NEONATOLOGY

NEONATOLOGY

Objectives


To recognize how to classify newborn baby To list the methods of gestational age assessment of newborn baby To recognize the physical and neuromuscular signs of maturity examination To list the causes of low birth weight baby To recognize the characteristic features and neonatal complications of preterm infants To understand the care and feeding of preterm baby To identify the features and complications of small-for-date baby To understand the definition , causes , features, and complications of large for-date baby To recognize the features and prognosis of post term baby


The neonatal period is defined as : less than 28 days of life and subdivided into 1- Early neonatal period (birth to less than 7 days) 2- Late neonatal period (7 days to less than 28 days)


Stillbirth : fetus born with no signs of life ≥24 weeks of pregnancy Perinatal mortality rate : stillbirths + deaths within the first week per 1000 live births and stillbirths Neonatal mortality rate : deaths of live-born infants within the first 4 weeks of age per 1000 live births

Definition (WHO)

A- Duration of gestation : 1.preterm = less than 37 completed weeks of gestation (258 days) 2.full term = between 37 weeks and 42 completed weeks of gestations (259-293 days)The American College of Obstetrics and Gynecology redefines term into subgroups: early term (37 0/7 wk of gestation to 38 6/7 wk), full term (39 0/7–40 6/7 wk), and late term (41 0/7–41 6/7 wk). 3.Post term or post mature = more than 42 completed weeks (294 days)

Definition of late preterm and early term

B- Birth weight :

1-Low birth weight = less than 2500 gm . (7% of all birth but represent 2/3 of all neonatal death ) 2-Very low birth weight = less than 1500 gm . Less than 1% of all birth but represent 50% of neonatal death ). 3-Extremely low birth weight = less than 1000 gm .

C- size for gestation

1.small for gestation (SGA) = less than 10th centile in weight expected for gestation ( small for date ) 2.Appropriate for gestation (AGA) = between 10 – 90th centile of weight expected for gestation . 3.Large for gestation (LGA) : more than 90th centile in wt expected for gestation .


Gestational age assessment 1-Date of last menses 2-Early fetal ultrasound: crown rump measurement 3-Date of first heart sound 4-Date of first fetal movement 5-Uterine size 6-Newborn physical maturity &neuromuscular maturity examination ( Newballard score )

Physical Maturity

Premature skin. This premature infant demonstrates translucent, paper-thin skin with a prominent venous pattern.


Friable, transparent skin of extremely preterm infant. Score = 1


Post term skin. Peeling and cracking of the skin are characteristics of the infant delivered after 42 weeks' gestation.

Lanugo. This fine body hair resembling "peach fuzz” is present on infants of 24 to 32 weeks' gestation.

Sole creases. Transverse sole creases cover approximately half the sole in this infant, indicating a gestational age of approximately 34 weeks

Ear cartilage. The lack of cartilage and the easy foldability (lack of recoil) are evident in the ear of this premature infant at 26 weeks.

Breast Tissue

32 weeks
36 weeks

Male Genitalia

28 weeks
32weeks
36 weeks



Premature female genitalia. Prominence of the labia minora in a premature female infant at 28 weeks.

Neuromuscular Maturity

General posture. The typical, marked flexor posture of the term infant.

Square-window test. The position for assessing the square window is shown.

Popliteal angle measurement

Scarf sign. The elbow cannot be drawn, with gentle traction on the upper extremity, across this term infant's chest.

Heel-to-ear maneuver. The position for assessing the heel-to-ear maneuver is demonstrated. The degree of extension seen is consistent with a 28- to 30-week infant

Low Birth Weight Baby (LBW)Birth weight of less than 2500 gm.LBW baby includes preterm &small for date babies.It represent large component of the neonatal& infant mortality rates.In the United States, approximately 10% of all births are preterm.In USA LBW account for two thirds of all neonatal deaths. Prematurity and IUGR are associated with increased neonatal morbidity and mortality


Maternal factors associated with LBW birth:1-low socioeconomic status2-low level of maternal education3-no antenatal care4-maternal age younger than 16 or older than 35years5-short interval between pregnancies6-cigarette smoking, alcohol& illicit drug use7-physical& psychological stresses8-low pre pregnancy weight <45kg9-poor weight gain during pregnancy<10Ib



Identifiable causes of preterm birthFetalfetal distress, multiple gestation, erythroblastosis, non-immune hydropsPlacental-placenta previa, abruptio placentaeUterine-bicornate uterus, incompetent cervix[ premature dilation]Maternal-pre eclampsia, chronic medical illness[ cyanotic heart disease, renal disease], infection[ Listeria monocytogen, group B streptococcus, UTI, chorioamnionitis] ,drug abuse[ cocaine]Others-premature rupture of membranes, polyhydromnias, iatrogenic, trauma, Assisted reproductive technology

Characteristics of Preterm Infants-Small but plump-Red or very pink-Lanugo hair-Skin shiny transparent,thin ,edematous-Ears, breast tissue, genitalia all immature-Hypotonic [floppy]

Stabilising the preterm infant

Examination : Respiratory distress - tachypnoea, laboured breathing with chest wall recession, nasal flaring, expiratory grunting, cyanosis Apnoea Management, as required: Clear the airway Oxygen CPAP (continuous positive airway pressure( Mechanical ventilation

Monitoring

Oxygen saturation (maintain at 88-95% if preterm) Heart rate Respiratory rate Temperature Blood pressure Blood glucose Blood gases Weight

Temperature control

Perform stabilization under a radiant warmer or in an incubator to avoid hypothermia, which increases mortality in preterm infants. Avoid hyperthermia, as may increase brain injury.



