Comparison of visual and computerised antenatal cardiotocography in the prevention of perinatal morbidity and mortality. A systematic review and meta-analysis

INTRODUCTION

Antenatal cardiotocography (CTG) is used to monitor fetal well-being. There are two methods: visual (vCTG) or computerised (cCTG). An earlier Cochrane review compared the effects of both approaches on maternal and fetal outcomes. The objective of this systematic review was to update this search and identify studies not included in the Cochrane review.

MATERIALS AND METHODS

MEDLINE, EMBASE, CINAHL and MIDIRS databases were searched up to February 2021. We included randomised controlled trials (RCT) and non-randomised studies (NRS) of pregnant women receiving antenatal CTG with comparison of cCTG to vCTG and clinical outcomes. The Cochrane Risk of Bias Tool and Joanna Briggs Institute Critical Appraisal Checklist were used for quality assessment. Data is presented as risk ratios with 95% confidence intervals and I² is used as the statistical measure of heterogeneity.

RESULTS

Three RCTs and three NRS were included. Meta-analysis of RCTs demonstrated a non-significant reduction in all-cause perinatal mortality (RR 0.23 [95%CI 0.04-1.30]), preventable perinatal mortality excluding congenital anomalies (RR 0.27 [95% CI 0.05-1.56]) and cesarean section (RR 0.91 [95%CI 0.68-1.22]). All RCTs included high-risk women and had a high risk of bias. There was one antenatal stillbirth across the three RCTs (n = 497). The NRS were at high-risk of bias and statistical analysis was not possible due to heterogeneity. Individual findings suggest reduced investigation and better prediction of neonatal outcomes with cCTG.

CONCLUSIONS

There is a non-significant reduction in perinatal mortality with cCTG. Despite no clear reduction in perinatal mortality and morbidity with cCTG, it is objective and may reduce time spent in hospital and further investigations for women.

COngenital heart disease and the Diagnostic yield with Exome sequencing (CODE) study: prospective cohort study and systematic review

OBJECTIVE

To determine the incremental yield of antenatal exome sequencing (ES) over chromosomal microarray analysis (CMA) or conventional karyotyping in prenatally diagnosed congenital heart disease (CHD).

METHODS

A prospective cohort study of 197 trios undergoing ES following CMA or karyotyping owing to CHD identified prenatally and a systematic review of the literature were performed. MEDLINE, EMBASE, CINAHL and ClinicalTrials.gov (January 2000 to October 2019) databases were searched electronically for studies reporting on the diagnostic yield of ES in prenatally diagnosed CHD. Selected studies included those with more than three cases, with initiation of testing based upon prenatal phenotype only and that included cases in which CMA or karyotyping was negative. The incremental diagnostic yield of ES was assessed in: (1) all cases of CHD; (2) isolated CHD; (3) CHD associated with extracardiac anomaly (ECA); and (4) CHD according to phenotypic subgroup.

RESULTS

In our cohort, ES had an additional diagnostic yield in all CHD, isolated CHD and CHD associated with ECA of 12.7% (25/197), 11.5% (14/122) and 14.7% (11/75), respectively (P = 0.81). The corresponding pooled incremental yields from 18 studies (encompassing 636 CHD cases) included in the systematic review were 21% (95% CI, 15-27%), 11% (95% CI, 7-15%) and 37% (95% CI, 18-56%), respectively. The results did not differ significantly when subanalysis was limited to studies including more than 20 cases, except for CHD associated with ECA, in which the incremental yield was greater (49% (95% CI, 17-80%)). In cases of CHD associated with ECA in the primary analysis, the most common extracardiac anomalies associated with a pathogenic variant were those affecting the genitourinary system (23/52 (44.2%)). The greatest incremental yield was in cardiac shunt lesions (41% (95% CI, 19-63%)), followed by right-sided lesions (26% (95% CI, 9-43%)). In the majority (68/96 (70.8%)) of instances, pathogenic variants occurred de novo and in autosomal dominant (monoallelic) disease genes. The most common (19/96 (19.8%)) monogenic syndrome identified was Kabuki syndrome.

CONCLUSIONS

There is an apparent incremental yield of prenatal ES in CHD. While the greatest yield is in CHD associated with ECA, consideration could also be given to performing ES in the presence of an isolated cardiac abnormality. A policy of routine application of ES would require the adoption of robust bioinformatic, clinical and ethical pathways. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Cause of intrauterine and neonatal death in twin pregnancies (CoDiT): development of a novel classification system

OBJECTIVE

Twin pregnancies have a significantly higher perinatal mortality than singleton pregnancies. Current classification systems for perinatal death lack twin-specific categories, potentially leading to loss of important information regarding cause of death. We introduce and test a classification system designed to assign a cause of death in twin pregnancies (CoDiT).

DESIGN

Retrospective cross-sectional study.

SETTING

Tertiary maternity unit in England with a perinatal pathology service.

POPULATION

Twin pregnancies in the West Midlands affected by fetal or neonatal demise of one or both twins between 1 January 2005 and 31 December 2016 in which postmortem examination was undertaken.

METHODS

A multidisciplinary panel designed CoDiT by adapting the most appropriate elements of singleton classification systems. The system was tested by assigning cause of death in 265 fetal and neonatal deaths from 144 twin pregnancies. Cause of death was validated by another obstetrician blinded to the original classification.

MAIN OUTCOME MEASURES

Inter-rater, intra-rater, inter-disciplinary agreement and cause of death.

RESULTS

Cohen's Kappa demonstrated 'strong' (>0.8) inter-rater, intra-rater and inter-disciplinary agreement (95% CI 0.70-0.91). The commonest cause of death irrespective of chorionicity was the placenta; twin-to-twin transfusion syndrome (TTTS) was the commonest placental cause in monochorionic twins and acute chorioamnionitis in dichorionic twins.

CONCLUSIONS

This novel classification system records causes of death in twin pregnancies from postmortem reports with high inter-user agreement. We highlight differences in aetiology of death between monochorionic and dichorionic twins.

TWEETABLE ABSTRACT

New classification system for #twin cause of death 'CoDiT' shows high rater agreement.

MicroRNA changes in maternal serum from pregnancies complicated by twin-twin transfusion syndrome: A discovery study

Objective

MicroRNAs (miRNAs) are used as biomarkers in cardiovascular disease and cancer. miRNAs are involved in placental development but have not previously been investigated in twin‐twin transfusion syndrome (TTTS). Our aim is to explore the miRNA profile of TTTS pregnancies.

