• 1.
  

  a) F b) F c) F d) T e) F

Generally fetal tumours are extremely rare and abdominal and umbilical cord tumours during very early pregnancy have not been reported. Gastroschisis will appear as echogenic bowel outside the umbilical cord. The diagnosis of gastroschisis at 10 weeks is uncommon. Exomphalos are unlikely to be detectable at 10 weeks because of the normal event of physiological mid-gut herniation. Only if the extra-abdominal echogenic bowel diameter is more than 7 mm, should a pathological condition be suspected. The mid-gut forms most of the small intestine (except the duodenum proximal to the bile duct), caecum, appendix, ascending colon, and the proximal one-half of the transverse colon. The superior mesenteric artery is the blood supply to the mid-gut. The mid-gut is arranged as a loop of bowel whose axis is the superior mesenteric artery. At 7 weeks, the mid-gut is still attached to the yolk sac by the vitelline or omphalomesenteric duct. It is not definitively known what the driving forces for the mid-gut herniation are. It might be that the embryonic abdominal cavity is too small, and that in addition the enlarging amniotic cavity drives/pushes the yolk sac away from the embryonic body. Thus, the vitelline duct in a way pulls the mid-gut into the umbilical cord. Rotation of the mid-gut takes place around the superior mesenteric artery, which divides the gut loop into cranial and caudal portions. When completed, the mid-gut is rotated 270° counter-clockwise. The mid-gut herniation begins at about 7.5 last menstrual-based weeks. Mid-gut herniation is at its largest at 10 weeks. The return of the bowel back into its proper anatomical position occurs between 11 and 12 weeks or a CRL between 40–50 mm, respectively. Extensive bleeding into the embryonic or early fetal abdomen and umbilical cord is unlikely and has not yet been described.

• 2.
  

  a) T b) F c) T d) T e) T

Several reports have described the detection of spina bifida as early as 9 weeks. Typically, the usually smooth contours of the spine appear irregular and in some cases cystic. It has been postulated that the decrease in the intraspinal pressure in fetuses with spina bifida causes the brain to shift downward. This shift decreases the intracranial pressure, which is reflected onto the fetal cranium. Because the frontal bones are the most vulnerable to the decreased intracranial pressure, they respond by flattening or scalloping inwards, which gives the head the typical ‘lemon shape’ appearance. The ‘banana sign’ is caused by herniation of the cerebellar vermis through the foramen magnum, giving the cerebellum the aspect of a banana. These signs usually do not develop before the end of the first trimester, and in most cases they become apparent in the early second trimester. In the mid-sagittal ultrasound plane, through the head including posterior fossa, one can identify the translucent fourth ventricle between the pons anteriorly and the roof of the fourth ventricle/choroid plexus posteriorly. The development of Arnold Chiari malformation II compresses the fourth ventricle. The reduction of Aqueduct-of-Sylvius-to-occiput-distance is also a consequence of the development of the Arnold–Chiari malformation II. Probably because of the same mechanisms as described above, the width of the head biparietal diameter decreases. By combining a biparietal diameter smaller than expected with alpha-fetoprotein and beta human chorionic gonadotropin, one identifies a risk group for spina bifida, which can be evaluated further with detailed ultrasound. About two-thirds of fetuses with spina bifida can be detected by this screening method.

• 3.
  

  a) F b) T c) T d) T e) F

The clear association of nuchal translucency and fetal growth restriction has not been described. A raised maternal serum alpha-fetoprotein (AFP), however, is associated with an increased risk of low birth weight in the absence of structural abnormality or aneuploidy. Low levels of maternal serum pregnancy-associated plasma protein A (at the lowest 5th percentile) are also associated with an increased risk of a smaller than gestational age infant. Extensive research has established that the measurement of nuchal translucency thickness provides effective screening for chromosomal defects. Even in the absence of aneuploidy, nuchal translucency is relevant because it is associated with an increase in adverse perinatal outcome caused by a variety of fetal malformations, such as dysplasias, deformations, and disruptions. With genetic syndromes and cardiac defects, the likelihood of associated anomalies increases with the thickness of nuchal translucency.

