Fetal gastric size in normal and abnormal pregnancies

Early and Higher Volumes of Formula Supplementation after Birth Impact Breastfeeding Rates at Discharge in Well-Baby Nursery: A Retrospective Cohort Study

OBJECTIVE

 Physiologic breast milk production in the first 24 hours is estimated to be between 2 and 10 mL per feed. Many mothers intending to breastfeed use formula supplementation (FS) early on, which can affect successful breastfeeding. Whether the volume and timing of FS introduced in the first 24 hours of life (24 HOL) impacts the rate of "breastfeeding at discharge" (BFAD) is not well-studied and was investigated herein.

STUDY DESIGN

 Single-center, retrospective, chart review of breastfeeding infants born at ≥35 weeks who received supplementation in the first 24 HOL. Comprehensive demographic data pertaining to maternal and infant characteristics, along with infant feeding data, were collected. Four supplementation characteristics, (timing, rate, volume [mL/kg per feed], and type [expressed breast milk (EBM) or formula]) were correlated with BFAD.

RESULTS

 Among 3,102 supplemented infants in whom mothers intended to breastfeed, 1,031 (33.2%) infants were BFAD. At baseline, African American, Medicaid-insured, and single mothers had lower odds of BFAD. The overall maximum volume of FS per feed was 11.0 mL/kg (interquartile range 8.0-14.4). With each hour of delay in first supplementation, the odds of BFAD increased by 2.8% (95% confidence interval [CI] 0.022, 0.035). With every 1 mL/kg increase in the first formula volume, subsequent supplementation frequency increased by 4.5%. A positive association was observed between BFAD and a lower rate of supplementation (cutoff value ≤35.1%). However, among infants with these lower rates of supplementation, each unit increase in maximum FS, from 2 to 15 mL/kg, decreased the probability of BFAD by 4.2% (3.6-4.7%). Additionally, we observed that infants who were given at least one EBM supplementation (n = 223; 7.2%) had substantially increased rates of BFAD (odds ratio [OR] = 9.8, 95% CI 7.2-13.3).

CONCLUSION

 Early and higher volumes of FS negatively impacted BFAD. Birthweight-based FS of feeding with physiological volumes may increase breastfeeding rates at discharge.

KEY POINTS

· Higher volumes of first supplementation increases subsequent supplementation frequency.. · For each unit increase in maximum supplementation, BFAD probability decreases by 4.2%.. · Even one EBM supplementation increases rates of BFAD..

Impact of feeding volumes in the first 24 h of life on neonatal feeding intolerance

Objective

This study investigates whether volumes of intake in the first 24 h of life (24 HOL), in relation to birth weight (BW) and gestational age (GA), impact neonatal feeding intolerance (FI).

Methods

This study employed a retrospective chart review of 6,650 infants born at ≥35 weeks. The volumes of each formula feed per kg BW in the first 24 HOL were assessed. FI was defined as evidenced by chart documentation of emesis, abdominal distension, abdominal x-ray, and/or switching to a sensitive formula.

Results

Overall, the maximum volume of formula intake per feed was inversely correlated with GA and was higher in infants with FI (β = -1.39, p < 0.001) compared with infants without FI (β = -1.28, p < 0.001). The odds of emesis in late preterm infants with first feeding of >8 ml/kg [adjusted odds ratio (AOR) = 2.5, 95% confidence interval (CI): 1.4-4.6] and formula switching in the exclusively formula-fed group with volumes >10.5 ml/kg [AOR =  2.2, 95% CI (1.8-2.6)] were high. In the breastfeeding group, the odds of FI increased by 2.8-, 4.6-, and 5.2-fold with 5-10, 10-15, and >15 ml/kg of supplementations, respectively.

Conclusion

A higher volume of intake in relation to BW often exceeds the physiological stomach capacity of newborns and is associated with early FI. Optimizing early feeding volumes based on infant BW and GA may decrease FI, which may be an issue of volume intolerance.