Method

Initial miRNA profiling was performed using a reverse transcription polymerase chain reaction (RT‐PCR) panel on maternal serum samples taken from five women prior to fetoscopic laser ablation for TTTS and compared with serum samples from five women with uncomplicated monochorionic diamniotic twin pregnancies. Validation RT‐PCR was performed in an additional cohort of eight TTTS pregnancies and eight uncomplicated pregnancies.

Results

Median gestational age at sampling in the TTTS and control groups was 20⁺⁰ weeks (interquartile range [IQR], 19⁺⁴‐20⁺⁰) and 20⁺² weeks (IQR, 20⁺⁰‐20⁺²), respectively. All samples passed quality control. One control sample was excluded as a biological outlier. Thirty‐one of 752 miRNAs were significantly different: 17 were upregulated and 14 downregulated in the TTTS group, although they did not remain significant following Benjamini‐Hochberg correction for multiple testing. The six miRNAs chosen for validation demonstrated no significant difference.

Conclusion

This is the first study to investigate miRNA changes in TTTS pregnancies. We did not demonstrate a statistically significant difference in miRNAs in TTTS pregnancies, but further investigation is required.

Congenital urinary tract obstruction

Congenital bladder neck obstruction (or lower urinary tract obstruction [LUTO]) describes a heterogeneous group of congenital anomalies presenting with similar prenatal ultrasonographic findings of dilated posterior urethra, megacystis, hydronephrosis, oligohydramnios and often with associated renal dysplasia. Untreated LUTO has high rate of perinatal morbidity and mortality from associated pulmonary hypoplasia and early-onset renal failure in infancy. Ultrasonographic features and prospective fetal urinalysis may help in predicting the overall prognosis of congenital LUTO. Currently, fetal vesicoamniotic shunt (of various designs), and fetal cystoscopy and fulguration of the obstruction are potential prenatal interventions. Retrospective and prospective cohort studies and a relatively small randomized controlled trial have demonstrated these treatments may possibly improve perinatal survival. Despite this, concerns remain as to the high rates of renal impairment observed in paediatric survivors. A clinical prospective scoring/staging system may improve prenatal diagnostic criteria and case selection for fetal therapy.

Prognosis of the co-twin following spontaneous single intrauterine fetal death in twin pregnancies: a systematic review and meta-analysis

BACKGROUND

Single intrauterine fetal death affects approximately 6% of twin pregnancies and can have serious sequelae for the surviving co-twin.

OBJECTIVES

Determine the prognosis of the surviving co-twin following spontaneous single intrauterine fetal death to aid counselling patients and highlight future research areas.

SEARCH STRATEGY

Medline, Embase, Web of Science, and Cochrane Library, from 1980 to June 2017.

SELECTION CRITERIA

Studies of five or more cases of spontaneous single intrauterine fetal death after 14 weeks gestation, in diamniotic twin pregnancies.

DATA COLLECTION AND ANALYSIS

Summary event rates were calculated and stratified by chorionicity. Monochorionic and dichorionic twins, and sub-groups, were compared by odds ratios.

MAIN RESULTS

In monochorionic twins, when single intrauterine fetal death occurred at less than 28 weeks' gestation, this significantly increased the rate of co-twin intrauterine fetal death [odds ratio (OR) 2.31, 95% confidence interval (CI) 1.02-5.25, I²  = 0.0%, 12 studies, 184 pregnancies] and neonatal death (OR 2.84, 95% CI 1.18-6.77, I²  = 0.0%, 10 studies, 117 pregnancies) compared with when the single intrauterine fetal death occurred at more than 28 weeks' gestation. Neonatal death in monochorionic twins was significantly higher if the pregnancy was complicated by fetal growth restriction (OR 4.83, 95% CI 1.14-20.47, I²  = 0.0%, six studies, 60 pregnancies) or preterm birth (OR 4.95, 95% CI 1.71-14.30, I²  = 0.0%, 11 studies, 124 pregnancies). Abnormal antenatal brain imaging was reported in 20.0% (95% CI 12.8-31.1, I²  = 21.9%, six studies, 116 pregnancies) of surviving monochorionic co-twins. The studies included in the meta-analysis demonstrated small study effects and possible selection bias.

CONCLUSIONS

Preterm birth was the commonest adverse outcome affecting 58.5 and 53.7% of monochorionic and dichorionic twin pregnancies. Outcomes regarding brain imaging and neurodevelopmental comorbidity are an important area for future research, but meta-analysis may be limited due to different methods of assessment.

TWEETABLE ABSTRACT

Preterm birth is the highest risk in single co-twin death. Abnormal antenatal brain imaging was found in 1/5 surviving MC twins.

Prenatal thoraco-amniotic chest drain insertion to manage a case of fetal hydrops secondary to FOXC2

Lymphoedema-distichiasis is an inherited autosomal dominant disorder of the lymphatic system. Rarely, it is associated with fetal hydrops; the risk and severity of which increases with successive generations. The causative gene is a member of the forkhead transcription factor family (FOXC2). We describe a fetus presenting with early-onset, rapidly progressing body wall oedema, bilateral pleural effusions and a pericardial effusion in a mother with known FOXC2 mutation. First trimester chorionic villus sampling confirmed FOXC2 mutation in the fetus when there was only a large nuchal translucency. As the phenotype progressed, the couple consented to in utero ultrasound-guided insertion of sequential bilateral pleuro-amniotic chest drains (at 23 weeks) which successfully drained the pleural effusions. The fetus was delivered at 39 weeks gestation by elective caesarean section in good condition. The shunts were removed postnatally, and the baby was discharged after 7 days. This is the first case described of a fetus with severe early-onset fetal hydrops secondary to FOXC2 mutation successfully treated by the prenatal insertion of bilateral pleuro-amniotic shunts.

Comparison of Solomon technique with selective laser ablation for twin-twin transfusion syndrome: a systematic review

OBJECTIVE

To compare the Solomon and selective techniques for fetoscopic laser ablation (FLA) for the treatment of twin-twin transfusion syndrome (TTTS) in monochorionic-diamniotic twin pregnancies.

METHODS

This was a systematic review conducted in accordance with the PRISMA statement. Electronic searches were performed for relevant citations published from inception to September 2014. Selected studies included pregnancies undergoing FLA for TTTS that reported on recurrence of TTTS, occurrence of twin anemia-polycythemia sequence (TAPS) or survival.

