Does antenatal identification of small-for-gestational age fetuses significantly improve their outcome?

Fetal MRI insular cortical morphometry and its association with neurobehavior in late-onset small-for-gestational-age fetuses

OBJECTIVE

To evaluate insular cortical morphometry assessed by magnetic resonance imaging (MRI) in late-onset small-for-gestational-age (SGA) fetuses compared with controls, and its association with neurobehavioral outcomes.

METHODS

MRI was performed in 65 late-onset SGA and 59 normally-grown fetuses at 37 weeks' gestation. T2-weighted half Fourier acquisition single-shot turbo spin echo (HASTE) anatomical and diffusion-weighted images were acquired. Insular cortical thickness, volume and fractional anisotropy values were assessed, and asymmetry indices were constructed. At 42 weeks of age, a Neonatal Behavioral Assessment Scale (NBAS) test was performed on the SGA neonates.

RESULTS

Late-onset SGA fetuses had significantly thinner insular cortical thickness and smaller insular cortical volume than did controls. SGA fetuses also presented a more pronounced left asymmetry in the posterior cortex and significantly lower fractional anisotropy values in the left insula. Insular measurements in the SGA group were significantly correlated with neurobehavior as assessed by NBAS scores.

CONCLUSIONS

Insular cortical morphometry was significantly different in late-onset SGA fetuses and correlated with poorer neurobehavioral performance. These data support the impact of growth restriction on brain development and the potential value of cortical assessment as a biomarker of neurodevelopment in at-risk fetuses.

Risk of intrauterine growth restriction among HIV-infected pregnant women: a cohort study

The purpose of this investigation was to study the risk of intrauterine growth restriction in human immunodeficiency virus (HIV)-infected women and to describe the associated risk factors. A cohort study was performed among HIV-infected women who delivered in a single tertiary centre in Barcelona, Spain, from January 2006 to December 2011. Consecutive singleton pregnancies delivered beyond 22 weeks of pregnancy were included. Intrauterine growth restriction (IUGR) was defined as a birth weight below the 10th customised centile for gestational age and IUGR babies were compared to non-IUGR newborns. Intrauterine Doppler findings were described among IUGR foetuses. Baseline characteristics, HIV infection data and perinatal outcome were compared between groups. The results were adjusted for potential confounders. A total of 156 singleton pregnancies were included. IUGR occurred in 23.4 % of cases (38/156). In two-thirds of the cases detected before birth, Doppler abnormalities compatible with placental insufficiency were observed. IUGR pregnancies presented a worse perinatal outcome, mainly due to a higher risk of iatrogenic preterm delivery [adjusted odds ratio 6.9, 95 % confidence interval (CI) 1.4-33.5]. IUGR foetuses also had a higher risk of emergent Caesarean section and neonatal intensive care unit admission. No cases of intrauterine foetal death occurred. A high rate of IUGR was observed among HIV pregnancies, and it was associated with adverse perinatal outcomes, mainly iatrogenic preterm and very preterm birth due to placental insufficiency. Our results support that ultrasound detection and follow-up of IUGR foetuses should be part of routine antenatal care in this high-risk population to improve antenatal management.

Outcome of fetuses with short femur length detected at second-trimester anomaly scan: a national survey

OBJECTIVE

To assess the relationship between the finding of fetal femur diaphysis length (FL) below the 5(th) percentile at the second-trimester scan and pregnancy outcome, in a population in which more than 90% of women attend first-trimester screening.

METHODS

This was a retrospective study of all Danish singleton pregnancies with a 17-22-week anomaly scan between 1 January 2008 and 30 June 2011. Information on FL and gestational age (GA) at anomaly scan, on birth weight and GA at delivery and on chromosomal abnormalities was obtained from the Danish Fetal Medicine Database.

RESULTS

Short FL was identified in 2718 (1.8%) of 147,766 fetuses and was present in 11 (16.2%) of the 68 fetuses affected by trisomy 21 (positive likelihood ratio (LR+) 8.8 (95% CI, 5.1-15.2)). Trisomy 13/18 and unbalanced autosomal structural abnormalities were also associated with a short FL in three (12.0%, LR+ 6.5 (95% CI, 2.3-18.9)) and eight (32.0%, LR+ 17.4 (95% CI, 9.8-30.9)) of the cases, respectively. The risk of a fetus having trisomy 21, trisomy 18, trisomy 13 or an unbalanced autosomal structural abnormality was 1 : 123 (95% CI, 79-192), given a short FL. Pregnancies with a fetus with short FL were more often affected by early preterm delivery (before 34 weeks) (5.6%; odds ratio (OR) = 4.2 (95% CI, 3.5-4.9)) and small-for-gestational-age (SGA) infants (13.9%; OR = 4.3 (95% CI, 3.8-4.8)).

CONCLUSION

Short FL at the second-trimester anomaly scan is associated with a significantly higher relative risk of chromosomal abnormalities, and a substantially higher absolute risk for SGA and early preterm delivery.

Angiogenic factors at diagnosis of late-onset small-for-gestational age and histological placental underperfusion

OBJECTIVE

This study was designed to explore the association between angiogenic factors levels at diagnosis of small-for-gestational age (SGA) and placental underperfusion (PUP).

METHODS

In a cohort of SGA singleton pregnancies, each delivered at >34 weeks, uterine (UtA), umbilical (UA), and middle cerebral (MCA) arteries were evaluated by Doppler upon diagnosis of SGA status. In addition, maternal circulating concentrations of placental growth factor (PlGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) were assayed by ELISA, and each placenta was evaluated for histologic signs of PUP using a hierarchical and standardized classification system. Logistic regression was applied to analyze independent relationships (at diagnosis) between angiogenic factors and Doppler parameters.

RESULTS

A total of 122 suspected SGA pregnancies were studied, 70 (57.4%) of which ultimately met PUP criteria. In this group, 85 placental findings qualified as PUP. Both mean UtA pulsatility index z-values (1.26 vs. 0.84; p = 0.038) and PlGF multiples of normal median (0.21 vs. 0.55; p = 0.002) differed significantly in pregnancies with and without PUP, respectively. By logistic regression, PlGF alone was independently predictive of PUP (OR = 0.11 [95% CI 0.025-0.57]; p = 0.008).