Improving prenatal detection of abdominal supraumbilical anomalies: The sonographic examination of fetal anechoic spaces of upper abdomen revisited

Visualization of the axial plane of the fetal abdomen is mandatory to obtain abdominal biometry in the assessment of fetal growth in the second and third trimesters. The main anatomic landmarks that must be identified in this view include the fetal stomach and the intrahepatic portion of the umbilical vein, which are easily identifiable as they appear anechoic on ultrasound. The gallbladder is the other prominent anechoic structure in this plane. Focused study of the morphological characteristics of, and spatial relationship among, these three anechoic spaces is a simple technique to detect anomalies involving fetal upper abdominal organs. In this review, the sonographic features of those conditions that can be detected using this technique, which was termed the Fetal Examination of the Anechoic Spaces of upper abdomen Technique (FEAST), are classified and illustrated.

Ultrasonographic Imaging of the Fetal Duodenal Tract

OBJECTIVES

To investigate whether fetal duodenal tract sections can be visualized in the prenatal ultrasonographic examination.

METHODS

This study was designed in cross-section. Healthy singleton pregnant women who applied to the perinatology outpatient clinic for second-level ultrasound scanning between September 2020 and February 2021 were included in the study. Demographic information of the participants was obtained and an ultrasound scan was performed. The fetal duodenal tract was evaluated in three sections, including the pylorus. The fetal duodenal tract was differentiated from adjacent organs by its anatomical location, hyperechoic nature, and presence of fluid in the lumen.

RESULTS

A total of 278 eligible participants between 18 and 22 weeks of gestation were evaluated. While the fetal pylorus was closed in 76.6% of the participants, it was open in 23.4%. Duodenum pars superior, pars descendens, and pars inferior imaging rates were 99.3%, 98.2%, and 95.7%, respectively. It was possible to distinguish these parts from neighboring organs by 99.6%, 100%, and 100%, respectively. While the first, second, and third parts of the duodenum were observed as solid in 42.0%, 58.2%, and 52.2%, respectively, 57.9%, 41.7%, and 47.7% had fluid in the lumen.

CONCLUSION

The fetal duodenal tract can be viewed with prenatal ultrasonography in pregnant women who are not in a dorsoanterior position. This may make an additional contribution to the diagnosis of duodenal obstructions, which is the most common cause of intestinal atresia in prenatal screening.

Fetal gastric area ratio to predict severe neonatal opioid withdrawal syndrome

OBJECTIVE

Neonatal opioid withdrawal syndrome (NOWS) can occur in newborns exposed to opioids in pregnancy. Opioids delay gastric emptying and inhibit gastric motility in adults, but little is known about their effect in the fetus. We sought to assess gastric area ratio (GAR) in opioid-exposed fetuses.

STUDY DESIGN

Retrospective cohort study including opioid-exposed maternal-neonatal dyads between 2007-2017. Primary outcome: severe NOWS (three consecutive Finnegan scores ≥8 or three scores totaling ≥24 within 96 h of life). GAR: (gastric area)/(transverse abdominal area) × 100. Data analysis was by descriptive, parametric, and non-parametric tests.

RESULTS

Forty-nine maternal-neonatal dyads were included, 67% (n = 33) with severe NOWS. GAR <95th percentile for gestational age was seen in 80% of neonates (n = 39). However, GAR was not different between groups (p = .90) and did not predict severe NOWS.

CONCLUSION

Fetal GAR was <95th percentile in 80% of opioid-exposed neonates. However, fetal GAR may not predict NOWS treatment.

Prenatal Ultrasound Measurement of Fetal Stomach Size Is Predictive of Postnatal Development of GERD in Isolated Cleft Lip and/or Palate

OBJECTIVE

To determine whether prenatal ultrasound measurement of fetal stomach size, as a surrogate marker of fetal swallowing, is predictive of postnatal development of gastroesophageal reflux disease (GERD) in cases of isolated cleft lip and/or palate (CL/P).

