Fetal macrosomia: a problem in need of a policy

Impact of screening for large-for-gestational-age fetuses on maternal and neonatal outcomes: a prospective observational study

OBJECTIVES

Debates on the management of macrosomia are still current. We have to consider the consequences of screening to contribute to these discussions. Our aim is to study the consequences of the 3rd trimester fetal macrosomia screening protocols used in several centres in the same French region in order to determine whether this screening affects maternal and neonatal outcomes: mode of delivery, maternal complications (haemorrhage, perineal lesions), neonatal health (pH, Apgar score) and the occurrence of neonatal trauma during delivery.

METHODS

Prospective observational, multicenter cohort study (Reims, Châlons en Champagne and Charleville-Mézières hospitals). All women with low-risk pregnancies who could benefit from screening for fetal macrosomia were included. Neonatal macrosomia was defined as a weight above the 90th percentile according to AUDIPOG adjusted growth curves. The principal outcome was the cesarean section rate. Secondary outcomes were instrumental deliveries and maternal and neonatal morbidity and mortality.

RESULTS

2,217 women were included. Rates of cesarean section and instrumental delivery were higher if macrosomia had been screened, whether rightly, in large-for-gestational-age newborns (respectively 9,802 [1.638-190.290], p=0.038 and 3,021 [1.099-8.846], p=0.036) or wrongly, in newborns who were ultimately appropriate-for-date (respectively ORa 3.562 [1.377-10.128], p=0.01 and 3.042 [1.139-8.596], p=0.36). This screening did not reduce maternal and neonatal morbidity and mortality.

CONCLUSIONS

Screening for fetal macrosomia may be associated with increased rates of cesarean section and instrumental delivery for large-for-gestational-age and appropriate-for-date newborns. These results do not show any impact of these variations on maternal or neonatal health, and do not allow us to change practices directly. They do, however, alert us to the consequences of widespread screening for LGA and its possible side effects, which could be better targeted to high-risk populations or improved according to other criteria.

Methodology Used in Studies Aimed at Measuring Fetal Soft Tissues by 2D Ultrasound for the Screening of Large for Gestational Age Fetuses: A Systematic Review

Management of suspected large for gestational age (LGA) fetuses remains unclear because ultrasound-estimated fetal weight (EFW) is not accurate. This was a systematic review of observational studies on fetal soft tissues measurements used alone or in combination to create a new EFW formula, to improve the screening for LGA fetuses. Studies were scored using a predefined set of independently agreed methodological criteria and an overall quality score was assigned for study design, statistical analysis, and reporting methods. There is a need to standardize methodologies for soft fetal tissue measurements. We propose a set of suggestions for this purpose.

Associations of prenatal urinary melamine, melamine analogues, and aromatic amines with gestational duration and fetal growth in the ECHO Cohort

Melamine, its analogues, and aromatic amines (AAs) were commonly detected in a previous study of pregnant women in the Environmental influences on Child Health Outcomes (ECHO) Cohort. While these chemicals have identified toxicities, little is known about their influences on fetal development. We measured these chemicals in gestational urine samples in 3 ECHO cohort sites to assess associations with birth outcomes (n = 1,231). We estimated beta coefficients and 95% confidence intervals (CIs) using adjusted linear mixed models with continuous dilution-standardized concentrations (log2 transformed and scaled by interquartile range, IQR) or binary indicators for detection. As secondary analyses, we repeated analyses using categorical outcomes. Forty-one of 45 analytes were detected in at least one sample, with > 95 % detection of melamine, cyanuric acid, ammelide, and aniline. Higher melamine concentration was associated with longer gestational age (β^ per IQR increase of log2-transformed: 0.082 [95 % CI: -0.012, 0.177]; 2nd vs 1st tertile: 0.173 [-0.048, 0.394]; 3rd vs 1st tertile: 0.186 [-0.035, 0.407]). Similarly in secondary analyses using categorical outcomes, an IQR increase in log2(melamine) was associated with 1.22 [0.99, 1.50] higher odds of post-term (>40 & ≤42 weeks) as compared to full-term (≥38 & ≤40 weeks). Several AAs were associated with birthweight and gestational length, with the direction of associations varying by AA. Some stronger associations were observed in females. Our findings suggest melamine and its analogs and AAs may influence gestational length and birthweight.

Dose birthweight matter to quality of life? A comparison between Japan, the U.S., and India

BACKGROUND

Birthweight is a widely accepted indicator of infant health and has significant and lasting associations. Several studies have found that low and high birthweight have significant negative associations with adult health. A new study in the field of social sciences has established that birthweight has significant negative associations with not only adult health but also social attributes, such as income and occupation; however, no studies have evaluated the associations between birthweight and quality-of-life (QOL) attributes such as happiness.

METHODS

In this study, we use data from Japan, the U.S., and India, collected in 2011, in which the respondents were asked about their own birthweights to examine the long-term associations between low and high birthweight and eight outcome variables related to the QOL: adolescent academic performance, height, education, marital status, body mass index, income, health, and happiness. We regressed each of the eight outcome variables on low and high birthweight and the interaction terms of the old age and the birthweight dummies for each country. We estimated both the reduced and the recursive-structural forms. While the former estimates the total, that is, the sum of direct and indirect associations between birthweight and each outcome, the latter reports the direct association between birthweight and each outcome.

RESULTS

In Japan, while low birthweight is negatively associated with all outcomes, the associations of high birthweight were limited. In the U.S., low birthweight was not associated with any outcomes, but high birthweight had significantly negative associations with health and happiness. In contrast, in India, high birthweight was significantly and positively associated with income, health, and happiness, while low birthweight was associated with several outcomes negatively, similar to Japan. These associations were stronger in youth than in old age.

CONCLUSION

Our study demonstrated that the associations of birthweight with QOL are widely diversified across countries: low birthweight, rather than high birthweight, is a problem in Japan and India. However, the opposite is true for the U.S., indicating that policymakers in developed countries must pay closer attention to the problems caused by high birthweight, whereas those in developing countries are better to focus on low birthweight.

Association between gestational abnormal glucose tolerance and maternal-fetal outcomes

AIM

To investigate the relationship between abnormal glucose tolerance during pregnancy and maternal-fetal outcomes, after categorizing women into groups with different levels of gestational abnormal glucose tolerance.

METHODS

A total of 1858 pregnant women who received two-step screening for gestational diabetes mellitus (GDM) at Fooyin University Hospital were categorized into four groups, according to their glucose abnormalities, and their maternal-fetal outcomes were investigated from October 2015 to June 2020.

RESULTS

Among the groups having different levels of abnormal glucose tolerance, there were significant differences and trends in mother's age, currently married status, and prepregnancy overweight or obesity, incidences of cesarean section, preterm, and gestational hypertension or preeclampsia; and with respect to neonatal incidence of large for gestational age (LGA), average weight, and average height (p < 0.05). After adjusting for potential factors, there were higher incidences of cesarean section (AOR = 1.71; 95% confidence interval [CI]: 1.12-2.61), preterm (AOR = 2.20; 95% CI: 1.23-3.91), neonatal LGA (AOR = 4.94; 95% CI: 2.87-8.51), and neonatal intensive care unit (NICU) admission (AOR = 2.66; 95% CI: 1.14-6.24) in the GDM group, relative to the control group. Furthermore, the women in the oral glucose tolerance test (OGTT)-1 group had a higher incidence of neonatal LGA when compared with the women in the normal group (AOR = 2.31; 95% CI: 1.02-5.33).

CONCLUSIONS

We found higher incidences of cesarean section, preterm, and neonatal LGA and NICU admission in the GDM women, and a higher incidence of neonatal LGA in the OGTT-1 group, relative to control group.

Accelerated fetal growth velocity across the third trimester is associated with increased shoulder dystocia risk among fetuses who are not large-for-gestational-age: A prospective observational cohort study

OBJECTIVE

To investigate whether fetuses with accelerated third trimester growth velocity are at increased risk of shoulder dystocia, even when they are not large-for-gestational-age (LGA; estimated fetal weight (EFW) >95th centile).

METHODS

Fetal growth velocity and birth outcome data were prospectively collected from 347 nulliparous women. Each had blinded ultrasound biometry performed at 28 and 36 weeks' gestation. Change in EFW and abdominal circumference (AC) centiles between 28-36 weeks were calculated, standardised over exactly eight weeks. We examined the odds of shoulder dystocia with increasing EFW and AC growth velocities among women with 36-week EFW ≤95th centile (non-LGA), who went on to have a vaginal birth. We then examined the relative risk (RR) of shoulder dystocia in cases of accelerated EFW and AC growth velocities (>30 centiles gained). Finally, we compared the predictive performances of accelerated fetal growth velocities to 36-week EFW >95th centile for shoulder dystocia among the cohort planned for vaginal birth.

