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Acrania

Acrania is a rare lethal congenital anomaly characterized by an absence of the calvaria. Epidemiology The estimated incidence is at ~1:1000 pregnancies 4. Pathology The condition is thought to result from abnormal migration of mesenchymal tissue, which normally covers the cerebral hemispher...

Birth trauma

Birth trauma (a.k.a. birth injury) relates to those conditions caused by both physical/mechanical and hypoxic injuries. Epidemiology Birth trauma occurs in ~5 per 1000 births 2. Risk factors asphyxia breech presentation shoulder dystocia instrument delivery macrosomia obstructed labor ...

Preterm premature rupture of membranes

Preterm premature rupture of membranes (PPROM) refers to rupture of membranes prior to 37 weeks of gestation. Epidemiology It is thought to occur in 0.4-2% of all pregnancies. It however may account for up to one-third of all preterm births (particularly in the United States 5). Pathology PP...

Placental chorioangioma

Placental chorioangiomas are benign vascular tumors of placental origin. It is the most common tumor of the placenta and is usually found incidentally. Epidemiology The estimated incidence is at ~1% of all pregnancies 3. Associations Recognized associations include: hydrops fetalis: also li...

Noonan syndrome

Noonan syndrome (NS) is a genetically and phenotypically heterogeneous non-aneuploidic congenital RASopathy. Affected individuals can bear some clinical features similar to that of Turner syndrome. Epidemiology The estimated incidence is at ~1 in 1000-2500 10. As individuals have normal numbe...

Fetal macrosomia

Fetal macrosomia, also sometimes termed large for gestational age (LGA), is usually defined when the estimated fetal weight (EFW) is greater than the 90th percentile. According to this definition, it affects up to 10% of all live births. Some also use an increased birth weight (i.e. >4500 g) in ...

Limb body wall complex

The limb-body wall complex (LBWC) is a rare variable group of congenital limb and body wall defects (involving mainly the chest and abdomen). They can include: abdominoschisis: usually large and left-sided 4, and almost always present thoracic wall defect / thoracoschisis ectopia cordis anom...

Cleft lip and palate

Cleft lip and palate is one of the commonest neonatal facial anomalies. In ~80% of cases, the two features tend to occur together 6. Epidemiology It is estimated to occur with an incidence of ~1 in 700-1000 live births 1. This can increase to 4% for a sibling of a previously affected fetus and...

Twin reversed arterial perfusion

Twin reversed arterial perfusion (TRAP) sequence is a rare complication of monochorionic pregnancies. It develops when the following conditions are present: 1. lack of a well-formed heart in one of the twins (so-called acardiac twin), and 2. a superficial artery to artery placental anastomosis...

Hysterosalpingogram

A hysterosalpingogram (HSG) is a fluoroscopic examination of the uterus and the fallopian tubes, most commonly used in the investigation of infertility or recurrent spontaneous abortions. Indications infertility: to assess uterine morphology and tubal patency Contraindications pregnancy act...

Polydactyly

Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as: preaxial polydactyly: extra digit(s) towards the thumb/hallux (radially) postaxial polydactyly: extra digit(s)...

Amniotic band syndrome

Amniotic band syndrome (ABS) comprises a wide spectrum of abnormalities, all of which result from entrapment of various fetal body parts in a disrupted amnion. Due to the randomness of entrapment, each affected individual has the potential to form a unique deficit. Epidemiology The phenomenon ...

Single umbilical artery

Single umbilical artery is a congenital absence of either the right or left umbilical artery. In the usual situation, there are paired umbilical arteries. For unknown reasons, the absence of the left umbilical artery is much more common (~70%). Epidemiology The estimated prevalence is ~0.4-1% ...

Radial ray anomaly

Radial ray anomalies comprise of a large spectrum of upper limb anomalies which range from partial (radial hypoplasia) to a complete (radial aplasia) deficiency of the radius with or without accompanying deficiency of the thumb bones. Pathology Associations They can be associated with a numbe...

Haematometrium

A haematometrium refers to retention of blood into the endometrial cavity due to obstruction at the level of the uterus, cervix, or vagina. Primary haematometrium occurs in young women, usually due to congenital anomalies such as an imperforate hymen or a non-communicating Müllerian duct. Secon...

Echogenic intracardiac focus

Echogenic intracardiac focus (EIF) is a relatively common sonographic observation that may be present on an antenatal ultrasound scan. Epidemiology They are thought to be present in ~4-5% of karyotypically normal fetuses. They may be more common in the Asian population 5. Associations trisom...

