A retrospective cohort study of the characteristics of unsuccessful operative vaginal deliveries

INTRODUCTION

Unsuccessful operative vaginal delivery (OVD) is associated with high rates of materno-fetal morbidity. We aimed to examine institutional rates of unsuccessful OVDs (uOVD) and compare them with successful OVD (sOVD) in order to identify factors to aid patient selection and education.

METHODS

A 6-month retrospective cohort study was performed on all unsuccessful and successful OVDs in a tertiary level maternity hospital in the Republic of Ireland. Maternal demographics and obstetric factors were assessed to evaluate potential underlying risk factors for unsuccessful operative vaginal delivery versus successful vaginal delivery.

RESULTS

There were 4,191 births during the study period with an OVD rate of 14.2% (n = 595) with 28 (4.7% of OVDs) being unsuccessful. Unsuccessful OVD were predominately nulliparous (25; 89.2%) with a mean maternal age of 30.1 years (range 20-42), with more than half (n = 15, 53.5%) being induced. The most common indication for induction was prolonged rupture of membranes (PROM) (n = 7, 25%) which was significantly different from the successful OVD group. A senior obstetrician was significantly more likely to be the primary operator in uOVD when compared to sOVD. (82.1 % V 54.1% p < 0.01). The majority of unsuccessful OVD were vacuum deliveries (n = 17; 60.7%), with a significantly higher mean birthweight when compared to successful OVD (3.695 kg V 3.483 kg; p < 0.01). Following an unsuccessful OVD, women were more likely to have a postpartum haemorrhage (64.2 % V 31.5% p < 0.01) and their infant was more likely to require admission to the neonatal intensive care unit (NICU) (32.1 % V 5.8% p < 0.01) when compared with successful OVD.

CONCLUSION

Risk factors for unsuccessful OVD were higher birth weight and induction of labour. There was a higher incidence of postpartum haemorrhage and NICU admission when compared with successful OVD.

Trends in instrument preference for operative vaginal delivery in a tertiary referral center: 2008-2021

OBJECTIVE

To examine temporal trends in operative vaginal deliveries as well as the ratio between vacuum and forceps deliveries over 15 years in a large tertiary hospital.

METHODS

This retrospective study assessed prospectively collected data from 2008 to 2021. Women with greater than 37 weeks of gestation who underwent an operative vaginal delivery were included. The rate and ratio of instrumental deliveries and perineal trauma were recorded.

RESULTS

From 2008 to 2021 there was a total of 109 230 term deliveries, of which 20 151 were an operative vaginal delivery. The rate of operative vaginal delivery as a proportion of all term deliveries decreased from 21.9% (1547 of 7069) in 2008 to 17.1% in 2021 (1428 of 8338, P < 0.001). The ratio between vacuum and forceps-assisted deliveries decreased significantly over the study period, from 7.06 in 2008 to 2.39 in 2021 (P < 0.001). Perineal trauma remained unchanged during the study period.

CONCLUSION

Operative vaginal delivery rates declined over the 15-year study period. While vacuum-assisted vaginal deliveries remain the favored instrument, forceps-assisted deliveries are becoming more prevalent. The cause for this change in practice is unclear but is likely multifactorial.

Mitigating the stress of transition: An exploration of the effects and effectiveness of a preparatory course for junior obstetric trainees transitioning to senior training roles

BACKGROUND

Attrition amongst obstetrics trainees is high worldwide and attributed to sources of stress and burnout. The role of formal education and simulation as a means to prepare trainees for stressful periods such as transition into senior roles is underexplored.

OBJECTIVE

This study set out to explore whether the creation of a dedicated educational intervention might positively influence burnout and self-estimated preparedness for practice among obstetric trainees transitioning into more senior roles.

STUDY DESIGN

A six-week preparatory training programme for year 2 trainees was created specifically for this study. The intervention used the flipped classroom design incorporating online learning that prepared participants for six simulation-based workshops. Participants were randomised by training cluster into an intervention group (n = 4) who participated in the educational intervention and a control group (n = 7) who received standard online and workplace training. The effects on trainee well-being was assessed using the Maslach burnout inventory (MBI) and a self-report questionnaire estimating preparedness for practice. Technical and non-technical skills were assessed using standardised OSAT and NOTSS assessment tools. The primary outcomes were MBI and preparedness for practice scores. Secondary outcomes included OSAT and NOTSS scores. Group comparisons were made using by t-test or Pearson Chi² analysis where appropriate.

RESULTS

The study indicated a positive, non-significant trend in pre-post burnout scores in the intervention group. The following improving trends were noted in all subscales: emotional exhaustion 21.5 ± 2.6 (pre-intervention 23 ± 6.2); depersonalisation 9.8 ± 4.0 (pre-intervention 12.3 ± 2.8); personal accomplishment 35.5 ± 6.51 (pre-intervention 33 ± 5.5). The educational intervention engendered an increase in self estimated preparedness for practice amongst the intervention group (p = 0.006). From a training perspective, increased preparedness was noted for the following practical skills: forceps delivery (p = 0.0001), rotational forceps delivery (p = 0.02), delivery of twins vaginally (p = 0.0007) and performing a pudendal block (p = 0.001).

CONCLUSION

This is one of the first studies to investigate whether the provision of a targeted training module can improve burnout scores and preparedness for practice amongst obstetrics trainees at an important time of transition. The positive but largely non-significant findings of this study should be examined in larger longitudinal and adequately powered studies.

Uterine activity in labour and the risk of neonatal encephalopathy: a case control study

OBJECTIVE

To determine the relationship between intrapartum contraction frequency, rest interval duration, and cervical dilation speed and the risk of neonatal hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

This was a retrospective case-control study conducted in a maternity hospital in Dublin, Ireland. Babies born without major congenital anomalies between September 2006 and November 2017 at ≥ 35 + 0 weeks' gestational age were eligible. Cases were diagnosed with moderate-severe HIE. The controls were the first eligible baby born before and after each case with normal Apgar scores and not admitted to the neonatal unit. Intrapartum uterine activity was assessed by automated analysis of external tocography recordings. Cervical dilation was assessed by linear interpolation between vaginal examination measurements. The speed of cervical dilation was expressed as the times from 4 to 6 cm, >6 cm to the start of pushing, and from pushing to delivery.