RESULTS

From 270 possible citations, three studies were included, two cohort studies and one randomized controlled trial (RCT), which directly compared the Solomon and selective techniques for FLA. The odds ratios (OR) of recurrent TTTS when using the Solomon vs the selective technique in the two cohort studies (n = 249) were 0.30 (95% CI, 0.00-4.46) and 0.45 (95% CI, 0.07-2.20). The RCT (n = 274) demonstrated a statistically significant reduction in risk of recurrent TTTS with the Solomon technique (OR, 0.21 (95% CI, 0.04-0.98); P = 0.03). The ORs for the development of TAPS following the Solomon and the selective techniques were 0.20 (95% CI, 0.00-2.46) and 0.61 (95% CI, 0.05-5.53) in the cohort studies and 0.16 (95% CI, 0.05-0.49) in the RCT, with statistically significant differences for the RCT only (P < 0.001). Observational evidence suggested overall better survival with the Solomon technique, which was statistically significant for survival of at least one twin. The RCT did not demonstrate a significant difference in survival between the two techniques, most probably owing to the small sample size and lack of power.

CONCLUSION

This systematic review of observational, comparative cohort and RCT data suggests a trend towards a reduction in TAPS and recurrent TTTS and an increase in twin survival, with no increase in the occurrence of complications or adverse events, when using the Solomon compared to the selective technique for the treatment of TTTS. These findings need to be confirmed by an appropriately-powered RCT with long-term neurological follow-up.

Outcome in fetal lower urinary tract obstruction: a prospective registry study

OBJECTIVE

To describe influences on decision-making and prognostic variables in the prenatal management of fetal lower urinary tract obstruction (LUTO).

METHODS

This was a prospective registry study of pregnant women with a male fetus with LUTO from centers within the British Isles and The Netherlands. Women and/or their clinicians were given the treatment option of either conservative management or vesicoamniotic shunting (VAS). Baseline characteristics of women in the registry, reasons for entry to the registry and pregnancy outcomes were assessed. The main study outcomes were survival to 28 days after delivery, further survival to 2 years and renal function. Logistic regression analysis was used to examine prognostic variables that affected outcome. Results were compared with those of women in a randomized controlled trial (RCT) who were allocated randomly to a treatment option.

RESULTS

Forty-five women were registered, of whom 78% (35/45) underwent conservative management. Twenty-seven women entered the registry owing to their clinician's preference for management and 18 because of their own preference. Compared to the conservative-management group of the RCT, a higher proportion of women in the registry opting for conservative management had a normal amniotic fluid volume at diagnosis (P = 0.05) and a diagnosis of LUTO ≥ 24 weeks' gestation (P = 0.003). On multivariable logistic regression analysis, these variables showed a significant association with perinatal survival (P < 0.001). Survival to 28 days after delivery was higher in the conservative-management group, at 69% (24/35), compared to 40% (4/10) in the VAS group (P = 0.02) but this difference had limited statistical significance owing to small study size (relative risk, 0.58 (95% CI, 0.26-1.29); P = 0.14).

CONCLUSION

In our prospective registry, the majority of fetuses with LUTO received conservative management, which was associated with better short- and long-term outcomes. A significant proportion of these pregnancies had normal amniotic fluid volume and a gestational age at diagnosis of ≥ 24 weeks, characteristics shown to be associated with improved survival.

When is birthweight at term (≥37 weeks' gestation) abnormally low? A systematic review and meta-analysis of the prognostic and predictive ability of current birthweight standards for childhood and adult outcomes

BACKGROUND

Health outcomes throughout the life course have been linked to fetal growth restriction and low birthweight. A variety of measures exist to define low birthweight, with a lack of consensus regarding which predict adverse outcome.

OBJECTIVES

To evaluate the relationship between birthweight standards and childhood and adult outcomes in term-born infants (≥37 weeks' gestation).

SEARCH STRATEGY

MEDLINE (1966-January 2011), EMBASE (1980-January 2011), and the Cochrane Library (2011:1) and MEDION were included.

SELECTION CRITERIA

Studies comprising live term-born infants (gestation ≥37 completed weeks), with weight or other anthropometric measurements recorded at birth along with childhood and adult outcomes.

DATA COLLECTION AND ANALYSIS

Data were extracted to populate 2 × 2 tables relating birthweight standard with outcome, and meta-analysis was performed where possible.

MAIN RESULTS

Fifty-nine articles (2 600 383 individuals) were selected. There was no significant relationship between birthweight <2.5 kg (odds ratio [OR] 0.98, 95% confidence intervals [CI] 0.87-1.10) and composite measure of childhood morbidity. Weight <10th centile on the population nomogram showed a small association (OR 1.49, 95% CI 1.02-2.19) for the same outcome. There was no significant association between either of the above measures and adult morbidity. The relationship between other measures and individual outcomes varied.

AUTHOR'S CONCLUSIONS

The association between low birthweight, by any definition, and childhood and adult morbidity was inconsistent. None of the current standards of low birthweight was a good predictor of adverse outcome.

Effectiveness of folic acid supplementation in pregnancy on reducing the risk of small-for-gestational age neonates: a population study, systematic review and meta-analysis

OBJECTIVES

To assess the effect of timing of folic acid (FA) supplementation during pregnancy on the risk of the neonate being small for gestational age (SGA).

DESIGN

A population database study and a systematic review with meta-analysis including the results of this population study.

SETTING AND DATA SOURCES

A UK regional database was used for the population study and an electronic literature search (from inception until August 2013) for the systematic review.

PARTICIPANTS AND INCLUDED STUDIES

Singleton live births with no known congenital anomalies; 111,736 in population study and 188,796 in systematic review.

OUTCOME MEASURES, DATA EXTRACTION AND ANALYSIS

The main outcome was SGA based on customised birthweight centile. Associations are presented as odds ratios (OR) and adjusted odds ratios (aOR), adjusted for maternal and pregnancy-related characteristics.

RESULTS

Of 108,525 pregnancies with information about FA supplementation, 92,133 (84.9%) had taken FA during pregnancy. Time of commencement of supplementation was recorded in 39,416 pregnancies, of which FA was commenced before conception in 10,036, (25.5%) cases. Preconception commencement of FA supplementation was associated with reduced risk of SGA <10th centile (aOR 0.80, 95% CI 0.71-0.90, P < 0.01) and SGA <5th centile (aOR 0.78, 95% CI 0.66-0.91, P < 0.01). This result was reproduced when the data were pooled with other studies in the systematic review, showing a significant reduction in SGA (<5th centile) births with preconception commencement of FA (aOR 0.75, 95% CI 0.61-0.92, P < 0.006). In contrast, postconception folate had no significant effect on SGA rates.

