Characteristics associated with antenatally unidentified small-for-gestational-age fetuses: prospective cohort study nested within DESiGN randomized controlled trial

OBJECTIVE

To identify the clinical characteristics and patterns of ultrasound use amongst pregnancies with an antenatally unidentified small-for-gestational-age (SGA) fetus, compared with those in which SGA is identified, to understand how to design interventions that improve antenatal SGA identification.

METHODS

This was a prospective cohort study of singleton, non-anomalous SGA (birth weight < 10th centile) neonates born after 24 + 0 gestational weeks at 13 UK sites, recruited for the baseline period and control arm of the DESiGN trial. Pregnancy with antenatally unidentified SGA was defined if there was no scan or if the final scan showed estimated fetal weight (EFW) at the 10th centile or above. Identified SGA was defined if EFW was below the 10th centile at the last scan. Maternal and fetal sociodemographic and clinical characteristics were studied for associations with unidentified SGA using unadjusted and adjusted logistic regression models. Ultrasound parameters (gestational age at first growth scan, number and frequency of ultrasound scans) were described, stratified by presence of indication for serial ultrasound. Associations of unidentified SGA with absolute centile and percentage weight difference between the last scan and birth were also studied on unadjusted and adjusted logistic regression, according to time between the last scan and birth.

RESULTS

Of the 15 784 SGA babies included, SGA was not identified antenatally in 78.7% of cases. Of pregnancies with unidentified SGA, 47.1% had no recorded growth scan. Amongst 9410 pregnancies with complete data on key maternal comorbidities and antenatal complications, the risk of unidentified SGA was lower for women with any indication for serial scans (adjusted odds ratio (aOR), 0.56 (95% CI, 0.49-0.64)), for Asian compared with white women (aOR, 0.80 (95% CI, 0.69-0.93)) and for those with non-cephalic presentation at birth (aOR, 0.58 (95% CI, 0.46-0.73)). The risk of unidentified SGA was highest among women with a body mass index (BMI) of 25.0-29.9 kg/m2 (aOR, 1.15 (95% CI, 1.01-1.32)) and lowest in those with underweight BMI (aOR, 0.61 (95% CI, 0.48-0.76)) compared to women with BMI of 18.5-24.9 kg/m2 . Compared to women with identified SGA, those with unidentified SGA had fetuses of higher SGA birth-weight centile (adjusted odds for unidentified SGA increased by 1.21 (95% CI, 1.18-1.23) per one-centile increase between the 0th and 10th centiles). Duration between the last scan and birth increased with advancing gestation in pregnancies with unidentified SGA. SGA babies born within a week of the last growth scan had a mean difference between EFW and birth-weight centiles of 19.5 (SD, 13.8) centiles for the unidentified-SGA group and 0.2 (SD, 3.3) centiles for the identified-SGA group (adjusted mean difference between groups, 19.0 (95% CI, 17.8-20.1) centiles).

CONCLUSIONS

Unidentified SGA was more common amongst women without an indication for serial ultrasound, and in those with cephalic presentation at birth, BMI of 25.0-29.9 kg/m2 and less severe SGA. Ultrasound EFW was overestimated in women with unidentified SGA. This demonstrates the importance of improving the accuracy of SGA screening strategies in low-risk populations and continuing performance of ultrasound scans for term pregnancies. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Improving antenatal detection of small-for-gestational-age fetus: economic evaluation of Growth Assessment Protocol

OBJECTIVE

To determine whether the Growth Assessment Protocol (GAP), as implemented in the DESiGN trial, is cost-effective in terms of antenatal detection of small-for-gestational-age (SGA) neonate, when compared with standard care.

METHODS

This was an incremental cost-effectiveness analysis undertaken from the perspective of a UK National Health Service hospital provider. Thirteen maternity units from England, UK, were recruited to the DESiGN (DEtection of Small for GestatioNal age fetus) trial, a cluster randomized controlled trial. Singleton, non-anomalous pregnancies which delivered after 24 + 0 gestational weeks between November 2015 and February 2019 were analyzed. Probabilistic decision modeling using clinical trial data was undertaken. The main outcomes of the study were the expected incremental cost, the additional number of SGA neonates identified antenatally and the incremental cost-effectiveness ratio (ICER) (cost per additional SGA neonate identified) of implementing GAP. Secondary analysis focused on the ICER per infant quality-adjusted life year (QALY) gained.