• 4.
  

  a) T b) T c) T d) F e) T

Increased nuchal translucency is a marker for chromosomal abnormalities, and is also associated with a wide spectrum of structural anomalies (most commonly heart anomalies), genetic syndromes, a higher risk of miscarriage, and intrauterine fetal death. These risks are all proportionally related to the degree of nuchal translucency enlargement. A gender influence on nuchal translucency is present, and male fetuses tend to have a slightly bigger nuchal translucency than females (about 0.06–0.1 mm).

• 5.
  

  a) F b) T c) F d) F e) F

Prenatally, Noonan syndrome is the most frequently reported genetic syndrome in association with increased nuchal translucency, with an incidence ranging from 2–5%. It is an autosomal dominant disorder and is caused in about 50% of the cases by a missense mutation in the PTPN11 gene on chromosome 12. Mutations in the SOS1 -, RAF1 -, KRAS -, BRAF -, MAP2K1/2 -, NRAS – and SHOC2 -genes account for a small percentage of Noonan syndrome cases. In chromosomally normal fetuses with enlarged nuchal translucency, the prevalence of Noonan syndrome tested by PTPN 11 seems to vary from 6–18%.

• 6.
  

  a) F b) T c) F d) F e) F

The heterogeneity in prenatal and postnatal studies means that information on the prevalence of neurodevelopmental delay in euploid fetuses with increased nuchal translucency is still difficult to interpret. In studies, in which a control group was used and after exclusion of chromosomal abnormalities, structural defects and genetic syndromes, no statistically significant difference was found between fetuses with an increased nuchal translucency compared with the general population, where developmental delay is about 4–5%.

• 7.
  

  a) T b) F c) F d) T e) F

Folic acid has played the greatest role in reducing the incidence of NTDs, with an estimated decline of 31–53% in various countries where fortification of the food supply has been mandated; however, most countries have not mandated folic-acid fortification of the food supply. A large public and private initiative is under way to improve fortification of the food supply worldwide. Recent data suggest a plateau in spina bifida rates in countries mandating fortification of the food supply with folic acid, which highlights the need for ongoing research and funding in the non-folate pathways involved in NTD formation. The incidence of NTDs varies globally, demonstrating the complex gene–environment interactions that play a role in NTD development. The availability of safe termination of pregnancy and inaccuracies in recording and reporting pregnancies that end in termination of pregnancy has made describing NTD rates throughout the world difficult. This is exemplified in a recent meta-analysis that showed significant heterogeneity in studies reporting termination of pregnancy rates in fetuses with NTD. Recently, it has been discovered that both maternal and embryonic genes play a role in NTD development with interactions that are not well understood. This has opened the door for new research into NTD prevention for the future. Development of the neural tube begins early in embryonic life; therefore, for folic acid supplementation to be effective for NTD prevention, it should begin before conception. All low-risk women with the potential for pregnancy should supplement with 0.4 mg of folic acid daily and high risk women should supplement with 4 mg daily.

• 8.
  

