Comparison of fetal and neonatal growth curves in detecting growth restriction

Pregnancy outcomes in inflammatory bowel disease: Data from a large cohort survey

OBJECTIVES

Inflammatory bowel disease (IBD) can affect young and reproductively active patients. Our aim was to analyze pregnancy outcomes in a large cohort of women with IBD.

METHODS

All women with at least one pregnancy were given a questionnaire regarding the outcome of their pregnancy. They were divided into IBD pregnancies and controls depending on whether pregnancy occurred within or over 10 years prior to the diagnosis of IBD.

RESULTS

Three hundred questionnaires were analyzed for a total of 478 pregnancies that led to live-born babies. Age at conception was older in IBD women than in the controls. Active smoking was more frequent in the control group. The risk of intrauterine growth restriction (IUGR) was higher in IBD pregnancies (odds ratio [OR] 3.028, 95% confidence interval [CI] 1.245-7.370, P = 0.013). The week of gestation at delivery was lower in the IBD population. And the risk of cesarean section was higher in IBD pregnancies (OR 1.963, 95% CI 1.274-3.028, P = 0.002). Among women with IBD pregnancy, the risk of preterm birth was higher in patients with active disease at the time of conception (OR 4.088, 95% CI 1.112-15.025, P = 0.030), but lower in patients who continued regular therapy during pregnancy. Similarly, the risk of urgent cesarean section was reduced in the case of disease remission, while the risk of a planned cesarean delivery was higher in patients with perianal disease (OR 11.314, 95% CI 3.550-36.058, P < 0.01).

CONCLUSIONS

Our study shows a higher risk of IUGR, cesarean section, and poor blood pressure control in IBD pregnancies. We emphasize the importance of achieving disease remission before considering pregnancy.

The Relationship Between Fetal Growth and Retinal Nerve Fiber Layer Thickness in a Cohort of Young Adults

Purpose

To explore relationships between patterns of fetal anthropometric growth, as reflective of fetal wellbeing, and global retinal nerve fiber layer (RNFL) thickness measured in young adulthood.

Methods

Participants (n = 481) from within a Western Australian pregnancy cohort study underwent five serial ultrasound scans during gestation, with fetal biometry measured at each scan. Optic disc parameters were measured via spectral-domain optical coherence tomography imaging at a 20-year follow-up eye examination. Generalized estimating equations were used to evaluate differences in global RNFL thickness between groups of participants who had undergone similar growth trajectories based on fetal head circumference (FHC), abdominal circumference (FAC), femur length (FFL), and estimated fetal weight (EFW).

Results

Participants with consistently large FHCs throughout gestation had significantly thicker global RNFLs than those with any other pattern of FHC growth (P = 0.023), even after adjustment for potential confounders (P = 0.037). Based on model fit statistics, FHC growth trajectory was a better predictor of global RNFL thickness than birth weight or head circumference at birth. RNFL thickness did not vary significantly between groups of participants with different growth trajectories based on FAC, FFL, or EFW.

Conclusions

FHC growth is associated with RNFL thickness in young adulthood and, moreover, is a better predictor than either birth weight or head circumference at birth.

Translational Relevance

This research demonstrates an association between intrauterine growth and long-term optic nerve health, providing a basis for further exploring the extent of the influence of fetal wellbeing on clinical conditions linked to RNFL thinning.

Associations of severe adverse perinatal outcomes among continuous birth weight percentiles on different birth weight charts: a secondary analysis of a cluster randomized trial

Objective

To identify neonatal risk for severe adverse perinatal outcomes across birth weight centiles in two Dutch and one international birth weight chart.

Background

Growth restricted newborns have not reached their intrinsic growth potential in utero and are at risk of perinatal morbidity and mortality. There is no golden standard for the confirmation of the diagnosis of fetal growth restriction after birth. Estimated fetal weight and birth weight below the 10^th percentile are generally used as proxy for growth restriction. The choice of birth weight chart influences the specific cut-off by which birth weight is defined as abnormal, thereby triggering clinical management. Ideally, this cut-off should discriminate appropriately between newborns at low and at high risk of severe adverse perinatal outcomes and consequently correctly inform clinical management.

Methods

This is a secondary analysis of the IUGR Risk Selection (IRIS) study. Newborns (n = 12 953) of women with a low-risk status at the start of pregnancy and that received primary antenatal care in the Netherlands were included.

We examined the distribution of severe adverse perinatal outcomes across birth weight centiles for three birth weight charts (Visser, Hoftiezer and INTERGROWTH) by categorizing birth weight centile groups and comparing the prognostic performance for severe adverse perinatal outcomes.

Severe adverse perinatal outcomes were defined as a composite of one or more of the following: perinatal death, Apgar score < 4 at 5 min, impaired consciousness, asphyxia, seizures, assisted ventilation, septicemia, meningitis, bronchopulmonary dysplasia, intraventricular hemorrhage, periventricular leukomalacia, or necrotizing enterocolitis.

Results

We found the highest rates of severe adverse perinatal outcomes among the smallest newborns (< 3^rd percentile) (6.2% for the Visser reference curve, 8.6% for the Hoftiezer chart and 12.0% for the INTERGROWTH chart). Discriminative abilities of the three birth weight charts across the entire range of birth weight centiles were poor with areas under the curve ranging from 0.57 to 0.61. Sensitivity rates of the various cut-offs were also low.

Conclusions

The clinical utility of all three charts in identifying high risk of severe adverse perinatal outcomes is poor. There is no single cut-off that discriminates clearly between newborns at low or high risk.

Trial Registration

Netherlands Trial Register NTR4367.

Registration date March 20^th, 2014.

Perinatal Adverse Effects in Newborns with Estimated Loss of Weight Percentile between the Third Trimester Ultrasound and Delivery. The GROWIN Study

Fetal growth restriction has been associated with an increased risk of adverse perinatal outcomes (APOs). We determined the importance of fetal growth detention (FGD) in late gestation for the occurrence of APOs in small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) newborns. For this purpose, we analyzed a retrospective cohort study of 1067 singleton pregnancies. The newborns with higher APOs were SGA non-FGD and SGA FGD in 40.9% and 31.5% of cases, respectively, and we found an association between SGA non-FGD and any APO (OR 2.61; 95% CI: 1.35–4.99; p = 0.004). We did not find an increased APO risk in AGA FGD newborns (OR: 1.13, 95% CI: 0.80, 1.59; p = 0.483), except for cesarean delivery for non-reassuring fetal status (NRFS) with a decrease in percentile cutoff greater than 40 (RR: 2.41, 95% CI: 1.11–5.21) and 50 (RR: 2.93, 95% CI: 1.14–7.54). Conclusions: Newborns with the highest probability of APOs are SGA non-FGDs. AGA FGD newborns do not have a higher incidence of APOs than AGA non-FGDs, although with falls in percentile cutoff over 40, they have an increased risk of cesarean section due to NRFS. Further studies are warranted to detect these newborns who would benefit from close surveillance in late gestation and at delivery.

