Abnormal Fetal Head Research Articles

Sonographic Estimation of the Fetal Head Circumference: Accuracy and Factors Affecting the Error

BackgroundSonographic measurement of fetal head circumference (HC) is an essential parameter for the estimation of fetal weight as well as in cases with abnormal fetal head size. Since there is a lack of data, the present study was to assess the accuracy of ultrasonographic estimation of fetal HC and to identify factors that affect the accuracy of fetal HC estimation.Material and MethodsA prospective cohort observational study was conducted for a year. Sonographic fetal biometry including HC was performed, and fetal HC was measured postnatally. Measures of accuracy and various factors which affect the accuracy are analyzed.ResultsUltrasonographic HC underestimated actual postnatal HC in 87.5% and overestimated actual HC in 12.5%. Sonographic underestimation of HC persisted throughout gestation and became more pronounced as gestational age increased. Error in HC was statistically significant in those with low liquor and anterior placenta and in those who had instrumental delivery. Parity, fetal presentation, and maternal diabetes did not affect the error in ultrasonographic measurement of head circumference. When the HC was beyond 95th centile on ultrasound, the error detected postnatally was significant (− 14 mm vs. − 8 mm), though not statistically significant (p value 0.82). The difference between the sonographic and postnatal HC was also related to the mode of delivery with the highest error seen in those who had instrumental vaginal delivery (p value 0.031).ConclusionThe ultrasound estimation of fetal HC is associated with significant underestimation of the actual HC measured postnatally. The error in measuring fetal HC increased in those with advanced gestational age, low liquor, and anterior location of the placenta and in those who had instrumental vaginal delivery. The measurement error may have important implications in specific clinical scenarios like monitoring pregnancy with fetal growth restriction, suspected fetal head growth abnormalities, and labor outcome.

Association between abnormal fetal head growth and autism spectrum disorder

IntroductionDespite evidence for the prenatal onset of abnormal head growth in ASD children, studies on fetal ultrasound data in ASD are limited and controversial.ObjectivesTo understand whether people with ASD have abnormal head growth during gestationMethodsA longitudinal matched case-sibling-control study on prenatal ultrasound biometric measures of ASD children was conducted. Children with ASD were matched to two control groups: (1) typically developed sibling (TDS) and (2) typically developed population (TDP). The cohort comprised 528 children (72.7% males): 174 ASD, 178 TDS, and 176 TDP.ResultsSecond-trimester ASD and TDS fetuses had significantly smaller biparietal diameter (BPD) than TDP fetuses (aORzBPD=0.685, 95%CI=0.527-0.890 and aORzBPD=0.587, 95%CI=0.459-0.751, respectively). However, these differences became statistically indistinguishable in the third trimester. Head biometric measures were associated with the sex of the fetus, with males having larger heads than females within and across groups. A linear mixed-effect model assessing the effects of sex and group assignment on fetal longitudinal head growth indicated faster BPD growth in TDS vs both ASD and TDP in males (β=0.084 and β=0.100 respectively; p<0.001) but not in females, suggesting an ASD–sex interaction in head growth during gestation. Fetal head shape showed sex-specific characteristics, and head growth was inversely correlated with ASD severity in males and females, thus further supporting the sex effect on the association between fetal head growth and ASD.ConclusionsOur findings suggest that abnormal fetal head growth is a familial trait of ASD, which is modulated by sex and is associated with the severity of the disorder.DisclosureNo significant relationships.

Association Between Abnormal Fetal Head Growth and Autism Spectrum Disorder

Despite evidence for the prenatal onset of abnormal head growth in children with autism spectrum disorder (ASD), studies on fetal ultrasound data in ASD are limited and controversial. We conducted a longitudinal matched case-sibling-control study on prenatal ultrasound biometric measures of children with ASD, and 2 control groups: (1) their own typically developed sibling (TDS) and (2) typically developed population (TDP). The cohort comprised 528 children (72.7% male), 174 with ASD, 178 TDS, and 176 TDP. During the second trimester, ASD and TDS fetuses had significantly smaller biparietal diameter (BPD) than TDP fetuses (adjusted odds ratio for the z score of BPD [aORzBPD] = 0.685, 95% CI= 0.527-0.890, and aORzBPD= 0.587, 95% CI= 0.459-0.751, respectively). However, these differences became statistically indistinguishable in the third trimester. Interestingly, head biometric measures varied by sex, with male fetuses having larger heads than female fetuses within and across groups. A linear mixed-effect model assessing the effects of sex and group assignment on fetal longitudinal head growth indicated faster BPD growth in TDS versus both ASD and TDP in male fetuses (β= 0.084 and β= 0.100 respectively; p< .001) but not in female fetuses, suggesting an ASD-sex interaction in head growth during gestation. Finally, fetal head growth showed conflicting correlations with ASD severity in male and female children across different gestation periods, thus further supporting the sex effect on the association between fetal head growth and ASD. Our findings suggest that abnormal fetal head growth is a familial trait of ASD, which is modulated by sex and is associated with the severity of the disorder. Thus, it could serve as an early biomarker for ASD.