CONCLUSION

Supplementation with FA significantly reduces the risk of SGA at birth but only if commenced preconceptually independent of other risk factors.

SYSTEMATIC REVIEW REGISTRATION

This systematic review was prospectively registered with PROSPERO number CRD42013004895.

The Percutaneous shunting in Lower Urinary Tract Obstruction (PLUTO) study and randomised controlled trial: evaluation of the effectiveness, cost-effectiveness and acceptability of percutaneous vesicoamniotic shunting for lower urinary tract obstruction

BACKGROUND

Congenital lower urinary tract obstruction (LUTO) is a disease associated with high perinatal mortality and childhood morbidity. Fetal vesicoamniotic shunting (VAS) bypasses the obstruction with the potential to improve outcome.

OBJECTIVE

To determine the effectiveness, cost-effectiveness and patient acceptability of VAS for fetal LUTO.

DESIGN

A multicentre, randomised controlled trial incorporating a prospective registry, decision-analytic health economic model and preplanned Bayesian analysis using elicited opinions. Patient acceptability was evaluated by interview in a qualitative study.

SETTING

Fetal medicine departments in the UK, Ireland and the Netherlands.

PARTICIPANTS

Pregnant women with a male singleton fetus with LUTO.

INTERVENTIONS

In utero percutaneous VAS compared with conservative care.

MAIN OUTCOME MEASURES

The primary outcome was survival to 28 days. Secondary outcome measures were survival and renal function at 1 year of age, cost of care and cost per additional life-year and per disability-free survival at the end of 1 year.

RESULTS

The trial stopped early with 31 women randomised because of difficulties in recruitment. Of those randomised to VAS and conservative management, 3/16 (19%) and 2/15 (13%), respectively, did not receive their allocated intervention. Based on intention-to-treat analysis, survival at 28 days was higher if allocated VAS (50%) than conservative management (27%) [relative risk (RR) 1.88, 95% confidence interval (CI) 0.71 to 4.96, p = 0.27]. At 12 months survival was 44% in the VAS arm and 20% in the conservative arm (RR 2.19, 95% CI 0.69 to 6.94, p = 0.25). Neither difference was statistically significant. Of survivors at 1 year, two in the VAS arm had no evidence of renal impairment and four in the VAS arm and two in the conservative arm required medical management. One baby in the conservative arm had end-stage renal failure at 1 year. VAS was more expensive because of additional surgery and intensive care. VAS cost £15,500 per survivor at 1 year and £43,900 per disability-free year. Elicited expert opinions showed uncertainty in the effect of VAS at 28 days. In a Bayesian analysis combining elicited opinion with the results, uncertainty of the benefit of VAS remained (RR 1.31, 95% credible interval 0.84 to 2.18). The acceptability study identified visualisation of the fetus during ultrasound scanning, perceiving a personal benefit, and altruism as positive influences on recruitment. Fear of the VAS procedure and the perceived severity of LUTO influenced non-participation. The need for more detailed information about the condition and its implications during pregnancy and following delivery was a further important finding of this research. Recruitment was hampered by logistical and regulatory difficulties, a lower incidence of LUTO and lower antenatal diagnosis rate [estimated to be 3.34 (95% CI 2.95 to 3.72) per 10,000 total births and 47%, respectively, in an associated epidemiological study] and high termination of pregnancy rates. In the registry women also demonstrated a clear preference for conservative management.

CONCLUSIONS

Survival to 28 days and 1 year appears to be higher with VAS than with conservative management, but it is not possible to prove benefit beyond reasonable doubt. Notably, prognosis in both arms for survival and renal function is poor. VAS was substantially more costly and unlikely to be regarded as cost-effective based on the 1-year data. Parents should be counselled about the risks of pregnancy loss with or without VAS insertion. The National Institute for Health and Care Excellence interventional procedures guidance (IPG 202) should be updated to reflect this new evidence. Babies in the PLUTO trial should be followed up long term for the different outcomes.

TRIAL REGISTRATION

ISRCTN53328556.

FUNDING

This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment ; Vol. 17, No. 59. See the NIHR Journals Library website for further project information.

Association and prediction of amniotic fluid measurements for adverse pregnancy outcome: systematic review and meta-analysis

BACKGROUND

Measurements of amniotic fluid volume are used for pregnancy surveillance despite a lack of evidence for their predictive ability.

OBJECTIVE

To evaluate the association and predictive value of ultrasound measurements of amniotic fluid volume for adverse pregnancy outcome.

SEARCH STRATEGY

Electronic databases (inception to October 2011), reference lists, hand searching of journals, contact with experts.

SELECTION CRITERIA

Studies comparing measurements of amniotic fluid volume with adverse outcome, excluding pre-labour ruptured membranes or congenital/structural anomalies.

DATA COLLECTION

Data on study characteristics, design, quality. Random effects meta-analysis to estimate summary odds ratios (prognostic association) and summary sensitivity, specificity and likelihood ratios (predictive ability).

MAIN RESULTS

Forty-three studies (244,493 fetuses) were included demonstrating a strong association between oligohydramnios (varying definitions) and birthweight <10th centile (summary odds ratio [OR] 6.31, 95% confidence interval [95% CI] 4.15-9.58; high-risk population [author definition] n = 6 studies, 28,510 fetuses), and mortality (neonatal death any population summary OR 8.72, 95% CI 2.43-31.26; n = 6 studies, 55,735 fetuses; and perinatal mortality high-risk population summary OR 11.54, 95% CI 4.05-32.9; n = 2 studies, 27;891 fetuses). There was a strong association between polyhydramnios (maximum pool depth >8 cm or amniotic fluid index ≥25 cm) and birthweight >90th centile (OR 11.41, 95% CI 7.09-18.36; n = 1 study, 3960 fetuses). Despite strong associations, predictive accuracy for perinatal outcome was poor.

AUTHOR'S CONCLUSION

Current evidence suggests that oligohydramnios is strongly associated with being small for gestational age and mortality, and polyhydramnios with birthweight >90th centile. Despite strong associations with poor outcome, they do not accurately predict outcome risk for individuals.

When is birthweight at term abnormally low? A systematic review and meta-analysis of the association and predictive ability of current birthweight standards for neonatal outcomes

Background

Intrauterine growth restriction is a cause of neonatal morbidity and mortality. A variety of definitions of low birthweight are used in clinical practice, with a lack of consensus regarding which definitions best predict adverse outcomes.