RESULTS

Intrapartum tocographs results were available in 49 of 88 cases and 121 of 176 controls. The median contraction rate in cases was 7.7 (Interquartile range [IQR]: 6.6-9.0) compared to 7.0 in controls (IQR: 6.2-7.9) (p = 0.021). The median rest interval duration was 56 s (IQR: 38-76) in cases and 62 s (IQR: 50-79) in controls (p = 0.058). Cases took longer to progress from > 6 cm to the start of pushing (cases: 02:58 [01:14-04:49], controls: 01:48 [00:51-03:34], p = 0.020) and from pushing to delivery (cases: 00:34 [00:24-01:10], controls: 00:27 [00:13-00:56], p = 0.036).

CONCLUSIONS

Higher contraction frequencies and slower progress towards the end of labour are both independently associated with the risk of moderate-severe HIE. Inter-contraction rest interval duration as measured by external tocography does not provide additional accuracy.

Fetal heart rate patterns in labor and the risk of neonatal encephalopathy: A case control study

OBJECTIVE

To describe the accuracy of intrapartum fetal heart rate abnormalities as defined by National Institute of Health and Care Excellence guidelines to predict moderate-severe neonatal encephalopathy of apparent hypoxic-ischemic etiology.

STUDY DESIGN

A case-control study of HIE risk factors was conducted. Eligible babies were born in a single maternity hospital in Dublin, Ireland between September 2006, and November 2017 at ≥35 + 0 weeks' gestational age. Cases were eligible babies with moderate-severe neonatal encephalopathy of definite or apparent hypoxic-ischemic etiology. Controls were eligible babies born before and after each case with normal Apgar scores. The included subjects who had intrapartum fetal heart rate recordings were identified. Pattern features (baseline rate, variability, accelerations, decelerations [early, late, variable, prolonged], bradycardia, sinusoidal pattern) were manually identified blind to all clinical details by one of the authors. Each 15-minute segment was then algorithmically categorized (uninterpretable, normal, suspicious, pathological).

RESULTS

Of 88 cases and 176 controls, 71 cases (81%) and 146 controls (83%) were admitted to the delivery suite in labor. From that group, intrapartum FHR traces longer than 15 min were available for 52 (73%) cases and 118 (83%) controls. The FHR pattern feature with the largest area under the receiver operating characteristic curve was the maximum number of consecutive segments in which the baseline was >160 bpm (0.71 [95% confidence interval: 0.62-0.80]). The category variable with the highest area under the curve was the number of suspicious segments (0.76 [95% confidence interval: 0.67-0.84]). A tri-variate logistic regression model incorporating the total number of segments, the number of "suspicious" segments classed, and the number of "pathological" segments achieved an area under the curve of 0.78 (95% confidence interval: 0.70-0.86). With 95% specificity, this model correctly identified 17 cases (33%) at a median time before delivery of 2 h and 18 min (interquartile range: 01:19-04:40).

CONCLUSIONS

The power of fetal heart rate analysis to predict neonatal encephalopathy is hampered by poor specificity given the rarity of the outcome. When analyzing a suspicious trace, it is beneficial to consider the overall duration of the suspicious pattern.

Health-related quality of life and quality of care in pregnant and postnatal women during the coronavirus disease 2019 pandemic: A cohort study

OBJECTIVE

Health-related quality of life (HRQoL) and the delivery of high-quality care are ongoing concerns when caring for pregnant women during the coronavirus disease 2019 (COVID-19) pandemic. We compared self-reported HRQoL and hospital quality of care among perinatal women with and without COVID-19.

METHODS

This is a prospective cohort study of perinatal women attending a tertiary maternity unit during the pandemic. Eighteen women who tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and 20 SARS-CoV-2-negative women were recruited. Participants completed the Short Form Health Survey (SF-12), Clinical Outcomes in Routine Evaluation-Outcome Measure, and Quality from the Patient's Perspective questionnaires. Mean scores were compared.

RESULTS

Of the Non-COVID-19 cohort, 95% (n = 19) were Caucasian, whereas 67% (n = 12) of the COVID-19 cohort were not Caucasian (χ²  = 16.01, P < 0.001). The mean SF-12 for physical health in the COVID-19 cohort had significantly lower scores (P < 0.002). There was no difference in mental health and well-being between cohorts. The quality of care experienced was notably similar and very positive.

CONCLUSION

There was a significantly greater burden on physical health among pregnant women with COVID-19. Mental health and psychological status were similar in both groups. High quality of care during a pandemic is possible to deliver in a maternity setting, irrespective of COVID-19 status.

Herpes encephalitis and hepatitis in pregnancy: A case report and literature review

We present the case of a healthy nulliparous woman who presented with persistent fever, proteinuria and elevated transaminases at 33 weeks’ gestation. Following initial treatment for suspected chorioamnionitis and potential pre-eclampsia, she had a caesarean section delivering a healthy male infant. However, on her third post-operative day, she developed neurological symptoms and accompanying severe sepsis, necessitating inotropic support and transfer to a higher level of care. A comprehensive work-up revealed Herpes Simplex Virus-2 (HSV-2) in serum and cerebrospinal fluid. Abdominal imaging was suggestive of accompanying hepatitis with micro-abscesses. This lady recovered well following intravenous acyclovir for 14 days. Her infant was not affected and was discharged home with his mother. Herpes simplex encephalitis and hepatitis associated with HSV-2 have been described three times previously in pregnancy. We delineate the diagnostic challenges that rare conditions such as this pose and emphasise the importance of multi-disciplinary care in managing complicated medical conditions in pregnancy.

Intrapartum uterine activity and neonatal outcomes: a systematic review

BACKGROUND

Increased uterine activity (UA) may not allow adequate recovery time for foetal oxygenation.

METHODS

The aim of the study was to determine if increased UA during labour is associated with an increased risk of either short- or long-term neurological injury in term neonates, or with neonatal proxy measures of intrapartum hypoxia-ischemia. MEDLINE, CINAHL, and ClinicalTrials.gov were searched using the following terms: uterine activity, excessive uterine activity, XSUA, uterine hyperstimulation, and tachysystole. Any study that analysed the relationship between UA during term labour and neurological outcomes/selected proxy neurological outcomes was eligible for inclusion. Outcomes from individual studies were reported in tables and presented descriptively with odds ratios (OR) and 95% confidence intervals (CI) for dichotomous outcomes and means with standard deviations for continuous outcomes. Where group numbers were provided, ORs and their CIs were calculated according to Altman.

