Screening for women at risk of spontaneous preterm birth, including cervical incompetence.

Preterm births remain one of the biggest challenges in obstetrics worldwide. With the advancement of neonatal care, more premature neonates survive with long term consequences. Therefore, preventing or delaying preterm births starting from the preconceptional or antenatal periods are important. Among the numerous screening strategies described, not one can fit into all. Nonetheless, approaches including identifying women with modifiable risk factors for preterm births, genitourinary infections and short cervical length are the most useful. In this article, the current evidence is summarized and the best strategies for common clinical scenerios including cervical incompetence, history of second trimester loss or early preterm births, incidental short cervix and multiple pregnancy are discussed.

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.

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.

Incidence of neonatal sepsis after universal antenatal culture-based screening of group B streptococcus and intrapartum antibiotics: A multicentre retrospective cohort study.

OBJECTIVE: To compare the incidences of early and late-onset neonatal sepsis, including group B streptococcus (GBS) and Escherichia coli (E. coli) before and after implementation of universal screening and intrapartum antibiotics prophylaxis (IAP). DESIGN: Retrospective cohort study. SETTING: Eight public hospitals and 31 Maternal and Child Health Centres (in Hong Kong. POPULATION: 460 552 women attending routine antenatal service from 2009 to 2020. METHODS: Universal culture-based GBS screening has been offered to eligible women since 2012. Total births, GBS screening tests, maternal GBS colonisation and neonatal sepsis with positive blood or cerebrospinal fluid were retrieved from clinical and laboratory database. MAIN OUTCOME MEASURES: Maternal GBS colonisation rate, early- and late-onset neonatal sepsis (including GBS and E. coli). RESULTS: Of 318 740 women with universal culture-based screening, 63 767 women (20.0%) screened positive. After implementation of GBS screening and IAP, the incidence of early-onset neonatal sepsis decreased (3.25 versus 2.26 per 1000 live births, p < 0.05), including those caused by GBS (1.03 versus 0.26 per 1000 live births, p < 0.05). Segmented regression showed that change in early-onse GBS sepsis incidence after screening was the only significant variable in the outcome trend. There was no significant evidence of increase in incidence of late-onset neonatal sepsis including those caused by GBS. CONCLUSIONS: Universal culture-based GBS screening and IAP were associated with reduction in early-onset neonatal sepsis including GBS disease. Although an increase in incidence of late-onset neonatal sepsis including those caused by GBS cannot be totally ruled out, we did not identify significant evidence that this occurred.

Tuberculosis in pregnancy.

Due to COVID-19 pandemic, the latest progress of the End Tuberculosis (TB) Strategy was far from optimal and services for TB needs to be quickly restored. Pregnancy is a unique opportunity to screen and manage TB, and it is an essential step in TB eradication. Early diagnosis and treatment for active disease can reduce maternal and neonatal morbidities and mortality. The more widespread utilization of newer rapid molecular assays with drug-susceptibility testing has significantly shortened the diagnostic process for active TB disease. First-line anti-TB drugs are proven to be safe in pregnancy. Management of latent TB infection (LTBI) during pregnancy is controversial, but puerperium is a period of increased susceptibility to progress to active disease. Extrapulmonary TB (EPTB), multidrug-resistant TB (MDR-TB) and HIV co-infection remain significant issues surrounding TB management during pregnancy and often require input from a multidisciplinary team including TB experts.

Iron deficiency anaemia associated with increased placenta praevia and placental abruption: a retrospective case-control study.

BACKGROUND/OBJECTIVES: A few studies reported association between placenta praevia (PP) and placental abruption (PA) with maternal iron deficiency anaemia (IDA), which is not an established risk factor for these conditions. This retrospective case-control study was performed to determine the relationship between IDA with PP and PA. METHODS: Maternal characteristics, risk factors for and incidence of antepartum haemorrhage overall, and PP and PA, were compared between women with IDA only and controls without IDA or haemoglobinopathies matched for exact age and parity (four controls to each index case), who carried singleton pregnancy to ≥22 weeks and managed under our care from 1997 to 2019. RESULTS: There were 1,176 women (0.8% of eligible women in the database) with IDA only, who exhibited slightly but significantly different maternal characteristics, and increased antepartum haemorrhage overall (3.4% versus 2.2%, p = 0.031, OR 1.522, 95% CI 1.037-2.234) and PP (1.8% versus 0.9%, p = 0.010, OR 1.953, 95% CI 1.164-3.279), but not PA (1.2% versus 1.1%, p = 0.804, OR 1.077, 95% CI 0.599-1.936). When stratified by parity status, increased PP was found in nulliparous women only. On multivariate analysis adjusting for parity, previous abortion history, overweight and obesity, short stature, other antenatal complications as a composite factor, preterm (<37) delivery, previous caesarean delivery, and infant gender, IDA was associated with PP (aOR 3.485, 95% CI 1.959-6.200) and PA (aOR 2.181, 95% CI 1.145-4.155). CONCLUSIONS: Both PP and PA are increased in women with IDA, the prevention of which could be a means to reduce the occurrence of both PP and PA.

