Deceleration of fetal growth rate as alternative predictor for childhood outcomes: a birth cohort study

Intrauterine Growth Restriction: Need to Improve Diagnostic Accuracy and Evidence for a Key Role of Oxidative Stress in Neonatal and Long-Term Sequelae

Intrauterine growth restriction (IUGR) and being small for gestational age (SGA) are two distinct conditions with different implications for short- and long-term child development. SGA is present if the estimated fetal or birth weight is below the tenth percentile. IUGR can be identified by additional abnormalities (pathological Doppler sonography, oligohydramnion, lack of growth in the interval, estimated weight below the third percentile) and can also be present in fetuses and neonates with weights above the tenth percentile. There is a need to differentiate between IUGR and SGA whenever possible, as IUGR in particular is associated with greater perinatal morbidity, prematurity and mortality, as well as an increased risk for diseases in later life. Recognizing fetuses and newborns being "at risk" in order to monitor them accordingly and deliver them in good time, as well as to provide adequate follow up care to ameliorate adverse sequelae is still challenging. This review article discusses approaches to differentiate IUGR from SGA and further increase diagnostic accuracy. Since adverse prenatal influences increase but individually optimized further child development decreases the risk of later diseases, we also discuss the need for interdisciplinary follow-up strategies during childhood. Moreover, we present current concepts of pathophysiology, with a focus on oxidative stress and consecutive inflammatory and metabolic changes as key molecular mechanisms of adverse sequelae, and look at future scientific opportunities and challenges. Most importantly, awareness needs to be raised that pre- and postnatal care of IUGR neonates should be regarded as a continuum.

Does decreased fetal growth estimation in the appropriate for gestational age range affect delivery outcomes?

PURPOSE

To study the effect of decreased estimated fetal weight (EFW) percentiles in appropriate for gestational age fetuses.

METHODS

This retrospective cohort study included women who had second and third trimester ultrasound examinations. Delivery and neonatal outcomes of pregnancies with decreased EFW of ≥  30 percentiles in EFW between ultrasound examinations (decreased growth group) and those without such a decrease (control group) were compared. Deliveries with EFW or birthweight below the 10th percentile were excluded.

RESULTS

Among 1610 deliveries, 57 were in the decreased growth group and 1553 in the control group. Maternal characteristics did not differ between the groups except for higher rate of nulliparity in the decreased growth group. We found similar rates of Category II/III monitoring, cesarean deliveries due to non-reassuring fetal heart rate and adverse neonatal outcomes. Neonatal birthweight was lower in the decreased growth group as compared to controls.

CONCLUSIONS

This study did not find association between the group of appropriate for gestational age fetuses with decreased growth, with adverse outcomes.

Maternal sleep disordered breathing and offspring growth outcome: A systematic review and meta-analysis

Sleep disordered breathing is extremely common in pregnancy and is a risk factor for maternal complications. Animal models demonstrate that intermittent hypoxia causes abnormal fetal growth. However, there are conflicting data on the association between maternal sleep disordered breathing and offspring growth in humans. We investigated this association by conducting a systematic review and meta-analysis. Sixty-three manuscripts, and total study population of 67, 671, 110 pregnant women were included. Thirty-one studies used subjective methods to define sleep disordered breathing, 24 applied objective methods and eight used international codes. Using a random effects model, habitual snoring, defined by subjective methods, and obstructive sleep apnea, diagnosed by objective methods, were associated with an increased risk for large for gestational age (OR 1.46; 95%CI 1.02-2.09 and OR 2.19; 95%CI 1.63-2.95, respectively), while obstructive sleep apnea, identified by international codes, was associated with an increased risk for small for gestational age newborns (OR 1.28; 95%CI 1.02-1.60). Our results support that maternal sleep disordered breathing is associated with offspring growth, with differences related to the type of disorder and diagnostic methods used. Future studies should investigate underlying mechanisms and whether treatment of sleep disordered breathing ameliorates the neonatal growth.