Congenital talipes equinovarus

Congenital talipes equinovarus is considered the most common anomaly affecting the feet diagnosed on antenatal ultrasound. Terminology While some use talipes equinovarus and clubfoot synonymously, in certain publications, the term clubfoot is considered a more general descriptive term that des...

Intrauterine growth restriction

Intrauterine growth restriction (IUGR) or fetal growth restriction (FGR) is defined as an estimated fetal weight (EFW) and/or abdominal circumference (AC) at one point in time during pregnancy being below 3rd percentile or EFW and/or AC below the 10th percentile for gestational age with derange...

Fetal echocardiography views

A standard fetal echocardiogram consists of several specific views which can be obtained to optimize visualization of different structures and anomalies. They include: Basic views abdominal situs view / transverse view of abdomen four chamber view left ventricular outflow tract ...

Birth fracture of the clavicle

Birth fractures of the clavicle occur in 0.5-1% of vaginal deliveries and are the most frequent birth-related fracture. They are most commonly seen following normal, uncomplicated births but there is recognized increased incidence with high birth weight babies, forceps delivery and shoulder dyst...

Iniencephaly

Iniencephaly is a rare neural tube defect resulting in the following features 1,2: occipital bone defect partial or total absence (rachischisis) of cervicothoracic vertebrae fixed fetal head retroflexion Epidemiology The estimated incidence is at ~0.1-10 per 10,000 live births 5. There is...

Choroid plexus cyst (antenatal)

Antenatal choroid plexus cysts are benign and are often transient typically resulting in utero from an infolding of the neuroepithelium. They should not be confused with adult choroid plexus cysts (which are very commonly found at autopsy and likely degenerative), large intraventricular simpl...

Apert syndrome

Apert syndrome (also known as type I acrocephalosyndactyly) is a syndrome that is predominantly characterized by skull and limb malformations. Epidemiology The estimated incidence is 1 case per 65-80,000 pregnancies. Risk factors increased paternal age has been proposed 6 Associations CNS ...

Abnormally eccentric gestational sac

An eccentrically-located gestational sac towards the fundus of the uterus is the normal sonographic appearance, however, an abnormally eccentric gestational sac on ultrasound may be apparent due to a number of causes: interstitial ectopic pregnancy 1 normally implanted pregnancy in a bicornu...

Cephalocele

Cephalocele refers to the outward herniation of CNS contents through a defect in the cranium. The vast majority are midline. Epidemiology The estimated incidence is 0.8-4:10,000 live births 13 with a well recognized geographical variation between types; however, this has been speculated to be ...

Circumvallate placenta

Circumvallate placenta refers to a variation in placental morphology in which, as a result of a small chorionic plate, the amnion and chorion fetal membranes ‘double back’ around the edge of the placenta. Epidemiology The prevalence is estimated to be around 1-7% 3. Pathology There is an inw...

Hydrops fetalis

Hydrops fetalis is excessive extravasation of fluid into the third space in a fetus which could be due to heart failure, volume overload, decreased oncotic pressure, or increased vascular permeability. Hydrops is defined as the accumulation of fluid +/- edema involving at least two fetal compone...

Fetal conditions associated with maternal diabetes

There are numerous fetal congenital anomalies associated with maternal diabetes. They include cardiac: congenital cardiac anomalies ventricular septal defect (VSD) 5 conotruncal anomalies transposition of the great arteries (TGA) truncus arteriosus fetal congestive cardiac failure (witho...

Corpus luteum

The corpus luteum (plural: corpora lutea) is a temporary endocrine structure involved in ovulation and early pregnancy. During ovulation, the primary follicle forms the secondary follicle and subsequently the mature vesicular follicle. At ovulation the follicle ruptures expelling the ovum into...

Failed early pregnancy

Failed early pregnancy (sometimes termed embryonic demise) refers to the death of the embryo and therefore, miscarriage. The most common cause of embryonic death is a chromosomal abnormality. Radiographic features Ultrasound Findings diagnostic of pregnancy failure crown-rump length (CRL)...

Skeletal dysplasia

Skeletal dysplasia (also known as osteochondrodysplasia) refers to any abnormality in bone formation. There is a very wide clinicopathological spectrum and any part of the skeleton can be affected. Epidemiology The overall prevalence is estimated at ~2 per 10,000 live births 3. Pathology Typ...