DESIGN

This is a retrospective case-control study. The outcome of interest is postnatal diagnosis of GERD in isolated CL/P. The exposure of interest is prenatal stomach size measurement by ultrasound.

SETTING

The study population was selected from an academic, tertiary care center between 2003 and 2011.

PATIENTS/PARTICIPANTS

Cases were neonates undergoing CL/P repair during the study period. Cases with other known structural or chromosomal abnormalities were excluded. Controls were contemporary, nondiabetic neonates that matched gestational age (within one week) to cases. Each case measurement was matched ∼1:2 with control measurement.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

The primary outcome was difference in mean prenatal ultrasound measurement of fetal stomach size between cases and controls. We hypothesized that patients with postnatal development of GERD would have smaller mean fetal stomach size.

RESULTS

There were 32 cases including 19 patients with unilateral cleft lip and palate, 8 with unilateral cleft lip, and 4 with bilateral cleft lip and palate. Cases were noted to have smaller mean anterior-posterior and transverse fetal stomach measurements as compared to controls. This was statistically significant from 16 to 21 weeks, 25 to 27 weeks, and 28 to 36 weeks (P < .01 for all).

CONCLUSIONS

Prenatal ultrasound measurement of fetal stomach size as a surrogate marker of fetal swallowing is predictive of postnatal development of GERD in isolated CL/P.

Outcomes of both complex and isolated cases of infants with large stomach on fetal ultrasound

BACKGROUND

A sonographically large fetal stomach has been associated with gastrointestinal obstruction, per case reports, and is often followed up with serial ultrasound examinations. The frequency of this phenomenon has not been systematically studied, resulting in challenges in counseling parents about the prognosis and making cost-benefit analysis of serial ultrasound follow-up difficult to assess.

OBJECTIVE

This study aimed to determine the frequency at which an enlarged fetal stomach as the sole abnormality on fetal ultrasound reflects a bowel obstruction to aid in parental counseling and determine the best practice for follow-up.

STUDY DESIGN

We performed a retrospective cohort study of all prenatal sonographic cases in which a large fetal stomach was visualized between January 1, 2002, and June 1, 2016. The inclusion criteria required a fetal diagnosis of a large stomach, defined as an increased measurement in ≥2 dimensions based on a nomogram, that resulted in a liveborn delivery within the Johns Hopkins Health System. We excluded pregnancy loss, pregnancy termination, and cases delivered outside of the Johns Hopkins Health System. Cases were subclassified as isolated or complex based on the absence or presence of additional ultrasound findings at initial presentation of the enlarged stomach. The perinatal outcomes and maternal demographics were determined and compared between isolated and complex cases.

RESULTS

Of 57,346 total cases with ultrasound examinations in the Johns Hopkins Health System within the study time frame, 348 fetuses had enlarged stomachs, with 241 (69.3%) who met the inclusion criteria as follows: 161 (66.8%) isolated and 80 (33.2%) complex. Of the 161 isolated cases, 1 resulted in neonatal small bowel obstruction (0.62%). Of note, 158 of the isolated large stomach cases (98.1%) had no postnatal abnormalities of any kind. Of the 80 complex cases, 18 (22.5%) resulted in neonatal gastrointestinal obstruction (14 cases of duodenal atresia and 4 cases of jejunal atresia). Those with isolated findings were significantly less likely to deliver preterm (n=24 [14.9%] vs n=35 [43.8%]; P<.001), be complicated by polyhydramnios (n=18 [11.2%] vs n=23 [28.8%]; P<.001), have a neonatal intensive care unit admission (n=31 [19.3%] vs n=76 [95.0%]; P<.01), or have a major surgical procedure (n=2 [1.2%] vs n=66 [82.5]; P<.001) compared with complex cases.