Genome-Wide Association Studies and Runs of Homozygosity to Identify Reproduction-Related Genes in Yorkshire Pig Population

Reproductive traits hold considerable economic importance in pig breeding and production. However, candidate genes underpinning the reproductive traits are still poorly identified. In the present study, we executed a genome-wide association study (GWAS) and runs of homozygosity (ROH) analysis using the PorcineSNP50 BeadChip array for 585 Yorkshire pigs. Results from the GWAS identified two genome-wide significant and eighteen suggestive significant single nucleotide polymorphisms (SNPs) associated with seven reproductive traits. Furthermore, we identified candidate genes, including ELMO1, AOAH, INSIG2, NUP205, LYPLAL1, RPL34, LIPH, RNF7, GRK7, ETV5, FYN, and SLC30A5, which were chosen due to adjoining significant SNPs and their functions in immunity, fertilization, embryonic development, and sperm quality. Several genes were found in ROH islands associated with spermatozoa, development of the fetus, mature eggs, and litter size, including INSL6, TAF4B, E2F7, RTL1, CDKN1C, and GDF9. This study will provide insight into the genetic basis for pig reproductive traits, facilitating reproduction improvement using the marker-based selection methods.

Postnatal catch-up growth in term newborns with altered fetal weight patterns. The GROWIN study

BACKGROUND

Small for gestational age (SGA) perform a postnatal catch-up growth to recover their genetic trajectory. We studied the postnatal catch-up growth pattern of fetuses born with an appropriate-for-gestational-age (AGA) weight but with fetal growth deceleration (FGD) to explore whether they catch up.

METHODS

Nine hundred and sixty-six newborns at Villalba University General Hospital (HUGV), were followed from 34 to 37 weeks to birth. Z-scores, adjusted for sex and age, of weight, length, and BMI at 3, 6, 9, and 12 months were calculated. We define catch-up as an increase in z-score greater than 0.67 SD in the growth curves.

RESULTS

AGA FGD had lower mean weight and length than AGA non-FGD at all time points; BMI was lower until 3 months. AGA FGD had a lower weight, length, and BMI z-score (until 9, 6 months, and at birth, respectively) than AGA non-FGD. AGA FGD newborns had a significantly increased likelihood of weight catch-up at 3 months (OR 1.79; 95% CI: 1.16, 2.78; p = 0.009) and BMI in all investigated periods (OR 1.90; 95% CI 1.30, 2.78; p < 0.001 at 3 months), compared to AGA non-FGD newborns.

CONCLUSIONS

AGA FGD newborns perform catch-up growth, especially in weight and BMI, in the first year of life, compared to AGA non-FGD.

IMPACT

Appropriate-for-gestational-age (AGA) newborns with fetal growth deceleration (FGD), between the third trimester of pregnancy and delivery, present a lower weight and height, during the first year of life, compared to AGA non-FGD. Appropriate-for-gestational-age (AGA) newborns with fetal growth deceleration (FGD), between the third trimester of pregnancy and delivery, present a higher likelihood of weight catch-up in the first 3 months of life and of BMI in the first year compared to AGA non-FGD. AGA FGD experienced early weight and BMI catch-up, especially in the first 3 months of life, like SGA. This finding should be considered in the future follow-up.

The impact of intrauterine growth restriction and prematurity on nephron endowment

In humans born at term, maximal nephron number is reached by the time nephrogenesis is completed - at approximately 36 weeks' gestation. The number of nephrons does not increase further and subsequently remains stable until loss occurs through ageing or disease. Nephron endowment is key to the functional capacity of the kidney and its resilience to disease; hence, any processes that impair kidney development in the developing fetus can have lifelong adverse consequences for renal health and, consequently, for quality and length of life. The timing of nephrogenesis underlies the vulnerability of developing human kidneys to adverse early life exposures. Indeed, exposure of the developing fetus to a suboptimal intrauterine environment during gestation - resulting in intrauterine growth restriction (IUGR) - and/or preterm birth can impede kidney development and lead to reduced nephron endowment. Furthermore, emerging research suggests that IUGR and/or preterm birth is associated with an elevated risk of chronic kidney disease in later life. The available data highlight the important role of early life development in the aetiology of kidney disease and emphasize the need to develop strategies to optimize nephron endowment in IUGR and preterm infants.