MAIN RESULTS

Twelve studies met the inclusion criteria. Seven studies featured umbilical artery pH as an individual outcome. Umbilical artery base excess and Apgar scores were both reported as individual outcomes in four studies. No study examined long term neurodevelopmental outcomes and only one study reported on encephalopathy as an outcome. The evidence for a relationship between UA and adverse infant outcomes was inconsistent. The reported estimated effect size varied from non-existent to clinically significant.

CONCLUSIONS

There is some evidence that increased UA may be a non-specific predictor of depressed neurological function in the newborn, but it is inconsistent and insufficient to support the conclusion that an association generally exists.

Anal Sphincter Injury Associated with Vaginal Twin Delivery

OBJECTIVE

Obstetric anal sphincter injury remains the most common cause of fecal incontinence in women, and research in twin pregnancies is sparse. This study aimed to examine risk factors for sphincter injury in twin deliveries over a 10-year period.

STUDY DESIGN

This was a retrospective study of twin vaginal deliveries in a tertiary-level hospital over 10 years. We examined the demographics of women who had a vaginal delivery of at least one twin. Logistic regression analysis was used to examine risk factors.

RESULTS

There were 1,783 (2.1%) twin pregnancies, of which 556 (31%) had a vaginal delivery of at least one twin. Sphincter injury occurred in 1.1% (6/556) women with twins compared with 2.9% (1720/59,944) singleton vaginal deliveries. Women with sphincter injury had more instrumental deliveries (83.3 vs. 27.6%; p = 0.008). On univariate analysis, only instrumental delivery was a significant risk factor (odds ratio: 2.93; p = 0.019).

CONCLUSION

Sphincter injury occurs at a lower rate in vaginal twin pregnancies than in singletons. No twin-specific risk factors were identified. Discussion of the risk of sphincter injury should form part of patient counseling with regard to the mode of delivery.

A wavelet-based algorithm for automated analysis of external tocography: How does it compare to human interpretation?

BACKGROUND

Studies which use external tocography to explore the relationship between increased intrapartum uterine activity and foetal outcomes are feasible because the technology is safe and ubiquitous. However, periods of poor signal quality are common. We developed an algorithm which aims to calculate tocograph summary variables based on well-recorded contractions only, ignoring artefact and excluding sections deemed uninterpretable. The aim of this study was to test that algorithm's reliability.

METHODS

Whole recordings from labours at ≥35 weeks of gestation were randomly selected without regard to quality. Contractions and rest intervals were measured by two humans independently, and by the algorithm using two sets of models; one based on a series of pre-defined thresholds, and another trained to imitate one of the human interpreters. The absolute agreement intraclass correlation coefficient (ICC) was calculated using a two-way random effects model.

RESULTS

The training dataset included data from 106 tocographs. Of the tested algorithms, AdaBoost showed the highest initial cross-validated accuracy and proceeded to optimization. Forty tocographs were included in the validation set. The ICCs for the per tocograph mean contraction rates were; human B to human A: 0.940 (0.890-0.968), human A to initial models: 0.944 (0.898-0.970), human A to trained models 0.962 (0.927-0.980), human B to initial models: 0.930 (0.872-0.962), human B to trained models: 0.948 (0.903-0.972).

CONCLUSIONS

The algorithm described approximates interpretation of external tocography performed by trained humans. The performance of the AdaBoost trained models was marginally superior compared to the initial models.

Inter-hospital comparison of Cesarean delivery rates should not be considered to reflect quality of care without consideration of patient heterogeneity: An observational study

OBJECTIVE

Contemporary approaches to monitoring quality of care in obstetrics often focus on comparing Cesarean Delivery rates. Varied rates can complicate interpretation of quality of care. We previously developed a risk prediction tool for nulliparous women who may require intrapartum Cesarean delivery which identified five key predictors. Our objective with this study was to ascertain if patient heterogeneity can account for much of the observed variation in Cesarean delivery rates, thereby enabling Cesarean delivery rates to be a better marker of quality of care.

MATERIALS AND METHODS

This is a secondary analysis of the Genesis study. This was a large prospective study of 2336 nulliparous singleton pregnancies recruited at seven hospitals. A heterogeneity score was calculated for each hospital. An adjusted Cesarean delivery rate was also calculated incorporating the heterogeneous risk score.

RESULTS

A cut-off at the 90th percentile was determined for each predictive factor. Above the 90th percentile was considered to represent 'high risk' (with the exception of maternal height which identified those below the 10th percentile). The patient heterogeneous risk score was defined as the number of risk factors > 90th percentile (<10th percentile for height). An unequal distribution of high-risk patients between centers was observed (p < 0.001). The correlation between the Cesarean delivery rate and the patient heterogeneous risk score was high (0.76, p < 0.05). When adjusted for patient heterogeneity, Cesarean delivery rates became closer aligned.

CONCLUSION

Inter-institutional diversity is common. We suggest that crude comparison of Cesarean delivery rates between different hospitals as a marker of care quality is inappropriate. Allowing for marked differences in patient characteristics is essential for correct interpretation of such comparisons.

Use of the Robson Ten Group Classification System to categorise operative vaginal delivery

BACKGROUND

Operative vaginal delivery (OVD), either vacuum or forceps, can be used to expedite vaginal delivery. While rates of OVD have been reducing worldwide, rates in Ireland remain high. The Robson Ten Group Classification System (TGCS) was originally created to compare rates of caesarean delivery between healthcare units, although no similar system exists for the analysis of OVD.

AIMS

We sought to examine rates of OVD using the TGCS in an effort to understand which patient groups make significant contributions to the overall rate of OVD.

MATERIALS AND METHODS

This is a retrospective cohort study of all women delivering in a tertiary-level university institution in Dublin, Ireland, from 2007 to 2016. Mode of delivery for all patients was extracted from contemporaneously recorded hospital records. Rates of OVD were analysed according to the TGCS, and the contribution of each group to the overall hospital population was calculated.

RESULTS

There were 86 191 deliveries of women in our institution, of which 19.3% (16 673/86 191) had an OVD. Women in Group 1 (singleton, cephalic, nulliparous women at term in spontaneous labour) contributed the most to the overall rate of OVD, accounting for almost half of all OVDs (46.1% (7679/16 673)). Nulliparous women with a singleton, cephalic fetus at term who were induced (Group 2) were more likely to have an OVD than similar patients who laboured spontaneously (Group 1).