DISCUSSION

Histologic placental abnormalities in term SGA neonates reflect latent insufficiency in uteroplacental blood supply. The heightened risk of adverse perinatal outcomes in this context underscores a need for new Doppler or biochemical prenatal markers of placental disease. Angiogenic factors may be pivotal identifying SGA neonates.

CONCLUSIONS

Diminished circulating levels of placental growth factor, determined upon discovery of SGA status, are associated with histologic evidence of PUP.

Can quadruple test parameters predict SGA infants?

The aim of this study was to investigate the role of quadruple test parameters in predicting the risk of delivering a small for gestational age (SGA) infant. The quadruple test results of patients performed at 16-18 weeks of pregnancy were searched retrospectively. Alpha-fetoprotein (AFP) levels higher than 2 MoM were associated with a risk of delivering an SGA infant (p = 0.025), sensitivity 8%, specificity 98%, positive predictive value 25%, negative predictive value 91%. Other quadruple test parameters were not related to delivery of an SGA infant. The introduction of AFP as a screening test for the detection of SGA infants does not seem feasible, but we suggest clinicians take it into account when counselling the patients about the results of Down syndrome screening tests.

The implications of diagnosis of small for gestational age fetuses using European and South Asian growth charts: an outcome-based comparative study

The antenatal condition of small for gestational age (SGA) is significantly associated with perinatal morbidity and mortality and it is known that there are significant differences in birth weight and fetal size among different populations. The aim of our study was to assess the impact on outcomes of the diagnosis of SGA according to Bangladeshi and European antenatal growth charts in Sri Lankan population. The estimated fetal weight before delivery was retrospectively reviewed according to Bangladeshi and European growth references. Three groups were identified: Group 1-SGA according to Bangladeshi growth chart; Group 2-SGA according to European growth chart but not having SGA according to Bangladeshi growth chart; Group 3-No SGA according to both charts. There was a difference in prevalence of SGA between Bangladeshi and European growth charts: 12.7% and 51.7%, respectively. There were statistically significant higher rates in emergency cesarean section, fetal distress in labour, and intrauterine death (P < 0.001) in Group 1 compared with Group, 2 and 3. No differences of outcomes occurred between Groups 2 and 3. Our study demonstrated that only cases diagnosed as SGA according to population-based growth charts are at risk of adverse outcome. The use of inappropriate prenatal growth charts might lead to misdiagnosis and potential unnecessary interventions.

First-trimester screening for early and late small-for-gestational-age neonates using maternal serum biochemistry, blood pressure and uterine artery Doppler

OBJECTIVE

To assess the effectiveness of first-trimester screening for early and late small-for-gestational-age (SGA) neonates using maternal serum biochemistry, blood pressure and uterine artery Doppler.

METHODS

This was a prospective study of 4970 women with a singleton pregnancy who underwent routine first-trimester screening between 2009 and 2011. A logistic regression-based predictive model for SGA, defined as birth weight < 10(th) percentile, divided into early- or late-onset based on gestational age at delivery before or after 34 weeks' gestation, was constructed. The model included maternal baseline characteristics: serum levels of pregnancy-associated plasma protein-A and free β-human chorionic gonadotropin at 8-12 weeks and blood pressure and uterine artery Doppler at 11 + 0 to 13 + 6 weeks.

RESULTS

The prevalence of early and late SGA was 0.6% and 7.9%, respectively. Association with pre-eclampsia was 67% and 8%, respectively. At a false-positive rate of 15%, the detection rate for early SGA was 73%; however it differed substantially for cases with and without pre-eclampsia (90% vs 40%). For late SGA, at false-positive rates of 15 and 50%, detection rates were 32% and 70%, respectively, and did not substantially differ between cases with and without pre-eclampsia.

CONCLUSIONS

First-trimester screening predicts early SGA mainly because of its strong association with pre-eclampsia. Although prediction of late SGA was poorer, at a high false-positive rate it might be considered as part of a first-trimester strategy to select women requiring ultrasound assessment in the third trimester.

Association between reduced stillbirth rates in England and regional uptake of accreditation training in customised fetal growth assessment

OBJECTIVE

To assess the effect that accreditation training in fetal growth surveillance and evidence-based protocols had on stillbirth rates in England and Wales.

DESIGN

Analysis of mortality data from Office of National Statistics.

SETTING

England and Wales, including three National Health Service (NHS) regions (West Midlands, North East and Yorkshire and the Humber) which between 2008 and 2011 implemented training programmes in customised fetal growth assessment.

POPULATION

Live births and stillbirths in England and Wales between 2007 and 2012.

MAIN OUTCOME MEASURE

Stillbirth.

RESULTS

There was a significant downward trend (p=0.03) in stillbirth rates between 2007 and 2012 in England to 4.81/1000, the lowest rate recorded since adoption of the current stillbirth definition in 1992. This drop was due to downward trends in each of the three English regions with high uptake of accreditation training, and led in turn to the lowest stillbirth rates on record in each of these regions. In contrast, there was no significant change in stillbirth rates in the remaining English regions and Wales, where uptake of training had been low. The three regions responsible for the record drop in national stillbirth rates made up less than a quarter (24.7%) of all births in England. The fall in stillbirth rate was most pronounced in the West Midlands, which had the most intensive training programme, from the preceding average baseline of 5.73/1000 in 2000-2007 to 4.47/1000 in 2012, a 22% drop which is equivalent to 92 fewer deaths a year. Extrapolated to the whole of the UK, this would amount to over 1000 fewer stillbirths each year.

CONCLUSIONS

A training and accreditation programme in customised fetal growth assessment with evidence-based protocols was associated with a reduction in stillbirths in high-uptake areas and resulted in a national drop in stillbirth rates to their lowest level in 20 years.