The yield of chromosomal microarray testing for cases of abnormal fetal head circumference.

Chromosomal microarray analysis (CMA) is the method of choice for genetic work-up in cases of fetal malformations. We assessed the detection rate of CMA in cases of abnormal fetal head circumference (HC). The study cohort was based on 81 cases of amniocenteses performed throughout Israel for the indication of microcephaly (53) or macrocephaly (28), from January 2015 through December 2018. We retrieved data regarding the clinical background, parental HCs and work-up during the pregnancy from genetic counseling summaries and from patients' medical records. There was only one likely pathogenic CMA result (1.89%): a 400-kb microdeletion at 16p13.3 detected in a case of isolated microcephaly. No pathogenic results were found in the macrocephaly group. Most fetuses with microcephaly were female (87.8%), while the majority with macrocephaly were males (86.4%). The results imply that CMA analysis in pregnancies with microcephaly may carry a small yield compared to other indications. Regarding macrocephaly, our cohort was too small to draw conclusions. In light of the significant gender effect on the diagnosis of abnormal HC, standardization of fetal HC charts according to fetal gender may normalize cases that were categorized outside the normal range and may increase the yield of CMA for cases of abnormal HC.

Analytic Approach for Fetal Head Biometric Measurements Based on Log Gabor Features

This paper presents a new analytical method for fetal biometric measurements. The proposed approach is used to validate doctor’s biometric measurements to detect the malformation of the head. Mainly, biparietal diameter, occipito-frontal diameter, and head circumference are the well-known clinical measurements used to detect the fetal head. Here, the ultrasound images (US) of the gestational age (GA = 22 weeks) are employed using a discriminative set of features. The proposed system consists of the following steps: First, the ultrasound fetal image is passed through the Contourlet preprocessing algorithm to reduce the speckle noise. The resulting image falls to hysteresis thresholding process to preserve the dominant head features. Then, log Gabor features are extracted from the US image to determine the biometric head measurements. The obtained measurements are compared to Expert results using normal and abnormal data sets. The proposed method has been tested on 50 normal and 10 neurological abnormal fetal head US sequences and it reach 98% of accuracy. The main advantages of the new proposed biometric measurement technique versus the existing procedures are: (1) automatic measure of the fetal head displayed on the computer screen of the expert machine without manual intervention; (2) the approach should be implemented and the biometric measure can be extracted automatically from the clinical US image.

Successful external cephalic version is an independent factor for caesarean section during trial of labor – a matched controlled study

IntroductionTo assess the mode of delivery and Caesarean Section (CS) rate after successful External Cephalic Version (ECV). Material and methodsA matched case-control study. Data were gathered from a tertiary care university hospital register from 1996–2015. All pregnant women who delivered after successful External Cephalic Version (ECV). Among 643 women who attempted ECV, we identified 198 with successful ECVs and compared them with the next two women who presented for labor management with spontaneous cephalic presentation, matching for delivery date, maternal age, parity, body mass index, and delivery history using univariate and stepwise logistic regression. The main outcome measure was the risk of caesarean. ResultsThe caesarean section rate was higher after successful ECV (respectively 20.7% versus 7.07%, P<0.05). Caesarean section for abnormal fetal head position (forehead, bregma, face) was higher after successful ECV (28.6% versus 0%). After adjustment for matching and confounding variables (variation of the caesarean section rate over the study period, gestational maternal complications, antepartum fetal complications, term of delivery, induction of labor, oxytocin use for dystocia, neonatal cephalic perimeter), a successful ECV increased the risk of caesarean section (adjusted OR 3.17, 95% CI 1.86–5.46). By stratifying on week, a trend for increased risk for caesarean section was observed at the week after ECV and at post term (28.6% before 37+6, 14.8% at 38+0–38+6, 13.8% at 39+0–39+6, 14.2% at 40+0–40+6 and 33.3% beyond 41+0 weeks’ gestation, P=0.06). ConclusionsWomen who have a successful ECV are at increased risk of caesarean section compared with women who experience spontaneous cephalic presentation.