CONCLUSION

OVD accounts for almost one in five deliveries in our population and is predominately performed in nulliparous women. These groups may be the subject of interventions to lower rates of OVD. The Robson TGCS is a freely available tool to hospitals and birthing centres to facilitate comparison of rates of OVD on local and national levels.

Is Activity Tracker-Measured Ambulation an Accurate and Reliable Determinant of Postoperative Quality of Recovery? A Prospective Cohort Validation Study

BACKGROUND

Quality of recovery (QOR) instruments measure patients' ability to return to baseline health status after surgery. Whether, and the extent to which, postoperative ambulation contributes to QOR is unclear, in part due to the lack of valid tools to measure ambulation in clinical settings. This cohort study of the cesarean delivery surgical model examines the accuracy and reliability of activity trackers in quantifying early postoperative ambulation and investigates the correlation between ambulation and QOR.

METHODS

A prospective cohort of 200 parturients undergoing cesarean delivery between July 2015 and June 2017 was fitted with wrist-worn activity trackers immediately postpartum. The trackers were collected 24 hours later, along with QOR assessments (QoR-15 scale). The relationship between QOR and various covariates, including ambulation, was explored using multivariable linear regression and Spearman correlation (ρ). Forty-eight parturients fitted with 2 trackers also completed a walk exercise accompanied by a step-counting assessor, to evaluate accuracy, inter-, and intradevice reliability using interclass correlation (ICC).

RESULTS

Compared to step counting, activity trackers had high accuracy (ICC = 0.93) and excellent inter- and intradevice reliability (ICC = 0.98 and 0.96, respectively). Correlation analysis suggested that early ambulation is moderately correlated with postcesarean QoR-15 scores, with a ρ (95% confidence interval) equivalent to 0.56 (0.328-0.728). Regression analysis suggested that ambulation is a determinant of postcesarean QoR-15 scores, with an effect estimate (95% confidence interval) equivalent to 0.002 (0.001-0.003). Ambulation was also associated with all QoR-15 domains, except psychological support. The patient's acceptable symptom state (subjective threshold for good ambulation) in the first 24 hours was 287 steps.

CONCLUSIONS

This study demonstrated the accuracy and reliability of activity trackers in measuring ambulation in clinical settings and suggested that postoperative ambulation is a determinant of postoperative QOR. A hypothetical implication of our findings is that interventions that improve ambulation may also help to enhance QOR, but further research is needed to establish a causal relationship.

Sonographic markers of fetal adiposity and risk of Cesarean delivery

OBJECTIVE

Increased fetal size is associated with shoulder dystocia during labor and subsequent need for assisted delivery. We sought to investigate if increased fetal adiposity diagnosed sonographically in late pregnancy is associated with increased risk of operative delivery.

METHODS

This secondary analysis of the Genesis Study recruited 2392 nulliparous women with singleton pregnancy in cephalic presentation, in a prospective, multicenter study, to examine prenatal and intrapartum predictors of Cesarean delivery. Participants underwent ultrasound and clinical evaluation between 39 + 0 and 40 + 6 weeks' gestation. Data on fetal biometry were not revealed to patients or to their managing clinicians. A fetal adiposity composite of fetal thigh adiposity and fetal abdominal wall thickness was compiled for each infant in order to determine whether fetal adiposity > 90^th centile was associated with an increased risk of Cesarean or operative vaginal delivery.

RESULTS

After exclusions, data were available for 2330 patients. Patients with a fetal adiposity composite > 90^th centile had a higher maternal body mass index (BMI) (25 ± 5 kg/m² vs 24 ± 4 kg/m² ; P = 0.005), birth weight (3872 ± 417 g vs 3585 ± 401 g; P < 0.0001) and rate of induction of labor (47% (108/232) vs 40% (834/2098); P = 0.048) than did those with an adiposity composite ≤ 90^th centile. Fetuses with adiposity composite > 90^th centile were more likely to require Cesarean delivery than were those with adiposity composite ≤ 90^th centile (P < 0.0001). After adjusting for birth weight, maternal BMI and need for induction of labor, fetal adiposity > 90^th centile remained a risk factor for Cesarean delivery (P < 0.0001). A fetal adiposity composite > 90^th centile was more predictive of the need for unplanned Cesarean delivery than was an estimated fetal weight > 90^th centile (odds ratio, 2.20 (95% CI, 1.65-2.94; P < 0.001) vs 1.74 (95% CI, 1.29-2.35; P < 0.001). Having an adiposity composite > 90^th centile was not associated with an increased likelihood of operative vaginal delivery when compared with having an adiposity composite ≤ 90^th centile (P = 0.37).

CONCLUSIONS

Fetuses with increased adipose deposition are more likely to require Cesarean delivery than are those without increased adiposity. Consideration should, therefore, be given to adding fetal thigh adiposity and abdominal wall thickness to fetal sonographic assessment in late pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

A simple clinical method to identify women at higher risk of preeclampsia

An outstanding issue is how to efficiently identify women at high risk of preeclampsia. This retrospective cohort study included 8672 pregnancies at a single centre in Toronto. We tested our simple method - presence vs. absence of≥1 major (pre-pregnancy BMI>30kg/m², chronic hypertension, pre-pregnancy diabetes mellitus and assisted reproductive therapy) or≥2 minor (prior stillbirth, age>40years, nulliparity, multifetal pregnancy, chronic kidney disease, and SLE) risk factors for PE. The RR of PE was 8.4 (95% CI 5.3-13.2) and the model C-statistic 0.74 (95% CI 0.69-0.79). Further testing of this method elsewhere is warranted.

Pregnancy-specific stress, fetoplacental haemodynamics, and neonatal outcomes in women with small for gestational age pregnancies: a secondary analysis of the multicentre Prospective Observational Trial to Optimise Paediatric Health in Intrauterine Growth Restriction

OBJECTIVES

To examine associations between maternal pregnancy-specific stress and umbilical (UA PI) and middle cerebral artery pulsatility indices (MCA PI), cerebroplacental ratio, absent end diastolic flow (AEDF), birthweight, prematurity, neonatal intensive care unit admission and adverse obstetric outcomes in women with small for gestational age pregnancies. It was hypothesised that maternal pregnancy-specific stress would be associated with fetoplacental haemodynamics and neonatal outcomes.