Maternal Nutrition, Body Composition and Gestational Weight Gain on Low Birth Weight and Small for Gestational Age-A Cohort Study in an Indian Urban Slum

Maternal nutritional status and care during pregnancy are essential for adequate birth weight. In this prospective cohort study (N = 1061) in an urban slum, we investigated the association of maternal anthropometry, body composition, gestational weight gain and dietary intakes with low birthweight (LBW, <2.5 kg). About one-third of the women were short (<150 cm), 35% were underweight (<45 kg), 23% suffered from chronic energy deficiency (CED, BMI < 18.5 kg/m2) and another 30% were overweight/obese. The mean age and BMI were 23 years and 21.7 kg/m2, respectively, and haemoglobin was 10.73 g/dL. The mean birthweight (N = 605) was 2.81 ± 0.5 kg, and the average gestational age was 38 ± 2 weeks. About 15% of infants had LBW, and 48% were small for gestational age (SGA). Maternal body composition was assessed by skinfold thickness (SFT) in all trimesters. In the first trimester (N = 762), we found that mean fat-free mass (FFM), fat mass (FM) and body fat percentage (% BF) were 38.86 kg, 11.43 kg and 21.55%, respectively. Low birthweight was significantly associated with preterm deliveries (p < 0.001) and less fat free mass (p = 0.02) in the third trimester. Among other factors were age (p = 0.017), maternal anthropometry (height: p = 0.031; weight: p = 0.059) and fewer antenatal check-ups (p = 0.037). Small size (SGA) was consistently associated with maternal bodyweight at all trimesters (term I, p = 0.013, term II, p = 0.003 and term III, p < 0.001), fat mass in the third trimester (p < 0.001) and maternal height (p = 0.003).

Household income, fetal size and birth weight: an analysis of eight populations

BACKGROUND

The age at onset of the association between poverty and poor health is not understood. Our hypothesis was that individuals from highest household income (HI), compared to those with lowest HI, will have increased fetal size in the second and third trimester and birth.

METHODS

Second and third trimester fetal ultrasound measurements and birth measurements were obtained from eight cohorts. Results were analysed in cross-sectional two-stage individual patient data (IPD) analyses and also a longitudinal one-stage IPD analysis.

RESULTS

The eight cohorts included 21 714 individuals. In the two-stage (cross-sectional) IPD analysis, individuals from the highest HI category compared with those from the lowest HI category had larger head size at birth (mean difference 0.22 z score (0.07, 0.36)), in the third trimester (0.25 (0.16, 0.33)) and second trimester (0.11 (0.02, 0.19)). Weight was higher at birth in the highest HI category. In the one-stage (longitudinal) IPD analysis which included data from six cohorts (n=11 062), head size was larger (mean difference 0.13 (0.03, 0.23)) for individuals in the highest HI compared with lowest category, and this difference became greater between the second trimester and birth. Similarly, in the one-stage IPD, weight was heavier in second highest HI category compared with the lowest (mean difference 0.10 (0 .00, 0.20)) and the difference widened as pregnancy progressed. Length was not linked to HI category in the longitudinal model.

CONCLUSIONS

The association between HI, an index of poverty, and fetal size is already present in the second trimester.

First Trimester Maternal Homocysteine and Embryonic and Fetal Growth: The Rotterdam Periconception Cohort