Congenital cerebral palsy, child sex and parent cardiovascular risk

Objective

Genes associated with cardiovascular disease may also be risk factors for congenital cerebral palsy (CP) and these associations may be modified by sex, since there is an increased risk of CP in male children. We investigated the association between CP of the child with cardiovascular disease in parents, taking sex of the child into consideration.

Methods

All parents of non-adopted singletons born in Denmark between 1973 and 2003 were included. Parents of a child with CP, confirmed by the Danish National CP registry, were considered exposed. Cox proportional hazards regressions were used to model risk of cardiovascular outcomes for exposed parents compared to all other parents beginning at the child’s 10^th birthday.

Results

We identified 733,730 mothers and 666,652 fathers among whom 1,592 and 1,484, respectively, had a child with CP. The mean age for mothers at end of follow up was 50±8 years. After adjustment for maternal age, parental education, child’s sex, child’s residence, child being small for gestational age and maternal hypertensive disorder during pregnancy, mothers of CP male children had an excess risk of cardiovascular disease (HR: 1.52, 95% CI: 1.16-2.00), attributable mostly to an increased incidence of hypertension and cerebrovascular disease. After additional adjustment for preterm birth, the association was markedly attenuated for cardiovascular disease (1.34, 95%CI: 1.02 - 1.76), became nonsignificant for hypertension, but remained significant for cerebrovascular disease (HR: 2.73, 95% CI: 1.45- 5.12). There was no increased risk of cardiovascular events in mothers of female CP children, or fathers of CP children of any sex.

Conclusions

Women that have a male child with CP are at increased risk for premature cardiovascular disease. Part of this association may be related to risk factors for preterm births.

Multivariable evaluation of term birth weight: a comparison between ultrasound biometry and symphysis-fundal height

OBJECTIVE

To derive a birth weight predictive equation and to compare its diagnostic value with that of ultrasound.

METHODS

A longitudinal observational cohort study, including singleton pregnancies at term, was performed at St. Orsola-Malpighi Hospital, University of Bologna (Italy). A birth weight prediction formula, including symphysis-fundal height (SFH), BMI, maternal abdominal circumference (mAC) and parity was derived from a general linear model (GLM) (retrospective study). Moreover, on a new series of patients, the fetal weight was estimated by using both GLM and ultrasound using Hadlock formula (prospective study). The residual analysis and the intraclass correlation coefficient (ICC) were used to test the accuracy of methods in predicting birth weight.

RESULTS

Between January and November 2012, 1034 patients were included in the retrospective study and 44 in the prospective one. The following GLM was derived: estimated birth weight (g) = 1485.61 + (SFH (cm) × 23.37) + (11.62 (cm) × mAC) + [BMI × (-6.81)] + (parity (0 = nulliparous, 1 = multiparous) × 72.25). When prospectively applied, the GLM and ultrasound provided a percentage of prediction within ±10% of the actual weight of 73% and 84%, respectively. Ultrasound estimation, as opposite of GLM one, was significantly associated with neonatal weight (R(2 )= 0.388, F = 26.607, p value <0.001, ICC = 0.767).

CONCLUSIONS

Although ultrasound biometry has provided the best values in fetal weight estimation, the predictive performance of both methods is limited.

Clinical prediction in early pregnancy of infants small for gestational age by customised birthweight centiles: findings from a healthy nulliparous cohort

Objective

Small for gestational age (SGA) infants comprise up to 50% of all stillbirths and a minority are detected before birth. We aimed to develop and validate early pregnancy predictive models for SGA infants.

Methods

5628 participants from SCOPE, a prospective study of nulliparous pregnant women, were interviewed at 15±1 weeks’ gestation. Fetal anthropometry, uterine and umbilical Doppler studies were performed at 20±1 weeks’. The cohort was divided into training (n = 3735) and validation datasets (n = 1871). All-SGA (birthweight <10th customised centile), Normotensive-SGA (SGA with normotensive mother) and Hypertensive-SGA (SGA with mother who developed hypertension) were the primary outcomes. Multivariable analysis was performed using stepwise logistic regression firstly using clinical variables and then with clinical and ultrasound variables. Receiver operator curves were constructed and areas under the curve (AUC) calculated.

Results

633 infants (11.3%) in the whole cohort were SGA; 465 (8.3%) Normotensive-SGA and 165 (3.0%) Hypertensive-SGA. In the training dataset risk factors for All-SGA at 15±1 weeks’ included: family history of coronary heart disease, maternal birthweight <3000 g and 3000 g to 3499 g compared with ≥3500 g, >12 months to conceive, university student, cigarette smoking, proteinuria, daily vigorous exercise and diastolic blood pressure ≥80. Recreational walking ≥4 times weekly, rhesus negative blood group and increasing random glucose were protective. AUC for clinical risk factors was 0.63. Fetal abdominal or head circumference z scores <10^th centile and increasing uterine artery Doppler resistance at 20±1 weeks’ were associated with increased risk. Addition of these parameters increased the AUC to 0.69. Clinical predictors of Normotensive and Hypertensive-SGA were sub-groups of All-SGA predictors and were quite different. The combined clinical and ultrasound AUC for Normotensive and Hypertensive-SGA were 0.69 and 0.82 respectively.

Conclusion

Predictors for SGA of relevance to clinical practice were identified. The identity and predictive potential differed in normotensive women and those who developed hypertension.

A new population-based reference curve for symphysis-fundus height

OBJECTIVE

To present a new gestational-age-specific percentile curve for symphysis-fundus (SF) height and to determine the effects of maternal and fetal covariates.

DESIGN

A population-based register study.

SETTING

Antenatal clinics in Västra Götaland County, Sweden, between 2005 and 2010.

POPULATION

A total of 42 018 women with ultrasound-dated singleton pregnancies who delivered at Sahlgrenska University Hospital.

MAIN OUTCOME MEASURES

Measurement of SF height.

METHODS

A non-linear regression of SF height on day of pregnancy was used to construct a reference chart for the median and other percentiles of SF height.