RESULTS

Of the 226 participants who had EFW ≤95th centile at 36-week ultrasound and birthed vaginally, six (2.7%) had shoulder dystocia. For each one centile increase in EFW between 28-36 weeks, the odds of shoulder dystocia increased by 8% (odds ratio (OR [95% Confidence Interval (CI)]) = 1.08 [1.04-1.12], p<0.001). For each one centile increase in AC between 28-36 weeks, the odds of shoulder dystocia increased by 9% (OR[95%CI] = 1.09 [1.05-1.12], p<0.001). When compared to the rest of the cohort with normal growth velocity, accelerated EFW and AC velocities were associated with increased relative risks of shoulder dystocia (RR[95%CI] = 7.3 [1.9-20.6], p = 0.03 and 4.8 [1.7-9.4], p = 0.02 respectively). Accelerated EFW or AC velocities predicted shoulder dystocia with higher sensitivity and positive predictive value than 36-week EFW >95th centile.

CONCLUSIONS

Accelerated fetal growth velocities between 28-36 weeks' gestation are associated with increased risk of shoulder dystocia, and may predict shoulder dystocia risk better than the commonly used threshold of 36-week EFW >95th centile.

Mediation role of low birth weight on the factors associated with newborn mortality and the moderation role of institutional delivery in the association of low birth weight with newborn mortality in a resource-poor setting

OBJECTIVES

To assess low birth weight's (LBW) mediation role on the factors associated with newborn mortality (NM), including stillbirth and the role of institutional delivery in the association between LBW and NM.

DESIGN AND PARTICIPANTS

I used the 2011-2015 event histories health demographic data collected by Iganga-Mayuge Health Demographic and Surveillance Site (HDSS). The dataset consisted of 10 758 registered women whose birth occurred at least 22 weeks of the gestation period and records of newborns' living status 28 days after delivery.

SETTING

The Iganga-Mayuge HDSS is in Eastern Uganda, which routinely collects health and demographic data from a registered population of at least 100 000 people.

OUTCOME MEASURE

The study's key outcomes or endogenous factors were perinatal mortality (PM), late NM and LBW (mediating factor).

RESULTS

The factors that were directly associated with PM were LBW (OR=2.55, 95% CI 1.15 to 5.67)), maternal age of 30+ years (OR=1.68, 95% CI 1.21 to 2.33), rural residence (OR=1.38, 95% CI 1.02 to 1.85), mothers with previous experience of NM (OR=3.95, 95% CI 2.86 to 5.46) and mothers with no education level (OR=1.63, 95% CI 1.21 to 2.18). Multiple births and mother's prior experience of NM were positively associated with NM at a later age. Institutional delivery had a modest inverse role in the association of LBW with PM. LBW mediated the association of PM with residence status, mothers' previous NM experience, multiple births, adolescent mothers and mothers' marital status. Of the total effect attributable to each of these factors, LBW mediated +25%, +22%, +100%, 25% and -38% of rural resident mothers, mothers with previous experience of newborn or pregnancy loss, multiple births, adolescent mothers and mothers with partners, respectively.

CONCLUSION

LBW mediated multiple factors in the NM pathways, and the effect of institutional delivery in reducing mortality among LBW newborns was insignificant. The findings demonstrate the need for a holistic life course approach that gears the health systems to tackle NM.

The second pregnancy has no effect in the incidence of macrosomia: a cross-sectional survey in two western Chinese regions

BACKGROUND

After the implementation of the universal two-child policy in China, the increase in parity has led to an increase in adverse pregnancy outcomes. The impact of one and two fetuses on the incidence of fetal macrosomia has not been fully confirmed in China. This study aimed to explore the differences in the incidence of fetal macrosomia in first and second pregnancies in Western China after the implementation of the universal two-child policy.

METHODS

A total of 1598 pregnant women from three hospitals were investigated by means of a cross-sectional study from August 2017 to January 2018. Participants were recruited by convenience and divided into first and second pregnancy groups. These groups included 1094 primiparas and 504 women giving birth to their second child. Univariate and multivariate logistic regression analyses were performed to discuss the differences in the incidence of fetal macrosomia in first and second pregnancies.

RESULTS

No significant difference was found in the incidence of macrosomia in the first pregnancy group (7.2%) and the second pregnancy group (7.1%). In the second-time pregnant mothers, no significant association was found between the macrosomia of the second child (5.5%) and that of the first child (4.7%). The multivariate logistic regression model showed that mothers older than 30 years are not likely to give birth to children with macrosomia (odds ratio (OR) 0.6, 95% confidence interval (CI) 0.4,0.9).

CONCLUSIONS

The incidence of macrosomia in Western China is might not be affected by the birth of the second child and is not increased by low parity.

Observer Influence with Other Variables on the Accuracy of Ultrasound Estimation of Fetal Weight at Term

Background and Objectives: The accuracy with which the estimation of fetal weight (EFW) at term is determined is useful in order to address obstetric complications, since it is a parameter that represents an important prognostic factor for perinatal and maternal morbidity and mortality. The aim of this study was to determine the role of the experienced observers with other variables that could influence the accuracy of the ultrasound used to calculate EFW at term, carried out within a period of seven days prior to delivery, in order to assess interobserver variability. Materials and Methods: A cross-sectional study was performed including 1144 pregnancies at term. The validity of the ultrasound used to calculate EFW at term was analyzed using simple error, absolute error, percentage error and absolute percentage error, as well as the percentage of predictions with an error less than 10 and 15% in relation to maternal, obstetric and ultrasound variables. Results: Valid predictions with an error less than 10 and 15% were 74.7 and 89.7% respectively, with such precision decreasing according to the observer as well as in extreme fetal weights. The remaining variables were not significant in ultrasound EFW at term. The simple error, absolute error, percentage error and absolute percentage error were greater in cases of extreme fetal weights, with a tendency to overestimate the low weights and underestimate the high weights. Conclusions: The accuracy of EFW with ultrasound carried out within seven days prior to birth is not affected by maternal or obstetric variables, or by the time interval between the ultrasound and delivery. However, accuracy was reduced by the observers and in extreme fetal weights.

The prevalence of urinary incontinence symptoms among multiparous women: a survey of Saudi health-care centers

OBJECTIVE

To determine the distribution of urinary incontinence (UI) symptoms and their relation to childbirth events.

METHODS

This cross-sectional study used a structured self-administered questionnaire that included the Questionnaire for Female Urinary Incontinence Diagnosis and the Urogenital Distress Inventory Short Form. The study included 802 women sampled from four primary health care centers in Dammam, KSA. A chi-square test and adjusted logistic regression models were used to examine the relation between UI symptoms and obstetric events.

RESULTS

Of the participants, 56.6% (n = 454) had at least one UI symptom. Symptoms were most commonly associated with grand multiparity (80.47%), a history of abortion (72%), assisted vaginal delivery (70%), an age of ≤ 18 years at first birth (66.67%) and ≥ 35 years at last birth (75.48%), and a history of macrosomia (84.62%) and episiotomy (67.89%). Unlike the risk of urgency UI, the risk of stress UI was statistically significantly linked to obstetric events. Grand multiparity was associated with a higher risk of both stress UI (odds ratio [OR]: 3.75, confidence interval [95% CI]: 1.68-8.40) and urgency UI (OR: 2.87, 95% CI: 1.07-7.73).

CONCLUSION

UI symptoms are common among grand multiparas. Unlike urgency UI, stress UI is associated with previous obstetric events.

Performance of local reference curve on the diagnosis of large for gestational age fetuses in diabetic pregnant women

Objective: To evaluate the performance of a local fetal weight curve based on the prediction for large gestational age (LGA) newborns in diabetic pregnant women and to compare it to reference curves established for other populations.Method: A reference model for estimated fetal weight was created from a local sample of 2211 singleton low-risk pregnancies. The estimated fetal weight from 194 women with gestational diabetes mellitus was then plotted on this curve, and the results were compared to those obtained by Intergrowth 21st and Hadlock curves.Results: The sensitivity of the proposed model to predict LGA fetuses was 55.6%, the specificity was 82.1%, and the accuracy was 74.7%. The sensitivity, specificity, and accuracy for the Intergrowth 21^st curve were 46.3%, 87.9%, and 76.3%, respectively, and no statistically significant difference was observed compared to the proposed model. Conversely, significant differences were observed for the Hadlock curve, which presented a lower sensitivity (24.1%), higher specificity (97.1%), and similar accuracy (76.8%).Conclusion: The sensitivity of the proposed model was higher compared to the Hadlock curve for the screening of LGA newborns in diabetic pregnant women. However, no significant differences were observed in comparison to the Intergrowth 21st curve.