Lung function between 8 and 15 years of age in very preterm infants with fetal growth restriction

BACKGROUND

The impact of intrauterine growth restriction (IUGR) on lung function in very preterm children is largely unknown as current evidence is mainly based on studies in children born small for gestational age but not necessarily with IUGR.

METHODS

Spirometry, transfer factor of the lung for carbon monoxide (TLco), and lung clearance index (LCI) were cross-sectionally evaluated at 8.0-15.0 years of age in children born <32 weeks of gestation with IUGR (n = 28) and without IUGR (n = 67). Controls born at term (n = 67) were also included.

RESULTS

Very preterm children with IUGR had lower mean forced expired volume in the first second (FEV₁) z-score than those with normal fetal growth (∆ -0.66, 95% confidence interval (CI) -1.12, -0.19), but not significant differences in LCI (∆ +0.24, 95% CI -0.09, 0.56) and TLco z-score (∆ -0.11, 95% CI -0.44, 0.23). The frequency of bronchopulmonary dysplasia (BPD) in the two groups was, respectively, 43% and 10% (P = 0.003). IUGR was negatively associated with FEV₁ (B = -0.66; P = 0.004), but the association lost significance (P = 0.05) when adjusting for BPD.

CONCLUSIONS

IUGR has an impact on conducting airways function of very preterm children at school age, with part of this effect being mediated by BPD. Ventilation inhomogeneity and diffusing capacity, instead, were not affected.

IMPACT

IUGR does not necessarily imply a low birthweight for gestational age (and vice versa). While a low birthweight is associated with worse respiratory outcomes, the impact of IUGR on lung function in premature children is largely unknown. IUGR affects conducting airways function in school-age children born <32 weeks with IUGR, but not ventilation inhomogeneity and diffusing capacity. The impact of IUGR on FEV₁ seems mainly related to the higher risk of BPD in this group.

Fetal growth velocity standards from the Fetal Growth Longitudinal Study of the INTERGROWTH-21st Project

BACKGROUND

Human growth is susceptible to damage from insults, particularly during periods of rapid growth. Identifying those periods and the normative limits that are compatible with adequate growth and development are the first key steps toward preventing impaired growth.

OBJECTIVE

This study aimed to construct international fetal growth velocity increment and conditional velocity standards from 14 to 40 weeks' gestation based on the same cohort that contributed to the INTERGROWTH-21st Fetal Growth Standards.

STUDY DESIGN

This study was a prospective, longitudinal study of 4321 low-risk pregnancies from 8 geographically diverse populations in the INTERGROWTH-21st Project with rigorous standardization of all study procedures, equipment, and measurements that were performed by trained ultrasonographers. Gestational age was accurately determined clinically and confirmed by ultrasound measurement of crown-rump length at <14 weeks' gestation. Thereafter, the ultrasonographers, who were masked to the values, measured the fetal head circumference, biparietal diameter, occipitofrontal diameter, abdominal circumference, and femur length in triplicate every 5 weeks (within 1 week either side) using identical ultrasound equipment at each site (4-7 scans per pregnancy). Velocity increments across a range of intervals between measures were modeled using fractional polynomial regression.

RESULTS

Peak velocity was observed at a similar gestational age: 16 and 17 weeks' gestation for head circumference (12.2 mm/wk), and 16 weeks' gestation for abdominal circumference (11.8 mm/wk) and femur length (3.2 mm/wk). However, velocity growth slowed down rapidly for head circumference, biparietal diameter, occipitofrontal diameter, and femur length, with an almost linear reduction toward term that was more marked for femur length. Conversely, abdominal circumference velocity remained relatively steady throughout pregnancy. The change in velocity with gestational age was more evident for head circumference, biparietal diameter, occipitofrontal diameter, and femur length than for abdominal circumference when the change was expressed as a percentage of fetal size at 40 weeks' gestation. We have also shown how to obtain accurate conditional fetal velocity based on our previous methodological work.

CONCLUSION

The fetal skeleton and abdomen have different velocity growth patterns during intrauterine life. Accordingly, we have produced international Fetal Growth Velocity Increment Standards to complement the INTERGROWTH-21st Fetal Growth Standards so as to monitor fetal well-being comprehensively worldwide. Fetal growth velocity curves may be valuable if one wants to study the pathophysiology of fetal growth. We provide an application that can be used easily in clinical practice to evaluate changes in fetal size as conditional velocity for a more refined assessment of fetal growth than is possible at present (https://lxiao5.shinyapps.io/fetal_growth/). The application is freely available with the other INTERGROWTH-21st tools at https://intergrowth21.tghn.org/standards-tools/.

Does in utero HIV exposure and the early nutritional environment influence infant development and immune outcomes? Findings from a pilot study in Pretoria, South Africa

Background

As mother-to-child transmission of HIV decreases, and the population of infants who are born HIV-exposed, but uninfected (HEU) continues to rise, there is a growing need to understand the development and health outcomes of infants who are HEU to ensure that they have the healthiest start to life.

Methods

In a prospective cohort pilot study at Kalafong Hospital, Pretoria, South Africa, we aimed to determine if we could recruit new mothers living with HIV on antiretrovirals (ART; n = 20) and not on ART (n = 20) and new mothers without HIV (n = 20) through our clinics to study the effects of HEU on growth and immune- and neurodevelopment in infants in early life, and test the hypothesis that infants who were HEU would have poorer health outcomes compared to infants who were HIV-unexposed, uninfected (HUU). We also undertook exploratory analyses to investigate relationships between the early nutritional environment, food insecurity and infant development. Infant growth, neurodevelopment (Guide for Monitoring Child Development [GMCD]) and levels of monocyte subsets (CD14, CD16 and CCR2 expression [flow cytometry]) were measured in infants at birth and 12 weeks (range 8–16 weeks).

Results

We recruited 33 women living with HIV on ART and 22 women living without HIV within 4 days of delivery from June to December 2016. Twenty-one women living with HIV and 10 without HIV returned for a follow-up appointment at 12 weeks postpartum. The high mobility of this population presented major challenges to participant retention. Preliminary analyses revealed lower head circumference and elevated CCR2+ (% and median fluorescence intensity) on monocytes at birth among infants who were HEU compared to HUU. Maternal reports of food insecurity were associated with lower maternal nutrient intakes at 12 weeks postpartum and increased risk of stunting at birth for infants who were HEU, but not infants who were HUU.