RESULTS

The new reference curve for SF height showed almost linear growth until term. The median value was considerably larger at each gestational age compared with the curves for SF height used in Norway and Denmark. Compared with the curve currently used in Sweden, higher median values were observed only at gestational ages >34 weeks, accompanied by an upward shift in all percentiles. The only notably influential covariates were maternal pre-pregnancy weight and height.

CONCLUSIONS

The new reference curve for SF height shows a pattern that is different from the Scandinavian reference curves of older origin, reflecting changes in the pregnant population, as well as methodological differences. The new curve can be adjusted for maternal and fetal covariates to suit individual pregnancies.

Predicting risk for large-for-gestational age neonates at term: a population-based Bayesian theorem study

OBJECTIVES

To evaluate the prediction of large-for-gestational age (LGA) term neonates using the routine third-trimester ultrasound examination and to investigate whether the prediction could be further improved by adding information on maternal characteristics.

METHODS

Information on 56,792 singleton term pregnancies with a routine ultrasound examination at 32-34 weeks' gestation was retrieved from a population-based perinatal register. Estimated fetal weights (FW) were expressed as gestational age-specific standard deviation scores (Z-scores). The prediction of LGA was assessed by receiver-operating characteristics (ROC) curves, with LGA defined as birth weight Z-score > + 2. The data set with complete clinical information (n = 48,809) was divided into a development and a validation set. Using the development set, multiple logistic regression analysis was performed to identify maternal characteristics associated with LGA. The odds ratios obtained were converted into likelihood ratios. These were then applied to the validation set and the probability for LGA for each infant was estimated using the Bayesian theorem.

RESULTS

The FW Z-score showed a high predictive ability for LGA (area under the ROC curve (AUC) 0.89 (95% CI, 0.89-0.90)). Prediction was further improved by using the model that included both FW Z-scores and maternal variables (AUC 0.91 (95% CI, 0.90-0.92)) (P for difference < 10(-6) ). The corresponding AUC for a model including maternal characteristics only was 0.74 (95% CI, 0.73-0.76).

CONCLUSIONS

Routine third-trimester ultrasound FW estimation is effective in the prediction of LGA neonates at term. The prediction of LGA might be further improved by using a model including maternal characteristics.

Maternal and fetal risk factors for stillbirth: population based study

OBJECTIVE

To assess the main risk factors associated with stillbirth in a multiethnic English maternity population.

DESIGN

Cohort study.

SETTING

National Health Service region in England.

POPULATION

92,218 normally formed singletons including 389 stillbirths from 24 weeks of gestation, delivered during 2009-11.

MAIN OUTCOME MEASURE

Risk of stillbirth.

RESULTS

Multivariable analysis identified a significant risk of stillbirth for parity (para 0 and para ≥ 3), ethnicity (African, African-Caribbean, Indian, and Pakistani), maternal obesity (body mass index ≥ 30), smoking, pre-existing diabetes, and history of mental health problems, antepartum haemorrhage, and fetal growth restriction (birth weight below 10th customised birthweight centile). As potentially modifiable risk factors, maternal obesity, smoking in pregnancy, and fetal growth restriction together accounted for 56.1% of the stillbirths. Presence of fetal growth restriction constituted the highest risk, and this applied to pregnancies where mothers did not smoke (adjusted relative risk 7.8, 95% confidence interval 6.6 to 10.9), did smoke (5.7, 3.6 to 10.9), and were exposed to passive smoke only (10.0, 6.6 to 15.8). Fetal growth restriction also had the largest population attributable risk for stillbirth and was fivefold greater if it was not detected antenatally than when it was (32.0% v 6.2%). In total, 195 of the 389 stillbirths in this cohort had fetal growth restriction, but in 160 (82%) it had not been detected antenatally. Antenatal recognition of fetal growth restriction resulted in delivery 10 days earlier than when it was not detected: median 270 (interquartile range 261-279) days v 280 (interquartile range 273-287) days. The overall stillbirth rate (per 1000 births) was 4.2, but only 2.4 in pregnancies without fetal growth restriction, increasing to 9.7 with antenatally detected fetal growth restriction and 19.8 when it was not detected.

CONCLUSION

Most normally formed singleton stillbirths are potentially avoidable. The single largest risk factor is unrecognised fetal growth restriction, and preventive strategies need to focus on improving antenatal detection.

Impact of maternal characteristics on fetal growth in the third trimester: a population-based study

OBJECTIVES

To investigate the association between maternal characteristics and fetal growth during the third trimester of pregnancy.

METHODS

Using a population-based perinatal register, 48809 term singleton pregnancies were identified for which a routine ultrasound examination in the third trimester had been performed between 1995 and 2009. Fetal and infant weight were expressed as gestational age-specific standard deviation scores (z-scores) using a Swedish ultrasound-based reference curve. The growth of each fetus was assessed using the difference between the birth-weight z-score and the fetal-weight z-score estimated at the ultrasound examination, adjusted for gestational age, and divided by the time elapsed between the ultrasound examination and delivery. Analyses were performed using multivariable linear and polynomial regression analyses.

RESULTS

Positive associations were found between maternal body mass index (BMI), height, pre-existing diabetes mellitus, female fetal gender and fetal growth, whereas maternal smoking had a negative association. In the univariate analyses, primiparity and parity with four or more previous children were significantly associated with reduced fetal growth, but in the multivariable analysis, no association between parity and fetal growth could be detected. Both univariate and multivariable analyses revealed a significant inverse U-shaped association between maternal age and fetal growth.

CONCLUSIONS

Third-trimester fetal growth was positively associated with increasing maternal BMI, height and pre-existing diabetes mellitus, and negatively associated with maternal smoking.

Independent risk factors for infants who are small for gestational age by customised birthweight centiles in a multi-ethnic New Zealand population

BACKGROUND

Infants born small for gestational age (SGA) by customised birthweight centiles are at increased risk of adverse outcomes compared with those SGA by population centiles. Risk factors for customised SGA have not previously been described in a general obstetric population.

AIM

To determine independent risk factors for customised SGA in a multi-ethnic New Zealand population.