Rhizomelic dwarfism

Rhizomelic dwarfism is a type of dwarfism where the dominant feature is proximal (i.e. femoral and humeral) limb shortening. Epidemiology Associations certain types of atelosteogenesis diastrophic dysplasia kyphomelic dysplasias Pathology Classification The following conditions fall unde...

Fetal tumors

Although rare, a number of tumors may be diagnosed antenatally. These fetal tumors are a diverse and a unique group of conditions, and include: neuroblastoma: most common tumor overall teratomas sacrococcygeal teratoma head and neck teratoma/epignathus mediastinal teratoma intrapericardial...

Syntelencephaly

Syntelencephaly, also known as middle interhemispheric variant (MIHV), is a mild subtype of holoprosencephaly that is characterized by an abnormal midline connection of the cerebral hemispheres between the posterior frontal and parietal regions. Epidemiology Syntelencephaly is a congenital ma...

Currarino syndrome

The Currarino syndrome is a complex condition variably comprised of characteristic congenital anomalies of the sacrum, anorectum and presacral soft tissues. It is also known as the Currarino triad or ASP triad, however, not all three features are always present 6. anorectal malformation or ...

Sacrococcygeal teratoma

Sacrococcygeal teratoma refers to a teratoma arising in the sacrococcygeal region. The coccyx is almost always involved 6. Epidemiology It is the most common congenital tumor in fetus 11 and neonate 3. The incidence is estimated at ~1:35,000-40,000. There is a recognized female predilection wi...

Meckel-Gruber syndrome

Meckel-Gruber syndrome (MGS) is classically characterized by the triad of: renal cystic dysplasia: multiple renal cysts (present in most cases) occipital encephalocele / holoprosencephaly (~70%) postaxial polydactyly: usually hexadactyly (~65%) Additional hepatic developmental defects and he...

Hydranencephaly

Hydranencephaly is a rare encephalopathy that occurs in-utero. It is characterized by destruction of the cerebral hemispheres which are transformed into a membranous sac containing cerebrospinal fluid and the remnants of cortex and white matter 1. Porencephaly is considered a less severe degree...

Endometrial thickness

Endometrial thickness is a commonly measured parameter on routine gynecological ultrasound and MRI. The appearance, as well as the thickness of the endometrium, will depend on whether the patient is of reproductive age or postmenopausal and, if of reproductive age, at what point in the menstrual...

Placenta accreta spectrum disorders

Placenta accreta spectrum (PAS) disorders describe the degree to which there is an invasion by chorionic villi into the myometrium because of a defect in the decidua basalis. Epidemiology placenta accreta: the commonest type of placental invasion (~75% of cases) occurs in ~1 in 7000 pregnanc...

Pentalogy of Cantrell

The pentalogy of Cantrell is an extremely rare phenomenon with an incidence estimated at around 6 per million live births 3. It encompasses the following 5 main features 1. omphalocele ectopia cordis (abnormal location of heart) diaphragmatic defect pericardial defect or sternal cleft car...

Neural tube defects

Neural tube defect (NTD) refers to the incomplete closure of the neural tube in very early pregnancy, resulting in cranial defects or spinal dysraphism. The neural tube comprises a bundle of nerve sheath which closes to form brain caudally and spinal cord rostrally. The closure should occur at ...

Esophageal atresia

Esophageal atresia refers to an absence in the continuity of the esophagus due to an inappropriate division of the primitive foregut into the trachea and esophagus. This is the most common congenital anomaly of the esophagus. Epidemiology It is thought to occur in ~1:3000-4500 live births 3. ...

Cornelia de Lange syndrome

Cornelia de Lange syndrome (CdLS) is an extremely rare clinically heterogeneous developmental disorder of unknown etiology. Although the described clinical symptomatology is very broad, the majority of cases include growth impairment, learning disability and dysmorphic facies. Epidemiology The...

Renal agenesis

Renal agenesis refers to a congenital absence of one or both kidneys. If bilateral (traditionally known as the classic Potter syndrome) the condition is fatal, whereas if unilateral, patients can have a normal life expectancy. Epidemiology Unilateral renal agenesis affects approximately 1 in ...

Cardiac rhabdomyoma

Cardiac rhabdomyomas are a type of benign myocardial tumor and are considered the most common fetal cardiac tumor. They have a strong association with tuberous sclerosis. Epidemiology Cardiac rhabdomyomas are often multiple and can represent up to 90% of cardiac tumors in the pediatric populat...