Phenotypes of fetal macrosomia and risk of stillbirth among term deliveries over the previous four decades

OBJECTIVES

To evaluate the association between macrosomia and stillbirth over the previous four decades and to determine the consistency of the relationship.

METHODS

This was a population-based retrospective cohort study using United States Natality and Fetal Death Data from 1982 to 2017 and restricted to the gestational age range of 37-41 weeks inclusive. Macrosomia was defined as birthweight ≥4000 g and subdivided into its grades as previously recommended: grade 1 (4000-4499 g), grade 2 (4500-4999 g), and grade 3 (≥5000 g). We calculated temporal trends of stillbirth among fetuses with macrosomia over the years using joinpoint regression. We generated odds ratios from adjusted binomial logistic regression models to examine the association between macrosomia and risk of stillbirth stratified by grades using normal-weight infants (2500-3999 g) as referent.

RESULTS

Within the fetal macrosomia group, the rate of stillbirth declined from 2.04/1000 in 1982 to 1.05/1000 by the end of the study period (2017), representing a drop of about 48.5%. For the normal-weight fetuses, stillbirth rate declined from 1.95/1000 to 0.83/1000, equivalent to a decline of 57.4%. Macrosomia was significantly associated with elevated risk for stillbirth: grade 2 (OR = 1.27; 95% CI = 1.22-1.32) and grade 3 (OR = 5.97; 95% CI = 5.69-6.22).

CONCLUSIONS

Fetal macrosomia is a significant risk factor for fetal demise with the worst intrauterine survival observed among those classified as grade 3. Fetal macrosomia is a heterogeneous rather than a homogeneous entity in terms of risk profiles, and this needs to be considered in future policy guidelines.

"INTERGROWTH21st vs customized fetal growth curves in the assessment of the neonatal nutritional status: a retrospective cohort study of gestational diabetes"

BACKGROUND

Gestational diabetes mellitus is associated with increased incidence of adverse perinatal outcomes including newborns large for gestational age, macrosomia, preeclampsia, polyhydramnios, stillbirth, and neonatal morbidity. Thus, fetal growth should be monitored by ultrasound to assess for fetal overnutrition, and thereby, its clinical consequence, macrosomia. However, it is not clear which reference curve to use to define the limits of normality. Our aim is to determine which method, INTERGROWTH21st or customized curves, better identifies the nutritional status of newborns of diabetic mothers.

METHODS

This retrospective cohort study compared the risk of malnutrition in SGA newborns and the risk of overnutrition in LGA newborns using INTERGROWTH21st and customized birth weight references in gestational diabetes. The nutritional status of newborns was assessed using the ponderal index. Additionally, to determine the ability of both methods in the identification of neonatal malnutrition and overnutrition, we calculate sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratios.

RESULTS

Two hundred thirty-one pregnant women with GDM were included in the study. The rate of SGA indentified by INTERGROWTH21st was 4.7% vs 10.7% identified by the customized curves. The rate of LGA identified by INTERGROWTH21st was 25.6% vs 13.2% identified by the customized method. Newborns identified as SGA by the customized method showed a higher risk of malnutrition than those identified as SGA by INTERGROWTH21st. (RR 4.24 vs 2.5). LGA newborns according to the customized method also showed a higher risk of overnutrition than those classified as LGA according to INTERGROWTH21st. (RR 5.26 vs 3.57). In addition, the positive predictive value of the customized method was superior to that of INTERGROWTH21st in the identification of malnutrition (32% vs 27.27%), severe malnutrition (22.73% vs 20%), overnutrition (51.61% vs 32.20%) and severe overnutrition (28.57% vs 14.89%).

CONCLUSIONS

In pregnant women with DMG, the ability of customized fetal growth curves to identify newborns with alterations in nutritional status appears to exceed that of INTERGROWTH21st.

Association between false positive glucose challenge test results and large-for-gestational-age infants: a retrospective cohort study

OBJECTIVES

There is no consensus regarding a possible relation between false positive glucose challenge test (GCT) results and large-for-gestational-age (LGA) infants. This study aimed to clarify the association between false positive GCT results and LGA, after adjusting for potential confounding factors, using a large clinical dataset.

DESIGN

Retrospective cohort study.

SETTING

National Hospital Organisation Kofu National Hospital, which is a community hospital, between January 2012 and August 2019.

PARTICIPANTS

Japanese women who underwent GCT between 24 and 28 weeks of gestation at the hospital were included. After excluding those with gestational diabetes mellitus, diabetes in pregnancy and multiple pregnancies, subjects were divided into a false positive GCT group (≥140 mg/dL) and a GCT negative group (<140 mg/dL).

METHODS

Obstetric records of patients were examined. The χ²-test and multivariable logistic regression analysis were used to investigate the association between false positive GCT results and LGA.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incidence of LGA and the association between false positive GCT results and LGA.

RESULTS

The mean subject age was 31.4±5.5 years, with 43.3% nulliparity (n=974) and 2160 (96.1%) term deliveries. The incidence of LGA was 9.4% (211/2248) and 11.4% (257/2248) of the women had false positive GCT results. False positive GCT results were significantly associated with an increased risk of LGA (OR, 1.51; 95% CI, 1.02 to 2.23), after controlling for maternal age, prepregnancy maternal weight, maternal weight gain during pregnancy and parity.

CONCLUSIONS

It appears that there is a significant association between false positive GCT results and LGA. Additional research is required to confirm these results and to investigate appropriate interventions for women with abnormal screens for gestational diabetes mellitus.

Impact of biometric measurement error on identification of small- and large-for-gestational-age fetuses

OBJECTIVES

First, to obtain measurement-error models for biometric measurements of fetal abdominal circumference (AC), head circumference (HC) and femur length (FL), and, second, to examine the impact of biometric measurement error on sonographic estimated fetal weight (EFW) and its effect on the prediction of small- (SGA) and large- (LGA) for-gestational-age fetuses with EFW < 10^th and > 90^th percentile, respectively.

METHODS

Measurement error standard deviations for fetal AC, HC and FL were obtained from a previous large study on fetal biometry utilizing a standardized measurement protocol and both qualitative and quantitative quality-control monitoring. Typical combinations of AC, HC and FL that gave EFW on the 10^th and 90^th percentiles were determined. A Monte-Carlo simulation study was carried out to examine the effect of measurement error on the classification of fetuses as having EFW above or below the 10^th and 90^th percentiles.

RESULTS

Errors were assumed to follow a Gaussian distribution with a mean of 0 mm and SDs, obtained from a previous well-conducted study, of 6.93 mm for AC, 5.15 mm for HC and 1.38 mm for FL. Assuming errors according to such distributions, when the 10^th and 90^th percentiles are used to screen for SGA and LGA fetuses, respectively, the detection rates would be 78.0% at false-positive rates of 4.7%. If the cut-offs were relaxed to the 30^th and 70^th percentiles, the detection rates would increase to 98.2%, but at false-positive rates of 24.2%. Assuming half of the spread in the error distribution, using the 10^th and 90^th percentiles to screen for SGA and LGA fetuses, respectively, the detection rates would be 86.6% at false-positive rates of 2.3%. If the cut-offs were relaxed to the 15^th and 85^th percentiles, respectively, the detection rates would increase to 97.0% and the false-positive rates would increase to 6.3%.

CONCLUSIONS

Measurement error in fetal biometry causes substantial error in EFW, resulting in misclassification of SGA and LGA fetuses. The extent to which improvement can be achieved through effective quality assurance remains to be seen but, as a first step, it is important for practitioners to understand how biometric measurement error impacts the prediction of SGA and LGA fetuses. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

The test accuracy of antenatal ultrasound definitions of fetal macrosomia to predict birth injury: A systematic review

OBJECTIVES

To determine which ultrasound measurement for predicted fetal macrosomia most accurately predicts adverse delivery and neonatal outcomes.

STUDY DESIGN

Four biomedical databases searched for studies published after 1966. Randomised trials or observational studies of women with singleton pregnancies, resulting in a term birth who have undergone an index test of interest measured and recorded as predicted fetal macrosomia ≥28 weeks. Adverse outcomes of interest included shoulder dystocia, brachial plexus injury (BPI) and Caesarean section.