METHODS

We performed a retrospective cohort analysis of prospectively recorded maternity data from 2006 to 2009 at National Women's Health, Auckland, New Zealand. After exclusion of infants with congenital anomalies and missing data, our final study population was 26,254 singleton pregnancies. Multivariable logistic regression analysis adjusted for ethnicity, body mass index, maternal age, parity, smoking status, social deprivation, hypertensive disease, antepartum haemorrhage (APH), diabetes and relevant pre-existing medical conditions.

RESULTS

Independent risk factors for SGA included obesity (adjusted odds ratio 1.24 [95% CI 1.11-1.39] relative to normal weight), maternal age ≥ 35 years (1.16 [1.05-1.30] relative to 20-29 years), nulliparity (1.13 [1.04-1.24] relative to parity 1), cigarette smoking (2.01 [1.79-2.27]), gestational hypertension (1.46 [1.21-1.75]), pre-eclampsia (2.94 [2.49-3.48]), chronic hypertension (1.68 [1.34-2.09]), placental abruption (2.57 [1.74-3.78]) and APH of unknown origin (1.71 [1.45-2.00]). Gestational diabetes (0.80 [0.67-0.96]) and type 1 diabetes (0.26 [0.11-0.64]) were associated with reduced risk.

CONCLUSIONS

We report independent pregnancy risk factors for customised SGA in a general obstetric population. In contrast to population SGA, obesity is associated with increased risk. Our findings may help identify pregnancies that require increased fetal growth surveillance.

Prediction of gestational diabetes mellitus based on an analysis of amniotic fluid by capillary electrophoresis

Aim: To detect gestational diabetes mellitus biomarkers in human amniotic fluid collected for age-related genetic testing using capillary electrophoresis and a sophisticated data analysis methodology. Materials & methods: Amniotic fluid samples were separated by capillary electrophoresis. Samples were classified using a genetic algorithm with Bayesian benefit function. The best model maximized the sensitivity and specificity and employed a leave-one-out cross-validation strategy. Results: Gestational diabetes mellitus (GDM; n = 14) was distinguished from non-GDM (n = 95) with 86% sensitivity and 99% specificity using two wavelets. These wavelets were located in the unresolved protein region and on the edge of the maternally derived albumin peak. Conclusion: GDM is a maternal pathology; however, it was shown that it alters the biochemical profile of amniotic fluid. Testing for GDM is normally carried out at 24–28 weeks, but changes can be detected at 15 weeks gestation, suggesting that GDM onset occurs early in gestation.

Placental pathology in pregnancies with maternally perceived decreased fetal movement--a population-based nested case-cohort study

Background

Decreased fetal movements (DFM) are associated with fetal growth restriction and stillbirth, presumably linked through an underlying placental dysfunction. Yet, the role of placental pathology has received limited attention in DFM studies. Our main objective was to explore whether maternal perceptions of DFM were associated with placental pathology in pregnancies recruited from a low-risk total population.

Methods/Principal Findings

Placentas from 129 DFM and 191 non-DFM pregnancies were examined according to standardized macro- and microscopic protocols. DFM was defined as any maternal complaint of DFM leading to a hospital examination. Morphological findings were timed and graded according to their estimated onset and clinical importance, and classified in line with a newly constructed Norwegian classification system for reporting placental pathology. With our population-based approach we were unable to link DFM to an overall measure of all forms of placental pathology (OR 1.3, 95% CI 0.8–2.2, p = 0.249). However, placental pathology leading to imminent delivery could be a competing risk for DFM, making separate subgroup analyses more appropriate. Our study suggests a link between DFM and macroscopic placental pathology related to maternal, uteroplacental vessels, i.e. infarctions, placental lesions (intraplacental hematomas) and abruptions. Although not statistically significant separately, a compound measure showed a significant association with DFM (OR 2.4, 95%CI 1.1–5.0, p = 0.023). This association was strengthened when we accounted for relevant temporal aspects. More subtle microscopic materno-placental ischemic changes outside the areas of localized pathology showed no association with DFM (OR 0.5, 95%CI 0.2–1.4, p = 0.203). There was a strong association between placental pathology and neonatal complications (OR 2.9, 95% CI 1.6–5.1, p<0.001).

Conclusions

In our population-based study we were generally unable to link maternally perceived DFM to placental pathology. Some associations were seen for subgroups.

Performance of third-trimester ultrasound for prediction of small-for-gestational-age neonates and evaluation of contingency screening policies

OBJECTIVES

To assess the performance of third-trimester fetal biometry and fetal Doppler studies for the prediction of small-for-gestational-age (SGA) neonates, and to explore contingency strategies using a first-trimester prediction model based on maternal and fetal parameters and third-trimester ultrasound.

METHODS

This was an observational cross-sectional study of uncomplicated singleton pregnancies. Risk assessment for chromosomal abnormality was carried out in 4702 pregnancies using a combination of ultrasound markers (fetal nuchal translucency thickness (NT) and nasal bone assessment) and biochemistry (free beta-human chorionic gonadotropin (β-hCG) and pregnancy-associated plasma protein-A (PAPP-A)) at 11 to 13 + 6 weeks. Maternal demographic characteristics and method of conception were recorded. Third-trimester (30-34 weeks) fetal biometry (biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL)) and umbilical artery (UA) and middle cerebral artery Doppler studies were performed routinely in a subgroup (n = 2310). Reference ranges for birth weight were constructed using the cohort of 4702 women, and neonates were classified as small (SGA, ≤ 5th centile) or appropriate (AGA) for gestational age. First-trimester, third-trimester and integrated first- and third-trimester prediction models for SGA were constructed using regression analysis and three different contingency strategies of rescanning in the third trimester were investigated.

RESULTS

According to the areas under the receiver-operating characteristics curves (AUCs), AC (AUC = 0.85) and ultrasound-estimated fetal weight (EFW, AUC = 0.87) were equally good predictors of SGA. The model was marginally improved by the addition of UA Doppler, smoking status and first-trimester indices (free β-hCG and PAPP-A multiples of the median) (combined model, AUC = 0.88), but the difference was not statistically significant. A contingency strategy of rescanning 50% of the population in the third trimester according to the risk estimated by a first-trimester prediction model yielded a detection rate of 79% for a 25% screen-positive rate.