Fetal Head Circumference as a Predictor of Successful Spontaneous Vaginal Delivery

Background: Intrapartum head circumference is an integral part of sonographic models and important for the purpose of fetal weight estimation as well as in cases which abnormal fetal head growth is suspected, it is considered the interface between maternal pelvis and fetus. Aim: This study aims to assess the accuracy of fetal head circumference compared to expected fetal weight as a predictor of spontaneous vaginal delivery Methods: A prospective observational study was conducted on 996 women in active stage of labor admitted to Labor ward of Ain Shams University Maternity Hospital and Labor ward in Manshiet El Bakry general hospital. Results large head circumference (odds ratio, 2.8; 95% CI, 1.37–5.73; p-value; .005 was independent predictors for cesarean delivery, and no significant difference on mode of delivery between different expected fetal weight, Conclusion: A large head circumference is more strongly associated with unplanned caesarian section than high expected fetal weight.

Prenatal diagnosis of parapagus diprosopus dibrachius dipus twins with spina bifida in the first trimester using two- and three-dimensional ultrasound

ObjectiveHere, we report a case of parapagus diprosopus twins with spina bifida diagnosed in the first trimester of pregnancy using two-dimensional (2D) and three-dimensional (3D) ultrasound. Case reportA 28-year-old Taiwanese woman, gravid 1, para 0, visited our hospital due to an abnormal fetal head shape discovered by 2D ultrasound at 11-weeks gestation. Parapagus diprosopus twins with spina bifida were diagnosed after ultrasound examination. The characteristics of parapagus diprosopus twins are more illustrative in 3D ultrasound than in 2D ultrasound. After counseling, termination of pregnancy was chosen by the couple. Although necropsy was declined, the gross appearance and radiograph of the abortus confirmed our diagnosis. ConclusionWith the help of 3D ultrasound, we made an early and definitive diagnosis of conjoined twins.

OC240: Abnormal fetal head shape: etiology and management

OC240: Abnormal fetal head shape: etiology and management

Changes in Fetal Position During Labor and Their Association With Epidural Analgesia

To evaluate whether epidural analgesia is associated with a higher rate of abnormal fetal head position at delivery. We conducted a prospective cohort study of 1,562 women to evaluate changes in fetal position during labor by using serial ultrasound examinations. Ultrasound examinations were performed at enrollment, epidural administration, 4 hours after the initial ultrasonography if epidural had not been administered, and late in labor (> 8 cm). Information about fetal head position at delivery was obtained from the provider. Regardless of fetal head position at enrollment (occiput transverse, occiput posterior, or occiput anterior), most fetuses were occiput anterior at delivery (enrollment position: occiput transverse 78%, occiput posterior 80%, occiput anterior 83%, P = .1). Final fetal position was established close to delivery. Of fetuses that were occiput posterior late in labor, only 20.7% were occiput posterior at delivery. Changes in fetal head position were common, and 36% of women had an occiput posterior fetus on at least one ultrasound examination. Women receiving epidural did not have more occiput posterior fetuses at the enrollment (23.4% epidural versus 26.0 no epidural, P = .9) or the epidural/4-hour ultrasound examination (24.9% epidural, 28.3% no epidural), but did have more occiput posterior fetuses at delivery (12.9% epidural versus 3.3% no epidural, P = .002); the association remained in a multivariate model (adjusted odds ratio 4.0, 95% confidence interval 1.4-11.1). Fetal position changes are common during labor, with the final fetal position established close to delivery. Our demonstration of a strong association of epidural with fetal occiput posterior position at delivery represents a mechanism that may contribute to the lower rate of spontaneous vaginal delivery consistently observed with epidural.