  a) F b) T c) F d) F e) F

MSAFP is a screening tool for open NTDs not a diagnostic test. An MSAFP of 2.5 MoMs provides 80–85% sensitivity for the presence of an open NTD. The gold standard diagnostic tool for NTDs is ultrasound. Although first-trimester ultrasound screening for NTDs is currently under investigation, it seems to be a sensitive screening tool, with the primary goal of ruling out an open NTD by identifying a normal posterior fossa during first-trimester aneuploidy screening. MRI may be a useful adjunct to ultrasound for surgical planning, particularly when fetal surgery may be an option, as MRI has demonstrated the ability to provide a detailed characterisation of the spinal lesion and accurately correlate lesion level with outcomes; however, when compared, MRI and ultrasound seem to be equal in their capability of accurately characterising the lesion level. The banana sign is the cerebellar sign indicative of the Chiari II malformation with downward migration of the cerebellar vermis, fourth ventricle and medulla oblongata through the foramen magnum. Development of ventriculomegaly is consistent with the progressive obstructive process of an open NTD, and nearly 100% of neonates with an open myelomeningocele will have hydrocephalus at birth; however, only 70% will demonstrate ventriculomegaly on ultrasound before delivery. Two-dimensional ultrasound is the gold standard technique for identifying lesion level in cases of open NTD, and provides an accurate diagnosis of lesion level in 92% of cases. Although three-dimensional ultrasound may provide a more detailed characterisation of the spinal lesion, it continues to be debated whether this improvement in imaging quality and level of detail is clinically relevant. Additional information may be provided by magnetic resonance imaging for surgical planning; however, MRI and ultrasound seem to be equal in prediction of lesion level.

• 9.
  

  a) F b) T c) T d) T e) F

Delayed postnatal repair was the standard of care for open spina bifida in the 1950s; however, published evidence of the benefit of immediate repair at 24–48 h of life began to surface in the 1950s and 1960s. Immediate surgical intervention is now considered the standard of care for postnatal repair of open spina bifida. The Management of Myelomeningocele Study (MOMS) trial is the first randomised-controlled trial of open fetal surgery for the repair of myelomeningocele compared with traditional neonatal repair. Despite considerable maternal risk, the improvement in neonatal outcomes were significant, including reduction in death, need for shunt, and hindbrain herniation by 12 months of age, a doubling of independent ambulation and vertebral level of function 2 or more levels higher than postnatal repair. Since the publication of the MOMS trial, the American Congress of Obstetricians and Gynecologists published a Committee Opinion endorsing the discussion of the option for open fetal surgery, with all patients presenting with a fetus with an open myelomeningocele. The College stresses the importance of careful patient selection and referral to specialised centres with adequate expertise and infrastructure to provide this specialised surgery. As demonstrated by the MOMS trial, most women presenting with a fetus affected by a myleomeningocele will not qualify for prenatal repair. Despite screening 1087 women referred, only 182 were randomised, roughly 17% of the screened population. As the only randomised-controlled trial available at this time, the benefits of the MOMS trial can only be applied to women that are selected as carefully as those followed in the trial.

• 10.
  

  a) F b) T c) F d) F e) T

Lesion level has been shown to correlate with short- and long-term outcomes. Although nearly 100% of neonates will have hydrocephalus at birth, only 70% will demonstrate hydrocephalus on ultrasound. Several studies are now available demonstrating short- and long-term outcomes of children and adults living with spina bifida. For the obstetrician looking for information for counselling, studies correlating outcomes with lesion level are helpful. Detailed short- and long-term outcomes are presented in Tables 1 and 2 in the corresponding chapter. Studies correlating ultrasound diagnosis of lesion level with paediatric outcomes using both ultrasound and MRI are available and should be used for evidence-based non-directive counselling. Pregnancy termination rates differ throughout the world. In many places in the world, varying cultural and political climates that drive public policy limit the availability of safe termination of pregnancy. Long term follow up of people living with spina bifida shows that many people living with spina bifida today lead happy productive lives; however, the unexpected death rates and medical complications associated with spina bifida continue to face patients living with spina bifida throughout their adult years. Outcomes of patients with myelomeningocele vary greatly depending on lesion level. With copious evidence available today about short- and long-term outcomes of patients living with spina bifida, the obstetrician has the ability and the responsibility to provide non-directive evidence based counselling on the prognosis of their child and discussion of pregnancy options.

• 11.
  

  a) F b) F c) F d) F e) T

A conclusive diagnosis of placenta praevia is possible only in the third trimester of pregnancies, because almost 90% of the placentas defined as low in the second trimester move away out of the lower uterine segment later on in gestation. Although placenta praevia can be easily diagnosed trans-abdominally, trans-vaginal ultrasound has been shown to better delineate the relationship between the lower placental edge and the internal cervical orifice.