Iron Deficiency Anaemia and Atonic Postpartum Haemorrhage Following Labour.

The purpose of this retrospective cohort study is to determine if iron deficiency anaemia (IDA) is associated with increased atonic postpartum haemorrhage (PPH) following labour. Women with singleton pregnancy carried to 24 or more weeks gestation, who were delivered under our care from 1997 to 2019, constituted the study population. A diagnosis of IDA was based on the finding of haemoglobin <10 g/dL and serum ferritin <15 µg/L in the absence of haemoglobinopathies. Women with elective caesarean section were excluded. Maternal characteristics, use of oxytocin, labour outcome and occurrence of PPH were compared between women with and without a diagnosis of IDA. The 1032 women (0.86%) with IDA exhibited slightly but significantly different maternal characteristics and had significantly higher incidence of total (4.5% versus 3.2%, p = 0.024) and atonic PPH (3.1% versus 2.0%, p = 0.011) despite similar incidences of labour induction, augmentation, and instrumental and intrapartum caesarean delivery. Multivariate analysis with adjustment for the effects of age, body mass index, height, parity, abortion history, labour induction and augmentation, instrumental delivery and infant macrosomia demonstrated that IDA was independently associated with total PPH (adjusted relative risk, aRR: 1.455, 95% confidence ratio, CI: 1.040-2.034) and atonic PPH (aRR: 1.588, 95% CI: 1.067-2.364). Our results indicate that despite the low prevalence in our population, IDA was independently associated with atonic PPH, probably consequent to placental adaptive changes in the presence of IDA. The correction and prevention of IDA could be the most important measure in countering the rising global prevalence of atonic PPH.

Parity status and the relationship between antenatal rubella serology with obstetric outcome.

Routine antenatal rubella serological testing is adopted in many countries. In a population covered by universal childhood rubella immunization for four decades, we have observed an association between pre-eclampsia with maternal rubella seronegativity among multiparous gravidae. This retrospective cohort study was further performed to elucidate the interaction between parity status and rubella seronegativity on obstetric outcome in singleton pregnancies carried to ≥ 24 weeks gestation managed from 1997 to 2019, with the data retrieved from a computerized database used for annual statistics and auditing. Of the 133,926 singleton pregnancies eligible for the study, the 13,320 (9.9%) rubella seronegative gravidae had higher mean booking weight and body mass index (BMI), but shorter height, and higher incidence of advanced age (≥ 35 years), high BMI, short stature, and lower incidence of nulliparas. Univariate analysis showed that adverse obstetric outcomes were more frequently found among the multiparas. On multivariate analysis, there was increased postdated (> 41 weeks) pregnancy irrespective of parity status, while nulliparas had reduced gestational hypertension (aRR 0.714, 95% CI 0.567-0.899) and gestational diabetes (aRR 0.850, 95% CI 0.762-0.950), and multiparas had increased pre-eclampsia (aRR 1.261, 95% CI 1.005-1.582), neonatal death (aRR 2.796, 95% CI 1.243-6.291), and perinatal death (aRR 2.123, 95% CI 1.257-3.587). In conclusion, in a population covered by universal childhood rubella immunization, antenatal rubella seronegativity is associated with increased pre-eclampsia and perinatal loss only in multiparas, suggesting that the rubella seronegativity in these women served as proxy for some form of altered immune response which increases adverse pregnancy outcome.

Prospective Evaluation of International Prediction of Pregnancy Complications Collaborative Network Models for Prediction of Preeclampsia: Role of Serum sFlt-1 at 11-13 Weeks' Gestation.

The study aimed to investigate whether serum sFlt-1 (soluble fms-like tyrosine kinase-1) at 11-13 weeks' gestation in pregnancies that subsequently developed preeclampsia was different from those without preeclampsia and compare screening performance of the International Prediction of Pregnancy Complications (IPPIC) reported models, which include various combinations of maternal factors, systolic blood pressure, diastolic blood pressure, PlGF (placental growth factor) and sFlt-1 and the competing risk (CR) models, which include various combinations of maternal factors, mean arterial pressure (MAP) and PlGF for predicting any-onset, early-onset, and late-onset preeclampsia. This was a prospective multicenter study in 7877 singleton pregnancies. The differences of the predictive performance between the IPPIC and CR models were compared. There were 141 women (1.79%) who developed preeclampsia, including 13 cases (0.17%) of early-onset preeclampsia and 128 cases (1.62%) of late-onset preeclampsia. In pregnancies that developed preeclampsia compared to unaffected pregnancies, median serum sFlt-1 levels and its MoMs were not significantly different (p>0.05). There was no significant association between gestational age at delivery and log10 sFlt-1 and log10 sFlt-1 MoM (p>0.05). The areas under the curve of CR models were significantly higher than the IPPIC models for the prediction of any-onset and late-onset preeclampsia but not for early-onset preeclampsia. In conclusion, there are no significant differences in the maternal serum sFlt-1 levels at 11-13 weeks' gestation between women who subsequently develop preeclampsia and those who do not. Moreover, the CR models for the prediction of any-onset and late-onset preeclampsia perform better than the IPPIC reported model.