Objectives

To evaluate the relationship between birthweight standards and neonatal outcome in term-born infants (at ≥ 37 weeks of gestation).

Search strategy

MEDLINE (1966–January 2011), EMBASE (1980–January 2011), and the Cochrane Library (2011:1) and MEDION were included in our search.

Selection criteria

Studies comprising live term-born infants (gestation ≥ 37 completed weeks), with weight or other anthropometric measurements recorded at birth along with neonatal outcomes.

Data collection and analysis

Data were extracted to populate 2 × 2 tables relating birthweight standard with outcome, and meta-analysis was performed where possible.

Main results

Twenty-nine studies including 21 034 114 neonates were selected. Absolute birthweight was strongly associated with mortality, with birthweight < 1.5 kg giving the largest association (OR 48.6, 95% CI 28.62–82.53). When using centile charts, regardless of threshold, the summary odds ratios were significant but closer to 1 than when using absolute birthweight. For all tests, summary predictive ability comprised high specificity and positive likelihood ratio for neonatal death, but low sensitivity and a negative likelihood ratio close to 1.

Author's conclusions

Absolute birthweight is a prognostic factor for neonatal mortality. The indirect evidence suggests that centile charts or other definitions of low birthweight are not as strongly associated with mortality as the absolute birthweight. Further research is required to improve predictive accuracy.

Diagnostic accuracy of spot urinary protein and albumin to creatinine ratios for detection of significant proteinuria or adverse pregnancy outcome in patients with suspected pre-eclampsia: systematic review and meta-analysis

OBJECTIVE

To determine the diagnostic accuracy of two "spot urine" tests for significant proteinuria or adverse pregnancy outcome in pregnant women with suspected pre-eclampsia.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Searches of electronic databases 1980 to January 2011, reference list checking, hand searching of journals, and contact with experts.

INCLUSION CRITERIA

Diagnostic studies, in pregnant women with hypertension, that compared the urinary spot protein to creatinine ratio or albumin to creatinine ratio with urinary protein excretion over 24 hours or adverse pregnancy outcome. Study characteristics, design, and methodological and reporting quality were objectively assessed.

DATA EXTRACTION

Study results relating to diagnostic accuracy were extracted and synthesised using multivariate random effects meta-analysis methods.

RESULTS

Twenty studies, testing 2978 women (pregnancies), were included. Thirteen studies examining protein to creatinine ratio for the detection of significant proteinuria were included in the multivariate analysis. Threshold values for protein to creatinine ratio ranged between 0.13 and 0.5, with estimates of sensitivity ranging from 0.65 to 0.89 and estimates of specificity from 0.63 to 0.87; the area under the summary receiver operating characteristics curve was 0.69. On average, across all studies, the optimum threshold (that optimises sensitivity and specificity combined) seems to be between 0.30 and 0.35 inclusive. However, no threshold gave a summary estimate above 80% for both sensitivity and specificity, and considerable heterogeneity existed in diagnostic accuracy across studies at most thresholds. No studies looked at protein to creatinine ratio and adverse pregnancy outcome. For albumin to creatinine ratio, meta-analysis was not possible. Results from a single study suggested that the most predictive result, for significant proteinuria, was with the DCA 2000 quantitative analyser (>2 mg/mmol) with a summary sensitivity of 0.94 (95% confidence interval 0.86 to 0.98) and a specificity of 0.94 (0.87 to 0.98). In a single study of adverse pregnancy outcome, results for perinatal death were a sensitivity of 0.82 (0.48 to 0.98) and a specificity of 0.59 (0.51 to 0.67).

CONCLUSION

The maternal "spot urine" estimate of protein to creatinine ratio shows promising diagnostic value for significant proteinuria in suspected pre-eclampsia. The existing evidence is not, however, sufficient to determine how protein to creatinine ratio should be used in clinical practice, owing to the heterogeneity in test accuracy and prevalence across studies. Insufficient evidence is available on the use of albumin to creatinine ratio in this area. Insufficient evidence exists for either test to predict adverse pregnancy outcome.

Effectiveness of fetal cystoscopy as a diagnostic and therapeutic intervention for lower urinary tract obstruction: a systematic review

OBJECTIVE

To determine the effectiveness of fetal cystoscopy in the prenatal diagnosis of and intervention for congenital lower urinary tract obstruction.

METHODS

This study was a literature search using MEDLINE, Embase, Cochrane Library, MEDION, Web of Science reference lists and contact with experts. All studies reporting on fetal cystoscopy in lower urinary tract obstruction with data for a 2 × 2 table were selected for review. No language restrictions were applied. There was independent selection of studies, data extraction and quality assessment by two reviewers. Peto odds ratios were calculated as a summary measure of effect.

RESULTS

A total of 2071 citations were identified and 66 papers selected for detailed evaluation, from which four papers with a total of 63 patients were selected for inclusion. Two papers had results for the use of cystoscopy in diagnosis, showing that fetal cystoscopy altered the ultrasound diagnosis of the underlying pathology in 36.4 and 25.0% of fetuses, respectively. Compared to no treatment, fetal cystoscopic intervention demonstrated an odds ratio for improved perinatal survival of 20.51 (95% CI, 3.87-108.69). However, comparing vesicoamniotic shunt (VAS) with fetal cystoscopy there appeared to be no significant improvement in the perinatal survival odds ratio of 1.49 (95% CI, 0.13-16.97). These results had wide CIs and for cystoscopy vs. VAS, all results crossed the line of no effect.

CONCLUSION

There is little published evidence for the effectiveness of therapeutic fetal cystoscopy as an intervention for congenital lower urinary tract obstruction and the quality of this evidence is poor. It should thus be considered to be an 'experimental intervention' and subjected to further investigation.

Fetal umbilical artery Doppler to predict compromise of fetal/neonatal wellbeing in a high-risk population: systematic review and bivariate meta-analysis

OBJECTIVE

We investigated the accuracy of fetal umbilical artery Doppler to predict the risk of compromise of fetal/neonatal wellbeing in a high-risk population.

METHODS

Searches in MEDLINE, Embase, The Cochrane Library and Medion (from inception to March 2009) were carried out, together with hand searching of relevant journals, reference list checking of included articles and contact with experts. Criteria for selection were observational studies with umbilical artery Doppler used in a high-risk pregnant population with an outcome measure for compromise of fetal/neonatal wellbeing. Data on study design, quality and results were extracted to construct 2 × 2 tables. Bivariate meta-analysis was performed. Likelihood ratios (LRs) were used as the summary measure of accuracy.