Conclusions

Our small feasibility pilot study suggests that HEU may adversely affect infant development, and further, infants who are HEU may be even more vulnerable to the programming effects of suboptimal nutrition in utero and postnatally. This pilot and preliminary analyses have been used to inform our research questions and protocol in our ongoing, full-scale study.

Prenatal intrauterine growth restriction and risk of retinopathy of prematurity

Low birthweight and decreased postnatal weight gain are known predictors of worse retinopathy of prematurity (ROP) but the role of prenatal growth patterns in ROP remains inconclusive. To distinguish small for gestational age (SGA) from intrauterine growth restriction (IUGR) as independent predictors of ROP, we performed a retrospective cohort study of patients who received ROP screening examinations at a level IV neonatal intensive care unit over a 7-year period. Data on IUGR and SGA status, worst stage of and need for treatment for ROP, and postnatal growth was obtained. 343 infants were included for analysis (mean gestational age = 28.6 weeks and birth weight = 1138.2 g). IUGR infants were more likely to have a worse stage of ROP and treatment-requiring ROP (both p < 0.0001) compared to non-IUGR infants. IUGR infants were more likely to be older at worst stage of ROP (p < 0.0001) and to develop postnatal growth failure (p = 0.01) than non-IUGR infants. Independent of postnatal growth failure status, IUGR infants had a 4-5 × increased risk of needing ROP treatment (p < 0.001) compared to non-IUGR infants. SGA versus appropriate for gestational age infants did not demonstrate differences in retinopathy outcomes, age at worst ROP stage, or postnatal growth failure. These findings emphasize the importance of prenatal growth on ROP development.

Intrauterine growth restriction and its associated factors in South Gondar zone hospitals, Northwest Ethiopia, 2019

Background

After prematurity, intrauterine growth restriction (IUGR) is the second leading cause of perinatal mortality. IUGR has significant consequences in fetal, neonatal, and adult life. Currently, Ethiopia lacks information on IUGR’s prevalence and its determinants. This study aimed to assess the proportion of IUGR at birth and its associated factors.

Methods

A cross-sectional study was carried out among women who give birth in four hospitals of south Gonder zone from November 2018 to February 2019. Multi-stage sampling was applied to select the required samples. IUGR was assessed using a standardized cutoff percentile/mean for each measurement. Data were collected by trained MSc clinical midwives. Bi-variable and multivariable logistic analyses were deployed to identify the association.

Results

A total of 803 maternity women were participating in this study with a response rate of 95%. The proportion of IUGR 23.5% (95% CI: 20.7–26.6), low birth weight 13.3%, small-for- gestational-age 19.7%,and preterm birth 23.16%. Women who was unable to read and write, (AOR; 2.46, 95% CI: 1.02–5.92), total family size ≥7 (AOR; 1.67, 95% CI: 1.04–2.66), maternal mid-upper arm circumference (MUAC) < 23 cm (AOR; 2.10, 95% CI: 1.39–3.01), body mass index (BMI) < 18.5 kg/m² (AOR; 2.57, 95% CI: 1.72–3.83), altitude > 3000 m (AOR; 1.89 95% CI: 1.19–3.01), small placental size (< 350 g) (AOR; 2.42, 95% CI: 1.67–3.54) and small-for-gestational-age (AOR; 1.94, 95% CI:1.86–4.52) were the most predictors of IUGR.

Conclusions

IUGR was a major public health concern in this study. Women who were unable to read and write, small-for-gestational-age, maternal BMI < 18.5 kg/m², family size ≥7, maternal MUAC < 23 cm, small placental size, and altitude > 3000 m were found the most predictor variables. Strengthen female education, nutritional intervention before and during pregnancy, and routine maternity care is critical. Further clinical follow-up research is essential which includes maternal, fetal, and placental gens.

Influence of genetic variants for birth weight on fetal growth and placental haemodynamics

OBJECTIVE

To determine the combined effect of 60 genetic variants (single nucleotide polymorphisms, SNPs), previously identified as being associated with birth weight, on fetal growth and placental haemodynamics throughout pregnancy.

DESIGN

Prospective birth cohort (Generation R Study).

SETTING

General multiethnic population.

PARTICIPANTS

5374 singleton liveborn children with genome-wide association arrays and fetal growth data.

METHODS

Longitudinal and cross-sectional analyses of a genetic score of the total number of birth weight-increasing alleles across the 59 available SNPs and repeated fetal growth and haemodynamic measures.

MAIN OUTCOME MEASURES

SD scores (SDS) of fetal weight, (femur) length, head circumference, umbilical artery pulsatility index, uterine artery mean resistance index and placental weight, in different periods of pregnancy until birth.

RESULTS

In longitudinal analyses, the effect of the genetic score on the fetal growth measures increased throughout pregnancy (p<0.001). At 20 weeks of gestation, the genetic score was not associated with any of the fetal growth measures, whereas at 30 weeks it was associated with all. The strongest effects were observed at birth: per SD increase in genetic score, birth weight increased by 0.15 SDS (95% confidence interval: 0.13 to 0.18), birth length by 0.12 SDS (0.08 to 0.19) and head circumference by 0.08 SDS (0.05 to 0.12). The genetic score was not associated with placental haemodynamics, but was associated with a 14 g (10 to 18) increase in placental weight per SDS increase in genetic score.

CONCLUSIONS

Our results suggest that genetic variants related to birth weight exert their combined effect on fetal growth from second half of pregnancy onwards and have no effect on placental haemodynamics.

Adverse pregnancy outcomes and subsequent development of connective tissue disease in the UK: an epidemiological study

OBJECTIVE

This study assessed prevalence of connective tissue disease (CTDs), systemic lupus erythematosus (SLE), antiphospholipid syndrome (APS) and antiphospholipid antibodies (aPL) in women with previous adverse pregnancy outcome compared with uncomplicated livebirths.

DESIGN

Retrospective case-control study.

SETTING

UK Primary Care.

POPULATION OR SAMPLE

Records of women, 18 years and older, within the Clinical Practice Research Datalink (CPRD) (1 January 2000-31 December 2013).

METHODS

Clinical Practice Research Datalink was searched for pregnancy terms to identify adverse pregnancy outcome. Each identified case was matched to five livebirths.

MAIN OUTCOME MEASURES

Diagnosis of SLE, CTD, APS or autoimmune antibodies. Poisson regression was performed to calculate relative risk ratios (RR), comparing adverse pregnancy outcome with livebirth cohorts.