CONCLUSION

Third-trimester ultrasound is effective in screening for SGA in uncomplicated pregnancies. The use of a contingency screening policy can reduce the need for unnecessary examinations.

Maternal serum placental growth hormone at 11-13 weeks' gestation in pregnancies delivering small for gestational age neonates

OBJECTIVE

To investigate whether the maternal serum concentration of human placental growth hormone (PGH) at 11-13 weeks' gestation is altered in pregnancies that deliver small for gestational age (SGA) neonates.

METHODS

Maternal serum concentration of PGH was measured in 60 cases that subsequently delivered SGA neonates in the absence of preeclampsia and compared to 120 non-SGA controls.

RESULTS

In the SGA group, compared to the non-SGA group, there was no significant difference in the median PGH MoM (0.95 MoM, IQR 0.60-1.30 vs. 1.00 MoM, IQR 0.70-1.30, p = 0.97). There was no significant association between PGH MoM and birth weight percentile in either the SGA (p = 0.72) or in the non-SGA group (p = 0.63).

CONCLUSION

Maternal serum PGH at 11-13 weeks' gestation is unlikely to be a useful biochemical marker for early prediction of SGA.

Perinatal outcomes after sonographic detection of isolated short femur in the second trimester

PURPOSE

To determine the association of fetal isolated short femur in the second-trimester ultrasound (US) examination with perinatal outcomes such as small-for-gestational age (SGA) and low-birth weight (LBW) neonates.

METHODS

This is a retrospective cohort study in fetuses routinely assessed by US examination at 18 to 24 weeks during 2006-2009. A fetal isolated short femur was defined as femur length below the 5th percentile and with no chromosomal or structural abnormalities. Fetuses with abdominal circumference below the 5th percentile at the time of US examination were excluded. Each case of short femur was matched with three controls according to gestational age at the time of the US examination.

RESULTS

Sixty-one fetuses met the inclusion criteria. Both the group of women carrying a fetus with isolated short femur and that of women carrying a fetus with normal femur length had similar general and obstetric characteristics. Women carrying a fetus with isolated short femur were significantly more likely to deliver a SGA neonate (19.7% versus 8.7%, p < 0.05) and a LBW neonate (19.7% versus 7.1%, p < 0.05) than women carrying a fetus with normal femur length. Logistic regression analysis found odds ratios for SGA and LBW of 2.6 (95% confidence interval, 1.1-5.9) and 2.9 (95% confidence interval, 1.2-7.1), respectively.

CONCLUSIONS

Isolated short femur in the second-trimester US examination is associated with a subsequent delivery of SGA and LBW neonates.

Antenatal care, identification of suboptimal fetal growth and risk of late stillbirth: findings from the Auckland Stillbirth Study

INTRODUCTION

Stillbirth remains an important public health problem in Australia and New Zealand. The role that antenatal care plays in the prevention of stillbirth in high-income countries is unclear.

METHODS

Cases were women with a singleton, late stillbirth without congenital abnormality, booked to deliver in the Auckland region and born between July 2006 and June 2009. Two controls with ongoing pregnancies were randomly selected at the same gestation at which the stillbirth occurred. Data were collected through interview-administered questionnaires and from antenatal records.

RESULTS

One hundred and fifty five of 215 (72%) cases and 310 of 429 (72%) controls consented to take part in the study. Accessing <50% of recommended antenatal visits was associated with a more than twofold increase in late stillbirth (adjusted odds ratio, aOR, 2.68; 95% CI, 1.04-6.90) compared with accessing the recommended number of visits. Small-for-gestational-age (SGA) babies that had not been identified as SGA prior to birth were significantly more at risk of being stillborn (aOR, 9.46; 95% CI, 1.98-45.13) compared with SGA babies that were identified as such in the antenatal period. No relationship was found between type or model of maternity care provider at booking and late stillbirth risk.

DISCUSSION

This study reinforces the importance of regular antenatal care attendance. Identification of SGA may be one way by which antenatal care reduces stillbirth.

Fetal movement counting improved identification of fetal growth restriction and perinatal outcomes--a multi-centre, randomized, controlled trial

Background

Fetal movement counting is a method used by the mother to quantify her baby's movements, and may prevent adverse pregnancy outcome by a timely evaluation of fetal health when the woman reports decreased fetal movements. We aimed to assess effects of fetal movement counting on identification of fetal pathology and pregnancy outcome.

Methodology

In a multicentre, randomized, controlled trial, 1076 pregnant women with singleton pregnancies from an unselected population were assigned to either perform fetal movement counting from gestational week 28, or to receive standard antenatal care not including fetal movement counting (controls). Women were recruited from nine Norwegian hospitals during September 2007 through November 2009. Main outcome was a compound measure of fetal pathology and adverse pregnancy outcomes. Analysis was performed by intention-to-treat.

Principal Findings

The frequency of the main outcome was equal in the groups; 63 of 433 (11.6%) in the intervention group, versus 53 of 532 (10.7%) in the control group [RR: 1.1 95% CI 0.7–1.5)]. The growth-restricted fetuses were more often identified prior to birth in the intervention group than in the control group; 20 of 23 fetuses (87.0%) versus 12 of 20 fetuses (60.0%), respectively, [RR: 1.5 (95% CI 1.0–2.1)]. In the intervention group two babies (0.4%) had Apgar scores <4 at 1 minute, versus 12 (2.3%) in the control group [RR: 0.2 (95% CI 0.04–0.7)]. The frequency of consultations for decreased fetal movement was 71 (13.1%) and 57 (10.7%) in the intervention and control groups, respectively [RR: 1.2 (95% CI 0.9–1.7)]. The frequency of interventions was similar in the groups.

Conclusions

Maternal ability to detect clinically important changes in fetal activity seemed to be improved by fetal movement counting; there was an increased identification of fetal growth restriction and improved perinatal outcome, without inducing more consultations or obstetric interventions.

Trial Registration

ClinicalTrials.govNCT00513942

Is the use of symphysis-fundal height measurement and ultrasound examination effective in detecting small or large fetuses?

