Time and EventWeek 1: ImplantationWeek 2: Formation of bilaminar diskWeek 3: Formation of primitive streakFormation of notochordGastrulationWeek 4: Limb buds begin to formNeural tube closesHeart begins to beatWeek 10: Genitals are differentiated

Glucose-6-phosphate dehydrogenase (G6PD) deficiency is the most common enzyme deficiency in humans.It has a high prevalence in persons of African, Asian, and Mediterranean descent. It is inherited as an X-linked recessive disorder.G6PD deficiency is polymorphic, with more than 300 variantsG6PD deficiency can present as neonatal hyperbilirubinemia. Besides, persons with this disorder can experience episodes of brisk haemolysis after ingesting fava beans or being exposed to certain infections or drugs. Less commonly, they may have chronic haemolysis. However, many individuals with G6PD deficiency are asymptomatic.Most individuals with G6PD deficiency do not need treatment. However, they should be taught to avoid drugs and chemicals that can cause oxidant stress. Infants with prolonged neonatal jaundice as a result of G6PD deficiency should receive phototherapy with a bili light.

The baby most likely has umbilical granuloma – granulation tissue may persist at the base of the umbilicus after cord separation| the tissue is composed of fibroblasts and capillaries and can grow to more than 1 cm.Medical therapy is indicated only when an infection is present.Silver nitrate application to umbilical granulomas is usually successful. One or more applications may be needed. Care must be taken to avoid contact with the skin. Silver nitrate can cause painful burns. Small umbilical granulomas with a narrow base may be safely excised in the office setting. Large granulomas and those growing in response to an umbilical fistula or sinus do not resolve with silver nitrate and must be surgically excised in the operating room setting.

A preterm with respiratory distress syndrome presents with the condition as a result of immature lungs and inadequate surfactant production. Management of RDS therefore includes surfactant therapy, oxygen administration and mechanical ventilation, as well as measures such maintaining acid base levels and blood haemoglobin in an intensive care unit. Dexamethasone is not shown to be particularly effective when given to a preterm, but can however be used to prevent or decrease RDS severity when given to the mother before delivery.

After birth, the infant takes its first breath and is exposed to a myriad of stimuli. The pulmonary vessels dilate, and pulmonary vascular resistance (PVR) decreases remarkably while the systemic vascular pressure rises above the PVR. This allows blood from the right ventricle to enter the lungs for oxygenation. In most cases, this increased oxygenation, along with other factors, causes the ductal wall to constrict and the ductus arteriosus to close functionally. As left-sided pressures rise higher than right-sided pressures, the foramen ovale functionally closes. With the clamping of the umbilical cord and the cessation of blood flow, pressures in the portal sinus decrease. This causes the muscle in the sinus wall near the ductus venosus to contract. The lumen of the duct becomes filled with connective tissue, and, in two months, the ductus venosus becomes a fibrous strand embedded in the wall of the liver, thus establishing adult circulation.

According per the national guidelines, 5 inflation breaths should be given with a gas pressure of 30cmH2O for term babies. Each breath should be given for 2-3 seconds. Pre-term babies should be aerated with a lower pressure of 20-25cmH2O.

Intrauterine growth restriction refers to the failure of the fetus to grow in accordance with the weeks of gestation. There are two types of growth restriction, symmetrical and asymmetrical. Causes include various genetic abnormalities, fetal infections, maternal health conditions, etc. Risk factors for the development of IUGR include fetal echogenic bowel, maternal age above 40 years, low PAPP-A levels, maternal smoking or cocaine use, etc. Fetal echogenic bowel implies a brighter than usual fetal intestines on ultrasonography. It is a marker associated with trisomy 21, which is a cause of IUGR.

An important predictor of the foetal well-being is the evaluation of amniotic fluid volumes, commonly done using ultrasonography. Amniotic fluid index (AFI) is calculated by measuring the largest vertical diameter of the fluid pocket in all four quadrants of the uterine cavity and then added together. Oligohydramnios or decreased amniotic fluid volume can be defined as an AFI less than 5cm and occurs in about 4-5% of the pregnancies. It is associated with a number of foetal abnormalities and complications. Foetal abnormalities that lead to oligohydramnios include premature rupture of membranes, intrauterine growth retardation, and congenital foetal abnormalities among others. A single umbilical artery is an anatomical defect of the umbilical cord, which leads to IUGR, uteroplacental insufficiency and may be associated with multiple congenital abnormalities as well, which all ultimately lead to the development of oligohydramnios. It also leads to multiple complications, out of which the incidence of chorioamnionitis is very high. Other complications include fetal growth retardation, limb contractures, GI atresia, and even fetal death.