RESULTS

Clinical Practice Research Datalink identified 20 123 adverse pregnancy outcomes matched to 97 323 livebirths, with a total of 875 590 person-years follow up. Median follow up from study entry was 7.29 years (SD 4.39). Compared with women with an uncomplicated livebirth, women with adverse pregnancy outcome had an increased risk of developing CTD or autoimmune antibodies (RR 3.20, 95% CI 2.90-3.51). Risk was greatest following a stillbirth (RR 5.82, 95% CI 4.97-6.81). For CTD and SLE, the risk was greatest within the first 5 years of adverse pregnancy outcome. Risk for aPL and APS diagnosis was highest ≥5 years from adverse pregnancy outcome.

CONCLUSIONS

Adverse pregnancy outcome is associated with increased risk of developing maternal CTD, including SLE. Either immunological factors predispose women to adverse pregnancy outcome and subsequent CTD diagnosis or, alternatively, adverse pregnancy outcome initiates autoimmune events which culminate in CTD in later life.

TWEETABLE ABSTRACT

Stillbirth is associated with increased maternal risk of developing systemic lupus erythematosus (SLE).

Gestational growth trajectories derived from a dynamic fetal-placental scaling law

Fetal trajectories characterizing growth rates in utero have relied primarily on goodness of fit rather than mechanistic properties exhibited in utero. Here, we use a validated fetal-placental allometric scaling law and a first principles differential equations model of placental volume growth to generate biologically meaningful fetal-placental growth curves. The growth curves form the foundation for understanding healthy versus at-risk fetal growth and for identifying the timing of key events in utero.

Effectiveness of routine third trimester ultrasonography to reduce adverse perinatal outcomes in low risk pregnancy (the IRIS study): nationwide, pragmatic, multicentre, stepped wedge cluster randomised trial

OBJECTIVES

To investigate the effectiveness of routine ultrasonography in the third trimester in reducing adverse perinatal outcomes in low risk pregnancies compared with usual care and the effect of this policy on maternal outcomes and obstetric interventions.

DESIGN

Pragmatic, multicentre, stepped wedge cluster randomised trial.

SETTING

60 midwifery practices in the Netherlands.

PARTICIPANTS

13 046 women aged 16 years or older with a low risk singleton pregnancy.

INTERVENTIONS

60 midwifery practices offered usual care (serial fundal height measurements with clinically indicated ultrasonography). After 3, 7, and 10 months, a third of the practices were randomised to the intervention strategy. As well as receiving usual care, women in the intervention strategy were offered two routine biometry scans at 28-30 and 34-36 weeks' gestation. The same multidisciplinary protocol for detecting and managing fetal growth restriction was used in both strategies.

MAIN OUTCOME MEASURES

The primary outcome measure was a composite of severe adverse perinatal outcomes: perinatal death, Apgar score <4, impaired consciousness, asphyxia, seizures, assisted ventilation, septicaemia, meningitis, bronchopulmonary dysplasia, intraventricular haemorrhage, periventricular leucomalacia, or necrotising enterocolitis. Secondary outcomes were two composite measures of severe maternal morbidity, and spontaneous labour and birth.

RESULTS

Between 1 February 2015 and 29 February 2016, 60 midwifery practices enrolled 13 520 women in mid-pregnancy (mean 22.8 (SD 2.4) weeks' gestation). 13 046 women (intervention n=7067, usual care n=5979) with data based on the national Dutch perinatal registry or hospital records were included in the analyses. Small for gestational age at birth was significantly more often detected in the intervention group than in the usual care group (179 of 556 (32%) v 78 of 407 (19%), P<0.001). The incidence of severe adverse perinatal outcomes was 1.7% (n=118) for the intervention strategy and 1.8% (n=106) for usual care. After adjustment for confounders, the difference between the groups was not significant (odds ratio 0.88, 95% confidence interval 0.70 to 1.20). The intervention strategy showed a higher incidence of induction of labour (1.16, 1.04 to 1.30) and a lower incidence of augmentation of labour (0.78, 0.71 to 0.85). Maternal outcomes and other obstetric interventions did not differ between the strategies.

CONCLUSION

In low risk pregnancies, routine ultrasonography in the third trimester along with clinically indicated ultrasonography was associated with higher antenatal detection of small for gestational age fetuses but not with a reduced incidence of severe adverse perinatal outcomes compared with usual care alone. The findings do not support routine ultrasonography in the third trimester for low risk pregnancies.

TRIAL REGISTRATION

Netherlands Trial Register NTR4367.

Prescriptive birthweight charts can improve the prediction of adverse outcomes in very preterm infants who are small for gestational age

AIM

We compared three anthropometric charts to determine which provided the best predictions for adverse outcomes in very preterm small for gestational age (SGA) infants to address a lack of consensus on this subject.

METHODS

This was a retrospective cohort study of infants born below 32 weeks, who were admitted to two-level three neonatal intensive care units in The Netherlands from 2008 to 2013. The birthweights of 1720 infants were classified as SGA using a conventional, gender-specific birthweight chart, based on births in The Netherlands between 2000 and 2007, a prescriptive, gender-specific birthweight chart, based on the same data but without risk factors for intrauterine growth restriction (IUGR), and a non-gender-specific foetal weight chart derived from American ultrasonographic measurements.

RESULTS

The conventional, prescriptive and foetal weight charts classified 126 (7.3%), 494 (28.7%) and 630 (36.6%) infants as SGA. The prescriptive chart, which excluded IUGR, identified 368 SGA infants with significantly increased risks of neonatal mortality and morbidity. The 136 SGA infants just classified by the American foetal weight chart were not at increased risk.

CONCLUSION

The prescriptive birthweight chart, which excluded infants with IUGR, was the most effective chart when it came to identifying clinically important risk increases in SGA infants.

Maternal hemodynamics: a method to classify hypertensive disorders of pregnancy

BACKGROUND

The classification of hypertensive disorders of pregnancy is based on the time at the onset of hypertension, proteinuria, and other associated complications. Maternal hemodynamic interrogation in hypertensive disorders of pregnancy considers not only the peripheral blood pressure but also the entire cardiovascular system, and it might help to classify the different clinical phenotypes of this syndrome.

OBJECTIVE

This study aimed to examine cardiovascular parameters in a cohort of patients affected by hypertensive disorders of pregnancy according to the clinical phenotypes that prioritize fetoplacental characteristics and not the time at onset of hypertensive disorders of pregnancy.

STUDY DESIGN

At the fetal-maternal medicine unit of Ziekenhuis Oost-Limburg (Genk, Belgium), maternal cardiovascular parameters were obtained through impedance cardiography using a noninvasive continuous cardiac output monitor with the patients placed in a standing position. The patients were classified as pregnant women with hypertensive disorders of pregnancy who delivered appropriate- and small-for-gestational-age fetuses. Normotensive pregnant women with an appropriate-for-gestational-age fetus at delivery were enrolled as the control group. The possible impact of obesity (body mass index ≥30 kg/m²) on maternal hemodynamics was reassessed in the same groups.