Impact of replacing or adding placental growth factor on Down syndrome screening: A prospective cohort study.

OBJECTIVES: To assess whether adding placental growth factor (PlGF) or replacing pregnancy-associated plasma protein-A (PAPP-A) improves the first trimester combined test performance for trisomy 21. METHODS: A total of 11,518 women with a singleton pregnancy who underwent the first trimester combined test between December 2016 and December 2019 were included. PlGF was measured and estimated term risk for trisomy 21 was calculated by (1) adding PlGF to the combined test and (2) replacing PAPP-A with PlGF. RESULTS: Twenty-nine pregnancies had trisomy 21. The combined tests detection rate (DR), false positive rate (FPR) and screen positive rate (SPR) were 89.7%, 5.7% and 6% respectively. DR when adding PlGF to the combined test or replacing PAPP-A remained unchanged. Replacing PAPP-A by PlGF increased FPR and SPR to 6.2% and 6.4% respectively. Adding PlGF to the combined test gave FPR and SPR rates of 5.5% and 5.7% respectively. Change in FPR and SPR was not significant (p > 0.1 for all). CONCLUSION: Adding PlGF to the combined test or replacing PAPP-A with PlGF did not improve trisomy 21 DR and resulted in a non-significant marginal change in FPR and SPR.

Impact of Maternal BMI on Rubella Nonimmunity at Antenatal Screening.

OBJECTIVE: The aim of this study was to examine the relationship between BMI and the incidence of rubella nonimmunity among pregnant women with regard to the World Health Organization categories. METHODS: This was a retrospective cohort study of 117,063 eligible gravidas, managed between 1998 and 2015 in a university hospital of Hong Kong, China. BMI at antenatal booking was banded using the following World Health Organization definitions: < 18.5 kg/m2 , 18.5 to 24.9 kg/m2 , 25.0 to 29.9 kg/m2 , and ≥30.0 kg/m2 . Maternal rubella nonimmunity status by BMI was assessed. Incidence rates were also assessed after adjusting for maternal advanced age, short stature < 151 cm, mothers' birthplace, and postobstetric history covariates. RESULTS: Rubella nonimmunity incidence increased as the BMI increased (P < 0.001). Gravidas with high BMI were more likely to be nonimmune if born in Hong Kong (odds ratio [OR], 1.234; 95% CI: 1.159-1.315; P < 0.001) compared with those born outside of Hong Kong (OR, 1.066; 95% CI: 0.997-1.141; P = 0.063). After adjusting for covariates, women with BMI ≥ 25 kg/m2 had 1.127 (P < 0.001; 95% CI: 1.074-1.182) greater odds of being nonimmune. CONCLUSIONS: High maternal BMI (≥ 25.0 kg/m2 ) is associated with reduced rubella immunity, an effect confined to gravidas with almost complete vaccine coverage in childhood.

Impact of the two-dose rubella vaccination regimen on incidence of rubella seronegativity in gravidae aged 25 years and younger.

OBJECTIVE: This study compared the incidence of rubella seronegativity among gravidae of 25 year-old and younger, between those born in Hong Kong after 1983 when the two-dose rubella vaccination was implemented, versus gravidae born before, to examine the impact of the two-dose regimen. METHODS: In this retrospective cohort study, the incidence of antenatal rubella seronegativity in our parturients managed in1997-2015 was analysed by their age from ≤16 to 25 years, and the effect of year of birth was determined adjusting for confounding factors including teenage status, obstetric history, anthropometric factors, and health parameters including anaemia, thalassaemia trait and hepatitis B carrier status. RESULTS: Among the 12743 gravidae, the 6103 gravidae born after 1983 had overall higher rubella seronegativity (9.1% versus 4.4%, OR 2.061, 95% CI 1.797-2.364), with significant difference (p = 0.006) and inverse correlation (p<0.001) with age, in contrast to the 6640 gravidae born in/before 1983 whom there was significant difference (p = 0.027) but a positive correlation (p = 0.008) with age. For each year of age, the former had significantly higher incidence of rubella seronegativity except for those of ≤16 years. Regression analysis confirmed that birth after 1983 was independently associated with rubella seronegativity (aOR 2.207, 95% CI 1.902-2.562). CONCLUSION: There was a significant trend between rubella seronegativity with age in young gravidae, but the pattern was opposite between gravidae born after versus in/before 1983, with the former having a higher incidence of seronegativity at all ages. Young women covered by the two-dose rubella immunisation programme have a paradoxically higher incidence of rubella seronegativity.