The survival rate of LBW and sick infants is higher when they are cared for at or near their neutral thermal environment. This environment is a at which heat production (measured experimentally as oxygen consumption) is minimal and the infant’s core temperature is within the normal range.

Overhead Radiant warmer

Air-heated Incubator


Milk for preterm infants:1- Breast milk: in preterm infant human milk is better tolerated than any currently available formula. Gastric emptying is quicker& stool frequency greater.NEC is many times less likely if breast milk given.2-Preterm formula: indicated in preterm baby<2 kg-more protein[ 1.8-2 gm/dl],-more energy [75-90 kcal/dl]-higher sodium,calcium,&phosphorus-addition of iron,vitamins[D,E,&B complex]3-Term formula: is given to infant weight> 2kg


Methods of Feeding Preterm and Low Birth Weight Infant :1-Baby> 2kg > 36week: oral feeding from breast or bottle.2-Baby 1.6- 2 kg >34 week: if stable& active can feed orally from breast or bottle.3-Baby 1.5 kg or less or <34 week: can feed expressed breast milk or preterm formula by gavages feeding[ by nasogastric or orogastric tube] either intermittent bolus feeding or continuous feeding.

SMALL FOR DATE BABY[IUGR]Definition:Baby less than 10th centile in weight expected for gestation .In developing countries 70% of LBW infants are small for date. 3-10% of all pregnancy associated with IUGR.Infants with IUGR have greater morbidity& mortality than appropriately grown gestational age-matched infants.

Factors often associated with IUGRFetal:-Chromosomal disorder[autosomal trisomies]-Chronic fetal infection[CMV,cong.Rubella,Syphilis…].-Congenital anamolies, syndromes, pancreatic aplasia-Radiation injury-Multiple gestationPlacental:-Decreased placental weight or cellularity or both-Decreased in surface area-Villous placentitis[ bacterial,viral,parasitic]-Infarction-Tumor[chorioangioma, hydatidiform mole]-Placental seperation-Twin transfusion syndrome


Maternal:-Toxemia-Hypertensive or renal disease or both-Hypoxemia[ high altitude,cyanotic cardiac or pulmonary disease]-Malnutrition or chronic illness-Sickle cell anemia-Drugs[ narcotics,alcohol,cigarretes, antimetabolites]

Types of IUGR

Symmetrical (head circumference, length and weight equally affected) Asymmetrical (with relative head growth sparing) growth restriction.

Features:

Baby with IUGR looks thin ,wasting ,with loose, peeling skin, with long nail, scaphoid abdomen & dispropertionatly large head. Baby vigorous &active. Sucking usually strong.


IUGR. This term baby weighed only 1.7 kg. The head appears disproportionately large for the thin, wasted body. This resulted from placental insufficiency late in pregnancy.

Wrinkled and hypoelastic skin, easily liftable and pliable skinfolds in a IUGR newborn

Large For Gestational Age Infant [LGA]

Definition: Baby more than 90th centile weight expected for gestation . Neonatal mortality rates decrease with increasing birthweight until approximately 4,000 g, after which they increase. These oversized infants are usually born at term, but preterm infants with weights high for gestational age also have a significantly higher mortality than infants of the same size born at term; maternal diabetes and obesity are predisposing factors. Some infants are constitutionally large because of large parental size.

LGA infants, regardless of their gestational age, have a higher incidence of birth injuries, such as cervical and brachial plexus injuries, phrenic nerve damage with paralysis of the diaphragm, fractured clavicles, cephalohematomas, subdural hematomas, and ecchymoses of the head and face. LGA infants are also at increased risk for hypoglycemia and polycythemia. The incidence of congenital anomalies, particularly congenital heart disease, is also higher in LGA infants than in term infants of normal weight. Intellectual and developmental retardation is statistically more common in high birthweight term and preterm infants than in babies of appropriate weight for gestational age.



LGA infant. This infant of a diabetic mother weighed 5 kg at birth and exhibits the typical rounded facies.

Post-Term InfantDefinition: Those born after 42 weeks of gestation[294days].The cause is unknown.

CLINICAL MANIFESTATIONS

Post term infants have normal length and head circumference but may have decreased weight if there is placental insufficiency. Infants born post term in association with presumed placental insufficiency may have various physical signs. Desquamation, long nails, abundant hair, pale skin, alert faces, and loose skin, especially around the thighs and buttocks, give them the appearance of having recently lost weight; meconium-stained nails, skin, vernix, umbilical cord, and placental membranes may also be noted . Common complications of postmaturity include perinatal depression, meconium aspiration, persistent pulmonary hypertension, hypoglycemia, hypocalcemia, and polycythemia.


PROGNOSIS When delivery is delayed 3 wk or more beyond term, mortality is significantly increased approximately 3 times that of a control group of infants born at term. Mortality has been lowered markedly through improved obstetric management.