RESULTS

Maternal age, parity, body mass index, and blood pressure were not significantly different between the hypertensive disorders of pregnancy/appropriate-for-gestational-age and hypertensive disorders of pregnancy/small-for-gestational-age groups. The mean uterine artery pulsatility index was significantly higher in the hypertensive disorders of pregnancy/small-for-gestational-age group. The cardiac output and cardiac index were significantly lower in the hypertensive disorders of pregnancy/small-for-gestational-age group (cardiac output 6.5 L/min, cardiac index 3.6) than in the hypertensive disorders of pregnancy/appropriate-for-gestational-age group (cardiac output 7.6 L/min, cardiac index 3.9) but not between the hypertensive disorders of pregnancy/appropriate-for-gestational-age and control groups (cardiac output 7.6 L/min, cardiac index 4.0). Total vascular resistance was significantly higher in the hypertensive disorders of pregnancy/small-for-gestational-age group than in the hypertensive disorders of pregnancy/appropriate-for-gestational-age group and the control group. All women with hypertensive disorders of pregnancy showed signs of central arterial dysfunction. The cardiovascular parameters were not influenced by gestational age at the onset of hypertensive disorders of pregnancy, and no difference was observed between the women with appropriate-for-gestational-age fetuses affected by preeclampsia or by gestational hypertension with appropriate-for-gestational-age fetuses. Women in the obese/hypertensive disorders of pregnancy/appropriate-for-gestational-age and obese/hypertensive disorders of pregnancy/small-for-gestational-age groups showed a significant increase in cardiac output, as well as significant changes in other parameters, compared with the nonobese/hypertensive disorders of pregnancy/appropriate-for-gestational-age and nonobese/hypertensive disorders of pregnancy/small-for-gestational-age groups.

CONCLUSION

Significantly low cardiac output and high total vascular resistance characterized the women with hypertensive disorders of pregnancy associated with small for gestational age due to placental insufficiency, independent of the gestational age at the onset of hypertension. The cardiovascular parameters were not significantly different in the women with appropriate-for-gestational-age or small-for-gestational-age fetuses affected by preeclampsia or gestational hypertension. These findings support the view that maternal hemodynamics may be a candidate diagnostic tool to identify hypertensive disorders in pregnancies associated with small-for-gestational-age fetuses. This additional tool matches other reported evidence provided by uterine Doppler velocimetry, low vascular growth factors in the first trimester, and placental pathology. Obesity is associated with a significantly higher cardiac output and outweighs other determinants of hemodynamics in pregnancy; therefore, in future studies on hypertensive disorders, obesity should be studied as an additional disease and not simply as a demographic characteristic.

Diagnostic accuracy of individual antenatal tools for prediction of small-for-gestational age at birth

OBJECTIVE

To determine the accuracy of fetal and newborn growth charts for the prediction of small-for-gestational age (SGA) at birth (birth weight < 10^th centile).

METHODS

This was a prospective cohort study performed within a UK specialist fetal growth clinic. A total of 105 consecutive pregnant women referred for a suspected SGA fetus were included. All pregnancies were managed according to a standard protocol using estimated fetal weight (EFW) plotted on customized Gestation Related Optimal Weight (GROW) charts. The last antenatal estimates of EFW (according to charts of GROW, Hadlock et al. and Mikolajczyk et al.), abdominal circumference (AC) (according to charts of Hadlock et al., INTERGROWTH-21^st Project and Chitty et al.) or change in AC over time (calculated according to Pregnancy Outcome Prediction (POP) study) were compared against four birth-weight charts (GROW, INTERGROWTH-21^st , Mikolajczyk et al. and World Health Organization (WHO)). The ability of each antenatal test to predict adverse perinatal outcome (APO) was assessed.

RESULTS

Birth weight < 10^th centile was assigned in 62 (59%) neonates using the GROW chart, 57 (54%) using the Mikolajczyk et al. chart, 55 (52%) using the INTERGROWTH-21^st chart and 51 (49%) using the WHO chart. AC-Hadlock had the best negative likelihood ratio (range, 0.3-0.4) and sensitivity (range, 74%-82%) for predicting SGA as defined by all four postnatal birth-weight charts. AC-INTERGROWTH-21^st had the best positive likelihood ratio (range, 5.9-10.9) and specificity (94%-96%). For prediction of APO, AC-Hadlock and EFW-GROW had the best sensitivities (57% and 52%, respectively), whereas AC-POP had the best positive likelihood ratio (2.2) and specificity (88%). Antenatal prediction of APO increased to a sensitivity of 61% when AC-POP and EFW-GROW were combined; however, specificity was only 56%.

CONCLUSIONS

We have identified wide variation in the diagnostic accuracy of various antenatal tools for the prediction of both SGA and APO, dependent on the choice of chart. Suboptimal diagnostic accuracy of commonly used antenatal tests may lead to increasing medicalization without prevention of APO. Researchers should focus their attention on a combination of fetal biometry and biomarkers for better prediction of SGA and prevention of APO. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Defining small-for-gestational-age: prescriptive versus descriptive birthweight standards

Descriptive population-based birthweight standards possess low sensitivity in detecting infants with growth impairment. A prescriptive birthweight standard based on a 'healthy' subpopulation without risk factors for intrauterine growth restriction might be superior. We created two birthweight standards based on live born, singleton infants with gestational age 24-42 weeks and born in The Netherlands between 2000 and 2007. Inclusion criteria for the prescriptive birthweight standard were restricted to infants without congenital malformations, born to healthy mothers after uncomplicated pregnancies. We defined small-for-gestational-age (SGA) as birthweight <10th percentile and assessed the ability of both standards to predict adverse neonatal outcomes. The prescriptive birthweight standard identified significantly more infants as SGA, up to 38.0 % at 29 weeks gestation. SGA infants classified according to both standards as well as those classified according to the prescriptive birthweight standard only, were at increased risk of both major and minor adverse neonatal outcomes. The prescriptive birthweight standard was both more sensitive and less specific, with a maximum increase in sensitivity predicting bronchopulmonary dysplasia (+42.6 %) and a maximum decrease in specificity predicting intraventricular haemorrhage (-26.9 %) in infants aged 28-31 weeks.

CONCLUSION

Prescriptive birthweight standards could improve identification of infants born SGA and at risk of adverse neonatal outcomes.