• 12.
  

  a) F b) F c) F d) T e) F

Ultrasound is usually used as the primary modality for antenatal diagnosis of invasive placentation, and is carried out especially in the second, third trimester of pregnancy, or both; however, early diagnosis of invasive placenta during the first trimester has been reported. Prenatal magnetic resonance imaging (MRI) is reported to be complementary to ultrasound. Magnetic resonance imaging may help in diagnosing invasive placentation, especially in those conditions when ultrasound is not conclusive in assessing the degree of invasion. A recent systematic review has reported a sensitivity of 91% and a specificity of 97% for the identification of all forms of invasive placentations using ultrasound.

• 13.
  

  a) F b) T c) F d) F e) F

A recent systematic review assessing the predictive accuracy of ultrasound in the identification of all forms of invasive placentation found that, among the different sonographic signs, the presence of abnormal vasculature using color Doppler showed the highest sensitivity and specificity; abnormality of the uterine bladder interface has the best specificity among the different US signs. Presence of placental lacunae and loss of the clear space between the placenta and the myometrium does not perform as well.

• 14.
  

  a) F b) F c) T d) F e) F

Chorioangiomas are usually asymptomatic, although they are occasionally associated with adverse fetal outcomes, such as non-immune hydrops fetalis, cardiomegaly, cardiac failure, anaemia, thrombocytopaenia, consumptive coagulopathy, preterm delivery, severe growth restriction, and sudden infant death. They are diagnosed with ultrasound and appear as a well-circumscribed, rounded, basically hypoechoic lesions next to the chorionic surface, often close to the cord insertion.

• 15.
  

  a) F b) F c) T d) F e) F

The classic presentation of vasa previa is the presence of painless vaginal bleeding usually after the rupture of the membranes associated with fetal distress at cardiotocography or fetal demise. Although not routinely screened for during pregnancy, it has been reported that the rate of adverse outcome associated with this condition is significantly lower if diagnosis is made before birth.

• 16.
  

  a) F b) F c) T d) F e) F

Although a normal anatomic survey reduces the risk for a chromosomal syndrome, it is only considered a screening test and is non-diagnostic. Therefore, a chromosomal syndrome may still be present in the setting of a normal anatomic survey. A first-trimester nuchal translucency 3 mm or over has a high sensitivity and specificity for a chromosomal syndrome, but is non-diagnostic. Only invasive testing modalities are considered diagnostic, whereas ultrasound is only a screening tool for chromosomal syndromes. Third-trimester ultrasound can be used as an adjunct, but its utility as a screening tool is limited. Studies have shown conflicting results but, overall, two-dimensional imaging is the superior method for screening purposes.

• 17.
  

  a) T b) T c) T d) T e) F

Cystic hygroma is commonly seen on ultrasound in fetuses with Turner syndrome.

Echogenic bowel is also commonly seen on ultrasound in fetuses with cytomegalovirus as well as severe intrauterine growth restriction in fetuses with triploidy. Polyhydramnios is similarly commonly seen on ultrasound in fetuses with Noonan syndrome. Pyelectasis is not however an associated finding on ultrasound in fetuses with Parvovirus.

• 18.
  

  a) F b) F c) T d) F e) F

Gastroschisis is observed on ultrasound as a full-thickness defect in the abdominal wall, in most cases to the right of the insertion of the umbilical cord. It is only rarely located to the left of cord insertion. Bowel loops and occasionally parts of other abdominal organs herniate outside the abdominal wall with no covering membrane or sac. A defect superior to cord insertion is observed in pentalogy of Cantrell, which is also characterised by anterior diaphragmatic hernia, sternal clefting, ectopia cordis and intracardiac defects. An abdominal wall defect below the insertion of the umbilical cord is seen in bladder and cloacal exstrophy.