RESULTS

Twenty-five observational studies (13,285 participants) were included. For BPI, the only significant positive association was found for Abdominal Circumference (AC) to Head Circumference (HC) difference > 50 mm (OR 7.2, 95 % CI 1.8-29). Shoulder dystocia was significantly associated with abdominal diameter (AD) minus biparietal diameter (BPD) ≥ 2.6 cm (OR 4.2, 95 % CI 2.3-7.5, PPV 11 %) and AC > 90th centile (OR 2.3, 95 % CI 1.3-4.0, PPV 8.6 %) and an estimated fetal weight (EFW) > 4000 g (OR 2.1 95 %CI 1.0-4.1, PPV 7.2 %).

CONCLUSIONS

Estimated fetal weight is the most widely used ultrasound marker to predict fetal macrosomia in the UK. This study suggests other markers have a higher positive predictive value for adverse outcomes associated with fetal macrosomia.

Does the Porter formula hold its promise? A weight estimation formula for macrosomic fetuses put to the test

Purpose

Estimating fetal weight using ultrasound measurements is an essential task in obstetrics departments. Most of the commonly used weight estimation formulas underestimate fetal weight when the actual birthweight exceeds 4000 g. Porter et al. published a specially designed formula in an attempt to improve detection rates for such macrosomic infants. In this study, we question the usefulness of the Porter formula in clinical practice and draw attention to some critical issues concerning the derivation of specialized formulas of this type.

Methods

A retrospective cohort study was carried out, including 4654 singleton pregnancies with a birthweight ≥ 3500 g, with ultrasound examinations performed within 14 days before delivery. Fetal weight estimations derived using the Porter and Hadlock formulas were compared.

Results

Of the macrosomic infants, 27.08% were identified by the Hadlock formula, with a false-positive rate of 4.60%. All macrosomic fetuses were detected using the Porter formula, with a false-positive rate of 100%; 99.96% of all weight estimations using the Porter formula fell within a range of 4300 g ± 10%. The Porter formula only provides macrosomic estimates.

Conclusions

The Porter formula does not succeed in distinguishing macrosomic from normal-weight fetuses. High-risk fetuses with a birthweight ≥ 4500 g in particular are not detected more precisely than with the Hadlock formula. For these reasons, we believe that the Porter formula should not be used in clinical practice. Newly derived weight estimation formulas for macrosomic fetuses must not be based solely on a macrosomic data set.

Electronic supplementary material

The online version of this article (10.1007/s00404-019-05410-7) contains supplementary material, which is available to authorized users.

Trends in the incidence of fetal macrosomia and its phenotypes in the United States, 1971-2017

PURPOSE

Studies have reported a surge in the prevalence of obesity among various demographic groups including pregnant women in the U.S. Given the association between maternal obesity and risk of fetal macrosomia, we hypothesized that the incidence of fetal macrosomia will be on the rise in the U.S. We examined trends in fetal macrosomia and macrosomia phenotypes in the U.S. among singleton live births within the gestational age of 28-42 weeks inclusive.

METHODS

This was a retrospective cohort study covering the period 1971-2017 using U.S. Natality Data files. We applied Joinpoint regression models to derive the average annual percentage change in the outcome. We measured incidence and trends of fetal macrosomia which was defined as birth weight ≥ 4000 g. We further subdivided macrosomia into its phenotypes as previously recommended: Grade 1 (4000-4499 g), Grade 2 (4500-4999 g) and Grade 3 (≥ 5000 g).

RESULTS

A total of 147,331,305 singleton births over the entire study period of 47 years were analyzed. From a baseline incidence of 8.84%, the rate of fetal macrosomia declined to 8.07% by the end of the study representing a drop of 8.70% in relative terms. The greatest drop was among infants with Grade 3 macrosomia, the most severe and lethal phenotype. The most impactful factors were maternal age and gestational weight gain.

CONCLUSION

This study is the largest population-based study conducted regarding fetal macrosomia. The rate of fetal macrosomia declined over the previous 5 decades with the most substantial drop observed in the phenotype with the worst prognosis.

Screening circulating proteins to identify biomarkers of fetal macrosomia

Objective

Fetal macrosomia is a major risk factor for shoulder dystocia, which can lead to birth asphyxia, maternal and neonatal traumatic injuries, and perinatal death. If macrosomia is diagnosed in the antenatal period, labour can be induced to decrease shoulder dystocia. But current clinical methods to diagnose fetal macrosomia antenatally perform with poor accuracy. Therefore, improved methods to accurately diagnose fetal macrosomia are required. Blood biomarkers that predict fetal macrosomia could be one such novel diagnostic strategy. We undertook a nested case–control study from a prospective collection of 1000 blood samples collected at 36 weeks’ gestation. We analysed plasma samples from 52 women who subsequently delivered a macrosomic (> 95th centile for gestational age) infant and 106 controls. Circulating concentrations of the proteins COBLL1, CSH1, HSD3B1, EGFL6, XAGE3, S100P, PAPPA-1, ERBB2 were assessed for their ability to predict macrosomic infants.

Results

We did not identify any significant changes in the plasma concentrations of COBLL1, CSH1, HSD3B1, EGFL6, XAGE3, S100P, PAPPA-1, ERBB2 from women who subsequently delivered macrosomic neonates relative to control samples. Although we have not identified any potential biomarkers of fetal macrosomia, we have ruled out these particular eight protein candidates.

Prediction of large-for-gestational-age neonate by routine third-trimester ultrasound

OBJECTIVES

First, to evaluate and compare the performance of routine ultrasonographic estimated fetal weight (EFW) and fetal abdominal circumference (AC) at 31 + 0 to 33 + 6 and 35 + 0 to 36 + 6 weeks' gestation in the prediction of a large-for-gestational-age (LGA) neonate born at ≥ 37 weeks' gestation. Second, to assess the additive value of fetal growth velocity between 32 and 36 weeks' gestation to the performance of EFW at 35 + 0 to 36 + 6 weeks' gestation for prediction of a LGA neonate. Third, to define the predictive performance for a LGA neonate of different EFW cut-offs on routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation. Fourth, to propose a two-stage strategy for identifying pregnancies with a LGA fetus that may benefit from iatrogenic delivery during the 38^th gestational week.

METHODS

This was a retrospective study. First, data from 21 989 singleton pregnancies that had undergone routine ultrasound examination at 31 + 0 to 33 + 6 weeks' gestation and 45 847 that had undergone routine ultrasound examination at 35 + 0 to 36 + 6 weeks were used to compare the predictive performance of EFW and AC for a LGA neonate with birth weight > 90^th and > 97^th percentiles born at ≥ 37 weeks' gestation. Second, data from 14 497 singleton pregnancies that had undergone routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation and had a previous scan at 30 + 0 to 34 + 6 weeks were used to determine, through multivariable logistic regression analysis, whether addition of growth velocity, defined as the difference in EFW Z-score or AC Z-score between the early and late third-trimester scans divided by the time interval between the scans, improved the performance of EFW at 35 + 0 to 36 + 6 weeks in the prediction of delivery of a LGA neonate at ≥ 37 weeks' gestation. Third, in the database of the 45 847 pregnancies that had undergone routine ultrasound examination at 35 + 0 to 36 + 6 weeks' gestation, the screen-positive and detection rates for a LGA neonate born at ≥ 37 weeks' gestation and ≤ 10 days after the initial scan were calculated for different EFW percentile cut-offs between the 50^th and 90^th percentiles.

RESULTS

First, the areas under the receiver-operating characteristics curves (AUC) of screening for a LGA neonate were significantly higher using EFW Z-score than AC Z-score and at 35 + 0 to 36 + 6 than at 31 + 0 to 33 + 6 weeks' gestation (P < 0.001 for all). Second, the performance of screening for a LGA neonate achieved by EFW Z-score at 35 + 0 to 36 + 6 weeks was not significantly improved by addition of EFW growth velocity or AC growth velocity. Third, in screening by EFW > 90^th percentile at 35 + 0 to 36 + 6 weeks' gestation, the predictive performance for a LGA neonate born at ≥ 37 weeks' gestation was modest (65% and 46% for neonates with birth weight > 97^th and > 90^th percentiles, respectively, at a screen-positive rate of 10%), but the performance was better for prediction of a LGA neonate born ≤ 10 days after the scan (84% and 71% for neonates with birth weight > 97^th and > 90^th percentiles, respectively, at a screen-positive rate of 11%). Fourth, screening by EFW > 70^th percentile at 35 + 0 to 36 + 6 weeks' gestation predicted 91% and 82% of LGA neonates with birth weight > 97^th and > 90^th percentiles, respectively, born at ≥ 37 weeks' gestation, at a screen-positive rate of 32%, and the respective values of screening by EFW > 85^th percentile for prediction of a LGA neonate born ≤ 10 days after the scan were 88%, 81% and 15%. On the basis of these results, it was proposed that routine fetal biometry at 36 weeks' gestation is a screening rather than diagnostic test for fetal macrosomia and that EFW > 70^th percentile should be used to identify pregnancies in need of another scan at 38 weeks, at which those with EFW > 85^th percentile should be considered for iatrogenic delivery during the 38^th  week.