Pseudodysraphism

A pseudodysraphism refers to the splayed appearance of a normal spine created due to excessive craniocaudal angulation during sonographic evaluation. This can erroneously lead to the diagnosis of a spinal neural tube defect.

Anencephaly

Anencephaly is the most severe form of cranial neural tube defect and is characterized by an absence of cortical tissue (although the brainstem and cerebellum may be variably present) as well as an absence of the cranial vault. The morphological spectrum within anencephaly ranges from holocrania...

Fetal heart beat

Fetal heart beat can be detected as early as 34 days (just under 6 weeks) gestation on good quality, high frequency transvaginal ultrasound, as a crown rump length (CRL) of as little as 1-2 mm. If a fetal heartbeat cannot be identified with a CRL ≥7 mm using transvaginal scanning, then embryona...

Yolk sac

Yolk sac is the first anatomical structure identified within the gestational sac. It plays a critical role in embryonal development by providing nutrients, serving as the site of initial hematopoiesis, providing endocrine, metabolic and immunological functions and contributing to the development...

Double bleb sign

A double bleb sign is a sonographic feature where there is visualization of a gestational sac containing a yolk sac and amniotic sac giving an appearance of two small bubbles 2. The embryonic disc is located between the two bubbles. It is an important feature of an intrauterine pregnancy and thu...

First trimester

The first trimester is defined as the first 13 weeks of pregnancy following the last normal menstrual period (some authors refer to early pregnancy as 0-10 weeks). It can be divided into a number of phases, each of which has typical clinical issues. These phases are: conceptus phase: 3-5 weeks ...

Intradecidual sac sign

Intradecidual sac sign (IDSS) is a useful feature in identifying an early intrauterine pregnancy (IUP) as early as 25 days of gestation1. The threshold level (earliest one can see the sign) is 24 days of gestation and the discriminatory level (one should always see the sac) is 47 days. As per th...

Ventricular septal defect

Ventricular septal defects (VSD) represent a hole or pathway in the interventricular septum that allows for communication between the right and left ventricles. It typically results in a left-to-right shunt. Epidemiology They represent one of the most common congenital cardiac anomalies and ma...

Thanatophoric dysplasia

Thanatophoric dysplasia is a lethal skeletal dysplasia. It is the most common lethal skeletal dysplasia followed by osteogenesis imperfecta type II. Epidemiology The estimated incidence is around 1:25,000-50,000 3. Associations polyhydramnios 4 Pathology Subtypes There are two recognized...

Missed miscarriage

A missed miscarriage, sometimes termed a missed abortion 3, is a situation when there is a non-viable fetus within the uterus, without symptoms of a miscarriage. Radiographic features Ultrasound Ultrasound diagnosis of miscarriage should only be considered when either a mean gestation sac d...

Semilobar holoprosencephaly

Semilobar holoprosencephaly is a subtype of holoprosencephaly characterized by incomplete forebrain division. It is intermediate in severity, being worse than lobar holoprosencephaly and better than alobar holoprosencephaly. Epidemiology Please refer to the general article of holoprosencephaly...

Müllerian duct anomalies

Müllerian duct anomalies (MDAs) are congenital abnormalities that occur when the Müllerian ducts (paramesonephric ducts) do not develop correctly. This may be as a result of complete agenesis, defective vertical or lateral fusion, or resorption failure. Epidemiology MDAs are estimated to occur...

Funneling of the internal cervical os

Cervical funnelling is a sign of cervical incompetence and represents the dilatation of the internal part of the cervical canal and reduction of the cervical length. Greater than 50% funnelling before 25 weeks is associated with ~80% risk of preterm delivery. Radiographic features Good scanni...

Inevitable miscarriage

Inevitable miscarriage refers to the presence of an open internal os in the presence of bleeding in the first trimester of pregnancy. Most often the conception products are not expelled and intracervical contents are present at the time of examination. A sac may be seen low within the uterus and...

Ileal atresia

Ileal atresia is a congenital abnormality where there is significant stenosis or complete absence of a portion of the ileum. There is an increased incidence in those with chromosomal abnormalities. This article will focus on ileal atresia alone but bear in mind that some cases correspond to jej...

Myelomeningocele

Myelomeningocele, also known as spina bifida cystica, is a complex congenital spinal anomaly that results in spinal cord malformation (myelodysplasia). Epidemiology It is one of the commonest congenital CNS anomalies and thought to occur in approximately 1:500 of live births 5. There may be a...

