Reference values for fetal limb biometry at 10-14 weeks of gestation

Antenatal size, early childhood growth, and asthma within a cohort created by data linkage

INTRODUCTION

The gestation when small for gestational age (SGA) is first associated with asthma is not well understood. Here, we use routinely acquired data from 10 weeks gestation to up to 28 years of age to test the hypothesis that SGA before birth is associated with an increased risk for asthma in a large population born between 1987 and 2015.

METHODS

Databases were linked to produce a single database that held antenatal fetal ultrasound measurements; maternal characteristics; birth measurements; childhood anthropometric measurements at age 5 years; hospital admission data (1987-2015); and family doctor prescribing (2009-2015). Asthma admission and receipt of any asthma medications were the outcomes. Analyses related single and then multiple anthropometric measurements to asthma outcomes.

RESULTS

Outcome data were available for 63,930 individuals. Increased length in the first-trimester size was associated with a reduced odds ratio (OR) for asthma admission of 0.991 [0.983, 0.998] per mm increase and also a shorter time to first admission, with a hazard ratio risk of 0.987 [0.980, 0.994] per mm increase. Independent of all earlier measurements, increased height at 5 years (available in a subset of 15,760) was associated with reduced OR for an asthma admission, with OR of 0.874 [0.790, 0.967] per z score. Longitudinal measurements of weight were not related to asthma outcomes.

CONCLUSIONS

Longer first-trimester length is associated with more favorable asthma outcomes, and subsequently, increased height in childhood is also independently associated with more favorable asthma outcomes. Interventions that reduce SGA and encourage healthy postnatal growth might improve asthma outcomes.

Fibular hemimelia

Fibular hemimelia is defined as a partial or complete absence of the fibula. Alongside fibular deformities, there is a wide spectrum of anomalies, foot deformities, and absent rays. A literature review showed only a handful of cases of prenatal diagnosis of fibular hemimelia. It is a rare disorder that might be isolated or associated with visceral anomalies.

Antenatal Fetal Size and Obesity in Five-Year-Old Children in a Large Cohort Created by Data Linkage

Background: What is not well understood is the gestational age at which the fetal size deviates from normal for children who develop obesity. Here we test the hypothesis that large-for-gestational age before birth is associated with increased risk for obesity in early childhood. Methods: In this retrospective study, routinely acquired antenatal ultrasound assessments in the first, second, and third trimester were linked to anthropometric measurements at 5.5 years. Results: There were 15,760 individuals, including 678 with obesity, 1955 overweight, and 1254 thin. Compared with children of healthy weight, children who had obesity were shorter in the first trimester [mean difference 0.19 z scores (0.10, 0.28)] and heavier in the second [mean difference z scores 0.15 (0.03, 0.27)] and third trimester [mean difference z scores 0.18 (0.05, 0.32)]. Children in the thin category were lighter compared with children of healthy weight in the third trimester and those in the overweight category were heavier compared with children of healthy weight in the third trimester. All associations were independent of birth weight. Conclusions: The difference in growth trajectories between children who have obesity compared with overweight or thin suggests different underlying mechanisms.

Quantitative anatomy of the primary ossification center of the radial shaft in human fetuses

Purpose

The medical literature still lacks studies on the size of the radial shaft primary ossification center, thus preventing us from potentially relevant data in diagnosing skeletal dysplasias, i.e., TAR syndrome, VATER syndrome, Holt–Oram syndrome, Fanconi anemia and Edwards syndrome, frequently characterized by disrupted or retarded fetal growth.

Materials and methods

The size of the radial shaft primary ossification center in 47 (25 males and 22 females) spontaneously aborted human fetuses aged 17–30 weeks was studied by means of CT, digital image analysis and statistics.

Results

With neither sex nor laterality differences, the best-fit growth dynamics for the radial shaft primary ossification center was modeled by the following functions: y = − 10.988 + 1.565 × age ± 0.018 for its length, y = − 2.969 + 0.266 × age ± 0.01 for its proximal transverse diameter, y = − 0.702 + 0.109 × age ± 0.018 for its middle transverse diameter, y = − 2.358 + 0.203 × age ± 0.018 for its distal transverse diameter, y = –189.992 + 11.788 × (age)² ± 0.018 for its projection surface area, and y = − 798.174 + 51.152 × age ± 0.018 for its volume.

Conclusions

The morphometric characteristics of the radial shaft primary ossification center show neither sex nor bilateral differences. The radial shaft primary ossification center grows proportionately in length, transverse dimensions and volume, and quadratically in its projection surface area. The obtained numerical findings of the radial shaft ossification center are considered age-specific reference of relevance in both the estimation of fetal ages and the diagnostic process of congenital defects.