Spina Bifida

Spina bifida is a serious birth defect that involves an incomplete closure of the spine, spinal cord, brain, and/or protective covering of the fetal spine. Even though the causes of spina bifida are still uncertain, diabetes, obesity, severe hyperthermia in early pregnancies, and poor nutrition are believed to be causes of neural tube defects (NTDs). Because spina bifida may go undetected by •-fetoprotein screening and amniocentesis, sonography becomes a valuable tool in its identification. Spina bifida can also affect the fetal brain, so sonography is important in detecting any abnormal fetal head signs associated with Arnold-Chiari (type II) malformation. Surgical planning is another important part of sonography’s role when detecting NTDs. Although still in experimental stages, in utero repair has proven beneficial in some cases of spina bifida after careful sonographic assessment as part of the treatment considerations.

Abnormal fetal head shape: diagnosis and management

An abnormal head shape is an uncommon finding on prenatal ultrasound, associated most commonly with spina bifida, aneuploidy or oligohydramnios. In other cases diagnosis can be difficult. The objective of this study was to define management pathways for the investigation of fetuses with an abnormal head shape. Fetuses with an abnormal skull shape seen over a 10-year period in our unit were identified by searching the computerised database. Sonographic findings, diagnosis and outcome were reviewed. Three hundred and thirty-one cases were identified, the majority being associated with spina bifida (30%, lemon-shaped), aneuploidy (12%, strawberry-shaped) or dolicocephaly (18%) secondary to fetal position or oligohydramnios. Of the remainder, eight had craniosynostosis, three of which had a skeletal dysplasia. There was also one fetus each with Aperts syndrome, Saethre Chotzen syndrome and I-cell disease and two with an as yet undefined craniosynostosis sydrome.

US assessment of the fetal head and neck: a state-of-the-art pictorial review.

When attention is paid to the details of normal and abnormal fetal head and neck anatomy, abnormalities that normally would be missed at prenatal ultrasonography can routinely be diagnosed. Five basic views are used to assess the fetal head and neck: a transverse view of the head in the plane of the cavum septum pellucidum and cerebellum, a sagittal and a coronal view of the face to visualize the nose and lips, a sagittal view of the cervical spine, and a transverse view of the orbits to measure the biorbital and interorbital distances. Thickened nuchal fold, a common sign of Down syndrome, can be assessed with transverse images of the head. Transverse views are also useful to demonstrate cystic hygroma, occipital meningocele, and encephalocele, all of which can be associated with other severe anomalies. Micrognathia, cleft lip and palate, and macroglossia, which are best depicted with sagittal and coronal views of the face, are also associated with other fetal abnormalities. Visualization of these entities should prompt further search and amniocentesis. Lymphangioma of the tongue appears similar to macroglossia but is an isolated anomaly. Transverse views through the orbits are helpful for demonstrating orbital teratoma, orbital encephalocele, and hypo- and hypertelorism (the latter two being associated with other abnormalities). Sagittal views of the neck can demonstrate cystic hygroma, teratoma, and an enlarged thyroid.

Volume imaging: three-dimensional appreciation of the fetal head and face.

Quasi-three-dimensional volume imaging provides an inexpensive means of evaluating the usefulness of three-dimensional imaging. The technique works most efficiently with water-skin interfaces and therefore we investigated its application in obstetrical ultrasonography. Three-dimensional perspectives of the normal and abnormal fetal head and face were spectacular and at times provided more information than the two-dimensional images. The ability of an inexperienced observer to interpret the three-dimensional image more easily may have a role in training sonographers and counseling parents whose fetuses have structural defects. Volume imaging has certain limitations and can only be used as a complementary technique.

Ultrasonic Demonstration In Utero of an Intracranial Teratoma

ALTHOUGH most fetal head enlargement is secondary to hydrocephalus, other etiologies, including tumor growth, must be considered. Technological improvements in ultrasound imaging have led to a greater definition of fetal pathological conditions and, as is shown by this article, allow a detailed study of such abnormalities. Report of a Case A 30-year-old woman, pregnant for the first time, underwent an ultrasonic examination demonstrating a 16-week fetus with normally displayed anatomy. This included multiple images of the intracranial structures. A repeated study was done near term to evaluate for placenta previa. At this time, an abnormal fetal head was demonstrated (Figure). An estimated cranial diameter of 10.5 cm was measured. The normal anatomic characteristics were replaced by bizarre cystic and echogenic regions filling the cranial vault. Fetal movements, although limited, were recorded in an otherwise normal-appearing term fetus. A cesarean section birth was performed the next day. The infant, weighing 4,800