CONCLUSION

We found that 0.62% of isolated large fetal stomachs (1 of 161) were associated with neonatal intestinal obstruction. Of the complex cases with an enlarged stomach, 18 of 80 (22.5%) were found to have a gastrointestinal obstruction; by definition, none of these complex cases began as an isolated large stomach as their initial ultrasound finding, but rather had other concurrent sonographic abnormalities, including a double bubble sign and intestinal dilation. With a prevalence of <1% resulting in the development of a small bowel obstruction, our results suggest that, when isolated, a large stomach does not seem to warrant serial prenatal ultrasound follow-up or postnatal imaging and is likely to reflect an incidental finding.

Fetal Physiologically Based Pharmacokinetic Models: Systems Information on the Growth and Composition of Fetal Organs

BACKGROUND

The growth of fetal organs is a dynamic process involving considerable changes in the anatomical and physiological parameters that can alter fetal exposure to xenobiotics in utero. Physiologically based pharmacokinetic models can be used to predict the fetal exposure as time-varying parameters can easily be incorporated.

OBJECTIVE

The objective of this study was to collate, analyse and integrate the available time-varying parameters needed for the physiologically based pharmacokinetic modelling of xenobiotic kinetics in a fetal population.

METHODS

We performed a comprehensive literature search on the physiological development of fetal organs. Data were carefully assessed, integrated and a meta-analysis was performed to establish growth trends with fetal age and weight. Algorithms and models were generated to describe the growth of these parameter values as functions of age and/or weight.

RESULTS

Fetal physiologically based pharmacokinetic parameters, including the size of the heart, liver, brain, kidneys, lungs, spleen, muscles, pancreas, skin, bones, adrenal and thyroid glands, thymus, gut and gonads were quantified as a function of fetal age and weight. Variability around the means of these parameters at different fetal ages was also reported. The growth of the investigated parameters was not consistent (with respect to direction and monotonicity).

CONCLUSION

Despite the limitations identified in the availability of some values, the data presented in this article provide a unique resource for age-dependent organ size and composition parameters needed for fetal physiologically based pharmacokinetic modelling. This will facilitate the application of physiologically based pharmacokinetic models during drug development and in the risk assessment of environmental chemicals and following maternally administered drugs or unintended exposure to environmental toxicants in this population.

Evaluation of pre- and postnatally diagnosed gastrointestinal tract obstructions

Purpose: Signs of congenital obstruction of the gastrointestinal tract (GIT) organs may present on prenatal ultrasonography. Prenatal detection is influenced by several factors, including obstruction site, lesion degree (partial or complete), the occurrence of associated malformations, and gestational week at screening. Here, we aimed to evaluate the success of prenatal diagnosis of GIT obstructions in a tertiary center in Turkey. Materials and methods: The study included 34 prenatally and 22 postnatally diagnosed babies with different GIT malformations. GIT obstructions were divided into five groups according to the level of obstruction (A. esophagus, B. stomach and proximal duodenum, C. small intestine, D. large intestine, E. multiple obstructions). Results: The prenatal detection rate among all cases was 60.7%. The associated structural malformation and aneuploidy rates were 21.4 and 5.4%, respectively. Twelve neonates died within the first day after birth due to various reasons. The remaining 43 babies underwent surgery at different times according to their clinical conditions. The mean time between birth and surgery was 4.5 days (range, 1-56 days). There were 12 postoperative deaths due to various complications, and one case died at 2 years of age. Overall, 31 of the 56 (55.4%) babies were alive during the follow-up period. The successful prenatal diagnosis rates were 57.2, 85.8, 75, 25, and 80% in groups A, B, C, D, and E, respectively. The median birth weight increased significantly in groups A through D (p = .04). However, there were no intergroup differences in the Apgar scores, associated abnormality rates, time to surgery, and number of babies operated. Conclusions: These findings demonstrate the importance of prenatal ultrasonography and success of prenatal detection especially for upper GIT abnormalities. Although there are some prenatal signs of GIT obstructions, such as double bubble, polyhydramnios, enlarged bowel, and failure to visualize the stomach, early prenatal diagnosis is difficult and can be delayed, resulting in the detection of GIT obstruction after birth. When suspecting GIT obstruction, clinicians should evaluate the fetal anatomy carefully and be aware of associated chromosomal abnormalities.