Cerclage pessary for preventing preterm birth in women with a singleton pregnancy and a short cervix at 20 to 24 weeks: a randomized controlled trial.

OBJECTIVE: To determine the effectiveness of cerclage pessary in the prevention of preterm birth in asymptomatic Chinese women with a short cervix at 20 to 24 weeks. METHODS: Low-risk women carrying singleton pregnancies were screened with transvaginal ultrasound, and those with a cervical length <25 mm at 20 to 24 weeks were recruited into a randomized controlled trial, comparing the prophylactic use of cerclage pessary with expectant management. The analysis was by intent-to-treat. The primary outcome measure was preterm delivery before 34 weeks. RESULTS: Among 4438 screened women, 203 women (4.6%) met the inclusion criteria and 108 (58%) consented for the study. A total of 53 and 55 women were allocated to pessary and control groups, respectively. There was no difference in background demographics, including the mean cervical length (19.6 mm versus 20.5 mm) and the mean gestational age at randomization (both 21.9 weeks). Delivery before 34 weeks occurred in 9.4% and 5.5% (p = 0.46) in the pessary and the control groups, respectively. No differences in major side effects were noted between the groups. CONCLUSION: In our population, <5% had a cervical length of less than 25 mm at 20 to 24 weeks' gestation. The prophylactic use of cerclage pessary did not reduce the rate of preterm delivery before 34 weeks.

Arabin cerclage pessary in the management of cervical insufficiency.

OBJECTIVE: To evaluate the use of Arabin cerclage pessary in the management of cervical insufficiency. METHODS: The pregnancy outcome of 20 women carrying singleton pregnancy referred for suspected cervical insufficiency and chose Arabin cerclage pessary for treatment from 2009-2011 were reviewed. Pregnancy outcome were analysed according to presence of risk factors, amniotic fluid sludge, cervical length and gestation at pessary insertion. RESULTS: At presentation, mean cervical length was 1.17 cm (range 0-2.33 cm), mean gestation at pessary insertion and delivery was 20.6 (12.9-26.1) weeks and 32.1 (14.7-40.1) weeks, respectively, and mean prolongation of pregnancy was 11.5 (0.5-25.2) weeks. Overall, 5 (25%) had fetal loss between 14.7-23.1 weeks, while 3 (15%) and 12 (60%) delivered before and after 34 weeks gestation, respectively with no perinatal mortality. Compared with women with cervical length <1.5 cm, all those with cervical length ≥1.5 cm had pregnancy prolonged for ≥49 days (100 vs. 54% p = 0.032) and 86% delivered beyond 34 weeks (86 vs. 46% p = 0.085). CONCLUSIONS: Arabin cerclage pessary appears to be optimal for treating women at high risk of cervical insufficiency with a cervical length of 1.5-2.5 cm, while it is an acceptable option for high risk women with cervical length <1.5 cm.

A prospective study on the prevalence of hydronephrosis in women with pelvic organ prolapse and their outcomes after treatment.

INTRODUCTION AND HYPOTHESIS: This work aims to study the prevalence of hydronephrosis and its associated factors in women with pelvic organ prolapse (POP) and to assess the effect on hydronephrosis following treatment for POP. METHODS: In this prospective observational study, 233 patients with POP were staged by the Pelvic Organ Prolapse-Quantification system, followed by sonographic measurement of bilateral renal pelvis to identify presence of hydronephrosis. Follow-up scan for hydronephrosis was performed after patients were treated for the POP. RESULTS: The prevalence of hydronephrosis was 10.3% (95% confidence interval (CI), 6% and 14%). Although patient's age, higher parity, and the presence of diabetes mellitus and hypertension were more common in the group with hydronephrosis, logistic regression analysis indicated that only the severity of POP was an independent risk factor for hydronephrosis. The odds ratio in stages 3 to 4 POP for hydronephrosis was 3.4 (95% CI, 1.3 and 9.2). Hydronephrosis resolved in 95% of patients after they received treatment for POP. CONCLUSIONS: The prevalence of hydronephrosis was 10.3% in patients with POP and patients with stages 3 to 4 POP were at particular higher risk. Hydronephrosis resolved in most of the patients after treatment for the prolapse.