Three-dimensional growth of tibial shaft ossification in the human fetus: a digital-image and statistical analysis

PURPOSES

Tibial shaft ossification in terms of its size and growth may be criticalin describing both the fetal stage and maturity, and in identifying innate disorders. The present study was executed to quantitatively assess ossification of the tibial shaft, taking its morphometric linear, planar and volumetric parameters into account.

MATERIALS AND METHODS

With the use of methods of CT, digital-image analysis and statistics, the evolutionof tibial shaft ossification in 47 spontaneously aborted human fetuses at the age of 17-30 weeks was studied.

RESULTS

Without any male-female and right-left morphometric differences, the best fit growth dynamics fortibial shaft ossification was modelled by the following functions: y = 5.312 + 0.034 × (age)² ± 0.001 (R² = 0.89) for its length, y = - 2.855 + 0.307 × age ± 0.009 (R² = 0.96) for its proximal transverse diameter, y = - 0.758 + 0.153 × age ± 0.005 (R² = 0.88) for its middle transverse diameter, y = - 1.844 + 0.272 × age ± 0.09 (R² = 0.90) for its distal transverse diameter, y = - 40.263 + 0.258 × (age)² ± 0.007 (R² = 0.94) for its projection surface area, and y = - 287.996 + 1.186 × (age)² ± 0.037 (R² = 0.92) for its volume. The femoral-to-tibial ossification length ratio was 1.15 ± 0.1.

CONCLUSIONS

The size of tibial shaft ossification displays neither sex nor laterality differences. Tibial shaft ossification follows quadratic functions with respect to its length, projection surface area and volume, and linear functions with respect to its proximal, middle and distal transverse diameters. The obtained morphometric data of tibial shaft ossification are considered normative age-specific references of relevance in both the estimation of fetal ages and the ultrasound diagnostics of congenital defects.

Maternal exposure to ambient air pollution and fetal growth in North-East Scotland: A population-based study using routine ultrasound scans

BACKGROUND

Maternal ambient air pollution exposure is associated with reduced birthweight. Few studies have examined the effect on growth in utero and none have examined the effect of exposure to particulates less than 2.5µm (PM_2.5) and possible effect modification by smoking status.

OBJECTIVES

Examine the effect of maternal exposure to ambient concentrations of PM₁₀, PM_2.5 and nitrogen dioxide (NO₂) for in utero fetal growth, size at birth and effect modification by smoking status.

METHODS

Administratively acquired second and third trimester fetal measurements (bi-parietal diameter, femur length and abdominal circumference), birth outcomes (weight, crown heel length and occipito-frontal circumference) and maternal details were obtained from routine fetal ultrasound scans and maternity records (period 1994-2009). These were modelled against residential annual pollution concentrations (calendar year mean) adjusting for covariates and stratifying by smoking status.

RESULTS

In the whole sample (n=13,775 pregnancies), exposure to PM₁₀, PM_2.5 and NO₂ was associated with reductions in measurements at birth and biparietal diameter from late second trimester onwards. Among mothers who did not smoke at all during pregnancy (n=11,075), associations between biparietal diameter and pollution exposure remained significant but were insignificant among those who did smoke (n=2700). Femur length and abdominal circumference were not significantly associated with pollution exposure.

CONCLUSIONS

Fetal growth is strongly associated with particulates exposure from later in second trimester onwards but the effect appears to be subsumed by smoking. Typical ambient exposures in this study were relatively low compared to other studies and given these results, it may be necessary to consider reducing recommended "safe" ambient air exposures.

Prenatal diagnosis of type 1 fibular hemimelia

Fibular hemimelia (FH) is a congenital longitudinal limb deficiency characterized by complete or partial absence of the fibula. Typically, it has been diagnosed at birth, when the neonate is seen to have lower limb shortening and a foot with missing toes. Although it is the most frequent lower limb deficiency anomaly, there are few published reports of prenatally diagnosed cases. Most of these published cases have involved the complete absence of the fibula, which is relatively easy to diagnose with antenatal ultrasound. In our opinion, our case is the first case of unilateral partial absence of the fibula detected using prenatal ultrasound imaging. Herein, we report a FH case associated with foot equinovalgus, and absence of the fourth and fifth foot rays diagnosed at 24 weeks' gestation. The anomaly was confirmed after birth by X-ray, and conservative orthopedic management was chosen. Our case shows that partial limb defects can also be detected by prenatal ultrasound imaging.