CONCLUSIONS

First, the predictive performance for a LGA neonate by routine ultrasonographic examination during the third trimester is higher if the scan is carried out at 36 than at 32 weeks, the method of screening is EFW than fetal AC, the outcome measure is birth weight > 97^th than > 90^th percentile and if delivery occurs within 10 days than at any stage after assessment. Second, prediction of a LGA neonate by EFW > 90^th percentile is modest and this study presents a two-stage strategy for maximizing the prenatal prediction of a LGA neonate. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Maternal and neonatal complications of fetal macrosomia: cohort study

OBJECTIVE

To estimate the risks of maternal and neonatal complications in pregnancies with macrosomia.

METHODS

This was a retrospective cohort study conducted at a large maternity unit in the UK between January 2009 and December 2016. The incidence of maternal and neonatal complications in pregnancies with macrosomia, defined as birth weight (BW) > 4000 g, and in those with severe macrosomia, defined as BW > 4500 g, was compared with that in pregnancies with normal BW (2500-4000 g). Regression analysis was performed to determine odds ratios (ORs) for complications in macrosomic pregnancies compared to those with normal BW.

RESULTS

The study population of 35 548 pregnancies included 4522 (12.7%) with macrosomia, of which 643 (1.8%) had severe macrosomia, and 31 026 (87.3%) with normal BW. In the macrosomia group, the adjusted OR was 3.1 (95% CI, 2.6-3.6) for Cesarean section for failure to progress, 2.4 (95% CI, 2.0-3.0) for severe postpartum hemorrhage, 2.3 (95% CI, 1.9-2.8) for obstetric anal sphincter injury, 10.4 (95% CI, 8.6-12.6) for shoulder dystocia, 28.5 (95% CI, 8.9-90.7) for obstetric brachial plexus injury, 32.3 (95% CI, 3.8-278.2) for birth fractures and 4.4 (95% CI, 2.2-8.8) for hypoxic-ischemic encephalopathy. The respective values in pregnancies with severe macrosomia were 4.3 (95% CI, 3.1-6.1), 2.9 (95% CI, 1.9-4.4), 3.1 (95% CI, 1.9-5.1), 28.7 (95% CI, 20.8-39.8), 73.9 (95% CI, 15.1-363.2), 87.2 (95% CI, 7.7-985.0) and 13.8 (95% CI, 5.2-36.8).

CONCLUSION

Macrosomia is associated with serious adverse perinatal outcomes. This study provides accurate estimates of risks to aid in pregnancy management. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Maternal and neonatal complications of fetal macrosomia: systematic review and meta-analysis

OBJECTIVE

To determine accurate estimates of risks of maternal and neonatal complications in pregnancies with fetal macrosomia by performing a systematic review of the literature and meta-analysis.

METHODS

A search of MEDLINE, EMBASE, CINAHL and The Cochrane Library was performed to identify relevant studies reporting on maternal and/or neonatal complications in pregnancies with macrosomia having a birth weight (BW) > 4000 g and/or those with birth weight > 4500 g. Prospective and retrospective cohort and population-based studies that provided data regarding both cases and controls were included. Maternal outcomes assessed were emergency Cesarean section (CS), postpartum hemorrhage (PPH) and obstetric anal sphincter injury (OASIS). Neonatal outcomes assessed were shoulder dystocia, obstetric brachial plexus injury (OBPI) and birth fractures. Meta-analysis using a random-effects model was used to estimate weighted pooled estimates of summary statistics (odds ratio (OR) and 95% CI) for each complication, according to birth weight. Heterogeneity between studies was estimated using Cochran's Q, I2 statistic and funnel plots.

RESULTS

Seventeen studies reporting data on maternal and/or neonatal complications in pregnancy with macrosomia were included. In pregnancies with macrosomia having a BW > 4000 g, there was an increased risk of the maternal complications: emergency CS, PPH and OASIS, which had OR (95% CI) of 1.98 (1.80-2.18), 2.05 (1.90-2.22) and 1.91 (1.56-2.33), respectively. The corresponding values for pregnancies with BW > 4500 g were: 2.55 (2.33-2.78), 3.15 (2.14-4.63) and 2.56 (1.97-3.32). Similarly, in pregnancies with a BW > 4000 g, there was an increased risk of the neonatal complications: shoulder dystocia, OBPI and birth fractures, which had OR (95% CI) of 9.54 (6.76-13.46), 11.03 (7.06-17.23) and 6.43 (3.67-11.28), respectively. The corresponding values for pregnancies with a BW > 4500 g were: 15.64 (11.31-21.64), 19.87 (12.19-32.40) and 8.16 (2.75-24.23).

CONCLUSION

Macrosomia is associated with serious maternal and neonatal adverse outcomes. This study provides accurate estimates of these risks, which can be used for decisions on pregnancy management. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The cost-effectiveness of universal late-pregnancy screening for macrosomia in nulliparous women: a decision analysis

Objective

To identify the most cost‐effective policy for detection and management of fetal macrosomia in late‐stage pregnancy.

Design

Health economic simulation model.

Setting

All English NHS antenatal services.

Population

Nulliparous women in the third trimester treated within the UK NHS.

Methods

A health economic simulation model was used to compare long‐term maternal–fetal health and cost outcomes for two detection strategies (universal ultrasound scanning at approximately 36 weeks of gestation versus selective ultrasound scanning), combined with three management strategies (planned caesarean section versus induction of labour versus expectant management) of suspected fetal macrosomia. Probabilities, costs and health outcomes were taken from literature.

Main outcome measures

Expected costs to the NHS and quality‐adjusted life‐years (QALYs) gained from each strategy, calculation of net benefit and hence identification of most cost‐effective strategy.

Results

Compared with selective ultrasound, universal ultrasound increased QALYs by 0.0038 (95% CI 0.0012–0.0076), but also costs by £123.50 (95% CI 99.6–149.9). Overall, the health gains were too small to justify the cost increase given current UK thresholds cost‐effective policy was selective ultrasound coupled with induction of labour where macrosomia was suspected.

Conclusions

The most cost‐effective policy for detection and management of fetal macrosomia is selective ultrasound scanning coupled with induction of labour for all suspected cases of macrosomia. Universal ultrasound scanning for macrosomia in late‐stage pregnancy is not cost‐effective.

Tweetable abstract

Universal late‐pregnancy ultrasound screening for fetal macrosomia is not warranted.

Universal late‐pregnancy ultrasound screening for fetal macrosomia is not warranted.

Dietary patterns before and during pregnancy and birth outcomes: a systematic review

BACKGROUND

Maternal diet before and during pregnancy could influence fetal growth and birth outcomes.

OBJECTIVE

Two systematic reviews aimed to assess the relationships between dietary patterns before and during pregnancy and 1) gestational age at birth and 2) gestational age- and sex-specific birth weight.

METHODS

Literature was searched from January, 1980 to January, 2017 in 9 databases including PubMed, Embase, and Cochrane. Two analysts independently screened articles using predetermined inclusion and exclusion criteria. Data were extracted from included articles and risk of bias was assessed. Data were synthesized qualitatively, a conclusion statement was drafted for each question, and evidence supporting each conclusion was graded.

RESULTS

Of the 9103 studies identified, 11 [representing 7 cohorts and 1 randomized controlled trial (RCT)] were included for gestational age and 21 (representing 19 cohorts and 2 RCTs) were included for birth weight. Limited but consistent evidence suggests that certain dietary patterns during pregnancy are associated with a lower risk of preterm birth and spontaneous preterm birth. These protective dietary patterns are higher in vegetables; fruits; whole grains; nuts, legumes, and seeds; and seafood (preterm birth, only), and lower in red and processed meats, and fried foods. Most of the research was conducted in healthy Caucasian women with access to health care. No conclusion can be drawn on the association between dietary patterns during pregnancy and birth weight outcomes. Although research is available, the ability to draw a conclusion is restricted by inconsistency in study findings, inadequate adjustment of birth weight for gestational age and sex, and variation in study design, dietary assessment methodology, and adjustment for key confounding factors. Insufficient evidence exists regarding dietary patterns before pregnancy for both outcomes.