Measurement of Gastric Circumference in Foetuses with Oesophageal Atresia

Background: The specific recognition of oesophageal atresia (OA) with or without a tracheal fistula in a foetus is a diagnostic challenge for prenatal medicine. The aim of the present work is to analyse the value of the measurement of gastric size in the diagnosis of this significant malformation. Materials and Methods: Altogether, the examinations of 433 pregnancies between the 18.4 and 39.1 weeks of gestation were retrospectively analysed. 59 of these foetuses exhibited an OA. By means of a linear regression analysis with normal foetuses, significant parameters influencing gastric size were examined. Subsequently the gastric sizes were transformed into z values and a comparison was made between OA with and without fistulae with the help of t tests. Results: In the normal foetuses there was a significant association between the gastric circumference and the abdominal circumference (circumference = 6.809 + 0.179 × abdominal circumference, r = 0.686, p < 0.0001). In the normal group the average was 43.0 (standard deviation [SD] 13.7) mm and those in foetuses with and without fistuale were 33.8 (SD 22.7) and 0.9 (SD 3.7) mm. In 34 (57.6 %) foetuses with an OA, the gastric circumference was below the 5th percentile. In detail, there were 13 (34.2 %) foetuses with a fistula and 21 (100 %) without a fistula. The average z values in the normal group and in the groups of OA with fistula and without fistula amounted to 0.0 (SD 1.0), -1.3 (SD 2.2) and -4.5 (SD 1.0). Conclusion: Measurements of the gastric circumference below the 5th percentile should lead to further diagnostic measures, especially when associated with polyhydramnios. Although OA without a fistula is always conspicuous, only about one in three OAs with fistula are associated with a significantly smaller stomach.

Morphogenesis and three-dimensional movement of the stomach during the human embryonic period

The stomach develops as the local widening of the foregut after Carnegie stage (CS) 13 that moves in a dramatic and dynamic manner during the embryonic period. Using the magnetic resonance images of 377 human embryos, we present the morphology, morphometry, and three-dimensional movement of the stomach during CS16 and CS23. The stomach morphology revealed stage-specific features. The angular incisura and the cardia were formed at CS18. The change in the angular incisura angle was approximately 90° during CS19 and CS20, and was <90° after CS 21. The prominent formations of the fundus and the pylorus differentiate at around CS20. Morphometry of the stomach revealed that the stomach gradually becomes "deflected" during development. The stomach may appear to move to the left laterally and caudally due to its deflection and differential growth. The track of the reference points in the stomach may reflect the visual three-dimensional movement. The movement of point M, representing the movement of the greater curvature, was different from that of points C (cardia) and P (pyloric antrum). The P and C were located just around the midsagittal plane in all the stages observed. Point M moved in the caudal-left lateral direction until CS22. Moreover, the vector CP does not rotate around the dorsoventral axis, as widely believed, but around the transverse axis. The plane CPM rotated mainly around the longitudinal axis. The data obtained will be useful for prenatal diagnosis in the near future.

Three-dimensional sonographic volume measurement of the fetal stomach

The objective of this study was to measure the fetal gastric volume using three-dimensional (3-D) ultrasound during pregnancy. Three-dimensional sonographic examinations were performed involving 35 pregnant women from 12 to 38 weeks of gestation. The fetal gastric volume was monitored every 5 min for a minimum of 40 min (40-60 min) in each woman. The rotational technique with Virtual Organ Computer-aided AnaLysis (VOCAL) was used to calculate the fetal gastric volume. Maximum and minimum gastric volumes were curvilinearly associated with the gestational age, respectively (R(2) = 0.611, p < 0.0001, and R(2) = 0.407, p < 0.0001, respectively). A curvilinear relationship was noted between the functional capacity (maximum volume - minimum volume) of the fetal stomach and gestational age (R(2) = 0.531, p < 0.0001). The maximum volume change [(maximum volume - minimum volume/maximum volume) × 100] did not change during pregnancy (mean and standard deviation, 64.1% ± 16.1%). However, gastric emptying cycles could not be determined in this study because of the short observation period and small number of subjects. Our findings suggest that the fetal gastric volume calculated by conventional two-dimensional ultrasound in previous investigations is approximately one-third of the maximum volume using 3-D ultrasound in the present study and that 3-D ultrasound is a superior means of evaluating the fetal gastric volume in utero. However, the data and their interpretation in the present study should be viewed with some degree of caution because of the small number of subjects. Further studies involving a larger sample size are needed to confirm these findings.