The UF Family of hybrid phantoms of the pregnant female for computational radiation dosimetry

Efforts to assess in utero radiation doses and related quantities to the developing fetus should account for the presence of the surrounding maternal tissues. Maternal tissues can provide varying levels of protection to the fetus by shielding externally-emitted radiation or, alternatively, can become sources of internally-emitted radiation following the biokinetic uptake of medically-administered radiopharmaceuticals or radionuclides located in the surrounding environment--as in the case of the European Union's SOLO project (Epidemiological Studies of Exposed Southern Urals Populations). The University of Florida had previously addressed limitations in available computational phantom representation of the developing fetus by constructing a series of hybrid computational fetal phantoms at eight different ages and three weight percentiles. Using CT image sets of pregnant patients contoured using 3D-DOCTOR(TM), the eight 50th percentile fetal phantoms from that study were systematically combined in Rhinoceros(TM) with the UF adult non-pregnant female to yield a series of reference pregnant female phantoms at fetal ages 8, 10, 15, 20, 25, 30, 35 and 38 weeks post-conception. Deformable, non-uniform rational B-spline surfaces were utilized to alter contoured maternal anatomy in order to (1) accurately position and orient each fetus and surrounding maternal tissues and (2) match target masses of maternal soft tissue organs to reference data reported in the literature.

Perinatal programming of childhood asthma: early fetal size, growth trajectory during infancy, and childhood asthma outcomes

The “fetal origins hypothesis” or concept of “developmental programming” suggests that faltering fetal growth and subsequent catch-up growth are implicated in the aetiology of cardiovascular disease. Associations between reduced birth weight, rapid postnatal weight gain, and asthma suggest that there are fetal origins to respiratory disease. The present paper first summarises the literature relating birth weight and post natal growth trajectories to asthma outcomes. Second, issues regarding the interpretation of antenatal fetal ultrasound measurements are discussed. Finally, recent reports linking antenatal measurement and growth trajectory to early childhood asthma outcomes are discussed. Understanding the nature and timing of factors which influence antenatal growth may give important insight into the antecedents of early-onset asthma with implications for interventions.

First- and second-trimester fetal size and asthma outcomes at age 10 years

RATIONALE

Greater early fetal size is associated with reduced asthma risk and improved lung function in early childhood.

OBJECTIVES

To test the hypothesis that associations between early fetal size, asthma symptoms, and lung function persist into later childhood.

METHODS

In a longitudinal study, first- and second-trimester fetal measurements were recorded. At 10 years of age a respiratory questionnaire was completed. Spirometry, bronchial challenge, and skin-prick testing were undertaken in a subset.

MEASUREMENTS AND MAIN RESULTS

Fetal measurements were available in the first trimester for 853 individuals and the second trimester for 1,453. Questionnaires were returned for 927 children and 449 underwent detailed phenotyping. For each millimeter increase in first trimester size, asthma risk reduced by 6% (95% confidence interval[CI], 1–11) and FEV1 was higher by an average of 6 ml (95% CI, 1–11).First-trimester size was reduced in those with asthma at both 5 and 10 years compared with early or late onset wheeze (P , 0.02). Compared with persistent high growth in first and second trimesters,persistent low growth was associated with increased asthma risk(odds ratio, 2.8; 95% CI, 1.2–6.9) and a mean reduction in FEV1 of 103 ml (95% CI, 13–194), whereas increasing fetal size was associated with increased eczema risk (odds ratio, 2.5; 95% CI, 1.2–5.3).

CONCLUSIONS

Reduced fetal size from the first trimester is associated with increased risk for asthma and obstructed lung function in childhood. Relative change in size after the first trimester is associated with eczema.

First-trimester ultrasound diagnosis of skeletal dysplasia associated with increased nuchal translucency thickness

A series of five cases of skeletal dysplasia is reported in which the diagnosis was reached at the 11-14-week routine ultrasound examination in our referral center. All five cases had increased nuchal translucency thickness (NT) associated with bone abnormalities. We review the current literature on skeletal dysplasia in the first trimester of pregnancy associated with increased NT.

First-trimester fetal limb biometry in Chinese population

OBJECTIVES

To establish reference ranges for fetal limb biometry obtained by transabdominal ultrasound examination at 12-14 weeks of gestation in Chinese women.

METHODS

A total of 1489 normal singleton fetuses between 12(+0) and 14(+6) weeks of gestation were examined transabdominally by two experienced observers. The gestation was ascertained by measurement of fetal crown-rump length (CRL) or biparietal diameter (BPD) and head circumference (HC). The lengths of the humerus and femur were prospectively worked out.

RESULTS

Gestation-specific reference ranges for limb measurements were calculated. The femur length (FL) (mean +/- SD) was 9.15 +/- 1.44 mm at 12-12(+6) weeks, 11.45 +/- 1.35 mm at 13-13(+6) weeks, and 13.64 +/- 1.60 mm at 14-14(+6) weeks; the corresponding humerus length (HL) (mean +/- SD) was 9.63 +/- 1.44 mm, 12.01 +/- 1.41 mm, 14.29 +/- 1.48 mm, respectively.