CONCLUSIONS

Maternal dietary patterns may be associated with a lower preterm and spontaneous preterm birth risk. The association is unclear for birth weight outcomes.

Disadvantages of a weight estimation formula for macrosomic fetuses: the Hart formula from a clinical perspective

Purpose

Sonographic fetal weight (FW) estimation to detect macrosomic fetuses is an essential part of everyday routine work in obstetrics departments. Most of the commonly used weight estimation formulas underestimate FW when the actual birth weight (BW) exceeds 4000 g. One of the best-established weight estimation formulas is the Hadlock formula. In an effort to improve the detection rates of macrosomic infants, Hart et al. published a specially designed formula including maternal weight at booking. The usefulness of the Hart formula was tested.

Methods

Retrospective study of 3304 singleton pregnancies, birth weight ≥ 3500 g. The accuracy of the Hadlock and Hart formula were tested. A subgroup analysis examined the influence of the maternal weight. The Chi-squared test and one-way analysis of variation were carried out. For all analyses, p < 0.05 was considered statistically significant.

Results

The overall percentages of births falling within ± 5% and ± 10% of the BW using the Hadlock formula were 27% and 53%, respectively. Using the Hart formula, 24% and 54% were identified within these levels. With the Hart formula, 94% of all weight estimations fall within 4200 g ± 5% and nearly 100% fall within 4200 g ± 10%.

Conclusions

Applying the Hart formula results in an overestimation of fetal weight in neonates with a birth weight < 4000 g and fails to identify high-risk fetuses. We, therefore, do not consider Hart’s formula to be of clinical relevance.

Prenatal prediction of postnatal large-for-dates neonates using a simplified MRI method: comparison with conventional 2D ultrasound estimates

OBJECTIVE

To evaluate the performance of a simple semi-automated method for estimation of fetal weight (EFW) using magnetic resonance imaging (MRI) as compared with two-dimensional (2D) ultrasound (US) for the prediction of large-for-dates neonates.

METHODS

Data of two groups of women with singleton pregnancy between March 2011 and May 2016 were retrieved from our database and evaluated retrospectively: the first group included women who underwent US-EFW and MRI-EFW within 48 h before delivery and the second group included women who had these evaluations between 35 + 0 weeks and 37 + 6 weeks of gestation, more than 48 h before delivery. US-EFW was based on Hadlock et al. and MRI-EFW on the formula described by Baker et al. For MRI-EFW, planimetric measurement of the fetal body volume (FBV) was performed using a semi-automated method and the time required for measurement was noted. Outcome measure was the performance of MRI-EFW vs US-EFW in the prediction of large-for-dates neonates, both ≤ 48 h and > 48 h before delivery. Receiver-operating characteristics (ROC) curves for each method were compared using the DeLong method.

RESULTS

Of the 270 women included in the first group, 48 (17.8%) newborns had birth weight ≥ 90^th centile and 30 (11.1%) ≥ 95^th centile. The second group included 83 women, and nine (10.8%) newborns had birth weight ≥ 95^th centile. Median time needed for FBV planimetric measurements in all 353 fetuses was 3.5 (range, 1.5-5.5) min. The area under the ROC curve (AUC) for prediction of large-for-dates neonates by prenatal MRI performed within 48 h before delivery was significantly higher than that by US (for birth weight ≥ 90^th centile, difference between AUCs = 0.085, standard error (SE) = 0.020, P < 0.001; for birth weight ≥ 95^th centile, difference between AUCs = 0.036, SE = 0.014, P = 0.01). Similarly, MRI-EFW was better than US-EFW in predicting birth weight ≥ 95^th centile when both examinations were performed > 48 h prior to delivery (difference between AUCs = 0.077, SE = 0.039, P = 0.045).

CONCLUSION

MRI planimetry using our purpose-designed semi-automated method is not time-consuming. The predictive performance of MRI-EFW performed immediately prior to or remote from delivery is significantly better than that of US-EFW for the prediction of large-for-dates neonates. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Antenatal risk factors associated with neonatal morbidity in large-for-gestational-age infants: an international prospective cohort study

INTRODUCTION

Large-for-gestational-age infants are associated with increased risk of neonatal morbidity and mortality. However, most of them will not have adverse outcomes. Our aim was to identify antenatal clinical factors associated with neonatal morbidity in large-for-gestational-age infants.

MATERIAL AND METHODS

Nulliparous women from the Screening for Pregnancy Endpoints (SCOPE) study were included. We compared maternal and fetal factors between large-for-gestational-age infants (birthweight >90th customized centile) with and without neonatal morbidity, defined as admission to a neonatal intensive care unit or severe neonatal morbidity. Factors were selected based on a priori hypotheses of association and included maternal demography, anthropometric measures and self-reported physical activity (15 and 20 weeks), fetal biometry (20 weeks), and clinical information. Multivariable logistic regression was used to identify risk factors. Stratified analyses were performed by maternal obesity and physical activity.

RESULTS

Among term pregnancies, prevalence of large-for-gestational-age infants was 9.3% (491/5255), with 11.8% (58/491) prevalence of neonatal morbidity. Random glucose at 20 weeks (odds ratio 1.52; 95% confidence interval 1.17-1.97, per 1 mmol/L increase) and no regular physical activity at 20 weeks (odds ratio 3.93; 95% confidence interval 1.75-8.83) were associated with increased risk of neonatal morbidity after adjustment for birthweight, gestational age at delivery and gestational diabetes. The increased risk associated with higher glucose levels was not evident in women with regular physical activity or without obesity.

CONCLUSIONS

Regular physical activity in mid-pregnancy is associated with lower risk for neonatal morbidity in large-for-gestational-age infants and seems to offer protection against the increased risk associated with higher maternal glucose levels.

Sonographic large fetal head circumference and risk of cesarean delivery

BACKGROUND

Persistently high rates of cesarean deliveries are cause for concern for physicians, patients, and health systems. Prelabor assessment might be refined by identifying factors that help predict an individual patient's risk of cesarean delivery. Such factors may contribute to patient safety and satisfaction as well as health system planning and resource allocation. In an earlier study, neonatal head circumference was shown to be more strongly associated with delivery mode and other outcome measures than neonatal birthweight.

OBJECTIVE

In the present study we aimed to evaluate the association of sonographically measured fetal head circumference measured within 1 week of delivery with delivery mode.

STUDY DESIGN

This was a multicenter electronic medical record-based study of birth outcomes of primiparous women with term (37-42 weeks) singleton fetuses presenting for ultrasound with fetal biometry within 1 week of delivery. Fetal head circumference and estimated fetal weight were correlated with maternal background, obstetric, and neonatal outcome parameters. Elective cesarean deliveries were excluded. Multinomial regression analysis provided adjusted odds ratios for instrumental delivery and unplanned cesarean delivery when the fetal head circumference was ≥35 cm or estimated fetal weight ≥3900 g, while controlling for possible confounders.

RESULTS

In all, 11,500 cases were collected; 906 elective cesarean deliveries were excluded. A fetal head circumference ≥35 cm increased the risk for unplanned cesarean delivery: 174 fetuses with fetal head circumference ≥35 cm (32%) were delivered by cesarean, vs 1712 (17%) when fetal head circumference <35 cm (odds ratio, 2.49; 95% confidence interval, 2.04-3.03). A fetal head circumference ≥35 cm increased the risk of instrumental delivery (odds ratio, 1.48; 95% confidence interval, 1.16-1.88), while estimated fetal weight ≥3900 g tended to reduce it (nonsignificant). Multinomial regression analysis showed that fetal head circumference ≥35 cm increased the risk of unplanned cesarean delivery by an adjusted odds ratio of 1.75 (95% confidence interval, 1.4-2.18) controlling for gestational age, fetal gender, and epidural anesthesia. The rate of prolonged second stage of labor was significantly increased when either the fetal head circumference was ≥35 cm or the estimated fetal weight ≥3900 g, from 22.7% in the total cohort to 31.0%. A fetal head circumference ≥35 cm was associated with a higher rate of 5-minute Apgar score ≤7: 9 (1.7%) vs 63 (0.6%) of infants with fetal head circumference <35 cm (P = .01). The rate among fetuses with an estimated fetal weight ≥3900 g was not significantly increased. The rate of admission to the neonatal intensive care unit did not differ among the groups.