Ontogeny of gastric emptying patterns in the human fetus

OBJECTIVE

Fetal swallowing and gastric emptying contribute importantly to amniotic fluid (AF) homeostasis and fetal gastrointestinal development. We speculated that fetal gastric emptying must be functional early in gestation to prevent rapid increases in AF. We sought to determine the human fetal ontogenic pattern of gastric emptying.

STUDY DESIGN

Gastric emptying of eighty normal fetuses at 12-39 weeks was studied. Real-time ultrasound of the fetal stomach was continuously recorded for 1 hour. The gastric area ratio (GAR) was defined as the gastric area divided by the abdominal transverse area. The delta GAR was defined as the change between the maximum and the minimum gastric area ratiox100 (expressed as percent). A change of the fetal gastric area more than the 10th percentile of the delta GAR at 36-39 weeks was used to define gastric emptying.

RESULTS

The 10th, 50th and 90th percentile of delta GAR at 36-39 weeks' was 5.2, 6.5 and 8.7%, respectively. Fetal gastric emptying was detected as early as 12 5/7 weeks of gestation. The proportion of fetuses demonstrating gastric emptying (>10th percentile delta GAR) increased with gestational age: 4/33 (12.1%) 12-23 weeks, 3/9 (33.3%) at 24-27 weeks, 8/11 (72.7%) at 28-31 weeks, 12/14 (85.7%) at 32-35 weeks, and 11/13 (84.6%) at 36-39 weeks.

CONCLUSIONS

Fetal gastric emptying occurs by the beginning of the second trimester, contributing to AF regulation. The increased frequency of gastric emptying in late gestation is likely secondary to increased swallowing, altered fetal behavioral state or endogenous production of gastrointestinal motility factors.

Current status of prenatal diagnosis, operative management and outcome of esophageal atresia/tracheo-esophageal fistula

Ultrasonographic features suggestive of esophageal atresia with or without tracheo-esophageal fistula (EA/TEF) are only in a small minority of fetuses with EA/TEF (<10%) identifiable on prenatal scans.The prenatal diagnosis of EA/TEF relies in principle, on two nonspecific signs: polyhydramnios and absent or small stomach bubble. Polyhydramnios is associated with a wide range of fetal abnormalities, but most commonly it pursues a benign course. Similarly the sonographic absence of a stomach bubble may point to a variety of fetal anomalies.The combination of polyhydramnios and absent stomach bubble in two small series offers a modest positive predictive value of 44 and 56% respectively. Prenatal scanning for EA/TEF identifies a larger proportion of fetuses with Edwards syndrome; there is also a higher proportion of isolated EA in comparison to postnatal studies.Current ultrasound technology does not allow for a definite diagnosis of EA/TEF and therefore, counseling of parents should be guarded.Postnatal diagnosis of EA is confirmed by the failure to pass a firm nasogastric tube into the stomach; on chest X-ray, the tube is seen curling in the upper esophageal pouch. Corrective surgery for EA/TEF is well established and survival rates of over 90% can be expected.

A report of two linked studies of knowledge and attitudes to prenatal screening and testing in adults of reproductive age in Japan and the UK

BACKGROUND

prenatal screening for fetal abnormality is being offered routinely in many countries. The need for informed consent demands that the nature of screening is understood by prospective parents, but the opportunities for providing information early in pregnancy before decision-making may be limited.

OBJECTIVE

to assess the knowledge about, and attitudes to, prenatal screening in adults of reproductive age in two countries.