WHAT IS KNOWN

• Descriptive birthweight standards possess low sensitivity in detecting growth restricted infants at risk of adverse neonatal outcomes. • Prescriptive standards could improve identification of very preterm small-for-gestational-age (SGA) infants at risk of intraventricular haemorrhage. What is New: • Prescriptive standards identify more preterm and term SGA infants at risk of major adverse neonatal outcomes. • Late preterm and term SGA infants classified according to the prescriptive standard are at increased risk of minor adverse neonatal outcomes with potentially harmful implications.

Intrauterine Growth Restriction: Antenatal and Postnatal Aspects

Intrauterine growth restriction (IUGR), a condition that occurs due to various reasons, is an important cause of fetal and neonatal morbidity and mortality. It has been defined as a rate of fetal growth that is less than normal in light of the growth potential of that specific infant. Usually, IUGR and small for gestational age (SGA) are used interchangeably in literature, even though there exist minute differences between them. SGA has been defined as having birth weight less than two standard deviations below the mean or less than the 10th percentile of a population-specific birth weight for specific gestational age. These infants have many acute neonatal problems that include perinatal asphyxia, hypothermia, hypoglycemia, and polycythemia. The likely long-term complications that are prone to develop when IUGR infants grow up includes growth retardation, major and subtle neurodevelopmental handicaps, and developmental origin of health and disease. In this review, we have covered various antenatal and postnatal aspects of IUGR.

Placental Insufficiency in Fetuses That Slow in Growth but Are Born Appropriate for Gestational Age: A Prospective Longitudinal Study

OBJECTIVES

To determine whether fetuses that slow in growth but are then born appropriate for gestational age (AGA, birthweight >10th centile) demonstrate ultrasound and clinical evidence of placental insufficiency.

METHODS

Prospective longitudinal study of 48 pregnancies reaching term and a birthweight >10th centile. We estimated fetal weight by ultrasound at 28 and 36 weeks, and recorded birthweight to determine the relative change in customised weight across two timepoints: 28-36 weeks and 28 weeks-birth. The relative change in weight centiles were correlated with fetoplacental Doppler findings performed at 36 weeks. We also examined whether a decline in growth trajectory in fetuses born AGA was associated with operative deliveries performed for suspected intrapartum compromise.

RESULTS

The middle cerebral artery pulsatility index (MCA-PI) showed a linear association with fetal growth trajectory. Lower MCA-PI readings (reflecting greater diversion of blood supply to the brain) were significantly associated with a decline in fetal growth, both between 28-36 weeks (p = 0.02), and 28 weeks-birth (p = 0.0002). The MCA-PI at 36 weeks was significantly higher among those with a relative weight centile fall <20%, compared to those with a moderate centile fall of 20-30% (mean MCA-PI 1.94 vs 1.61; p<0.05), or severe centile fall of >30% (mean MCA-PI 1.94 vs 1.56; p<0.01). Of 43 who labored, operative delivery for suspected intrapartum fetal compromise was required in 12 cases; 9/18 (50%) cases where growth slowed, and 3/25 (12%) where growth trajectory was maintained (p = 0.01).

CONCLUSIONS

Slowing in growth across the third trimester among fetuses subsequently born AGA was associated with ultrasound and clinical features of placental insufficiency. Such fetuses may represent an under-recognised cohort at increased risk of stillbirth.

Shining light in dark corners: diagnosis and management of late-onset fetal growth restriction

Fetal growth restriction (FGR) is the single biggest risk factor for stillbirth. In the absence of any effective treatment for fetal growth restriction, the mainstay of management is close surveillance and timely delivery. While such statements are almost self-evident, the daily clinical challenge of late-onset fetal growth restriction remains; the competing priorities of minimising stillbirth risk, while avoiding excessive obstetric intervention and the neonatal sequelae of iatrogenic preterm birth. This dilemma is made harder because the tools for late-onset FGR diagnosis and surveillance compare poorly to those used in early-onset FGR; screening tests in early pregnancy have limited predictive value; most cases escape clinical detection, a phenomenon set to worsen given the obesity epidemic; there is a failure of consensus on the definition of small for gestational age, and ancillary tools, such as umbilical artery Doppler--of value in identification of preterm FGR--are less useful in the late-preterm period and at term. Most importantly, the problem is common; 96% of all births occur after 32 weeks. This means a poor noise/signal ratio of any test or management algorithm will inevitably have large clinical consequences. Into such a dark corner, we cast some light; a summary on diagnostic criteria, new developments to improve the diagnosis of late-onset FGR and a suggested approach to management.

New Japanese neonatal anthropometric charts for gestational age at birth

BACKGROUND

More than 10 years have passed since the previous Japanese neonatal growth charts were published, therefore the aim of this study was to develop an updated set of Japanese neonatal growth charts.

METHODS

We used data from the registry database of the Japan Society of Obstetrics and Gynecology from 2003 until 2005. A total of 150,471 singleton live births without stillbirth or severe congenital malformation were enrolled in the preliminary analysis. It was found that the distribution of the 10th centile charts based on these subjects was skewed toward lower birthweight for preterm infants, because of the significantly lower birthweight in the 10th centile in neonates delivered by cesarean section than those delivered vaginally. Therefore, the data of subjects delivered by cesarean section were also excluded.

RESULTS

Finally, 104,748 singleton vaginal births at 22-41 weeks of gestation were used to construct a new set of Japanese neonatal anthropometric charts. The birthweight chart is parity and sex specific. The differences between the Japanese fetal growth chart and the new neonatal birthweight chart were small.

CONCLUSION

The present new neonatal anthropometric charts may reveal unrestricted growth pattern mimicking fetal growth. Use of these charts may result in recognition of abnormal fetal growth and risk in preterm infants. Further studies are needed to evaluate the risk for adverse neonatal and long-term outcome among small-for-gestational-age infants using these neonatal charts.

Inflammatory markers in umbilical cord blood from small-for-gestational-age newborns

This study investigates the role of inflammation in intrauterine growth retardation by exploring the levels of inflammatory markers in umbilical cord blood from neonates who were born small-for-gestational-age (SGA) and comparing them to neonates who were born appropriate-for-gestational-age (AGA). Interleukin 6 (IL-6), Tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were measured by standard methods in term or near-term (gestational age >36 weeks) neonates born SGA (n = 45) and a matched group of neonates born AGA (n = 45). Infants exposed to maternal chronic diseases, diabetes or pre-eclampsia were excluded. SGA was defined as two standard derivations below the expected for term and gender. In multivariate regression analyses significant elevation in cord blood concentration of IL-6 was demonstrated in the SGA group (mean 4.56 vs. 2.38, p = 0.002). The results indicate the presence of elevated inflammatory markers in the cord blood from SGA infants compared to AGA infants, and consequently the results suggest an inflammatory component in intrauterine growth restriction (IUGR).