DESIGN

This is a secondary analysis of data collected for a large-scale prospective observational study.

SETTING

This study was conducted in the seven major obstetric hospitals in Ireland and Northern Ireland.

PARTICIPANTS

Participants included 331 women who participated in the Prospective Observational Trial to Optimise Paediatric Health in Intrauterine Growth Restriction. Women with singleton pregnancies between 24 and 36 weeks gestation, estimated fetal weight <10th percentile and no major structural or chromosomal abnormalities were included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Serial Doppler ultrasound examinations of the umbilical and middle cerebral arteries between 20 and 42 weeks gestation, Pregnancy Distress Questionnaire (PDQ) scores between 23 and 40 weeks gestation and neonatal outcomes.

RESULTS

Concerns about physical symptoms and body image at 35-40 weeks were associated with lower odds of abnormal UAPI (OR 0.826, 95% CI 0.696 to 0.979, p=0.028). PDQ score (OR 1.073, 95% CI 1.012 to 1.137, p=0.017), concerns about birth and the baby (OR 1.143, 95% CI 1.037 to 1.260, p=0.007) and concerns about physical symptoms and body image (OR 1.283, 95% CI 1.070 to 1.538, p=0.007) at 29-34 weeks were associated with higher odds of abnormal MCA PI. Concerns about birth and the baby at 29-34 weeks (OR 1.202, 95% CI 1.018 to 1.421, p=0.030) were associated with higher odds of AEDF. Concerns about physical symptoms and body image at 35-40 weeks were associated with decreased odds of neonatal intensive care unit admission (OR 0.635, 95% CI 0.435 to 0.927, p=0.019).

CONCLUSIONS

These findings suggest that fetoplacental haemodynamics may be a mechanistic link between maternal prenatal stress and fetal and neonatal well-being, but additional research is required.

Evaluation of normalization of cerebro-placental ratio as a potential predictor for adverse outcome in SGA fetuses

BACKGROUND

Intrauterine growth restriction accounts for a significant proportion of perinatal morbidity and mortality currently encountered in obstetric practice. The primary goal of antenatal care is the early recognition of such conditions to allow treatment and optimization of both maternal and fetal outcomes. Management of pregnancies complicated by intrauterine growth restriction remains one of the greatest challenges in obstetrics. Frequently, however, clinical evidence of underlying uteroplacental dysfunction may only emerge at a late stage in the disease process. With advanced disease the only therapeutic intervention is delivery of the fetus and placenta. The cerebroplacental ratio is gaining much interest as a useful tool in differentiating the at-risk fetus in both intrauterine growth restriction and the appropriate-for-gestational-age setting. The cerebroplacental ratio quantifies the redistribution of the cardiac output resulting in a brain-sparing effect. The Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction group previously demonstrated that the presence of a brain-sparing effect is significantly associated with an adverse perinatal outcome in the intrauterine growth restriction cohort.

OBJECTIVE

The aim of the Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction study was to evaluate the optimal management of fetuses with an estimated fetal weight <10th centile. The objective of this secondary analysis was to evaluate if normalizing cerebroplacental ratio predicts adverse perinatal outcome.

STUDY DESIGN

In all, 1116 consecutive singleton pregnancies with intrauterine growth restriction completed the study protocol over 2 years at 7 centers, undergoing serial sonographic evaluation and multivessel Doppler measurement. Cerebroplacental ratio was calculated using the pulsatility and resistance indices of the middle cerebral and umbilical artery. Abnormal cerebroplacental ratio was defined as <1.0. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death.

RESULTS

Data for cerebroplacental ratio calculation were available in 881 cases, with a mean gestational age of 33 (interquartile range, 28.7-35.9) weeks. Of the 87 cases of abnormal serial cerebroplacental ratio with an initial value <1.0, 52% (n = 45) of cases remained abnormal and 22% of these (n = 10) had an adverse perinatal outcome. The remaining 48% (n = 42) demonstrated normalizing cerebroplacental ratio on serial sonography, and 5% of these (n = 2) had an adverse perinatal outcome. Mean gestation at delivery was 33.4 weeks (n = 45) in the continuing abnormal cerebroplacental ratio group and 36.5 weeks (n = 42) in the normalizing cerebroplacental ratio group (P value <.001).

CONCLUSION

The Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction group previously demonstrated that the presence of a brain-sparing effect was significantly associated with an adverse perinatal outcome in our intrauterine growth restriction cohort. It was hypothesized that a normalizing cerebroplacental ratio would be a further predictor of an adverse outcome due to the loss of this compensatory mechanism. However, in this subanalysis we did not demonstrate an additional poor prognostic effect when the cerebroplacental ratio value returned to a value >1.0. Overall, this secondary analysis demonstrated the importance of a serial abnormal cerebroplacental ratio value of <1 within the <34 weeks' gestation population. Contrary to our proposed hypothesis, we recognize that reversion of an abnormal cerebroplacental ratio to a normal ratio is not associated with a heightened degree of adverse perinatal outcome.

Prenatal prediction of significant intertwin birthweight discordance using standard second and third trimester sonographic parameters

INTRODUCTION

Our study aim was to evaluate standard ultrasound-derived fetal biometric parameters in the prediction of clinically significant intertwin birthweight discordance defined as ≥18%.

MATERIAL AND METHODS

This was a secondary analysis of a prospective cohort study of 1028 unselected twin pairs recruited over a two-year period. Dichorionic twins underwent two-weekly ultrasonographic surveillance from 24 weeks' gestation, with surveillance of monochorionic twins two-weekly from 16 weeks. Ultrasonographic biometric data from 24 to 36 weeks were evaluated for the prediction of an intertwin birthweight discordance threshold ≥18%. Umbilical artery Doppler waveform data was also analyzed to evaluate whether it was predictive of birthweight discordance.

RESULTS

Of the 956 twin pairs analyzed for discordance, 208 pairs were found to have a clinically significant birthweight discordance ≥18%. All biometric parameters were predictive of significant inter-twin birthweight discordance at low cut-offs, with low discriminatory powers when ROC curves were analyzed. Discordance in estimated fetal weight was predictive of a significant birthweight discordance at all gestational categories with cut-offs between 8 and 11%. A low-discriminatory power and poor sensitivity and specificity were also observed. An abnormal umbilical artery Doppler was predictive of birthweight discordance ≥18% between 28 and 32 weeks' gestation, although with poor sensitivity and specificity.