CONCLUSION

Sonographic fetal head circumference ≥35 cm, measured within 1 week of delivery, is an independent risk factor for unplanned cesarean delivery but not instrumental delivery. Both fetal head circumference ≥35 cm and estimated fetal weight ≥3900 g significantly increased the risk of a prolonged second stage of labor. Fetal head circumference measurement in the last days before delivery may be an important adjunct to estimated fetal weight in labor management.

Accelerated fetal growth in early pregnancy and risk of severe large-for-gestational-age and macrosomic infant: a cohort study in a low-risk population

INTRODUCTION

Our objective was to examine the association between fetal growth in early pregnancy and risk of severe large-for-gestational-age (LGA) and macrosomia at birth in a low-risk population.

MATERIAL AND METHODS

Cohort study that included 68 771 women with non-anomalous singleton pregnancies, without history of diabetes or hypertension, based on an electronic database on pregnancies and deliveries in Stockholm-Gotland Region, Sweden, 2008-2014. We performed multivariable logistic regression to estimate the association between accelerated fetal growth occurring in the first through early second trimester as measured by ultrasound and LGA and macrosomia at birth. Restricted analyses were performed in the groups without gestational diabetes and with normal body mass index (18.5-24.9 kg/m² ).

RESULTS

When adjusting for confounders, the odds of having a severely LGA or macrosomic infant were elevated in mothers with fetuses that were at least 7 days larger than expected as compared with mothers without age discrepancy at the second-trimester scan (adjusted odds ratio 1.80; 95% CI 1.23-2.64 and adjusted odds ratio 2.15; 95% CI 1.55-2.98, respectively). Additionally, mothers without gestational diabetes and mothers with normal weight had an elevated risk of having a severely LGA or macrosomic infant when the age discrepancy by second-trimester ultrasound was at least 7 days.

CONCLUSIONS

In a low-risk population, ultrasound-estimated accelerated fetal growth in early pregnancy was associated with an increased risk of having a severely LGA or macrosomic infant.

Clinical, ultrasound and molecular biomarkers for early prediction of large for gestational age infants in nulliparous women: An international prospective cohort study

Objective

To develop a prediction model for term infants born large for gestational age (LGA) by customised birthweight centiles.

Methods

International prospective cohort of nulliparous women with singleton pregnancy recruited to the Screening for Pregnancy Endpoints (SCOPE) study. LGA was defined as birthweight above the 90^th customised centile, including adjustment for parity, ethnicity, maternal height and weight, fetal gender and gestational age. Clinical risk factors, ultrasound parameters and biomarkers at 14–16 or 19–21 weeks were combined into a prediction model for LGA infants at term using stepwise logistic regression in a training dataset. Prediction performance was assessed in a validation dataset using area under the Receiver Operating Characteristics curve (AUC) and detection rate at fixed false positive rates.

Results

The prevalence of LGA at term was 8.8% (n = 491/5628). Clinical and ultrasound factors selected in the prediction model for LGA infants were maternal birthweight, gestational weight gain between 14–16 and 19–21 weeks, and fetal abdominal circumference, head circumference and uterine artery Doppler resistance index at 19–21 weeks (AUC 0.67; 95%CI 0.63–0.71). Sensitivity of this model was 24% and 49% for a fixed false positive rate of 10% and 25%, respectively. The addition of biomarkers resulted in selection of random glucose, LDL-cholesterol, vascular endothelial growth factor receptor-1 (VEGFR1) and neutrophil gelatinase-associated lipocalin (NGAL), but with minimal improvement in model performance (AUC 0.69; 95%CI 0.65–0.73). Sensitivity of the full model was 26% and 50% for a fixed false positive rate of 10% and 25%, respectively.

Conclusion

Prediction of LGA infants at term has limited diagnostic performance before 22 weeks but may have a role in contingency screening in later pregnancy.

Revisiting the Healthy Migrant Paradox in Perinatal Health Outcomes Through a Scoping Review in a Recent Host Country

Ample evidence shows that, in many developed countries, immigrants have similar or better perinatal health outcomes than natives despite facing socioeconomic disadvantages in the host country ("healthy migrant paradox" -HMP). This scoping review aims to: (1) summarize the literature on perinatal health among immigrants and natives in Spain and (2) examine whether there is evidence of the HMP in a context of recent migration. A total of 25 articles published between 1998 and 2014 were reviewed. Overall, we found evidence of the HMP in low birthweight and to a lesser extent in preterm, though the patterns vary by origin, but not in macrosomia and post-term. The results are consistent across settings, levels of adjustment, and birth year. Policies should be oriented towards identifying the modifiable risk factors leading to a higher risk of macrosomia and post-term among immigrants.

Implications of maternal obesity on fetal growth and the role of ultrasound

Over fifty percent of women entering pregnancy are overweight or obese. This has a significant impact on short and long term maternal and infant health outcomes, and the intergenerational effects of obesity are now a major public health problem globally. Areas covered: There are two major pathways contributing to fetal growth. Glucose and insulin directly affect growth, while other substrates such as leptin, adiponectin and insulin-like growth factors indirectly influence growth through structural and morphological effects on the placenta, uteroplacental blood flow, and regulation of placental transporters. Advances in ultrasonography over the past decade have led to interest in the prediction of the fetus at risk of overgrowth and adiposity utilizing both standard ultrasound biometry and fetal body composition measurements. However, to date there is no consensus regarding the definition of fetal overgrowth, its reporting, and clinical management. Expert commentary: Maternal dietary intervention targeting the antenatal period appear to be too late to sufficiently affect fetal growth. The peri-conceptual period and early pregnancy are being evaluated to determine if the intergenerational effects of maternal obesity can be altered to improve newborn, infant and child health.

Estimation of fetal weight in pregnancies past term

INTRODUCTION

The aim of the study was to investigate the accuracy of estimating fetal weight with ultrasound in pregnancies past term, using the eSnurra algorithm.

MATERIAL AND METHODS

In all, 419 women with pregnancy length of 290 days, attending a specialist consultation at Stavanger University Hospital, Norway, were included in a prospective observational study. Fetal weight was estimated using biparietal diameter (BPD) and abdominal circumference (AC). The algorithm implemented in an electronic calculation (eSnurra) was used to compute estimated fetal weight (EFW). Results were compared with birthweight (BW).

RESULTS

The mean interval between the ultrasound examination and birth was 2 days (SD 1.4). The median difference between BW and EFW was -6 g (CI -40 to +25 g) and the median percentage error was -0.1% (95% CI -1.0 to 0.6%). The median absolute difference was 190 g (95% CI 170-207 g). The BW was within 10% of EFW in 83% (95% CI 79-87%) of cases and within 15% of EFW in 94% (95% CI 92-96%) of cases. Limits of agreement (95%) were from -553 g to +556 g. Using 5% false-positive rates, the sensitivity in detecting macrosomic and small for gestational age fetuses was 54% (95% CI 35-72%) and 49% (95% CI 35-63%), respectively.

CONCLUSION

The accuracy of fetal weight estimation was good. Clinicians should be aware of limitations related to prediction at the upper and lower end, and the importance of choosing appropriate cut-off levels.

Exercise and pregnancy in recreational and elite athletes: 2016 evidence summary from the IOC expert group meeting, Lausanne. Part 2-the effect of exercise on the fetus, labour and birth

This is Part 2 of 5 in the series of evidence statements from the IOC expert committee on exercise and pregnancy in recreational and elite athletes. Part 1 focused on the effects of training during pregnancy and on the management of common pregnancy-related symptoms experienced by athletes. In Part 2, we focus on maternal and fetal perinatal outcomes.

Prediction of large-for-gestational-age neonates: screening by maternal factors and biomarkers in the three trimesters of pregnancy

OBJECTIVE

To develop a model based on maternal characteristics and medical history (maternal factors) for the prediction of delivery of large-for-gestational-age (LGA) neonates, and to examine the potential value of first-, second- and third-trimester fetal biometry and biomarkers in improving such a model.

METHODS

This was a screening study in 76 300, 54 999, 25 727 and 6181 singleton pregnancies at 11-13, 19-24, 30-34 and 35-37 weeks' gestation, respectively. The a-priori risk for LGA with birth weight > 95(th) percentile (LGA > 95(th) ) was calculated using multivariable logistic regression analysis to determine which of the maternal factors had a significant contribution. Regression analysis was then used to determine whether screening by a combination of maternal factors, fetal biometry and various biophysical and biochemical markers had significant contribution in predicting delivery of LGA neonates.