We investigated the accuracy of using symphysis pubis-fundal height measurement and ultrasonically derived estimation of fetal weight for identifying small-for-gestational-age (SGA) and large-for-gestational-age (LGA) fetuses. A retrospective cohort study was performed using computerised records of all non-diabetic women referred for an ultrasound growth scan (US) with clinically suspected SGA or LGA singleton fetuses from 35 weeks' gestation between October 2008 and March 2009 (n = 185). Birth weight data were also collected for all births over the study period (n = 3200). One-third (34%) of ultrasound estimated fetal weights were inaccurate by >10%. However, an inaccurate ultrasound estimation did not significantly increase the likelihood of spontaneous or induced onset of labour or delivery by caesarean section. Most (79%) growth scans were performed on well-grown fetuses. The majority (80%) of SGA and LGA babies in our cohort were not identified by clinicians during routine antenatal care. From 3,200 live births, there were a total of 59 infants weighing <2,500 g or >5,000 g. Of these, only 12 had been referred for an ultrasound growth scan, indicating that abdominal palpation and fundal height measurement has a 20% sensitivity in detecting SGA or LGA fetuses. Of the 12, four were detected using ultrasound, indicating a 33% detection rate. Although ultrasound has a slightly higher sensitivity, neither clinical examination using fundal height measurements nor 3rd trimester ultrasound examinations are effective at detecting SGA or LGA fetuses.

Self-administered symphysis-fundus measurements analyzed with a novel statistical method for detection of intrauterine growth restriction: a clinical evaluation

OBJECTIVE

To assess the ability of self-administered symphysis-fundus measurements used with the Shiryaev-Roberts statistical method (SR method) to identify growth-restricted (IUGR) fetuses and compare it with the traditional SF method (symphysis-fundus measurements used with a population-based reference curve).

DESIGN

Longitudinal study.

SETTING

Pregnant women attending primary antenatal care centres.

POPULATION

From a population of 1 888 women with singleton ultrasound-dated pregnancies, we analyzed data from 1 122 women.

METHODS

Weekly self-administered SF measurements from gestational week 25 until delivery were analyzed according to the SR method. Neonatal morbidity and small for gestational age (SGA) were used as proxies for IUGR. Small for gestational age was defined as a birthweight less than two standard deviations (SD) and <10th percentile. We assessed the sensitivity of the SR and the SF methods to detect neonatal morbidity and SGA.

MAIN OUTCOME MEASURES

Birth-related mortality, respiratory distress, hypoglycemia, Apgar score ≤6 at five minutes, pH ≤7.00 in the umbilical artery, neonatal care, preterm delivery, operative delivery for fetal distress and SGA. Results. For the SR method, the sensitivity for neonatal morbidity was between 6.0 and 36.4%, for SGA <2SD 36.8%, and for SGA <10th percentile 20.9%. The SF method had a sensitivity between 6.0 and 13.8% for neonatal morbidity, 52.3% for SGA <2SD and 28.6% for SGA <10th percentile.

CONCLUSIONS

The SR and the SF methods had low sensitivities for neonatal morbidity.

Intrauterine growth restriction: new concepts in antenatal surveillance, diagnosis, and management

Intrauterine growth restriction (IUGR) remains one of the main challenges in maternity care. Improvements have to start from a better definition of IUGR, applying the concept of the fetal growth potential. Customized standards for fetal growth and birthweight improve the detection of IUGR by better distinction between physiological and pathological smallness and have led to internationally applicable norms. Such developments have resulted in new insights in the assessment of risk and surveillance during pregnancy. Serial fundal height measurement plotted on customized charts is a useful screening tool, whereas fetal biometry and Doppler flow are the mainstay for investigation and diagnosis of IUGR. Appropriate protocols based on available evidence as well as individualized clinical assessment are essential to ensure good management and timely delivery.

Turning the pyramid of prenatal care

The current approach to prenatal care, which involves visits at 16, 24, 28, 30, 32, 34 and 36 weeks and then weekly until delivery, was established 80 years ago. The high concentration of visits in the third trimester implies, firstly, that most complications occur at this late stage of pregnancy and, secondly, that most adverse outcomes are unpredictable during the first or even second trimester. This review presents evidence that many pregnancy complications can now be predicted at an integrated first hospital visit at 11-13 weeks by combining data from maternal characteristics and history with findings of biophysical and biochemical tests. It is therefore proposed that the traditional pyramid of care should be inverted with the main emphasis placed in the first rather than third trimester of pregnancy.

Early fetal growth, PAPP-A and free β-hCG in relation to risk of delivering a small-for-gestational age infant

OBJECTIVES

To examine early fetal growth, pregnancy-associated plasma protein-A (PAPP-A) and free β-human chorionic gonadotropin (β-hCG) in relation to the risk of delivering a small-for-gestational age (SGA) infant.

METHODS

Included in the study were 9450 singleton pregnant women who attended the prenatal screening program at Aarhus University Hospital, Denmark, between January 2005 and December 2007. Maternal serum levels of PAPP-A and free β-hCG were measured between gestational weeks 8 and 13. Two ultrasound examinations were performed, the first at 11-13 weeks and the second at 18-22 weeks, from which gestational age was estimated based on crown-rump length and biparietal diameter, respectively. Early fetal growth was expressed as an index: the ratio between the estimated number of days from the first to the second scan and the actual calendar time elapsed in days. SGA was defined as birth weight < 5(th) centile for gestational age, and the risk of SGA was evaluated according to different cut-offs of the early fetal growth index and the serum markers.

RESULTS

PAPP-A < 0.4 MoM combined with an early fetal growth index < 10(th) centile resulted in an increased risk of SGA (odds ratio (OR), 5.8; 95% CI, 2.7-12.7). Low PAPP-A, low free β-hCG and slow early fetal growth were statistically, independently associated with SGA, and the association between free β-hCG < 0.3 MoM and SGA was as strong as that between PAPP-A < 0.3 MoM and SGA (OR, 3.1 and 3.0, respectively).