• 19.
  

  a) F b) T c) F d) F e) F

In 2011, based on the European registries included in the EUROCAT network, the total prevalence of gastroschisis was 3.09 per 10,000 births, with a livebirth prevalence of 2.63 per 10,000. The corresponding figures for omphalocele were 3.29 and 1.13 per 10,000. The prevalence of gastroschisis has increased from 1980 to 2011, whereas that of omphalocele has remained basically stable.

• 20.
  

  a) T b) F c) F d) F e) F

Postnatally, Beckwith–Wiedemann syndrome is a growth disorder characterised by macroglossia, macrosomia, omphalocele, and hypoglycaemia, leading to seizures, visceromegaly, hemihyperplasia, renal abnormalities, ear creases and pits, nevus flammeus, and embryonic tumours. Although omphalocele is not invariably present, when observed prenatally, it should guide a targeted ultrasound examination searching for all possible prenatal features of the syndrome, which include additionally polyhydramnios, placentomegaly, and placental mesenchymal dysplasia (observed on ultrasound as multiple cystic changes in the placenta). Beckwith–Wiedemann syndrome involves dysregulation of imprinted growth regulatory genes on chromosome 11p15.5. Regulation may be disrupted by any one of numerous mechanisms. Comprehensive laboratory evaluation includes karyotype analysis, DNA methylation tests, and genomic analysis of chromosome 11p15.5. About 85% of individuals have no family history of Beckwith–Wiedemann syndrome, whereas about 15% have a family history consistent with autosomal dominant transmission. Cytogenetically detectable abnormalities involving chromosome 11p15 are found in 1% or fewer of affected individuals. Molecular genetic testing can identify epigenetic and genomic alterations of chromosome 11p15 in individuals with Beckwith–Wiedemann syndrome: (1) loss of methylation on the maternal chromosome at imprinting centre 2 in 50% of affected individuals; (2) paternal uniparental disomy for chromosome 11p15 in 20%; and (3) gain of methylation on the maternal chromosome at imprinting centre 1 in 5%. Sequence analysis of CDKN1C identifies mutations in about 40% of familial cases and between 5 and 10% of cases with no family history of the syndrome.

• 21.
  

  a) F b) F c) T d) F e) T

Cell-free fetal DNA can only be detected from around 4–5 weeks. Most of the cell-free DNA in maternal plasma is maternal. Cell-free fetal DNA indeed emanates from the placenta. Cell-free fetal DNA can be used to diagnose the major trisomies but not all other rearrangements yet. Cell-free fetal DNA can be use to analyse fetal sex with more than 99% accuracy.

• 22.
  

  a) F b) F c) T d) F e) T

There is no universally agreed point at which the fetus is considered to be a patient, but one widely accepted suggestion is that it is a patient when presented by the mother to the clinician for diagnosis, management, or both. Before viability, the fetus has dependent status as a patient, as it cannot survive independently of its mother, and she has the power to withdraw that status if she chooses. After viability, which will depend on fetal size, the presence of anomalies and local facilities for support, the fetus has the ability to survive independently of its mother, and may be considered as a patient in its own right. This approach is tacitly or explicitly supported by many legal codes that restrict termination of pregnancy after survival is likely. Personhood is recognised at different times by different cultures and faiths, and is not necessary for the fetus to have a moral status requiring consideration of its wellbeing in management decisions.

• 23.
  

  a) F b) F c) F d) F e) T

In most jurisdictions, the fetus has no legal rights or status before birth, but has potential rights that crystallise at delivery, placing a duty of care on attending doctors and midwives. The fetus has no autonomous status, so the ethical principles of beneficence and non-maleficence apply but not respect for autonomy. The best interests of the mother take precedence over those of the baby in most jurisdictions. In many, even if a mother takes a decision not to undergo treatment that may be life-saving for her baby, this cannot be imposed against her will unless she lacks capacity to make decisions. If a baby is born alive after termination of pregnancy it acquires full independent legal status and treatment must be provided in its best interests. Great care should be taken to avoid language promoting an antenatal treatment under trial, as this may give a false impression of its likelihood of success.

