this method among laboratories.

Wider implications of the findings: In light of current findings, AI-based sperm selection method may provide high predictive values of sperm fertilization potential for clinical purposes. This method is particularly applicable to patients who had poor fertilization outcomes after conventional IVF treatments or those with high degree of defective sperm-ZP binding ability.

Trial registration number

Not applicable

Outcome of radiofrequency ablation for selective fetal reduction before vs at or after 16 gestational weeks in complicated monochorionic pregnancy

OBJECTIVE

To investigate whether gestational age at intervention (< or ≥ 16 weeks) and other factors affect the risk of loss of the cotwin after selective fetal reduction using radiofrequency ablation (RFA) in monochorionic (MC) pregnancy.

METHODS

This was a single-center retrospective analysis of 63 consecutive RFA procedures performed at our institution from January 2011 to October 2019 for selective fetal reduction in complicated MC pregnancies. Indications for RFA were twin reversed arterial perfusion sequence (13 cases), twin-to-twin transfusion syndrome (12 cases), twin anemia-polycythemia sequence (two cases), selective fetal growth restriction (10 cases), discordant anomalies (17 cases) and multifetal pregnancy reduction in triplets or quadruplets with a MC pair (nine cases). Twenty-six (41.3%) of these procedures were performed before and 37 (58.7%) after 16 weeks. Potential factors that could affect the risk of loss of the cotwin, including gestational age at RFA, order of multiple pregnancy, amnionicity, indication for RFA and number of ablation cycles, were assessed first by univariate analysis and then by multivariate analysis.

RESULTS

There were 17 (27.0%) cotwin losses. Ablation cycles numbering four or more was the only factor among those investigated to be associated with loss of the cotwin after RFA (P = 0.035; odds ratio, 5.21), while the indication for RFA, order of multiple pregnancy, amnionicity and gestational age at RFA had no effect. Comparing RFA performed at < 16 vs ≥ 16 weeks, there was no difference in the rate of cotwin loss (23.1% vs 29.7%; P = 0.558) or preterm prelabor rupture of the membranes before 34 weeks (7.7% vs 5.4%; P = 0.853), or in the median gestational age at delivery (36.2 vs 37.3 weeks; P = 0.706).

CONCLUSIONS

RFA is a promising tool for early selective fetal reduction in MC pregnancy before 16 weeks. Four or more ablation cycles is a major risk factor for cotwin loss. Careful assessment pre- and post-RFA, together with proficient operative skills to minimize the number of ablation cycles, are the mainstay to ensure that this procedure is effective and safe. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.