CONCLUSIONS

There was a general increase in fetal limb biometry with gestation. Fetal limb length can be an early marker of early growth restriction as well as fetal skeletal dysplasia among women in the local population.

Correlation between first trimester fetal bone length and maternal serum pregnancy-associated plasma protein-A (PAPP-A)

BACKGROUND

Pregnancy-associated plasma protein-A (PAPP-A) is produced by the embryo and placenta during pregnancy, and its maternal serum concentrations are related to subsequent fetal growth. Evidence from animal models and in vitro experiments suggests that PAPP-A is particularly involved in the regulation of bone development. The aim of this study was to assess the correlation between late first trimester fetal bone length and maternal serum levels of PAPP-A.

METHODS

In a cross-sectional observational study, ultrasound measurements of fetal long bones and fluorimetric immunoassays for maternal serum PAPP-A were performed in 514 singleton pregnancies at 10-14 weeks of gestation.

RESULTS

There were 501 uncomplicated pregnancies. There were significant correlations between PAPP-A values and length of humerus, femur and tibia [r values 0.12 (P = 0.01), 0.11 (P = 0.01) and 0.10 (P = 0.03), respectively]. The association with the length of ulna and foot did not reach statistical significance (r values 0.08 and -0.03, respectively).

CONCLUSIONS

Maternal serum PAPP-A levels at 10-14 weeks of gestation are significantly associated with the length of fetal long bones such as humerus, femur and tibia. This provides further evidence that PAPP-A may be involved in the regulation of bone development.

First-trimester diagnosis of osteogenesis imperfecta associated with encephalocele by conventional and three-dimensional ultrasound

To illustrate the three-dimensional sonographic features of a rare genetic disorder, we report on prenatal diagnosis of osteogenesis imperfecta congenita associated with encephalocele at 13 weeks of gestation, using conventional and three-dimensional ultrasound. Because the parents were first-degree cousins and on the basis of the family history, a recessive autosomal inheritance was suspected. Of seven previous pregnancies, five were unaffected and two had been terminated in the second trimester owing to a similar abnormality (one affected boy and one affected girl). In the case we present, the diagnosis was made on the basis of two-dimensional ultrasound performed by physicians aware of the history; the quality of three-dimensional ultrasound imaging suggests that this technique might have contributed toward establishing a precise diagnosis in the absence of a positive family history. Besides, the global view provided by three-dimensional surface-rendering images made the parents more confident of the accuracy of the diagnosis. Although osteogenesis imperfecta congenita is generally considered as autosomal dominant, the case we report suggests that it may be inherited in a recessive autosomal fashion at least when associated with encephalocele. Three-dimensional ultrasound confirmed the conventional two-dimensional examination and was helpful in convincing the parents of the accuracy of the diagnosis.

Revisiting first-trimester fetal biometry

INTRODUCTION

Although advances in ultrasound have facilitated the diagnosis of fetal abnormalities in the first trimester, fetal biometry at this stage of pregnancy remains underused in prenatal diagnosis. We hypothesized that charts which directly correlate measurements to crown-rump length (CRL) could be more accurate than those based on gestational age (GA) derived from CRL measurement. The aim of this study was to construct CRL-based biometric charts.

METHODS

Measurements of biparietal diameter (BPD), head circumference (HC) and abdominal circumference (AC) were prospectively collected from 939 normal singleton fetuses. Charts and predictive equations were constructed from data obtained from pregnancies in which the CRL was between 45 and 84 mm and for which the outcome was normal.

RESULTS

Measurements of BPD, HC and AC from 880 fetuses who met the criteria were correlated with CRL and used to construct charts and predictive equations. The standard error of estimates using CRL was significantly lower than that using GA in all cases.

DISCUSSION

First-trimester growth charts and predictive equations based on CRL instead of GA are more accurate. They might have a role in quality control of first-trimester ultrasound examination and may help in the diagnosis of fetal conditions that involve early growth abnormalities.

First trimester anatomy scan: pushing the limits. What can we see now?

PURPOSE OF REVIEW

The aim of this review article is to familiarize the reader with the current developments dealing with ultrasound during the first trimester of pregnancy.

RECENT FINDINGS

The main emphasis of this article is to review the anatomy seen during the first trimester and to bring to the reader the fact that the first anatomical survey of the fetus does not have to wait until the 18th to 20th week of gestation. The fetus can be surveyed adequately as early as the 12th week of gestation and ideally between the 13th and 14th weeks. Of course, not all malformations will be detected during the first trimester, and a follow-up scan between 20 and 23 weeks is indicated.

SUMMARY

The ongoing improvements in ultrasound technology allow us to see more details of the embryo or fetus at earlier gestational ages than ever before. This is resulting in a rethinking of when the first anatomical survey should be performed.