CONCLUSIONS

Calculation of estimated fetal weight and birthweight discordance between twins allows minimal margin for error. These margins make it difficult to accurately predict those who are at or above the discordance threshold of 18%. These findings highlight that small intertwin discrepancies in weight and biometry should not be overlooked and merit further investigation.

Altered Platelet Function in Intrauterine Growth Restriction: A Cause or a Consequence of Uteroplacental Disease?

Objective A limited number of platelet function studies in intrauterine growth restriction (IUGR) have yielded conflicting results. We sought to evaluate platelet reactivity in IUGR using a novel platelet aggregation assay. Study Design Pregnancies with IUGR were recruited from 24 weeks' gestation (estimated fetal weight < 10th centile) and had platelet function testing performed after diagnosis. A modification of light transmission aggregometry created dose-response curves of platelet reactivity in response to multiple agonists at differing concentrations. Findings were compared with healthy third trimester controls. IUGR cases with a subsequent normal birth weight were analyzed separately. Results In this study, 33 pregnancies retained their IUGR diagnosis at birth, demonstrating significantly reduced platelet reactivity in response to all agonists (arachidonic acid, adenosine diphosphate, collagen, thrombin receptor-activating peptide, and epinephrine) when compared with 36 healthy pregnancy controls (p < 0.0001). Similar results were obtained for cases demonstrating an increasing in utero growth trajectory. When IUGR preceded preeclampsia or gestational hypertension, platelet function was significantly reduced compared with normotensive IUGR. Conclusion Using this comprehensive platelet assay, we have demonstrated a functional impairment of platelets in IUGR. This may reflect platelet-derived placental growth factor release. Further evaluation of platelet function may aid in the development of future platelet-targeted therapies for uteroplacental disease.

Gestational hypertensive disease in twin pregnancy: Influence on outcomes in a large national prospective cohort

OBJECTIVE

Gestational hypertensive disease (GHD) is associated with pregnancy-related complications and poor maternal and fetal outcomes in singleton pregnancies. We sought to examine the influence of GHD in a large prospective cohort of twin pregnancies.

STUDY DESIGN

The ESPRIT study was a national multicenter observational cohort study of 1028 structurally normal twin pregnancies. Each pregnancy underwent sonographic surveillance with two-week ultrasound from 24 weeks for dichorionic and from 16 weeks for monochorionic gestations. Characteristics and demographics as well as labour and delivery outcome data were prospectively recorded. Perinatal mortality, admission to the neonatal intensive care unit (NICU) and a composite of morbidity of respiratory distress syndrome, hypoxic ischaemic encephalopathy, periventricular leukomalacia, necrotising enterocolitis and sepsis were documented for all cases. Outcomes for patients with documented GHD (pre-eclampsia and gestational hypertension) were compared with those without GHD.

RESULTS

Perinatal outcome data were recorded for 977 patients. Women with GHD had a higher body mass index (27.1 ± 6.4 vs 25.2 ± 4.5, P < 0.0001) than those without and were more likely to be nulliparous (65% (59/92) vs 46% (407/885), P = 0.001). Both groups had similar mean birthweights, but those with GHD were more likely to have a birthweight discordance ≥18% (35% (32/92) vs 20% (179/885), P = 0.001). Rates of caesarean delivery were higher in those twin pregnancies affected by GHD, and while the rate of composite morbidity was similar in both groups, twins in the GHD group had higher rates of NICU admission.

CONCLUSION

In twin gestations, gestational hypertension independently confers an increased risk for emergency caesarean delivery, birthweight discordance and NICU admission, such that intensive maternal-fetal monitoring is justified when hypertension develops in a twin pregnancy.

The effect of maternal obesity on sonographic fetal weight estimation and perinatal outcome in pregnancies complicated by fetal growth restriction

PURPOSE

Maternal obesity represents a challenge in the sonographic (US) assessment of fetal weight, and is a recognized risk factor for adverse pregnancy outcome. The objective of this secondary analysis of data from the Prospective Observational Trial to Optimize Pediatric Health in fetal growth restriction (FGR) Study (PORTO) was to describe the effect of maternal obesity on the accuracy of US in determining the estimated fetal weight (EFW) and the perinatal outcome of pregnancies affected by FGR.

METHODS

Between 2010 and 2012, 1,116 women with nonanomalous singleton pregnancies with an EFW in less than the tenth centile were recruited for the PORTO study. Maternal body mass index (BMI) was divided into five subcategories: normal (BMI < 24.9 kg/m(2) ), overweight (25-29.9), obese class 1 (30-34.9), obese class 2 (35-39.9), and obese class 3 (>40). The accuracy of the EFW was determined in women who delivered within 2 weeks of their last US scan. Perinatal outcomes were analyzed by BMI subcategory.

RESULTS

Of the 1,074 patients with complete records, 691 (64%) were of normal weight, 258 (24%) were overweight, 93 (9%) were in obese class 1, 32 (3%) were in obese class 2, and none were in obese class 3. Overall, the EFW determined prior to delivery was within 6% of the actual birth weight in all BMI subcategories. Overweight and obese women delivered more commonly by cesarean section and at earlier gestational ages than did women with a normal BMI (p = 0.0008), resulting in lower birth weights (p = 0.0031) and significantly increased composite perinatal morbidity (p < 0.0001) and mortality (p = 0.0215) rates.

CONCLUSIONS

US examination is reliable for assessing the weight of fetuses with FGR in overweight women. Maternal obesity, however, has a significant adverse effect on perinatal outcomes. Thus, health education should focus on awareness of this adverse effect, with optimization of prepregnancy weight as its main goal.

The effect of maternal subclinical hypothyroidism on IQ in 7- to 8-year-old children: A case-control review

BACKGROUND

In Ireland, pregnant women are not routinely screened for subclinical hypothyroidism (SCH).

AIM

Our objective was to compare the intelligence quotient (IQ) of children whose mothers had been diagnosed with SCH prenatally with matched controls using a case-control retrospective study.