RESULTS

The expected incremental cost (including hospital care and implementation costs) of GAP over standard care was £34 559 per 1000 births, with a 68% probability that implementation of GAP would be associated with increased costs to sustain program delivery. GAP identified an additional 1.77 SGA neonates per 1000 births (55% probability of it being more clinically effective). The ICER for GAP was £19 525 per additional SGA neonate identified, with a 44% probability that GAP would both increase cost and identify more SGA neonates compared with standard care. The probability of GAP being the dominant clinical strategy was low (11%). The expected incremental cost per infant QALY gained ranged from £68 242 to £545 940, depending on assumptions regarding the QALY value of detection of SGA.

CONCLUSION

The economic case for replacing standard care with GAP is weak based on the analysis reported in our study. However, this conclusion should be viewed taking into account that cost-effectiveness analyses are always limited by the assumptions made. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

A review of the obstetric management of patients with epidermolysis bullosa

Epidermolysis bullosa (EB) is a rare inherited skin condition characterized by the development of blisters after minor mechanical friction or trauma. There are few reported pregnancies in the literature in these women. We describe a pregnancy we recently managed. The collated series of pregnancies show that there are no additional antenatal or postnatal problems and that the skin itself does not worsen during pregnancy. Vaginal delivery is most favourable, but if a caesarean section is required, regional anaesthesia should be attempted. A multidisciplinary team should be active throughout the pregnancy of these women and a well-documented labour plan should be made in advance.

World Health Organisation multicentre randomised trial of supplementation with vitamins C and E among pregnant women at high risk for pre-eclampsia in populations of low nutritional status from developing countries

OBJECTIVE

To determine if vitamin C and E supplementation in high-risk pregnant women with low nutritional status reduces pre-eclampsia.

DESIGN

Multicentred, randomised, controlled, double-blinded trial.

SETTING

Antenatal care clinics and Hospitals in four countries.

POPULATION

Pregnant women between 14 and 22 weeks' gestation.

METHOD

Randomised women received 1000 mg vitamin C and 400 iu of vitamin E or placebo daily until delivery.

MAIN OUTCOME MEASURES

Pre-eclampsia, low birthweight, small for gestational age and perinatal death.

RESULTS

Six hundred and eighty-seven women were randomised to the vitamin group and 678 to the placebo group. Groups had similar gestational ages (18.1; SD 2.4 weeks), socio-economic, clinical and demographical characteristics and blood pressure at trial entry. Risk factors for eligibility were similar, except for multiple pregnancies: placebo group (14.7%), vitamins group (11.8%). Previous pre-eclampsia, or its complications, was the most common risk factor at entry (vitamins 41.6%, placebo 41.3%). Treatment compliance was 87% in the two groups and loss to follow-up was low (vitamins 2.0%, placebo 1.3%). Supplementation was not associated with a reduction of pre-eclampsia (RR: 1.0; 95% CI: 0.9-1.3), eclampsia (RR: 1.5; 95% CI: 0.3-8.9), gestational hypertension (RR: 1.2; 95% CI: 0.9-1.7), nor any other maternal outcome. Low birthweight (RR: 0.9; 95% CI: 0.8-1.1), small for gestational age (RR: 0.9; 95% CI: 0.8-1.1) and perinatal deaths (RR: 0.8; 95% CI: 0.6-1.2) were also unaffected.

CONCLUSION

Vitamins C and E at the doses used did not prevent pre-eclampsia in these high-risk women.

Dexamethasone in the treatment of obstetric cholestasis: A case series

Twelve women with obstetric cholestasis were given dexamethasone after failure to respond to ursodeoxycholic acid. Clinical improvement was achieved in eight cases, without complete resolution of symptoms. Biochemical response was achieved in seven cases. All but two cases had good correlation between clinical and biochemical response. Women of Asian and South American origin were more likely to respond to dexamethasone than Caucasians. There were no reported maternal or fetal side-effects. However, the subsequent consequences of dexamethasone treatment for the mother and fetus have not been thoroughly evaluated. Therefore, even in Asian and South American women, larger studies of dexamethasone are required before this treatment can be recommended as a universally safe and effective treatment for obstetric cholestasis.