DESIGN

two groups of adults were surveyed using a specifically designed tool to assess knowledge about fetal abnormalities and potential screening tests, attitudes to screening and termination of pregnancy, and information required by parents before making decisions.

SETTING AND PARTICIPANTS

90 participants were surveyed in Japan, 72% of whom were pregnant or had a partner who was pregnant; 93 participants were surveyed in the UK, none of whom were pregnant. All respondents were aged between 18 and 45 years.

MEASUREMENTS

demographic data were collected and analysed. Frequencies were calculated for each questionnaire response. A series of t-tests and chi(2) tests were used to assess differences between the two groups. Free-text data were analysed using content analysis.

FINDINGS

overall knowledge of prenatal tests and the conditions for which screening is offered was low in both groups. Significant differences exist between the perception of the conditions for which screening or testing can be offered and the types of conditions that can actually be detected prenatally. Most respondents in both countries would consider termination of pregnancy for fetal abnormality. The information most frequently cited by respondents as important when deciding about testing were the chances of damage to the health of fetus, mother, or both.

KEY CONCLUSIONS

women and men of reproductive age in the groups studied are not well-prepared to make decisions about screening or testing in pregnancy.

IMPLICATIONS FOR PRACTICE

improvements in preconceptual education on prenatal screening and testing may be required to ensure prospective parents can make informed decisions in early pregnancy.

The development of stomach during the fetal period

The objective of this study was to explore the fetal development of the stomach, its morphology and relationship with neighboring structures. The study is carried out in 2003 using 160 human embryos and fetuses (81 males and 79 females) aged between 9 and 40 weeks of gestation. None of the cases had any external pathology or anomaly. Its topographical localization and relationship with surrounding structures were revealed with anatomical dissections. Width and height of the stomach, lengths of the greater and lesser curvatures, the angle between horizontal and vertical axes of the stomach and types of stomach were established. During the fetal life stomach was most commonly located above the transverse axis passing through the umbilicus, in left and right hypochondrium (81%). There were significant differences among trimester groups with respect to the localization of the stomach in the quadrants (P < 0.001). There were no significant sex differences in parameters. After the second trimester, the height of the stomach increased more than the width of the stomach and anterior abdominal height. The angle of stomach decreased from 100 degrees to 50 degrees throughout the fetal period. During the fetal period, wide angles stomach was more common in the first(f) and second trimesters while acute-angled stomach was more common in the third trimester and term fetuses. Diagnosis and treatment of fetal anomalies and pathologies of the stomach requires knowledge of fetal anatomy of the stomach. Data acquired in this study are believed to contribute to the studies of obstetrics, perinatology, forensic medicine and fetal pathology on fetal development of the stomach, and diagnosis and treatment of its anomalies, pathologies, and variations.

Nomogram of the fetal gastric size development in normal pregnancy

OBJECTIVE

To construct an ultrasonographic nomogram of the fetal gastric size with gestational age in normal singleton pregnancy.

PATIENTS AND METHODS

Out of 17 000 outpatient pregnant women who were admitted to our hospital, a total of 250 fetal measurements were randomly collected from routine ultrasonographic examinations performed in women with normal singleton pregnancies between 13 and 39 weeks of gestation without medical or obstetric complications. None of the fetuses had detectable fetal malformations. The ultrasound plane which provided the largest stomach area including the pylorus on a transverse and oblique section was used for definition and measurement of gastric longitudinal dimensions. The transverse section at the center of the gastric corpus was used for transverse and anteroposterior dimensions. Biparietal diameter, abdominal circumference were also measured.

RESULTS

The fetal gastric longitudinal, anteroposterior and transverse dimensions were significantly correlated with gestational age (r values 0.74, 0.71, and 0.49, respectively). There was a significant correlation measurements between gastric size and AC. The correlation coefficents for gastric dimensions with gestational age was larger than those with AC (r=0.732, 0.702 and 0.489, respectively). The ratio of fetal gastric anteroposterior dimension to fetal AC was a constant parameter calculated as 1/3.