• 24.
  

  a) T b) F c) F d) F e) F

Cleft lip is caused by abnormal facial development of the nasal processes. The maxillary process forms the primary palate.

• 25.
  

  a) F b) F c) T d) T e) F

Three-dimensional ultrasound plays an important role in diagnosing the extent of a facial cleft, particularly of the palate. Campbell Lees described the ‘reverse face view’ in 2003 and Platt et al. described the ‘flipped face view’ in 2006.

• 26.
  

  a) T b) T c) F d) T e) F

During intrauterine life, three renal systems develop: the pronephros, mesonephros and metanephros. The pronephros and mesonephros are transient excretory systems and disappear without contributing to the permanent renal system. The mesonephric duct gives rise to some reproductive organs in male fetuses, but degenerates in females. The nephrons continue to be formed till birth, when they are about 1 million in number. During infancy, the nephrons grow in size but do not increase in number.

• 27.
  

  a) F b) T c) T d) F e) T

Normal kidneys and bladder can be visible on scan from as early as 9 weeks. The kidneys grow as long as the pregnancy continues, and the size is directly proportional to gestational age. Fetal urine production begins between 8 and 10 weeks’ gestation. Oligohydramnios cannot be found before 10 weeks of age, as amniotic fluid at this gestation is mainly formed by the secretions of the placenta, fetal membranes, and skin. In the absence of the kidneys in their normal positions in the renal fossae, the adrenals can occupy the renal fossae and mimic the renal structures.

• 28.
  

  a) T b) F c) T d) T e) F

Bilateral renal agenesis is not compatible with life, and occurs in 0.1–0.3 per 1000 births. Isolated unilateral agenesis accounts for 1 in 1000 births. Renal agenesis can be an isolated finding, but is more commonly a part of a syndrome and warrants a detailed anomaly scan to look for associated anomalies. The ratio of antero–posterior to transverse renal diameter gives a better guide to the size of the contralateral kidney. If the ratio is greater than 0.9, it is highly suggestive of absence of the other kidney, and has a sensitivity, specificity, and accuracy of 100%. Dysplastic kidneys are often of abnormal size, structure, or both, and are identified prenatally with or without cystic changes. The dysplasia is thought to be due to altered interactions between the ureteric bud and the metanephric mesenchyme.

• 29.
  

  a) T b) F c) F d) T e) F

Polycystic kidney diseases comprises two entities. Infantile polycystic kidney disease is also known as Potter type I, which has an autosomal recessive inheritance. It is the most common cystic disease in pregnancy. Infantile polycystic kidney disease might not develop until late in the second trimester. The onset of renal cysts in adult type varies from the fetal to neonatal period, but renal failure usually develops at adulthood and multiple cysts of varying sizes are seen with cysts in the pancreas, liver, spleen, and central nervous system.

• 30.
  

  a) T b) F c) T d) T e) F

Upper urinary tract dilatation is commonly caused by transient urine flow impairment at the level of the pelvi-ureteric junction and vesico-ureteric junction. A normal renal pelvis is readily visualised when the antero-posterior diameter of the renal pelvis is greater than 2 mm. Pelvi-ureteric junction anomalies are the most common, accounting for 35% of prenatal urological problems. The incidence of pelvi-ureteric junction is 1 in 2000, with male predominance, and in most (90%) cases, obstruction is unilateral. Fetuses with bladder diameters greater than 17 mm in the first trimester are very likely to result from obstructive causes and experience progressive obstruction, whereas most fetusess with diameters of 8–12 mm will resolve by 20 weeks; however, there is 25% risk of an aneuploidy (trisomy 13 and 18) and associated malformations in 33% of fetuses. Males are affected more commonly and if females are affected, a more complex pathology should be suspected, such as cloacal plate abnormalities or megacystis-microcolonintestinal hypoperistalsis syndrome.