Methodological and technical issues related to the diagnosis, screening, prevention, and treatment of pre-eclampsia and eclampsia

In contrast with advances made in treating or eliminating many other serious disorders, severe morbidity and mortality associated with pre-eclampsia/eclampsia remain among the leading problems that threaten safe motherhood, particularly in developing countries. This article reviews technical issues related to diagnosis, screening, prevention, and treatment of pre-eclampsia and identifies corresponding needs. The authors stress the lack of standardized definitions of pre-eclampsia and eclampsia and discuss problems in blood-pressure measurements and assessment of urinary protein. They summarize the evidence for prevention strategies and screening tests for early detection. For treatment, magnesium sulfate has been proven effective, but not widely used. The authors outline priorities for narrowing the identified gaps and emphasize the need for coordinated efforts to reduce the morbidity and mortality due to pre-eclampsia/eclampsia. They conclude that the mystery of this disease must be resolved to achieve primary prevention of it.

Effect of concentration and biochemical assay on the accuracy of urine dipsticks in hypertensive pregnancies

OBJECTIVE

To assess how urine concentration and biochemical assay influence the assessment of proteinuria.

METHODS

This was a prospective study to assess the accuracy of detection and quantification of proteinuria within the day assessment unit and antenatal ward of a teaching hospital in Leicester, United Kingdom. We studied hypertensive pregnancies (of mixed parity) referred to day care assessment or attending the antenatal hypertension clinic after 20 completed weeks of gestation (n = 197). Aliquots of a well-mixed 24-h urine collection were tested by routine dipstick urinalysis and then assayed for protein using the Benzethonium Chloride and the Bradford assays (n = 197).

MAIN OUTCOME MEASURES

Total protein excretion in 24 h and protein concentration per liter of urine for both biochemical assays were compared to semiquantitative dipstick protein measurement.

RESULTS

The prevalence of proteinuria in the study group varied according to the method used for testing. Dipstick urinalysis recorded the lowest prevalence (16.2%) and the Benzethonium Chloride assay measuring total protein excretion in 24 h recorded the highest (70.1%). When the positive and negative predictive values for dipstick urinalysis were calculated, performance was found to be dependent on both the units of measurement compared and the type of assay used as the "gold standard." Positive predictive values ranged from 87.5% to 96.9% and negative predictive values ranged from 35.2% to 92.1%.

CONCLUSIONS

The prevalence of proteinuria in hypertensive pregnancies is dependent on the method used to detect it. The amount of protein assessed quantitatively is further dependent on the biochemical assay employed. However, regardless of the quantitative assessment, dipstick urinalysis has a significant false-negative rate. This first reporting of a variation in performance between dipstick urinalysis and two different biochemical assays in pregnancy may be explained in relation to protein assay specificity and the observed protein compositions of the samples on electrophoretic analysis. The significance of proteinuria should be considered in light of the method used to detect it, but, ultimately, it must be related to clinical outcome.

Analysis of ambulatory blood pressure monitor data using a hierarchical model incorporating restricted cubic splines and heterogeneous within-subject variances

Hypertensive disorders of pregnancy are associated with significant maternal and foetal morbidity. Measurement of blood pressure remains the standard way of identifying individuals at risk. There is growing interest in the use of ambulatory blood pressure monitors (ABPM), which can record an individual's blood pressure many times over a 24-hour period. From a clinical perspective interest lies in the shape of the blood pressure profile over a 24-hour period and any differences in the profile between groups. We propose a two-level hierarchical linear model incorporating all ABPM data into a single model. We contrast a classical approach with a Bayesian approach using the results of a study of 206 pregnant women who were asked to wear an ABPM for 24 hours after referral to an obstetric day unit with high blood pressure. As the main interest lies in the shape of the profile, we use restricted cubic splines to model the mean profiles. The use of restricted cubic splines provides a flexible way to model the mean profiles and to make comparisons between groups. From examining the data and the fit of the model it is apparent that there were heterogeneous within-subject variances in that some women tend to have more variable blood pressure than others. Within the Bayesian framework it is relatively easy to incorporate a random effect to model the between-subject variation in the within-subject variances. Although there is substantial heterogeneity in the within-subject variances, allowing for this in the model has surprisingly little impact on the estimates of the mean profiles or their confidence/credible intervals. We thus demonstrate a powerful method for analysis of ABPM data and also demonstrate how heterogeneous within-subject variances can be modelled from a Bayesian perspective.