CONCLUSION

Fetal stomach dimensions in normal pregnancy correlate with gestational age and nomogram of fetal gastric development appears to be useful in assessment of normal fetal growth.

Gastric emptying cycles in the human fetus

OBJECTIVE

Fetal swallowing contributes greatly to amniotic fluid homeostasis and fetal somatic development. Despite the absorption and recirculation of significant volumes of amniotic fluid, little is known about the rates of fetal gastric emptying or gastrointestinal absorption. We sought to determine the patterns of human fetal gastric emptying cycles across gestation.

STUDY DESIGN

The gastric emptying cycle of 80 normal human fetuses at 12 to 39 weeks of gestation was studied. Real-time ultrasound examination of the fetal stomach (defined as the largest gastric area inclusive of the pylorus) was recorded continuously for a minimum of 1 hour (60-112 minutes). Images were replayed with measurements of gastric size every minute. The gastric area ratio was defined as the ratio of the fetal gastric area divided by the area of the fetal abdominal transverse section. The changes in gastric area ratio of all subjects were analyzed with the discrete Fourier transform method. The calculable maximum cycle was 60 or 112 minutes, and the minimum cycle was 2 minutes. The highest and second highest peaks of all power spectrum were recorded, and each cycle was converted from frequency of each peak.

RESULTS

The gastric emptying cycles of the highest peak before 24 weeks of gestation were scattered between 30 and 100 minutes with low power. At 32 to 35 weeks of gestation, cycles were focused at approximately 40 minutes with increased power. At term, the cycles increased to >80 minutes. The gastric emptying cycles of the second highest peak were constant at 20 minutes, with stronger power after 24 weeks of gestation.

CONCLUSION

Fetal gastric emptying cycles normalize during the early third trimester. The near-term evidence of delayed emptying may contribute to newborn infant feeding satiation.

Correlation between fetal gastric size and amniotic fluid volume

PURPOSE

Since abnormal conditions of the fetal digestive tract may alter both amniotic fluid volume and fetal gastric volume, we sought to determine whether amniotic fluid volume is correlated with fetal gastric volume in normal pregnancy.

METHODS

A total of 280 fetal gastric size measurements were made prospectively from routine sonographic examinations of women with normal singleton pregnancies between 16 and 42 weeks of gestation. The fetal stomach was defined as the largest area including the pyloric site on transverse or oblique real-time sonographic scans. Gastric volume was calculated according to the formula for a prolate ellipsoid. The amniotic fluid index (AFI) was used for the evaluation of amniotic fluid volume.

RESULTS

Both fetal gastric volume and AFI were significantly correlated with gestational age (R2= 0.422 and R2= 0.128, respectively). Only a weak correlation was found between gastric volume and AFI (R2= 0.036, p <0.001). On multivariate linear regression analysis adjusting for gestational age and fetal biometric measurements, gastric volume was not an independent and significant predictor of AFI.

CONCLUSIONS

Although sonographically determined fetal gastric volume measurements appear to be useful in the assessment of fetal digestive tract anomalies, fetal gastric volume has no clinically significant effect on the amniotic fluid volume in normal pregnancy.

Correlation between fetal age and ultrasonographic measurements during the second half of pregnancy in domestic cats (Felis catus)

We ultrasonographically evaluated the prenatal development in cats, from Day 30 to the end of pregnancy, subjecting a group of pregnant cats (n = 8) to daily ultrasonographic examinations. The ultrasonographic images allowed us to measure the diameter of the fetal abdomen, the biparietal diameter of the fetal skull and the diameter of the fetal stomach. A correlation between these measurements and gestational age was found with a linear, parabolic and exponential regression analysis. From Days 38 to 43 after breeding we also performed fetal gender determination by evaluating the external genitalia. All queens successfully carried their pregnancies to term. This study compiled useful new data in order to clinically monitor the normal course of pregnancy in cats and to determine gestational age.