MATERIALS AND METHODS

In a previous study from our group, 1000 healthy nulliparous women were screened anonymously for SCH. This was a laboratory diagnosis involving elevated TSH with normal fT4 or normal TSH with hypothyroxinaemia. We identified 23 cases who agreed to participate. These were matched with 47 controls. All children underwent neurodevelopmental assessment at age 7-8. Wechsler Intelligence Scale for Children IV assessment scores were used to compare the groups. Our main outcome measure was to identify whether there was a difference in IQ between the groups.

RESULTS

From the cohort of cases, 23 mothers agreed to the assessment of their children as well as 47 controls. The children in the control group had higher mean scores than those in the case group across Verbal Comprehension Intelligence, Perceptual Reasoning Intelligence, Working Memory Intelligence, Processing Speed Intelligence and Full Scale IQ. Mann-Whitney U-test confirmed a significant difference in IQ between the cases (composite score 103.87) and the controls (composite score 109.11) with a 95% confidence interval (0.144, 10.330).

CONCLUSIONS

Our results highlight significant differences in IQ of children of mothers who had unrecognised SCH during pregnancy. While our study size and design prevents us from making statements on causation, our data suggest significant potential public health implications for routine prenatal screening.

Defining the residual risk of adverse perinatal outcome in growth-restricted fetuses with normal umbilical artery blood flow

OBJECTIVE

We sought to determine the cause of adverse perinatal outcome in fetal growth restriction (FGR) where umbilical artery (UA) Doppler was normal, as identified from the Prospective Observational Trial to Optimize Pediatric Health (PORTO). We compared cases of adverse outcome where UA Doppler was normal and abnormal.

STUDY DESIGN

The PORTO study was a national multicenter study of >1100 ultrasound-dated singleton pregnancies with an estimated fetal weight <10th centile. Each pregnancy underwent intensive ultrasound, including multivessel Doppler. UA Doppler was considered abnormal when the pulsatility index was >95th centile or end-diastolic flow was absent/reversed. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, or death.

RESULTS

In all, 57 (5.0%) of the 1116 fetuses had an adverse perinatal outcome. Nine (1.3%) of 698 fetuses with normal UA Doppler had an adverse outcome, compared with 48 (11.5%) of 418 with abnormal UA Doppler (P < .0001). There were 2 perinatal deaths in the normal group and 6 in the abnormal group (P = .01). The perinatal deaths in the normal group were 1 case of pulmonary hypoplasia after prolonged preterm rupture of the membranes from 12 weeks' gestation and a case of placental abruption. Gestation at delivery was 33 ± 3 vs 31 ± 4 weeks (P = .05) and mean birthweight was 1830 ± 737 vs 1146 ± 508 g (P = .001) in the respective groups. Neonatal sepsis was the commonest adverse outcome in both groups: 0.1% and 0.4%, respectively (P = .01).

CONCLUSION

Adverse perinatal outcome is uncommon in FGR with normal UA Doppler. The cases we identified were associated with heterogenous pathologies. FGR with normal UA blood flow is a largely benign condition.

The role of brain sparing in the prediction of adverse outcomes in intrauterine growth restriction: results of the multicenter PORTO Study

OBJECTIVE

The aim of the Prospective Observational Trial to Optimize Pediatric Health in IUGR Study was to evaluate the optimal management of fetuses with an estimated fetal weight less than the 10th centile. The objective of this secondary analysis was to describe the role of the cerebroplacental ratio (CPR) in the prediction of adverse perinatal outcome.

STUDY DESIGN

More than 1100 consecutive singleton pregnancies with intrauterine growth restriction (IUGR) were recruited over 2 years at 7 centers, undergoing serial sonographic evaluation including multivessel Doppler measurement. CPR was calculated using the pulsatility and resistance indices of the middle cerebral and umbilical artery. Adverse perinatal outcome was defined as a composite of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death.

RESULTS

Data for CPR calculation was available in 881 cases, which was performed at a mean gestational age of 33 weeks (interquarile range, 28.7-35.9). Of the 146 cases with CPR less than 1, 18% (n = 27) had an adverse perinatal outcome. This conferred an 11-fold increased risk (odds ratio, 11.7; P < .0001) when compared with cases with normal CPR (2%; 14 of 735). An abnormal CPR was present in all 3 cases of mortality. Prediction of adverse outcomes was comparable when using all definitions of abnormal CPR.

CONCLUSION

Irrespective of the CPR calculation used, brain sparing is significantly associated with an adverse perinatal outcome in IUGR. This adds further weight to integrating CPR evaluation into the clinical assessment of IUGR pregnancies. The impact of this finding on long-term neurodevelopmental outcomes in this patient cohort is underway.

A rapidly enlarging cutaneous hemangioma in pregnancy

This is a case of a rapidly enlarging cutaneous pedunculated tumor on a patient’s thumb during her pregnancy. This was excised and identified as a hemangioma. A literature search identified a possible hormonal factor in causing an accelerated growth of this tumor.

Perinatal outcomes of women with a prior history of unexplained recurrent miscarriage

OBJECTIVE

We sought to determine subsequent pregnancy outcomes in a cohort of women with a history of unexplained recurrent miscarriage (RM) who were not receiving medical treatment.

STUDY DESIGN

This was a prospective cohort study, of women with a history of three unexplained consecutive first trimester losses, who were recruited and followed in their subsequent pregnancy. Control patients were healthy pregnant patients with no previous adverse perinatal outcome.

RESULTS

A total of 42 patients with a history of unexplained RM were recruited to the study. About nine (21.4%) experienced a further first trimester miscarriage, one case of ectopic and one case of partial molar pregnancy. About 74% (23/31) of the RM cohort had a vaginal delivery. There was one case of severe pre-eclampsia. The RM group delivered at a mean gestational age of 38 + 2 weeks and with a mean birthweight of 3.23 kg. None of the neonates were under the 10th centile for gestational age. Overall, there was no significant difference in pregnancy outcomes between the two cohorts.

CONCLUSION

Our study confirms the reassuring prognosis for achieving a live birth in the unexplained RM population with a very low incidence of adverse events with the majority delivering appropriately grown fetuses at term.

The influence of maternal body mass index on fetal weight estimation in twin pregnancy

OBJECTIVE

Sonographic estimated fetal weight (EFW) is important in the management of high-risk pregnancies. The possibility that increased maternal body mass index (BMI) adversely affects EFW assessments in twin pregnancies is controversial. The aim of this study was to investigate the effect of maternal BMI on the accuracy of EFW assessments in twin gestations prospectively recruited for the ESPRiT (Evaluation of Sonographic Predictors of Restricted growth in Twins) study.