Homocysteine is a marker for derangements in one-carbon metabolism. Elevated homocysteine may represent a causal link between poor maternal nutrition and impaired embryonic and fetal development. We sought to investigate associations between reference range maternal homocysteine and embryonic and fetal growth. We enrolled 1060 singleton pregnancies (555 natural and 505 in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) pregnancies) from November 2010 to December 2020. Embryonic and fetal body and head growth was assessed throughout pregnancy using three-dimensional ultrasound scans and virtual reality techniques. Homocysteine was negatively associated with first trimester embryonic growth in the included population (crown-rump length B −0.023 mm, 95% CI −0.038,−0.007, p = 0.004, embryonic volume B −0.011 cm3, 95% CI −0.018,−0.004, p = 0.003). After stratification for conception mode, this association remained in IVF/ICSI pregnancies with frozen embryo transfer (crown-rump length B −0.051 mm, 95% CI −0.081,−0.023, p < 0.001, embryonic volume B −0.024 cm3, 95% CI −0.039,−0.009, p = 0.001), but not in IVF/ICSI pregnancies with fresh embryo transfer and natural pregnancies. Homocysteine was not associated with longitudinal measurements of head growth in first trimester, nor with second and third trimester fetal growth. Homocysteine in the highest quartile (7.3−14.9 µmol/L) as opposed to the lowest (2.5−5.2 µmol/L) was associated with reduced birth weight in natural pregnancies only (B −51.98 g, 95% CI −88.13,−15.84, p = 0.005). In conclusion, high maternal homocysteine within the reference range is negatively associated with first trimester embryonic growth and birth weight, and the effects of homocysteine are dependent on conception mode.

Translational insights into mechanisms and preventive strategies after renal injury in neonates

Adverse perinatal circumstances can cause acute kidney injury (AKI) and contribute to chronic kidney disease (CKD). Accumulating evidence indicate that a wide spectrum of perinatal conditions interferes with normal kidney development and ultimately leads to aberrant kidney structure and function later in life. The present review addresses the lack of mechanistic knowledge with regard to perinatal origins of CKD and provides a comprehensive overview of pre- and peri-natal insults, including genetic predisposition, suboptimal nutritional supply, obesity and maternal metabolic disorders as well as placental insufficiency leading to intrauterine growth restriction (IUGR), prematurity, infections, inflammatory processes, and the need for life-saving treatments (e.g. oxygen supplementation, mechanical ventilation, medications) in neonates. Finally, we discuss future preventive, therapeutic, and regenerative directions. In summary, this review highlights the perinatal vulnerability of the kidney and the early origins of increased susceptibility toward AKI and CKD during postnatal life. Promotion of kidney health and prevention of disease require the understanding of perinatal injury in order to optimize perinatal micro- and macro-environments and enable normal kidney development.

Recurrence Risk of Fetal Growth Restriction: Management of Subsequent Pregnancies

Fetal growth restriction (FGR) is a common obstetric complication that predisposes to mortality across the lifespan. Women with a prior pregnancy affected by FGR have a 20% to 30% risk of recurrence, but effective preventive strategies are lacking. Pharmacologic interventions to prevent FGR are lacking. Low-dose aspirin may be somewhat effective, but low-molecular-weight heparin and sildenafil are not. Surveillance in a subsequent pregnancy may consist of serial ultrasonography with timing and frequency determined by the clinical severity in the index pregnancy. Once FGR is diagnosed, the principal management strategy consists of close surveillance and carefully timed delivery.

Associations Between Fetal Growth Trajectories and the Development of Myopia by 20 Years of Age

Purpose

To evaluate the contribution of genetic and early life environmental factors, as reflected by fetal anthropometric growth trajectories, toward the development of myopia during childhood and adolescence.

Methods

This analysis included 498 singleton Caucasian participants from the Raine Study, a pregnancy cohort study based in Western Australia. Serial fetal biometric measurements of these participants were collected via ultrasound scans performed at 18, 24, 28, 34, and 38 weeks’ gestation. At a 20-year follow-up, the participants underwent a comprehensive ophthalmic examination, including cycloplegic autorefraction and ocular biometry measurements. Using a group-based trajectory modeling approach, we identified groups of participants with similar growth trajectories based on measurements of fetal head circumference (HC), abdominal circumference, femur length (FL), and estimated fetal weight (EFW). Differences between trajectory groups with respect to prevalence of myopia, axial length (AL), and corneal radius of curvature measured at the 20-year follow-up were evaluated via logistic regression and analysis of variance.