Added value of umbilical vein flow as a predictor of perinatal outcome in term small-for-gestational-age fetuses

OBJECTIVE

To compare umbilical vein (UV) flow with standard Doppler parameters in prediction of adverse perinatal outcome in late-onset small-for-gestational age (SGA) fetuses.

METHODS

Umbilical, uterine and middle cerebral arteries, and UV blood flow were evaluated by Doppler before delivery in a cohort of 193 term SGA fetuses. The value of the Doppler parameters to predict risk of emergency delivery for non-reassuring fetal status and neonatal metabolic acidosis was analyzed.

RESULTS

Fifty-three (27%) fetuses had non-reassuring fetal status requiring emergency delivery, whereas 21 (11%) newborns developed neonatal metabolic acidosis. Multivariable analysis showed that significant contributions to prediction of emergency delivery for non-reassuring fetal status and neonatal metabolic acidosis were provided by middle cerebral artery (MCA) pulsatility index (PI) and UV blood flow normalized by fetal weight. Decision tree analysis defined three groups with increasing risk of need for emergency delivery for non-reassuring fetal status: MCA-PI > 1.46 (risk 15.6%); MCA-PI ≤ 1.46 and UV blood flow > 68 mL/min/kg (risk 25%); and MCA-PI ≤ 1.46 and UV flow ≤ 68 mL/min/kg (risk 53.1%); and two groups with different risks of neonatal metabolic acidosis: UV flow > 68 mL/min/kg or UV flow ≤ 68 mL/min/kg and MCA-PI > 1.23 (risk ≤ 10%); and UV flow ≤ 68 mL/min/kg and MCA-PI ≤ 1.23 (risk 39.1%).

CONCLUSION

The evaluation of UV blood flow with spectral brain Doppler allows better identification of SGA fetuses with late-onset intrauterine growth restriction at risk of adverse perinatal outcome.

Early diagnosis and treatment referral of children born small for gestational age without catch-up growth are critical for optimal growth outcomes

Approximately 10% of children born small for their gestational age (SGA) fail to show catch-up growth and may remain short-statured as adults. Despite treatment guidelines for children born SGA that recommend referral for growth hormone (GH) therapy evaluation and initiation by ages 2 to 4 years, the average age of GH treatment initiation is typically much later, at ages 7 to 9 years. Delayed referral for GH treatment is problematic as studies show younger age at GH treatment initiation in children born SGA is an independent predictor for responses such as optimal growth acceleration, normalization of prepubertal height, and most importantly, adult height (AH). This review discusses the importance and associated challenges of early diagnosis of children born SGA who fail to show catch-up growth, contrasts the recommended age of referral for these patients and the average age of GH treatment initiation, and discusses studies showing the significant positive effects of early referral and treatment with GH on AHs in short-statured children born SGA. To optimize the eventual height in short-statured SGA children who fail to manifest catch-up growth, a lowering of the average age of referral for GH therapy evaluation is needed to better align with consensus recommendations for SGA management. The importance of increasing parental and physician awareness that most children born SGA will do well developmentally and will optimally benefit from early initiation of GH treatment when short-statured is addressed, as is the need to shift the age of referral to better align with consensus recommendations.

Recurrence and severity of abnormal pregnancy outcome in patients treated by low-molecular-weight heparin: a prospective pilot study

OBJECTIVE

This prospective pilot study assesses the recurrence rate and severity of abnormal pregnancy outcome (APO), excluding early pregnancy complications, in pregnant patients, without acquired thrombophilia, treated by prophylactic doses of low-molecular-weight heparin (LMWH), independently from their congenital thrombophilic condition.

METHODS

We recruited a cohort of 128 pregnant patients with previous APO; 100 of whom with APO and intrauterine growth restriction (IUGR) and 28 with maternal APO only. LMWH treatment was started at recruitment. Composite cross-over recurrence rate IUGR, gestational hypertension, preeclampsia, help syndrome, abruptio placenta were analyzed. The main outcome measure was severe APOs with iatrogenic delivery ≤ 32 weeks of gestation.

RESULTS

Median gestational age at LMWH treatment was 20 weeks. Severe APO decreased in treated pregnancies from 45% to 4% (relative risk = 0.3, confidence interval 95% = 0.2-0.8). This value was not significantly different in thrombophilic and nonthrombophilic patients. When severe and minor complications were analyzed altogether, the recurrence rate was 28%. In patients with APO and fetal growth restriction (FGR) in the index pregnancy, newborn weights were significantly better in the treated pregnancy: 1090 g (1035-1145) vs. 850 g (535-1200), p < 0.01.

CONCLUSIONS

Prophylactic regimen of LMWH significantly reduced the recurrence rate of severe composite APO in pregnancies affected in the index pregnancy by APO and FGR or small for gestational age newborns. This result was independent from the patients' inherited thrombophilic conditions.

Customized versus population-based growth curves: prediction of low body fat percent at term corrected gestational age following preterm birth

OBJECTIVE

Compare customized versus population-based growth curves for identification of small-for-gestational-age (SGA) and body fat percent (BF%) among preterm infants.

METHODS

Prospective cohort study of 204 preterm infants classified as SGA or appropriate-for-gestational-age (AGA) by population-based and customized growth curves. BF% was determined by air-displacement plethysmography. Differences between groups were compared using bivariable and multivariable linear and logistic regression analyses.

RESULTS

Customized curves reclassified 30% of the preterm infants as SGA. SGA infants identified by customized method only had significantly lower BF% (13.8 ± 6.0) than the AGA (16.2 ± 6.3, p = 0.02) infants and similar to the SGA infants classified by both methods (14.6 ± 6.7, p = 0.51). Customized growth curves were a significant predictor of BF% (p = 0.02), whereas population-based growth curves were not a significant independent predictor of BF% (p = 0.50) at term corrected gestational age.

CONCLUSION

Customized growth potential improves the differentiation of SGA infants and low BF% compared with a standard population-based growth curve among a cohort of preterm infants.