STUDY DESIGN

One thousand one twin pair pregnancies were recruited. After exclusion, BMI, birthweights, and ultrasound determination of EFW (within 2 weeks of delivery) were available for 943 twin pairs. The accuracy of EFW determination was defined as the difference between EFW and actual birthweight for either twin (absolute difference and percent difference). Cells with less than 5% of the population were combined for analysis resulting in the following 3 maternal categories: (1) normal/underweight, (2) overweight, and (3) obese/extremely obese.

RESULTS

Analysis of the 3 categories revealed mean absolute variation values of 184 g (8.0%) in the normal/underweight group (n = 531), 196 g (8.5%) in the overweight group (n = 278), and 206 g (8.6%) in the obese/extremely obese group (n = 134) (P = .028, which was nonsignificant after adjustment for multiple testing). Regression analysis showed no linear or log-linear relationship between BMI and the accuracy of EFW (P value for absolute difference = .11, P value for percentage difference = .27).

CONCLUSION

Contrary to a commonly held clinical impression, increasing maternal BMI has no significant impact on the accuracy of EFW in twin pregnancy.

Fetal growth restriction and the risk of perinatal mortality-case studies from the multicentre PORTO study

Background

Intrauterine growth restriction (IUGR) is the single largest contributing factor to perinatal mortality in non-anomalous fetuses. Advances in antenatal and neonatal critical care have resulted in a reduction in neonatal deaths over the past decades, while stillbirth rates have remained unchanged. Antenatal detection rates of fetal growth failure are low, and these pregnancies carry a high risk of perinatal death.

Methods

The Prospective Observational Trial to Optimize Paediatric Health in IUGR (PORTO) Study recruited 1,200 ultrasound-dated singleton IUGR pregnancies, defined as EFW <10^th centile, between 24⁺⁰ and 36⁺⁶ weeks gestation. All recruited fetuses underwent serial sonographic assessment of fetal weight and multi-vessel Doppler studies until birth. Perinatal outcomes were recorded for all pregnancies. Case records of the perinatal deaths from this prospectively recruited IUGR cohort were reviewed, their pregnancy details and outcome were analysed descriptively and compared to the entire cohort.

Results

Of 1,116 non-anomalous singleton infants with EFW <10^th centile, 6 resulted in perinatal deaths including 3 stillbirths and 3 early neonatal deaths. Perinatal deaths occurred between 24⁺⁶ and 35⁺⁰ weeks gestation corresponding to birthweights ranging from 460 to 2260 grams. Perinatal deaths occurred more commonly in pregnancies with severe growth restriction (EFW <3^rd centile) and associated abnormal Doppler findings resulting in earlier gestational ages at delivery and lower birthweights. All of the described pregnancies were complicated by either significant maternal comorbidities, e.g. hypertension, systemic lupus erythematosus (SLE) or diabetes, or poor obstetric histories, e.g. prior perinatal death, mid-trimester or recurrent pregnancy loss. Five of the 6 mortalities occurred in women of non-Irish ethnic backgrounds. All perinatal deaths showed abnormalities on placental histopathological evaluation.

Conclusions

The PNMR in this cohort of prenatally identified IUGR cases was 5.4/1,000 and compares favourably to the overall national rate of 4.1/1,000 births, which can be attributed to increased surveillance and timely delivery. Despite antenatal recognition of IUGR and associated maternal risk factors, not all perinatal deaths can be prevented.

Eclampsia: trends in incidence and outcomes over 30 years

OBJECTIVE

This study set out to describe the incidence, mortality rates, and treatment of eclampsia over a 30-year period in a large urban population.

STUDY DESIGN

A detailed report of all pregnancies delivered in the Dublin area from 1977 to 2006 was reviewed for incidence, mortality, and treatment of eclampsia. Almost all pregnancies in this area are managed at one of three major obstetric hospitals. All offer comprehensive antenatal care and operate a restrictive policy to magnesium sulfate prophylaxis, in which MgSO4 is reserved for patients with severe preeclampsia or who have already had an eclamptic seizure.

RESULTS

During the 30-year study period, there were a total of 626,929 deliveries. Of the 247 cases of eclampsia (3.9/10,000 deliveries) and four maternal deaths (0.63/100,000 deliveries) attributed to eclampsia, none received MgSO4. The mortality rate due to eclampsia was 1.6% (4/247). The use of MgSO4 increased significantly from 11% (13/115) in the first decade of the study to 88.1% (67/76) in the last decade (p < 0.001). The incidence of eclampsia decreased from 5.4/10,000 in the first decade to 3.5/10,000 in the final decade of the study (p < 0.0001).

CONCLUSION

Over the study period, MgSO4 has become the leading antiseizure medication used, and this has led to a significant decrease in rates of eclampsia.

The correlation of ultrasonographic placental architecture with placental histology in the low-risk primigravid population

AIM

To determine the association, if any, between placental architecture findings assessed ultrasonographically at 22 and 36 weeks and placental histology.

METHODS

There was prospective recruitment of 1011 low-risk primigravids from the antenatal clinic at the Rotunda Hospital, Dublin, Ireland. Ultrasound of the placenta was performed at 22 and 36 weeks and histological assessment was made of the placenta of all participants.

RESULTS

Complete data pertaining to ultrasound and placental histology was available for 810 women (80%). Placental calcification on ultrasound in the third trimester was associated with a higher incidence of placental infarction identified following placental histology (80.0% vs. 21.5%; P=0.009: r=0.115). The placental thickness on ultrasound in the second trimester was less in cases complicated by chorioamnionitis (2.62 cm vs. 3.07 cm; P=0.039: r=-0.176). Chronic villitis was associated with a statistically significant increased incidence of antenatal placental infarction identified on ultrasound in the third trimester (10.7% vs. 1.9%; P=0.020: r=0.113). Intervillous thrombi occurred more frequently in cases with reduced placental thickness on ultrasound in the second trimester (3.0 cm vs. 3.3 cm; P=0.035: r=-0.171).

CONCLUSIONS

Antenatal ultrasound of the placenta may aid detection of placental disease, particularly in the identification of placental infarction.