Epidural and spinal analgesia and labour

Epidural and spinal analgesia for pain relief in labour are now commonplace. Adverse effects such as hypotension and toxicity to anaesthetic agents are well described and easily managed. The effects on obstetric outcome, however, have been unclear to both obstetricians and anaesthetists, but are important due to the large number of pregnancies involved. Efforts to define implications for mother and child have been frustrated by a relative lack of evidence derived from good quality, large randomized trials. Ethical and methodological difficulties together with an abundance of confounding factors have conspired to cause considerable difficulties for researchers in this area. Nevertheless, recent evidence has significantly advanced knowledge in the field and has implications for future practice.

Home monitoring of blood pressure in pregnancy at high risk of pre-eclampsia

The early detection of pre-eclampsia is a major challenge in obstetric care. We report a case where pre-eclampsia was detected by home blood pressure monitoring between routine antenatal visits. This novel management approach allows early diagnosis and optimises antenatal care in fulminating disease.

Inpatient monitoring on an outpatient basis: managing hypertensive pregnancies in the community using automated technologies

Automated measurement of blood pressure and urinalysis is reviewed, and the strengths and weaknesses of these devices are compared with conventional techniques. The few early reports of such management strategies are reviewed with emphasis on the advantages of automated monitoring. The article concludes with a review of published pilot data in this field and places those findings in the context of recent recommendations for the development of obstetric care in the United Kingdom.

Birth weight and 24-hour ambulatory blood pressure in nonproteinuric hypertensive pregnancy

OBJECTIVE

The aim of this study was to examine the relationship between maternal ambulatory blood pressure monitor measurements during pregnancy and birth weight in a population of women considered to have hypertension according to conventional antenatal clinic measurement.

STUDY DESIGN

A prospective observational study was carried out within the obstetric departments of Leicester Royal Infirmary and Queen Charlotte's Hospital. A total of 237 women were found to have hypertension (blood pressure >/=140/90 mm Hg) without significant proteinuria during examination in the antenatal assessment area. Sequential-day unit blood pressure recordings and a 24-hour automated ambulatory blood pressure recording were performed, and the results were compared with the principal outcome measure of birth weight.

RESULTS

A significant inverse association (gradient, -13.5; 95% confidence interval -23.4 to -3.6) was found between daytime ambulatory diastolic blood pressure measurement and birth weight. An increase of 5 mm Hg in daytime mean diastolic blood pressure was associated with a fall in birth weight of 68.5 g. This association remained after adjustment for potential confounders that included maternal age, maternal weight, smoking status, ethnicity, and gestational age at delivery. No such association was found between obstetric day unit assessment of blood pressure and birth weight.

CONCLUSION

There is a significant association between blood pressure and birth weight in nonproteinuric hypertensive pregnancies. The best predictor of this association is the daytime mean ambulatory diastolic blood pressure measurement. This is further evidence that maternal blood pressure may be an important confounding and potentially genetic variable in the association between birth weight and subsequent adult hypertension.

Automated blood pressure measurement as a predictor of proteinuric pre-eclampsia

OBJECTIVES

To investigate the relation between antenatal clinic, obstetric day unit and 24-hour ambulatory blood pressure measurements and 24-hour proteinuria levels in hypertensive pregnancies.

DESIGN

An observational study.

PARTICIPANTS

Forty-eight women presenting with new hypertension after 20 weeks of gestation.

RESULTS

The closest relation was found between ambulatory blood pressure measurements and 24-hour proteinuria levels. No significant relation was found between the conventional diastolic blood pressure threshold of 90 mmHg and 24-hour proteinuria levels.

CONCLUSIONS

Ambulatory blood pressure measurement gives better information about disease status in pre-eclampsia as assessed by proteinuria than does conventional sphygmomanometry.

Blood pressure and fetal heart rate changes with patient-controlled combined spinal epidural analgesia while ambulating in labour

OBJECTIVE

To determine the effect of patient-controlled combined spinal epidural analgesia (PCEA) on maternal pulse and blood pressure, and fetal heart rate in primigravid women, when adapting different positions in labour.

DESIGN

A prospective study.

SETTING

Queen Charlotte's and Chelsea hospital, London.