RESULTS

One-hundred and four studies met the selection criteria (19 191 fetuses). In a high-risk population, umbilical artery Doppler predicted small-for-gestational age with a pooled LR+ of 3.76 (2.96, 4.76) and pooled LR- of 0.52 (0.45, 0.61), and compromise of fetal/neonatal wellbeing with a pooled LR+ of 3.41 (2.68, 4.34) and pooled LR- of 0.55 (0.48, 0.62). In this group it was also possible to predict, with accuracy, intrauterine death (pooled LR+ = 4.37 (0.88, 21.8); pooled LR- = 0.25 (0.07, 0.91)) and acidosis (pooled LR+ = 2.75 (1.48, 5.11); pooled LR- = 0.58 (0.36, 0.94)).

CONCLUSIONS

In a high-risk population, fetal umbilical artery Doppler is a moderately useful test with which to predict mortality and risk of compromise.

Fetoscopic laser coagulation for severe twin-to-twin transfusion syndrome: factors influencing perinatal outcome, learning curve of the procedure and lessons for new centres

OBJECTIVE

  To evaluate the effects of operator experience on perinatal outcome in a single centre.

DESIGN

  Prospective consecutive cohort study.

SETTING

  Regional tertiary referral Fetal Medicine Centre in the UK.

POPULATION

  Pregnant women with monochorionic twin pregnancies complicated by severe twin-to-twin transfusion syndrome (TTTS) (at ≤26 completed weeks of gestatiuon) treated by fetoscopic laser coagulation (FLC) between October 2004 and November 2009.

METHODS

  Pregnancy characteristics and outcomes were collected. Logistic regression analysis was employed to determine the effect of a priori defined variables on outcome.

MAIN OUTCOME MEASURE

  Perinatal survival (survival to 28 days or beyond) for one or more twins.

RESULTS

  There were 164 consecutive sets of monochorionic twins. The median gestational age (GA) at FLC was 20.4 weeks (interquartile range 18-22.1 weeks), the median interval from FLC to delivery was 88.5 days (interquartile range 53-101 days) and the median GA at delivery was 33.2 weeks (interquartile range 29.7-34.9 weeks). The overall survival was 62%; perinatal survival of one or more twins was 85%. These outcomes improved after about 61 procedures were performed, and after about 3.4 years of experience. Univariate logistic regression analysis indicated that Quintero stage-IV disease decreased (OR 0.26; 95% CI 0.10-0.69) and prolongation of GA at delivery increased the survival of the twins (OR 1.34; 95% CI 1.12-1.60) (P < 0.01). Increasing experience of the procedure by operator led to a significant increase in perinatal survival (P < 0.01; OR 4.59; 95% CI 1.84-11.44). Multivariate logistic regression analysis indicated that only GA at delivery increased survival overall (OR 1.34; 95% CI 1.12-1.60; P = 0.01).

CONCLUSIONS

  These data indicate that both relatively large numbers treated and experience with FLC minimises any adverse outcome in monochorionic pregnancies with severe TTTS.

Single twin demise: consequence for survivors

Multiple pregnancies, the majority of which are twins, are at substantially higher risk of fetal morbidity and mortality when compared with singleton pregnancies. Single fetal demise occurs in up to 6.2% of all twin pregnancies. It may cause considerable risk for the co-twin including increased risk of fetal loss, premature delivery, neurovascular injury and end-organ damage. In this review we seek to summarise the most contemporary literature on the aetiology of single twin demise, the pathophysiology of injury to the surviving twin and the evidence for current management strategies.

Congenital urinary tract obstruction

Congenital urinary tract obstruction is a heterogenous condition with a varying natural history. Accurate diagnosis within the late-first and second trimesters allows for counselling of the parents and planning of multi-disciplinary care for the pregnancy and newborn. Antenatal investigations to predict postnatal renal function are of varying accuracy. However, some factors have been shown to be predictive of poor outcome in terms of renal function at birth and infancy. There is the possibility of in-utero intervention in these fetuses.

Vesicoamniotic shunting for fetal lower urinary tract obstruction: an overview

Efficacy and complications of prenatal in utero treatment

Systematic review of accuracy of fetal urine analysis to predict poor postnatal renal function in cases of congenital urinary tract obstruction

OBJECTIVE

To evaluate the clinical usefulness of analysis of fetal urine in the prediction of poor postnatal renal function in cases of congenital urinary tract obstruction.

METHODS

A systematic review was performed. We conducted extensive electronic searches (database inception-2006). The reference lists of articles obtained were searched for any further articles. Two reviewers independently selected the articles in which the accuracy of fetal urinalysis was evaluated to predict poor postnatal renal function. There were no language restrictions. Data were extracted on study characteristics, quality and results, to construct 2 x 2 tables. Likelihood ratios for positive (LR+) and negative (LR-) test results were generated for the different fetal urinary analytes at various thresholds.

RESULTS

There were 23 articles that met the selection criteria, including a total of 572 women and 63 2 x 2 tables. The two most accurate tests were calcium > 95th centile for gestation (LR + 6.65, 0.23-190.96; LR - 0.19, 0.05-0.74) and sodium > 95th centile for gestation (LR + 4.46, 1.71-11.6; LR - 0.39, 0.17-0.88). beta(2)-microglobulin was found to be less accurate (LR + 2.92, 1.28-6.69; LR - 0.53, 0.24-1.17).

CONCLUSION

The current evidence demonstrates that none of the analytes of fetal urine investigated so far can be shown to yield clinically significant accuracy to predict poor postnatal renal function.

Learning new word meanings from context: a study of eye movements

This study examined how readers establish the meaning of a new word from the sentence context during silent reading. Readers' eye movements were monitored while they read pairs of sentences containing a target word, context, and a word related to the target word. The target word varied in familiarity (high, low, or novel). The context varied in informativeness about the meaning of the target word (informative or neutral). The amount of time readers spent on the context depended on both the familiarity of the target word and the informativeness of the context. Readers spent additional time on the related word only when the context was neutral and the target was novel. These results indicate that readers were able to determine which areas of text were relevant and used the information to infer a meaning for the novel word.