RESULTS

The likelihood of LGA > 95(th) increased with increasing maternal weight and height and was lower in women of Afro-Caribbean and South Asian racial origins, in cigarette smokers and in nulliparous women. The risk was higher in women with pre-existing diabetes mellitus Type I and lower in those with chronic hypertension. In parous women, the risk increased with birth-weight Z-score in previous pregnancy and prior history of gestational diabetes and decreased with interpregnancy interval. Screening by maternal factors at 11-13 weeks predicted 32%, 44% and 60% of LGA > 95(th) at false-positive rates (FPRs) of 5%, 10% and 20%, respectively. With the addition of fetal biometry, the detection rates improved to 37%, 51% and 68% at 19-24 weeks, 50%, 65% and 81% at 30-34 weeks and 60%, 73% and 85% at 35-37 weeks at FPRs of 5%, 10% and 20%, respectively. The addition of biomarkers did not improve the detection rates achieved when screening by a combination of maternal factors and fetal biometry.

CONCLUSION

Combined screening by maternal factors and fetal biometry can predict a high proportion of pregnancies that will deliver LGA neonates. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

A large head circumference is more strongly associated with unplanned cesarean or instrumental delivery and neonatal complications than high birthweight

OBJECTIVE

Fetal size impacts on perinatal outcomes. We queried whether the fetal head, as the fetal part interfacing with the birth canal, might impact on obstetric outcomes more than birthweight (BW). We examined associations between neonatal head circumference (HC) and delivery mode and risk of perinatal complications as compared to high BW.

STUDY DESIGN

This was an electronic medical records-based study of term singleton births (37-42 weeks' gestation) from January 2010 through December 2012 (N = 24,780, 6343 primiparae). We assessed risks of unplanned cesarean or instrumental delivery and maternal and fetal complications in cases with HC or BW ≥95th centile (large HC, high BW) vs those with parameters <95th centile (normal). Newborns were stratified into 4 subgroups: normal HC/normal BW (reference, n = 22,548, primiparae 5862); normal HC/high BW (n = 817, P = 213); large HC/normal BW (n = 878, P = 265); and large HC/high BW (n = 537, P = 103). Multinomial multivariable regression provided adjusted odds ratio (aOR) while controlling for potential confounders.

RESULTS

Infants with HC ≥95th centile (n = 1415) were delivered vaginally in 62% of cases, unplanned cesarean delivery 16%, and instrumental delivery 11.2%; 78.4% of infants with HC <95th centile were delivered vaginally, 7.8% unplanned cesarean, and 6.7% instrumental delivery. Odds ratio (OR) for unplanned cesarean was 2.58 (95% confidence interval [CI], 2.22-3.01) and for instrumental delivery OR was 2.13 (95% CI, 1.78-2.54). In contrast, in those with BW ≥95th centile (n = 1354) 80.3% delivered vaginally, 10.2% by unplanned cesarean (OR, 1.2; 95% CI, 1.01-1.44), and 3.4% instrumental delivery (OR, 0.46; 95% CI, 0.34-0.62) compared to infants with BW <95th centile: spontaneous vaginal delivery, 77.3%, unplanned cesarean 8.2%, instrumental 7.1%. Multinomial regression with normal HC/normal BW as reference group showed large HC/normal BW infants were more likely to be delivered by unplanned cesarean (aOR, 3.08; 95% CI, 2.52-3.75) and instrumental delivery (aOR, 3.03; 95% CI, 2.46-3.75). Associations were strengthened in primiparae. Normal HC/high BW was not associated with unplanned cesarean (aOR, 1.18; 95% CI, 0.91-1.54), while large HC/high BW was (aOR, 1.93; 95% CI, 1.47-2.52). Analysis of unplanned cesarean indications showed large HC infants had more failure to progress (27.7% vs 14.1%, P < .001), while smaller HC infants had more fetal distress (23.4% vs 16.9%, P < .05).

CONCLUSION

A large HC is more strongly associated with unplanned cesarean and instrumental delivery than high BW. Prospective studies are needed to test fetal HC as a predictive parameter for prelabor counseling of women with "big babies."

Historic cohort study on mode of delivery of a macrosomic baby: the women's point of view

INTRODUCTION

A historic cohort study was conducted to evaluate satisfaction with childbirth of a macrosomic baby according to mode of delivery.

MATERIAL AND METHODS

All 559 nulliparous women who delivered a neonate weighing >4000 g between 2008 and 2012 were included. The degree of women's satisfaction with childbirth after elective cesarean, vaginal delivery or cesarean during labor was assessed using a five-level scale. Immediate neonatal and maternal outcomes were retrieved from clinical records. Long-term maternal outcomes were evaluated using four questionnaires on urinary incontinence, anal incontinence, and sexual functioning.

RESULTS

Ninety-nine women underwent elective cesarean, whereas 460 attempted a vaginal delivery. In the latter group, 276 women delivered vaginally, whereas 184 underwent a cesarean during labor. Long-term outcomes were assessed in 273 women (49%; elective cesarean, n = 55; vaginal delivery, n = 135; cesarean in labor, n = 83) after a mean 3-year follow up. The proportion of long-term stress or mixed urinary incontinence was, respectively, 8%, 34%, and 12%, whereas that of anal incontinence was 7%, 19%, and 6%. Sexual functioning was similar in the three groups. No major neonatal complications were observed. When pooling the vaginal delivery and the cesarean in labor groups, the likelihood of being satisfied with childbirth was 63% in the "attempted vaginal delivery" group and 85% in the elective cesarean group (adjusted risk ratio, 0.72; 95% CI 0.61-0.84).

CONCLUSIONS

About one-third of women attempting a vaginal delivery of a macrosomic baby, would choose an elective cesarean if they could turn back time.

Assessing the association of oxytocin augmentation with obstetric anal sphincter injury in nulliparous women: a population-based, case-control study

OBJECTIVE

To assess the association of oxytocin augmentation with obstetric anal sphincter injury among nulliparous women.

DESIGN

Population-based, case-control study.

SETTING

Primary and secondary teaching hospital serving a Norwegian region.

POPULATION

15 476 nulliparous women with spontaneous start of labour, single cephalic presentation and gestation ≥37 weeks delivering vaginally between 1999 and 2012.

METHODS

Based on the presence or absence of oxytocin augmentation, episiotomy, operative vaginal delivery and birth weight (<4000 vs ≥4000 g), we modelled in logistic regression the best fit for prediction of anal sphincter injury. Within the modified model of main exposures, we tested for possible confounding, and interactions between maternal age, ethnicity, occiput posterior position and epidural analgaesia.

MAIN OUTCOME MEASURE

Obstetric anal sphincter injury.

RESULTS

Oxytocin augmentation was associated with a higher OR of obstetric anal sphincter injuries in women giving spontaneous birth to infants weighing <4000 g (OR 1.8; 95% CI 1.5 to 2.2). Episiotomy was not associated with sphincter injuries in spontaneous births, but with a lower OR in operative vaginal deliveries. Spontaneous delivery of infants weighing ≥4000 g was associated with a threefold higher OR, and epidural analgaesia was associated with a 30% lower OR in comparison to no epidural analgaesia.

CONCLUSIONS

Oxytocin augmentation was associated with a higher OR of obstetric anal sphincter injuries during spontaneous deliveries of normal-size infants. We observed a considerable effect modification between the most important factors predicting anal sphincter injuries in the active second stage of labour.

Diabetes in pregnancy: timing and mode of delivery

Diabetes in pregnancy represents a risk condition for adverse maternal and feto-neonatal outcomes and many of these complications might occur during labor and delivery. In this context, the obstetrician managing women with pre-existing and gestational diabetes should consider (1) how these conditions might affect labor and delivery outcomes; (2) what are the current recommendations on management; and (3) which other factors should be considered to decide about the timing and mode of delivery. The analysis of the studies considered in this review leads to the conclusion that the decision to deliver should be primarily intended to reduce the risk of stillbirth, macrosomia, and shoulder dystocia. In this context, this review provides useful information for managing specific subgroups of diabetic women that may present overlapping risk factors, such as women with insulin-requiring diabetes and/or obesity and/or prenatal suspicion of macrosomic fetus. To date, the lack of definitive evidences and the complexity of the problem suggest that the "appropriate" clinical management should be customized according with the clinical condition, the type and mode of intervention, its consequences on outcomes, and considering the woman's consent and informed decisions.