PARTICIPANTS

Fifty-five primigravid women in labour at > or = 37 weeks of gestation; 40 women had supervised standing top-ups given by an anaesthetist. A further 15 women had PCEA top-ups given in each of standing, sitting and lying positions.

MAIN OUTCOME MEASURES

Maternal pulse rate, blood pressure and fetal heart rate changes following epidural top-ups.

RESULTS

In the first 40 women there was no clinically significant fall in their blood pressure (< 5 mmHg). The subsequent 15 women who had PCEA top-ups had no fall in blood pressure in the standing and sitting positions, though the average blood pressure fell significantly when a top-up was given in the lying position. Maternal heart rate increased significantly at 12 min post top-up when the women were in the standing position (P = 0.0018). In the 15 women who had PCEA top-ups, the CTG showed improvement in decelerations when women were in the standing position but deterioration when in the lying position (P < 0.01).

CONCLUSION

Patient-controlled epidural analgesia top-ups with maternal mobility may be beneficial to the fetus possibly by reducing the hypotension normally associated with top-ups in the lying position.

Efficacy and safety of lidocaine-prilocaine cream for pain during circumcision

BACKGROUND

Neonatal circumcision is a painful surgical procedure often performed without analgesia. We assessed the efficacy and safety of 5 percent lidocaine-prilocaine cream (Emla) in neonates undergoing circumcision.

METHODS

We carried out a double-blind, randomized, controlled trial in 68 full-term male neonates: 38 were assigned to receive lidocaine-prilocaine cream, and 30 to receive placebo. One gram of lidocaine-prilocaine or placebo cream was applied to the penis under an occlusive dressing for 60 to 80 minutes before circumcision. Behavioral (facial activity and time spent crying) and physiologic (heart rate and blood pressure) responses were recorded during the procedure. Blood samples were obtained at various times after drug application for measurements of methemoglobin and plasma lidocaine, prilocaine, and o-toluidine (a metabolite of prilocaine).

RESULTS

A total of 68 and 59 neonates were included in the safety and efficacy analyses, respectively. Demographic characteristics such as gestational age and birth weight did not differ between the lidocaine-prilocaine and placebo groups. During circumcision, the neonates in the lidocaine-prilocaine group had less facial activity (P= 0.01), spent less time crying (P<0.001), and had smaller increases in heart rate (P=0.007) than the neonates in the placebo group. Facial-activity scores were 12 to 49 percent lower during various steps of the procedure in the lidocaine-prilocaine group. As compared with neonates in the placebo group, infants in the lidocaine-prilocaine group cried less than half as much and had heart-rate increases of 10 beats per minute less. Blood methemoglobin concentrations (expressed as a percentage of the hemoglobin concentration) were similar (1.3 percent) in both groups. Lidocaine and prilocaine were detected in plasma in 23 (61 percent) and 21 (55 percent) of the infants treated with lidocaine-prilocaine cream, respectively.

CONCLUSIONS

Lidocaine-prilocaine cream is efficacious and safe for the prevention of pain from circumcision in neonates.

Hypertension in pregnancy: which method of blood pressure measurement is most predictive of outcome?

OBJECTIVE

To determine the clinical effectiveness of blood pressure (BP) measurement using conventional sphygmomanometry in the antenatal clinic and obstetric day unit compared with automated BP monitoring at home.

METHODS

The study population consisted of 109 nulliparous white women with BPs of at least 140 or 90 mmHg at the antenatal clinic after 20 weeks' gestation, who underwent obstetric day unit and 24-hour automated BP monitoring on the same day. Automated measurement was obtained every half hour for 24 hours using a commercially available device that had been previously validated in pregnancy.

RESULTS

At the traditional BP cutoff point (140/90 mmHg), the relative risk for subsequent development of adverse obstetric outcome was greatest for automated BP measurement: The relationships between outcome and automated diastolic BP were all statistically significant: proteinuria (P = .034), preterm delivery (P < .001), birth weight below the tenth percentile (P = .001), admission to the special care neonatal unit (P = .001), and cesarean delivery (P = .007).

CONCLUSION

Automated BP measurement appears to improve the identification of patients who are at high risk of poor obstetric outcome. Automated BP measurement is worthy of further evaluation as an antenatal screening and diagnostic test.