Stress grouping improves performance on an immediate serial list recall task

Five experiments investigated whether perceptual patterning afforded by imposing a recurrent stress pattern on auditorially presented lists has a positive effect on list recall. The experiments also addressed whether the recall advantage reflected the salience that the stress pattern created for certain items or whether the recall advantage arose from the distinct grouping configurations that were produced by the stress pattern. The authors explored these issues by examining immediate serial-recall performance for spoken lists that either did or did not have a stress pattern imposed on them. Lists had an anapest or dactylic stress pattern or were monotone and consisted of two stimulus types, either digit names or common English nouns. Results showed that stress patterns enhanced serial-recall performance and that the recall benefit derived primarily from the perceptual grouping afforded by the stress patterns. Results also showed that the grouping benefit derived from stress patterning generalizes to monotone lists. In contrast, salience effects are attached to the stimulus per se and do not transfer.

Priming in sentence processing: intralexical spreading activation, schemas, and situation models

A series of eye-tracking experiments investigated priming in natural language understanding. Intralexical spreading activation accounts of priming predict that the response to a target word will be speeded (i.e., primed) when strong associates appear prior to the target. Schema-based priming accounts predict that priming will occur when the target word is a component of an activated schema or script. Situation model accounts predict that priming will occur when a target word can be integrated easily into an evolving discourse representation. In separate experiments, we measured the effect of associated words, synonyms, and identity primes on processing times for subsequently encountered target words. Our designs crossed prime type (e.g., synonyms vs. unassociated words) with semantic plausibility (i.e., the target word was a plausible vs. an implausible continuation of the sentence). The results showed that identity primes, but not associates or synonyms, primed target words in early measures of processing like first fixation and gaze duration. Plausibility effects tended to emerge in later measures of processing (e.g., on total reading time), although some evidence was obtained for early effects of semantic plausibility. We propose that priming in naturalistic conditions is not caused by intralexical spreading activation or access to precompiled schemas.

Lexical processing and text integration of function and content words: evidence from priming and eye fixations

The results of two experiments comparing processing of function words and content words are reported. In Experiment 1, priming was present for both related function and related content word pairs, as measured in lexical decision response times. In Experiment 2, participants' eye movements were monitored as they read sentences containing either a high- or a low-frequency function or content target word. Average word length and word frequency were matched across the function and content word conditions. Function words showed frequency effects in first-fixation and gaze duration that were similar to those seen for content words. Clear differences in on-line processing of function and content words emerged in later processing measures. These differences were reflected in reading patterns and reading time measures. There was inflated processing time in the phrase immediately following a low-frequency function word, and participants made more regressions to the target word in this condition than in the other three conditions. The priming effects in lexical decision and the word frequency effects in initial processing measures in silent reading for both word types were taken as evidence of common lexical processing for function and content words. The observed differences in later processing measures in the eye-movement data were taken as evidence of differences in the role that the two word types have in sentence processing beyond the lexical level.

Focus as a contextual priming mechanism in reading

In two experiments, we found that readers are sensitive to manipulations of syntactically marked focus and that focus is an effective message level contextual priming mechanism. Changes in focus resulted in changes in sentence context effects on subsequent target word processing. This was demonstrated in latency to name the target word (Experiment 1) and in initial looking time on the target in silent reading (Experiment 2). Experiment 2 also revealed direct effects on the focused items, as readers made fewer regressions and spent less total time on a word that was focused than when it was not focused. However, no initial processing time effects were found on the focused word.

Eye movements and lexical ambiguity resolution: effects of prior encounter and discourse topic

Eye movements were monitored as participants read passages that contained 2 occurrences of a balanced ambiguous word. In Experiment 1, local context was manipulated so that the meaning of the ambiguous word either remained the same or changed from the 1st to 2nd encounter. In Experiments 2 and 3. global context was manipulated by shifting the discourse topic between the 2 instances of the ambiguous word. Gaze durations on the 2nd instance of the ambiguous word were shorter when the meaning remained consistent than when the meaning changed, and this facilitation was impervious to changes in the discourse structure. In contrast, processing time in the region immediately following the target was longer when the word meaning changed, but only when the topic of the discourse remained the same throughout the passage. When the topic was shifted, this effect disappeared.

Lexical and message-level sentence context effects on fixation times in reading

Readers' eye movements were recorded as they read an unambiguous noun in a sentence context. In Experiment 1, fixation durations on a target noun were shorter when it was embedded in context containing a subject noun and a verb that were weakly related to the target than when either content word was replaced with a more neutral word. These results were not affected by changes in the syntactic relations between the content words. In Experiment 2, the semantic relations between the message-level representation of the sentence and the target word were altered whereas the lexical content was held constant. Fixation time on the target word was shorter when the context was semantically related to the target word than when it was unrelated. Intralexical priming effects between the subject noun and the verb were also observed. The results suggest that both lexical and message-level representations can influence the access of an individual lexical item in a sentence context.

Lexical and message-level sentence context effects on fixation times in reading

Readers' eye movements were recorded as they read an unambiguous noun in a sentence context. In Experiment 1, fixation durations on a target noun were shorter when it was embedded in context containing a subject noun and a verb that were weakly related to the target than when either content word was replaced with a more neutral word. These results were not affected by changes in the syntactic relations between the content words. In Experiment 2, the semantic relations between the message-level representation of the sentence and the target word were altered whereas the lexical content was held constant. Fixation time on the target word was shorter when the context was semantically related to the target word than when it was unrelated. Intralexical priming effects between the subject noun and the verb were also observed. The results suggest that both lexical and message-level representations can influence the access of an individual lexical item in a sentence context.

Phonological codes are used in integrating information across saccades in word identification and reading

A major issue in reading is the extent to which phonological information is used in visual word perception. The present experiments demonstrated that phonological information acquired on 1 fixation from a word in the parafovea is used to help identify that word when it is later fixated. A homophone of a target word, when presented as a preview in the parafovea, facilitated processing of the target word seen on the next fixation more than a preview of a word matched with the homophone in visual similarity to the target word. This facilitation was observed both in the time to name an isolated target word and in the fixation time on the target word while silently reading a sentence; the preview was virtually never consciously identified in either task. Because the visual similarity of the preview to the target also plays a part in the facilitative effect on the preview, however, codes other than phonological codes are preserved across saccades.

Eye movement control in reading: evidence against semantic preprocessing

Prior experiments reported by Underwood and his colleagues have suggested that information about the informative parts of parafoveal words that have not yet been fixated can influence where readers fixate next. The basic finding that they have reported is that the eyes move farther into a word when the information that uniquely identifies the word is at the end of the word rather than at the beginning of the word. On the basis of such results, it has been suggested that semantic preprocessing influences eye movement behavior in reading. Some theoretical and methodological problems are raised with the prior experiments and then an attempt to replicate the finding is reported. With a highly accurate eyetracking system, the basic finding could not be replicated. An alternative account of eye movement control in reading is discussed.