Uterine artery blood flow volume in pregnant women with an abnormal pulsatility index of the uterine arteries delivering normal or intrauterine growth restricted newborns

The aim of this study was to assess and compare uterine artery (UtA) blood flow volume in pregnant patients with an abnormal uterine Doppler pulsatility index (PI) who delivered fetuses with an appropriate weight for gestational age (AGA) or with intrauterine growth restricted (IUGR). We prospectively recruited singleton pregnancies with abnormal uterine arteries P.I. between 18 and 38 weeks of gestation regardless of estimated fetal weight (EFW). Vessel diameter and blood flow velocity were measured along the UtA upstream to the vessel bifurcation in both the right and left UtAs. Uterine blood flow volumes measured in these pregnancies were compared to historical Control-pregnancies. Forty-three patients delivered at term a normal weight newborn (AGA-pregnancies). Thirty patients delivered growth restricted newborns at 32 weeks (i.r. 29-36w) with a median weight of 1160 gr (i.r. 1000-2065 gr) (IUGR-pregnancies). At mid-gestation (18 + 0 - 25 + 6 weeks + days of gestation) a significantly lower uterine blood flow volume per unit weight was observed between the two study groups and compared to controls: 142 ml/min/kg in IUGR-pregnancies, 217 ml/min/kg in AGA-pregnancies and 538 ml/min/kg in Control-pregnancies. These striking differences in blood flow volume were already present at mid-gestation, at a time when EFW was still normal. In late gestation (27 + 0 - 37 + 6 weeks + days of gestation), pregnancies with an abnormal uterine P.I. showed persistently low UtA flow (<50% of controls) even when corrected for fetal weight: 81 ml/min/kg in IUGR-pregnancies, 105 ml/min/kg in AGA-pregnancies, and 193 ml/min/kg in Control-pregnancies; p < 0.0001. Our findings are consistent with other recent studies regarding the association between reduced uterine blood flow volume and fetal growth restriction. However, the study brings new insight into the finding of abnormal uterine P.I. in normally grown fetuses typically dismissed as "falsely abnormal" or "false positive" findings. Our study suggests that blood flow volume measurement may serve as a new tool to assess this group of patients and possibly those with ischemic placental diseases that may provide some basis for therapeutic interventions.

Diagnosis and management of fetal growth restriction

Fetal growth restriction (FGR) remains a leading contributor to perinatal mortality and morbidity and metabolic syndrome in later life. Recent advances in ultrasound and Doppler have elucidated several mechanisms in the evolution of the disease. However, consistent classification and characterization regarding the severity of FGR is lacking. There is no cure, and management is reliant on a structured antenatal surveillance program with timely intervention. Hitherto, the time to deliver is an enigma. In this paper, the challenges in the diagnosis and management of FGR are discussed. The biophysical profile, Doppler, biochemical and molecular technologies that may refine management are reviewed. Finally, a model pathway for the clinical management of pregnancies complicated by FGR is presented.

Differences in birth weight for gestational age distributions according to the measures used to assign gestational age

Population-based standards for infant size for gestational age depend on accurate assessments of birth weight and gestational age; the accuracy of the latter measure has been questioned. The authors sought to explore how different methods of assigning gestational age in vital records data affect distributions of birth weight for gestational age. The 2005 US natality file was used to create 4 measures of gestational age for singleton births consisting of measures found on the 1989 (last menstrual period (LMP) and clinical estimate) and 2003 (LMP and obstetric estimate) revisions of the US standard birth certificate: clinical or obstetric estimate and LMP-based estimate agree within 7 days ("gold standard"); clinical estimate only; obstetric estimate only; and LMP-based estimate only. Birth weight for gestational age distributions differed according to the measurement of gestational age. Regardless of birth certificate revision, the median, 10th, and 90th percentile distributions were virtually identical for the gold standard, clinical estimate, and obstetric estimate. Birth weights for the LMP estimate were higher for preterm births and lower for postterm births for both birth certificate revisions. Agreement between the gold standard estimate and clinical and obstetric estimates of gestational age suggests that using the LMP-based estimate for establishing norms should be revisited.

Approaching the diagnosis of growth-restricted neonates: a cohort study

BACKGROUND

The consequences of in utero growth restriction have been attracting scholarly attention for the past two decades. Nevertheless, the diagnosis of growth-restricted neonates is as yet an unresolved issue. Aim of this study is the evaluation of the performance of simple, common indicators of nutritional status, which are used in the identification of growth-restricted neonates.

METHODS

In a cohort of 418 consecutively born term and near term neonates, four widely used anthropometric indices of body proportionality and subcutaneous fat accretion were applied, singly and in combination, as diagnostic markers for the detection of growth-restricted babies. The concordance of the indices was assessed in terms of positive and negative percent agreement and of Cohen's kappa.

RESULTS

The agreement between the anthropometric indices was overall poor with a highest positive percent agreement of 62.5% and a lowest of 27.9% and the kappa ranging between 0.19 and 0.58. Moreover, 6% to 32% of babies having abnormal values in just one index were apparently well-grown and the median birth weight centile of babies having abnormal values of either of two indices was found to be as high as the 46th centile for gestational age (95%CI 35.5 to 60.4 and 29.8 to 63.9, respectively). On the contrary, the combination of anthropometric indices appeared to have better distinguishing properties among apparently and not apparently well-grown babies. The median birth weight centile of babies having abnormal values in two (or more) indices was the 11th centile for gestational age (95%CI 6.3 to 16.3).

CONCLUSIONS

Clinical assessment and anthropometric indices in combination can define a reference standard with better performance compared to the same indices used in isolation. This approach offers an easy-to-use tool for bedside diagnosis of in utero growth restriction.

Neonatal management and long-term sequelae

Intrauterine or fetal growth restriction is best defined by using customised birth weight percentiles based upon the growth potential for an individual infant. Growth restriction in utero may be classified as asymmetric or symmetric depending upon the duration of the process. Asymmetric growth restriction is caused by placental insufficiency, maternal hypertensive conditions, long-standing maternal diabetes, smoking, living at altitude or multiple gestation. Symmetric growth restriction may be due to congenital infections, chromosomal or other abnormalities, fetal alcohol syndrome, low socioeconomic status or be constitutional. The underlying cause of growth restriction often predicts the potential adverse effects on the foetus and newborn and later effects in childhood and adulthood. With placental insufficiency, there may be chronic or acute on chronic fetal hypoxia with birth asphyxia and hypothermia, neonatal hypoglycaemia, polycythaemia and coagulopathy. Management is directed at prevention or early treatment of these conditions. In contrast, symmetrically growth-restricted infants should be examined carefully to look for congenital infections and malformations that may need specific interventions. Infants with constitutional short stature generally do not need any specific management. Feeding of growth-restricted infants is important to overcome deficiencies incurred in utero. Most infants show catch-up growth although about 10% do not. Those with excessive catch-up growth may be at greatest risk of developing insulin resistance in adulthood leading to diabetes, obesity and heart disease. The so-called fetal origins of disease may actually have a postnatal onset related more to excessive weight gain in infancy. There is still controversy over the indications for growth hormone treatment in growth-restricted infants who remain of short stature in early childhood. Intrauterine growth restriction is also associated with a five- to seven-fold increased risk of cerebral palsy probably due to chronic placental insufficiency.