CONCLUSION

The combination of slow early fetal growth and low PAPP-A resulted in a nearly six-fold increased risk of delivery of an SGA infant. These findings might improve our chances of early identification of fetuses at increased risk of growth restriction.

Clinical strategies for improving the detection of fetal growth restriction

The single most important condition affecting the viable fetus is intrauterine growth retardation (IUGR). IUGR is a common condition, affecting about 10% to 15% of the general maternity population. Despite its importance and relatively high prevalence, IUGR detection is poor. This article will focus on how to improve on IUGR detection.

Maternal serum adiponectin at 11-13 weeks of gestation in pregnancies delivering small for gestation neonates

OBJECTIVE

To investigate whether maternal serum levels of adiponectin in the first trimester are altered in pregnancies that subsequently deliver small for gestational age (SGA) neonates.

METHODS

Maternal serum adiponectin and pregnancy-associated plasma protein A (PAPP-A) were measured at 11-13 weeks' gestation in 50 singleton normotensive pregnancies that delivered SGA neonates and 300 non-SGA controls. The median adiponectin and PAPP-A levels in the SGA and non-SGA groups, expressed as multiple of the unaffected median (MoM), were compared.

RESULTS

The distribution of serum adiponectin was made gaussian by square root (sqrt) transformation. Regression analysis in the non-SGA group demonstrated that for sqrt adiponectin a significant independent contribution was provided by maternal age, weight, smoking status, African and South-Asian racial origin. Each value in the SGA and non-SGA group was then converted into a multiple of the non-SGA median (MoM) after adjustment for maternal characteristics. In the SGA group, compared to the non-SGA controls, median maternal serum PAPP-A was decreased (0.79, interquartile range [IQR] 0.54-1.06 MoM vs. 1.00, IQR 0.71-1.39 MoM) but adiponectin MoM was not significantly different (0.89, IQR 0.65-1.31 MoM vs. 1.02, IQR 0.70-1.29 MoM).

CONCLUSION

Maternal serum adiponectin is not a useful biochemical marker for early prediction of SGA.

The effects of pre- and post-pregnancy inflammatory bowel disease diagnosis on birth outcomes

BACKGROUND

Inflammatory bowel diseases are frequent in women at their optimum age for reproduction. Possible effects on pregnancy are therefore of interest.

AIM

To assess pregnancy outcomes in 212 women: 135 of whom were diagnosed with inflammatory bowel disease before pregnancy and 77 after pregnancy.

METHODS

A clinical birth database was examined retrospectively. Odds ratios (ORs) for the main outcomes were calculated with 95% confidence intervals; these were adjusted for confounding factors.

RESULTS

Overall, pregnancy outcomes were good. No increased risk of preterm births or need for neonatal intensive care was observed. However, women with inflammatory bowel disease had more growth-retarded newborns, at an adjusted OR of 2.08 (1.26-3.44) and the mode of delivery was more frequently Caesarean section, with an OR of 2.75 (1.82-4.16). In the women who were diagnosed with inflammatory bowel disease after the pregnancy, we found no difference in the obstetric outcome as compared with the general obstetric population.

CONCLUSIONS

Most women with inflammatory bowel disease have a normal pregnancy outcome and, overall, inflammatory bowel disease during pregnancy poses low-to-moderate risks, the main concern being increased risk of impaired foetal growth. Normal maternal weight gain during pregnancy, possibly indicating a more stable disease, appeared to protect against adverse outcomes.

Histomorphometric characteristics of first trimester chorionic villi in pregnancies with low serum pregnancy-associated plasma protein-A levels: relationship with placental three-dimensional power doppler ultrasonographic vascularization

OBJECTIVE

To evaluate histomorphometric vascular characteristics from samples obtained by chorionic villus sampling (CVS) in pregnancies with low serum pregnancy-associated plasma protein-A (PAPP-A) levels and to relate these findings to three-dimensional (3D) placental volume and power Doppler vascularization.

METHODS

Immediately before CVS, placental 3D-power Doppler ultrasonography was performed at 11 + 0 to 13 + 6 weeks in 12 pregnancies with PAPP-A concentrations <0.3 multiples of median (MoM) as well as in 11 control women. Using a standardized setting placental volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) were measured. Histomorphometric parameters of villi were blindly evaluated with a video-computerized-image-analysis system.

RESULTS

Pregnancies with low PAPP-A showed a significantly reduced number of capillary vessels per villus cross-section (p = 0.005) and a smaller capillary diameter (p = 0.041). Placental vascular indices were significantly related to the number of fetal capillary vessels per villus (VI: r = 0.51, p = 0.03; FI: r = 0.48, p = 0.04; VFI: r = 0.56, p = 0.01).

CONCLUSIONS

Differences in placental vascularization are present in first trimester in pregnancies with low PAPP-A and they are associated to altered 3D placental Doppler indices.

Use of fetal colon thickness for auxiliary term dating of pregnancy

OBJECTIVE

To verify whether fetal colon thickness can be used as a marker for estimating, independent of biometrics and fetal weight percentile, the gestational age (GA) of fetuses between 37 and 40 weeks.

METHODS

The study group was 1296 fetuses aged between 33 and 40 weeks. The correlation between GA and colon thickness was assessed by the Pearson correlation test. For term fetuses (≥ 37 weeks), comparisons among the mean colon thickness for different weight percentiles at each GA (in weeks) were made with an analysis of variance test.

RESULTS

A significant relationship was observed between GA and colon thickness (P < 0.001, r(2) = 0.6). For term fetuses, significant differences were observed among the mean colon thickness values for different weight percentiles at 38 and 39 weeks. Of the 157 term fetuses for which biometrics would have underestimated GA by 2 weeks or more, 126 (80.3%) had a colon thickness equal to, or greater than, 14 mm. This colon thickness was also observed in 52 (70.3%) of term fetuses weighing less than the 10th percentile (n = 74).

CONCLUSION

The present study suggested that colon thickness might be a good marker for 37 weeks of gestation, and might identify term fetuses for which biometrics has underestimated the GA.