Transient tachypnoea of the new-born (TTN) is the commonest cause of respiratory distress in new-borns and self-limiting. It can affect any new-born shortly after birth. Its most prominent feature is tachypnoea. Nasal flaring, grunting, or intercostal retractions may also be present.

Ventilatory rates of 40-60 breaths/min should be provided initially, with proportionally fewer assisted breaths provided if the infant’s spontaneous respiratory efforts increase. Although this practice has not been extensively studied, initial inflation of the new-born’s lungs with either slow-rise or square-wave inflation to a pressure of 30-40 cm H2 O for approximately 5 seconds has been reported to result in more rapid formation of Functional Residual Capacity (FRC).At the moment of delivery and first breath, the neonatal lung is converting from a fetal non-aerated status to a neonatal status. The neonatal lung requires gas exchange, and this necessitates the development of FRC with the resorption of lung fluid and the resolution of most of the atelectasis. Therefore, initial slow ventilation with more prolonged inspiratory times may be useful to assist in this task, balanced against the need to avoid inappropriate inspiratory pressures.Flow-controlled, pressure-limited mechanical devices are acceptable for delivering PPV. These mechanical devices control flow and limit pressure and be more consistent than bags. Self-inflating and flow-inflating bags remain a standard of care. Laryngeal mask airways are effective for assisted ventilation when bag-mask ventilation and intubation are unsuccessful.

Group B beta-haemolytic Streptococcus (GBS) and Escherichia coli are the most common cause of early sepsis. Group B Streptococcus (GBS), also known as Streptococcus agalactiae, is best known as a cause of postpartum infection and as the most common cause of neonatal sepsis. The GBS organism colonizes the vagina, GI tract, and the upper respiratory tract of healthy humans. GBS infection is almost always associated with underlying abnormalities. In elderly persons aged 70 years or older, GBS infection is strongly linked with congestive heart failure and being bedridden.Penicillin remains the drug of choice for group B streptococcal infection but resistance may occur.

Polycythaemia is described as an abnormal increase in the red cell mass. As this influences hyper-viscosity, a peripheral venous sample of blood haematocrit can be used to determine the packed cell volume. Polycythaemia is present if the venous haematocrit is >65% or <22g/dl if converted into a haemoglobin value. Though it is the method of choice for screening, capillary blood samples obtained though heel pricks in new-born may be as much as 15% higher than venous samples and thus high values must be confirmed with a venous sample.

A transverse lie is a common malpresentation. It occurs when the fetal longitudinal axis is perpendicular to the long axis of the uterus. The location of the spine determines if the foetus is back up (the curvature of the spine is in the upper part of the uterus) or back down (the curvature of the spine is in the lower part of the uterus).Good antenatal care, ECV, and elective caesarean section are the mainstay of the management.Spontaneous delivery of a term foetus is impossible with a persistent transverse lie and, in general, the onset of labour is an indication for the lower segment caesarean section (LSCS) in a case of a transverse lie.

The baby needs more oxygen saturation which could be attempted by increasing the mean airway pressureAfter initial resuscitation and stabilization, the following should be the ventilator settings used:Rate: 30-40/minutePeak inspiratory pressure (PIP) – determined by adequate chest wall movement.An infant weighing less than 1500 grams: 16-28 cm H2O.An infant weighing greater than 1500 grams: 20-30 cm H2O. Positive end expiratory pressure (PEEP): 4 cm of H2O OR 5-6 cm if FiO2 > 0.90.FiO2: 0.4 to 1.0, depending on the clinical situation.Inspiratory time: 0.3-0.5 sec.After 15 to 30 minutes, check arterial blood gases and pH.If the PaO2 or the O2 saturation is below accepted standards, the FiO2 can be raised to a maximum of 1.0. If the PaO2 or O2 saturation is still inadequate, the mean airway pressure can be raised by increasing either the PIP, PEEP, inspiratory time or the rate, leaving inspiratory time constant.If the PaCO2 is elevated, the rate or peak inspiratory pressure can be raised.

An important predictor of the foetal well-being is the evaluation of amniotic fluid volumes, commonly done using ultrasonography. Amniotic fluid index (AFI) is calculated by measuring the largest vertical diameter of the fluid pocket in all four quadrants of the uterine cavity and then added together. Oligohydramnios or decreased amniotic fluid volume can be defined as an AFI less than 5cm and occurs in about 4-5% of the pregnancies. It is associated with a number of foetal abnormalities and complications. Foetal abnormalities that lead to oligohydramnios include: premature rupture of membranes, intrauterine growth retardation, and congenital foetal abnormalities among others. A single umbilical artery is an anatomical defect of the umbilical cord, which leads to IUGR, uteroplacental insufficiency and may be associated with multiple congenital abnormalities as well, which all ultimately lead to the development of oligohydramnios. Foetal hydrops, developmental dysplasia of the hip and, macrosomia lead to polyhydramnios. Cleft palate is not associated with any of them.