Results

Prevalence of myopia was highest among participants with consistently short or consistently long FLs (P = 0.04). There was also a trend toward increased prevalence with larger HC in late gestation, although not at a statistically significant level. Trajectory groups reflecting faster HC, FL, or EFW growth correlated with significantly flatter corneas (P = 0.03, P = 0.04, and P = 0.01, respectively) and a general, but not statistically significant, increase in AL.

Conclusions

Environmental or genetic factors influencing intrauterine skeletal growth may concurrently affect ocular development, with effects persisting into adulthood.

Antenatal Antidepressant Prescription Associated With Reduced Fetal Femur Length but Not Estimated Fetal Weight: A Retrospective Ultrasonographic Study

PURPOSE/BACKGROUND

Antidepressants are among the most frequently prescribed medications during pregnancy and may affect fetal weight. Associations between antenatal antidepressant use and ultrasonographic measures of fetal development have rarely been examined. We hypothesized that the prescription of an antenatal antidepressant would be associated with lower estimated fetal weight (EFW).

METHODS/PROCEDURES

A retrospective analysis of routine ultrasonographic data extracted from electronic medical records was performed on a cohort of pregnant women with psychiatric diagnoses and grouped according to the presence of an antenatal antidepressant prescription (n = 32 antidepressant-prescribed and n = 44 antidepressant prescription-free). After stratifying for gestational age, comparisons included 13 ultrasonographic parameters, frequency of oligohydramnios and polyhydramnios and growth deceleration, and maternal serum protein markers assessed per routine care, including α-fetoprotein, free β-human chorionic gonadotropin, and unconjugated estriol levels, using t tests, nonparametric and Fisher tests, and effect sizes (ESs) were computed.

FINDINGS/RESULTS

No statistically significant EFW differences between groups at any time point were detected (P > 0.05). Antenatal antidepressant prescription was associated with lower femur length at weeks 33 to 40 (P = 0.046, ES = 0.75) and greater left ventricular diameter at weeks 25 to 32 (P = 0.04, ES = 1.18). No differences for frequency of oligohydramnios or polyhydramnios or growth deceleration were observed (P > 0.05). We did not detect group differences for maternal proteins (P > 0.05).

IMPLICATIONS/CONCLUSIONS

Our evidence suggested a lack of association between antenatal antidepressant prescription and lower EFW but indicated an association with lower femur length and greater left ventricular diameter in mid-late gestation. Future research should examine the clinical implications of these findings.

Prematurity, perinatal inflammatory stress, and the predisposition to develop chronic kidney disease beyond oligonephropathy

Prematurity and perinatal stress, such as intrauterine growth restriction (IUGR) and chorioamnionitis, are pathological processes creating an impaired intrauterine environment. These intrauterine factors are associated with the development of proteinuria, hypertension, and chronic kidney disease (CKD) later in life. Initially, this was thought to be secondary to oligonephropathy, subsequent glomerular hypertrophy, and hyperfiltration, leading to glomerulosclerosis, a further decrease in nephron number, and finally CKD. Nowadays, there is increasing evidence that prematurity and perinatal stress affect not only nephron endowment but also the maturation of podocytes and vasculogenesis. IUGR is associated with podocyte damage and an aggravated course of nephrotic syndrome. Moreover, preterm birth and IUGR are known to cause upregulation of the postnatal renin-angiotensin system, resulting in hypertension. Chorioamnionitis causes damage to the glomeruli, thereby predisposing to the development of glomerulosclerosis. This review aims to summarize current knowledge on the influence of prematurity, IUGR, and chorioamnionitis on the development of different glomerular structures. After summarizing human and experimental data on low nephron number in general, a specific focus on the current understanding of podocyte and glomerular capillary formation in relation to prematurity and different causes of perinatal stress is presented.

'Postnatal growth during the first five years of life in SGA and AGA neonates with reduced fetal growth'

BACKGROUND

Even though a lot of research has been done on postnatal growth and the occurrence of catch-up growth in small-for-gestational age (SGA) neonates, this phenomenon has not been studied well in appropriate-for-gestational age (AGA) neonates. Postnatal catch-up growth may also occur in AGA neonates indicating a compensatory mechanism for undiagnosed intrauterine growth restriction, especially in AGA neonates with reduced fetal growth velocity.