Phonological codes are used in integrating information across saccades in word identification and reading

A major issue in reading is the extent to which phonological information is used in visual word perception. The present experiments demonstrated that phonological information acquired on 1 fixation from a word in the parafovea is used to help identify that word when it is later fixated. A homophone of a target word, when presented as a preview in the parafovea, facilitated processing of the target word seen on the next fixation more than a preview of a word matched with the homophone in visual similarity to the target word. This facilitation was observed both in the time to name an isolated target word and in the fixation time on the target word while silently reading a sentence; the preview was virtually never consciously identified in either task. Because the visual similarity of the preview to the target also plays a part in the facilitative effect on the preview, however, codes other than phonological codes are preserved across saccades.

Elaborative inferencing as an active or passive process

O'Brien, Shank, Myers, and Rayner (1988) reported that readers generated elaborative inferences only when a text contained characteristics that virtually eliminated the possibility of an inference being disconfirmed. We reanalyzed the data of O'Brien et al. (1988) and also conducted an experiment in which we varied (a) whether or not there was an anaphoric relation between a target word and its prior mention in the text and (b) the explicitness of the prior mention. Two refinements to O'Brien et al.'s conclusions are offered. First, the two text characteristics they manipulated (a strong biasing context or a demand sentence) may have produced different types of elaborative inferencing. We argue that a biasing context results in a passive form of elaborative inferencing, involving setting up a context of interpretation, whereas the presence of a demand sentence invites the reader to actively predict a subsequent expression. Second, clear evidence for either type of inference will be apparent only with truly anaphoric materials.

Eye movement guidance in reading: The role of parafoveal letter and space information

The relation between parafoveal letter and space information in eye movement guidance during reading was investigated in 2 experiments. Contingent upon the reader's fixation, the type of parafoveal information available to the right of fixation was varied by (a) space information only, (b) space information with letter information added at some delay, or (c) letter and space information simultaneously. In addition, the onset of the relevant parafoveal information was delayed between 0 and 250 ms into the fixation. The time course of processing the 2 types of information (letters or spaces) differed, as did the nature of their impact on the eye movement record. Although both letter and space information influenced saccade length and initial landing positions within words, only letter information had an effect on fixation duration. In addition, fixation duration was affected only by information entering within the first 50 ms of the fixation, whereas saccade length was affected by information arriving at any time during the fixation. The results are consistent with a model of eye movement control in which 2 independent processes are operating in tandem to determine when and where to move the eyes during reading.

Elaborative inferencing as an active or passive process

O'Brien, Shank, Myers, and Rayner (1988) reported that readers generated elaborative inferences only when a text contained characteristics that virtually eliminated the possibility of an inference being disconfirmed. We reanalyzed the data of O'Brien et al. (1988) and also conducted an experiment in which we varied (a) whether or not there was an anaphoric relation between a target word and its prior mention in the text and (b) the explicitness of the prior mention. Two refinements to O'Brien et al.'s conclusions are offered. First, the two text characteristics they manipulated (a strong biasing context or a demand sentence) may have produced different types of elaborative inferencing. We argue that a biasing context results in a passive form of elaborative inferencing, involving setting up a context of interpretation, whereas the presence of a demand sentence invites the reader to actively predict a subsequent expression. Second, clear evidence for either type of inference will be apparent only with truly anaphoric materials.

Semantic facilitation of lexical access during sentence processing

In three experiments we investigated the effect of a sentence context on naming time for a target word. Contexts were presented by using a rapid serial visual presentation; subjects named the last word of the sentence. In the first two experiments, facilitation was observed for a fully congruent context containing a subject and verb that were weakly related to the target word. No facilitation was observed when either the subject or verb was replaced with a more neutral word. In the third experiment, the fully congruent contexts were modified either to preserve or to disrupt the original relation between the subject and verb. Facilitation was observed in both conditions. The full pattern of results suggests that a combination of lexical items can prime a target word in the absence of priming by any of the lexical items individually. This combination priming is not dependent upon the overall meaning of the sentence.

Semantic facilitation of lexical access during sentence processing

In three experiments we investigated the effect of a sentence context on naming time for a target word. Contexts were presented by using a rapid serial visual presentation; subjects named the last word of the sentence. In the first two experiments, facilitation was observed for a fully congruent context containing a subject and verb that were weakly related to the target word. No facilitation was observed when either the subject or verb was replaced with a more neutral word. In the third experiment, the fully congruent contexts were modified either to preserve or to disrupt the original relation between the subject and verb. Facilitation was observed in both conditions. The full pattern of results suggests that a combination of lexical items can prime a target word in the absence of priming by any of the lexical items individually. This combination priming is not dependent upon the overall meaning of the sentence.

Lesions in the preoptic area suppressed sexual receptivity in ovariectomized rats with estrogen implants in the ventromedial hypothalamus

The objective of the experiment was to determine if electrolytic ablation of a portion of the preoptic area (POA) influenced the activation of female lordosis behavior by implants of estradiol benzoate in the ventromedial hypothalamus (VMH) of ovariectomized (OVX) rats. Two weeks after ovariectomy, rats received either bilateral electrolytic lesions (2 mA for 10 sec in Experiment 1, or 1 mA for 5 sec in Experiment 2) in the POA, or sham lesions (all procedures except passage of current). On the same day (day 0 of the experiment) thirty-gauge stainless steel cannulae containing crystalline estradiol benzoate were stereotaxically placed bilaterally into the VMH of all the rats. Subsequently, females were tested for the lordosis response to stud males on days 2, 4, 6, 8, and 10 in Experiment 1 or on days 7, 14 and 15 in Experiment 2. All rats received 0.5 mg progesterone (SC) only before the last test. A female was considered sexually receptive if she exhibited a lordosis quotient (LQ) greater than or equal to 10 (LQ = No. lordosis responses/10 mounts by male X 100). The frequencies for sexual receptivity in females with POA lesions were significantly lower than those for control females without lesions in both experiments. Additionally the degree of receptivity (lordosis quotient) was significantly lower on each test day for rats with POA lesions than that for rats without POA lesions. The results imply that the maintenance of the integrity of the POA under this experimental condition was important for the expression of the facilitative influence of the VMH on lordotic responsiveness.