Chiari II malformation

Chiari II malformations are relatively common congenital malformations of the spine and posterior fossa characterized by myelomeningocele (lumbosacral spina bifida aperta) and a small posterior fossa with descent of the brainstem, cerebellar tonsils, and vermis through the foramen magnum. Numero...

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a complication of controlled ovarian stimulation, which is an assisted reproduction technique used for in vitro fertilisation (IVF). Rarely, it may also occur spontaneously in pregnancy (see below). It consists of ovarian enlargement with an extravascu...

Congenital infections (mnemonic)

The group of the most common congenital infections are referred to by the mnemonic TORCH or STORCH. They usually cause mild maternal morbidity but are related to serious fetal consequences 4. In cases where no serological, microbiological or immunological evidence of infection can be identified...

Apgar score

Apgar score was originally described by Virginia Apgar (American anaesthesiologist, 1909-1974) in 1952. Helpfully, her surname is also a useful mnemonic for remembering the 5 factors: each is graded as 0, 1 or 2 with a total possible score of 10. The lower the score the worse the prognosis. Th...

Ovarian artery

The ovarian artery is a paired structure and is the main gonadal artery in females. Gross anatomy Origin The ovarian artery arises anterolaterally from the aorta just inferior to the renal arteries and superior to the inferior mesenteric artery (between L2 and L3). Course Descends caudally ...

Uterine artery

The uterine artery is seen bilaterally and is a branch of the anterior division of the internal iliac artery. Gross anatomy Course It runs medially in the pelvis, within the base of the broad ligament, to the outer surface of the uterus. From lateral to medial it has a descending, transverse ...

Autosomal recessive polycystic kidney disease

Autosomal recessive polycystic kidney disease (ARPKD) is one of many pediatric cystic renal diseases. On imaging, it usually presents on ultrasound with enlarged echogenic kidneys with multiple small cysts. Liver involvement with coarse echotexture, biliary tract cystic changes, and portal hype...

Intrauterine contraceptive device

Intrauterine contraceptive devices (IUCD) (also known as intrauterine devices (IUD) and colloquially commonly as the coil) are one of the most frequently used methods of contraception throughout the world. It prevents pregnancy by: thinning the endometrial lining preventing sperm motility pre...

Fetal death in utero

Fetal death in utero (FDIU), also known as intrauterine death (IUD), is the term used when the death of a fetus occurs after the 20th week of pregnancy. Prior to this, it is considered a miscarriage. Terminology IUD is often also used as an abbreviation for an intrauterine contraceptive device...

Vagina

The vagina is a midline fibromuscular tubular organ positioned in the female perineum extending superiorly from the vulva, to the cervix and uterus in the pelvis. Gross anatomy The vagina is 6-8 cm in length, extending posterosuperior from the vestibule through the urogenital diaphragm to the...

Causes of oligohydramnios (mnemonic)

A helpful mnemonic for remembering some causes of oligohydramnios is: DRIPPC Mnemonic D: demise R: renal abnormalities (decreased urine output) I: IUGR P: premature rupture of membranes P: post-dates C: chromosomal anomalies

Oligohydramnios

Oligohydramnios refers to a situation where the amniotic fluid volume is less than expected for gestational age. Often these fetuses have <500 mL of amniotic fluid. When there is almost no amniotic fluid present, this is termed anhydramnios. Epidemiology The estimated prevalence can be up to ~...

Polyhydramnios

Polyhydramnios refers to a situation where the amniotic fluid volume is more than expected for gestational age. It is generally defined as: amniotic fluid index (AFI) >25 cm largest fluid pocket depth (maximal vertical pocket (MVP)) greater than 8 cm 6 some centers, particularly in Australi...

Twin-to-twin transfusion syndrome

Twin-to-twin transfusion syndrome (TTTS) is a potential complication that can occur in a monochorionic (either MCDA or MCMA) twin pregnancy. Epidemiology This complication can occur in ~10% (range 15-25%) of monochorionic pregnancies, giving an estimated prevalence of ~1:2000 of all pregnanci...

Small for date fetus

A small for dates fetus can result from a number of factors Fetal factors aneuploidy trisomy triploidy skeletal dysplasia(s) structural anomalies (syndromes) Maternal factors Common hypertension medication(s): fetal Warfarin syndrome hydantoin embryopathy (Dilantin TM) cytotoxic dru...

Uterus

The uterus is an extraperitoneal hollow, thick-walled, muscular organ of the female reproductive tract that lies in the lesser pelvis. Gross anatomy The uterus has an inverted pear shape. It measures about 7.5 cm in length, 5 cm wide at its upper part, and nearly 2.5 cm in thickness in adults....