Physiological jaundice is the condition in which there is a yellow discolouration of the eyes and the skin of the baby caused by the build up of bilirubin in the blood due to an immature liver. No other symptoms accompany physiological jaundice, thus it will not present with difficulty in feeding. All the other conditions listed can present with feeding problems.

Cow’s milk differs in composition to human breast milk. The sodium content of cows milk is too high, which can easily overwhelm a baby’s developing kidneys and lead to hypernatremia and dehydration. In addition to its iron content being too low, cows milk can cause further increase iron deficiency anaemia by irritating the baby’s intestinal lumen and causing blood loss per rectum. After 12 months a baby’s gastrointestinal tract and organs are able to tolerate cows milk.

Neonatal hypoglycaemia is a common yet serious condition characterized by blood sugar levels less than 2.2mmol/L during the first 3 days of life and less than 2.5mmol/L later on. There are multiple aetiologies and various risk factors that lead to hypoglycaemia in new-borns like prematurity, sepsis, inborn errors of metabolism, and maternal diabetes- induced hyperinsulinism in the new-born. Among the inborn errors of metabolism, fatty acid oxidation defects can lead to persistent hypoglycaemia in new-borns. One such defect is the medium- chain acyl CoA dehydrogenase deficiency, which is the enzyme needed for the breakdown of medium- chain fatty acids.

Severe cyanotic heart diseases such as pulmonary stenosis, transposition of the great vessels, hypoplastic left heart syndrome and truncus arteriosus all run the risk of a poor prognosis for a neonate. To continue the supply of oxygen the ductus arteriosus must be kept patent. This can be done with the immediate administration of Prostaglandin E1 as a temporary measure until a surgical intervention such as an atrial septostomy can be done. The closure of the duct can subsequently be initiated with the administration of indomethacin and oxygen.

Spontaneous intestinal perforation (SIP) of the new-born, also referred to as isolated perforation or focal intestinal perforation (FIP) of the new-born, is a single intestinal perforation that is typically found at the terminal ileum. SIP occurs primarily in preterm infants with very low birth weight (VLBW, birth weight <1500 g) and extremely low birth weight (ELBW, birth weight <1000 g), umbilical catheter placement, maternal drug use and twin-to-twin transfusion syndrome. SIP is a separate clinical entity from necrotizing enterocolitis, the most severe gastrointestinal complication of preterm infants.

The perinatal mortality rate is defined as the number of perinatal deaths per 1000 total births. Perinatal death includes the death of a live-born neonate within 7-days of life (early neonatal death) and the death of a fetus ≥ 22 weeks of gestation (stillbirth). Hence, the perinatal mortality rate is calculated by dividing the number of still births+ the number of early neonatal deaths by 1000 births.

Time- EventWeek 1: ImplantationWeek 2: Formation of bilaminar diskWeek 3: Formation of primitive streakFormation of notochordGastrulationWeek 4: Limb buds begin to formNeural tube closesHeart begins to beatWeek 10: Genitals are differentiated

Fetal alcohol syndrome (FAS) is a common yet under-recognized condition resulting from maternal consumption of alcohol during pregnancy. The diagnosis of fetal alcohol syndrome (FAS) is based on findings in the following 3 areas: (1) characteristic facial anomalies (see image below), (2) growth retardation (intrauterine growth restriction and failure to have catch-up growth), and (3) CNS involvement (cognitive impairment, learning disabilities, or behavioural abnormalities).Key characteristic craniofacial abnormalities include the following:- Smooth philtrum- Thin, smooth vermilion border of the upper lipShort palpebral fissures (< 10th percentile for age)Other craniofacial abnormalities are as follows:- Midface hypoplasia- Microphthalmia- Strabismus- PtosisCNS and neurobehavioral abnormalities include the following:- Microcephaly- Intellectual impairment (mild-to-moderate mental retardation)- Cognitive impairment- Developmental delay- Irritability in infancy- Hyperactivity in childhood or attention deficit hyperactivity disorder (ADHD)- Seizures- Delayed or deficient myelination- Agenesis or hypoplasia of the corpus callosumSkeletal abnormalities include the following:- Radioulnar synostosis- Flexion contractures- Camptodactyly- Aberrant palmar creases, especially hockey-stick palmar crease- Clinodactyly- Klippel-Feil anomaly- Hemivertebrae- Scoliosis- Dislocated jointsOther major congenital anomalies include the following:- Cleft palate- Heart defects- Renal anomalies- DiGeorge sequenceFunctional problems include the following:- Refractive problems (e.g., myopia, astigmatism)- Hearing lossGrowth deficiency includes the following:- Infant small for gestational age (< 10th percentile for weight or length)- Postnatal growth deficiency