AIMS

To describe postnatal growth during the first 5 years of life in SGA and AGA neonates and evaluating the role of fetal growth velocity in catch-up growth.

STUDY DESIGN

Retrospective study in a Dutch tertiary hospital.

SUBJECTS

740 singleton neonates, without congenital anomalies, with ultrasound fetal growth data from 20 weeks and 32 weeks of pregnancy.

OUTCOME MEASURES

Postnatal growth measurements of height (cm) and weight (kg) from birth until five years of age. Postnatal catch-up growth defined as difference (delta) in both height and weight between 4 weeks and 3 years of age.

RESULTS AND CONCLUSIONS

SGA neonates had a significantly lower height and weight compared to the AGA group for all available measurement moments till 3 years. The catch-up growth between the SGA and AGA groups from 4 weeks up to 3 years after birth was not different between the two groups. However, neonates with reduced fetal growth velocity had a significantly higher risk for catch-up growth in height during the first 3 years after birth. This suggests a role for fetal growth velocity measurement in predicting fetal and subsequent postnatal growth potential.

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.

Appropriate-for-gestational-age infants who exhibit reduced antenatal growth velocity display postnatal catch-up growth

Background

Postnatally, small-for-gestational-age (SGA; birthweight <10th centile) infants who are growth restricted due to uteroplacental insufficiency (UPI) demonstrate ‘catch-up growth’ to meet their genetically-predetermined size. Infants who demonstrate slowing growth during pregnancy are those that cross estimated fetal weight centiles at serial ultrasound examinations. These infants that slow in growth but are born appropriate-for-gestational-age (AGA; ≥10th centile), exhibit antenatal, intrapartum and postnatal indicators of UPI. Here, we examine if and when these infants (labelled as AGA-FGR) also demonstrate catch-up growth like SGA infants, when compared with AGA infants with normal antenatal growth velocity (AGA-NG).

Methods

We followed-up the infants of women who had previously undergone ultrasound assessment of fetal size at 28- and 36-weeks’ gestation, enabling calculation of antenatal growth velocity. To assess postnatal growth, we asked parents to send their infant’s growth measurements, up to two years post-birth, which are routinely collected through the state-wide Maternal-Child Health service. Infants with medical conditions affecting postnatal growth were excluded from the analysis. From the measurements obtained we calculated age-adjusted z-scores for postnatal weight, length and body mass index (BMI; weight(kg)/height(m²)) at birth and 4, 8, 12, 18 and 24 months. We used linear spline regression modelling to predict mean weight, length and BMI z-scores at intervals post birth. Predicted mean age-adjusted z-scores were then compared between three groups; SGA, AGA with low antenatal growth (AGA-FGR; loss of >20 customised estimated fetal weight centiles), and AGA-NG to determine if catch-up growth occurred. In addition, we compared the rates of catch-up growth (defined as an increase in weight age-adjusted z-score of ≥0.67 over 1 year) between the groups with Fisher’s exact tests.

Results

Of 158 (46%) infant growth records received, 146 were AGA, with low antenatal growth velocity occurring in 34/146 (23.2%). Rates of gestational diabetes and SGA birthweight were higher in those lost to follow-up. Compared to AGA-NG infants, AGA-FGR infants had significantly lower predicted mean weight (p<0.001), length (p = 0.04) and BMI (p = 0.001) z-scores at birth. These significant differences were no longer evident at 4 months, suggesting that catch-up growth had occurred. As expected, the catch-up growth that occurred among the AGA-FGR was not as great in magnitude as that demonstrated by the SGA. When assessed categorically, there was no significant difference between the rate of catch-up growth among the AGA-FGR and the SGA. Catch-up growth was significantly more frequent among both the AGA-FGR and the SGA groups compared to the AGA-NG.

Conclusions

AGA infants that have exhibited reduced antenatal fetal growth velocity also exhibit significant catch-up growth in the first 12 months of life. This finding represents further evidence that AGA fetuses that slow in growth during pregnancy do so due to UPI.