Cervix

The cervix or uterine cervix is the lower constricted segment of the uterus providing the passage between the uterus proper and the vagina. Gross anatomy The cervix is somewhat conical in shape, with its truncated apex directed posteriorly and inferiorly. The inferior aspect of the cervix pro...

Intracranial teratoma

Intracranial teratomas are uncommon intracranial neoplasms, which can have a bewildering variety of components and thus a wide range of appearances. They can be divided into two broad categories, intra- and extra-axial, which differ in epidemiology and clinical presentation. Another method of cl...

Postpartum angiopathy

Postpartum angiopathy is a subset of reversible cerebral vasoconstriction syndrome (RCVS), although is has been described as a separate condition. It is also known as postpartum angiitis and puerperal vasospasm. Please refer to the main article on reversible cerebral vasoconstriction syndrome (R...

Roberts syndrome

Roberts syndrome, also known as Roberts-SC phocomelia syndrome, pseudothalidomide syndrome, or Appelt-Gerken-Lenz syndrome, is a rare congenital malformation syndrome. Clinical presentation general intrauterine growth restriction postnatal growth retardation failure to thrive thrombocytope...

Vein of Galen aneurysmal malformation

Vein of Galen aneurysmal malformations (VGAMs), probably better termed as median prosencephalic arteriovenous fistulas, are uncommon intracranial anomalies that tend to present dramatically during early childhood with features of a left-to-right shunt and high-output cardiac failure. Epidemiolo...

Uteroplacental blood flow assessment

Uteroplacental blood flow assessment is an important part of fetal well-being assessment and evaluates Doppler flow in the uterine arteries and rarely the ovarian arteries. Pathology In a non-gravid state and at the very start of pregnancy the flow in the uterine artery is of high pulsatility ...

VACTERL association

VACTERL is an acronym that describes a non-random constellation of congenital anomalies. It is not a true syndrome as such and is equivalent to the VATER anomaly. Epidemiology The estimated incidence is 1 in 10,000-40,000 births 3. Associations Several conditions have features in common with...

Twin peak sign

The twin peak sign, also known as the lambda (λ) sign, is the triangular appearance of the chorion insinuating between the layers of the intertwin membrane and strongly suggests a dichorionic diamniotic twin pregnancy. It is best seen in the first trimester (between 10-14 weeks) 5. While the pre...

Turner syndrome

Turner syndrome, also known as 45XO or 45X, is the most common of the sex chromosome abnormalities in females. Epidemiology The incidence is estimated at 1:2000-5000 of live births, although the in utero rate is much higher (1-2% of conceptions) due to a significant proportion of fetuses with...

Tubal ring sign

The tubal ring sign, also referred to as a bagel sign or blob sign, is one of the ultrasound signs of a tubal ectopic pregnancy. It comprises an echogenic ring that surrounds an unruptured ectopic pregnancy. It is said to have a 95% positive predictive value (PPV) for ectopic pregnancy. Differe...

Tubal ectopic pregnancy

Tubal ectopic pregnancy, also known as adnexal ectopic pregnancy, is the most common location of an ectopic pregnancy. Epidemiology It is the most common type of ectopic by far, accounting for 93-97% of cases. Pathology Although the fallopian tube has many anatomical parts, for the purposes ...

Trisomies

The trisomies are chromosomal anomalies which usually occur due to non-disjunction. The vast majority of affected fetuses are spontaneously aborted, often very early during gestation. Only three are compatible with extrauterine life (T13, T18, T21), and only one beyond early infancy (T21). In o...

Threatened miscarriage

Threatened miscarriage (or threatened abortion) is mainly a clinical term, used when a pregnant woman in first 20 weeks of gestation presents with spotting, mild abdominal pain and contractions, with a closed cervical os 3. Epidemiology It occurs in 20-25% of pregnancies and is associated with...

T sign (obstetrics)

The T sign is really the absence of a twin peak sign (or lambda (λ) sign) and is used in ultrasound assessment of a multifetal pregnancy. It refers to the lack of chorion extending between the layers of the intertwin membrane, denoting a monochorionic pregnancy. The intertwin membrane comes to ...

Strawberry skull

Strawberry skull refers to the shape of the head on an antenatal ultrasound. Epidemiology Associations In general, strawberry skull is considered one of the non-specific 'soft markers' for abnormal fetal development. It is considered more closely associated with trisomy 18 (Edward syndrome). ...

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