Neonatal hyperbilirubinemia is a common clinical condition and can be categorized as conjugated and unconjugated hyperbilirubinemia. Conjugated hyperbilirubinemia results from obstructive or hepatocellular causes mainly. The causes of conjugated hyperbilirubinemia include inborn errors of metabolism like galactosemia and aminoaciduria, obstruction from choledochal cysts, and biliary atresia. Long term TPN also leads to conjugated hyperbilirubinemia. Spherocytosis is a hereditary condition belonging to the group of haemolytic anaemias, resulting from plasma membrane protein deficiency. This defect of the RBC plasma membrane decreases their life span, making them osmotically fragile and prone to haemolysis. This leads to an increase in the unconjugated bilirubin levels, with a risk of developing kernicterus.

Alpha-fetoprotein (AFP) is a plasma protein produced by the embryonic yolk sac and the fetal liver. AFP levels in serum, amniotic fluid, and urine functions as a screening test for congenital disabilities, chromosomal abnormalities, as well as some other adult occurring tumours and pathologies.Pregnant maternal serum AFP levels are elevated in:- Neural tube defects (e.g., spina bifida, anencephaly)- Omphalocele- Gastroschisis- posterior urethral valves- nephrosis- GI obstruction- teratomas

Haemolytic disease of the new-born due to ABO incompatibility is usually less severe than Rh incompatibility. One reason is that fetal RBCs express less of the ABO blood group antigens compared with adult levels. In addition, in contrast to the Rh antigens, the ABO blood group antigens are expressed by a variety of fetal (and adult) tissues, reducing the chances of anti-A and anti-B binding their target antigens on the fetal RBCs.ABO HDN occurs almost exclusively in the offspring of women of blood group O, although reports exist of occasional cases in group A mothers with high‐titre anti‐(group B) IgG

Germinal matrix/intraventricular haemorrhage (GM/IVH) is a complication of premature delivery that can result in life-long medical and developmental consequences.Loss of autoregulation of cerebral blood flow is a pathophysiologic feature of germinal matrix/intraventricular haemorrhage (GM/IVH). Prematurity itself results in derangements in cerebral autoregulation. In some patients, a history of additional events that result in loss of autoregulation can be obtained. Furthermore, events that can result in beat-to-beat variability of cerebral blood flow may be identified in some patients.There may be no symptoms. The most common symptoms seen in premature infants include:- Breathing pauses (apnoea)- Changes in blood pressure and heart rate- Decreased muscle tone- Decreased reflexes- Excessive sleep- Lethargy- Weak suck- Seizures and other abnormal movements

Oligohydramnios is a deficiency in the amniotic fluid volume, measured via ultrasound. Maternal factors associated with oligohydramnios include conditions where there is placental insufficiency such as chronic hypertension, preeclampsia or a thrombotic disorder, post-term pregnancy, premature rupture of membranes, certain chromosomal abnormalities, and obstructions of the foetal urinary tract. On the other hand conditions that are associated with polyhydramnios (excess amniotic fluid) include maternal diabetes, multiple gestations, Rh incompatibility and pulmonary abnormalities.

The origins of the neural tube and the nape of the neck where nuchal translucency measurements are taken are from embryonic ectoderm.The structural development of the head and neck occurs between the third and eighth weeks of gestation. The 5 pairs of branchial arches, corresponding to the primitive vertebrae gill bars, that form on either side of the pharyngeal foregut on day 22 are the embryologic basis of all the differentiated structures of the head and neck. Each arch consists of 3 layers: an outer covering of ectoderm, an inner covering of endoderm, and a middle core of mesenchyme. These arches are separated further into external, ectoderm-lined pharyngeal clefts and internal, endoderm-lined pharyngeal pouchesA population of ectodermal cells adjacent to the neural fold and not included in the overlying surface (somatic) ectoderm gives rise to the formation of the neural crest. These neuroectodermal crest cells are believed to migrate widely throughout the developing embryo in a relatively cell-free enriched extracellular matrix and differentiate into a wide array of cell and tissue types, influenced by the local environment. Most connective and skeletal tissues of the cranium and face ultimately come from the derivatives of neural crest cells.

Infants may require tracheal intubation if:- direct tracheal suctioning is required- effective bag-mask ventilation cannot be provided- chest compressions are performed- endotracheal (ET) administration of medications is desired- congenital diaphragmatic hernia is suspected, or – a prolonged need for assisted ventilation exists.