Neonate and Neonatal Diseases (Introduction) Rongxiu Zheng, MD Pediatric Dpt. General Hospital of Tianjin Medical University
Classification and definition of neonate
Characteristic and nursing care of neonate
Neonatology: The branch of pediatrics that deals with the diseases and care of newborns.
Neonatal period: From birth to the 28th day of life (4 weeks after birth).
Perinatal period: From the 28th completed week of gestation to the 7th day after birth. .
The two periods are highly vulnerable for life with the highest morbidity and mortality.
Classification of the neonates By both GA and BW By birth weight By gestational age
Gestation is the period of time between conception and birth, during which the fetus grows and develops inside its mother's uterus.
Gestational age is measured in weeks from the first day of the mother's last normal menstrual period to the day of delivery
Full term infant: An infant born at a gestational age between 37 and 42 completed weeks
Preterm infant: An infant that is born prior to 37 weeks of gestation
Post-term infant: An infant that is born after the 42nd week of gestation.
早产儿 足月儿 过期产儿
Birth weight, BW the first weight of an infant, obtained within the first hour after birth.
Normal birth weight(NBW): This refers to all infants whose weight at birth is between 2500g and 4000g.
Low birth weight(LBW): BW<2500g
Very low birth weight(VLBW): BW<1500g
Extremely low birth weight(ELBW): BW<1000g)
Low birth weight
An extremely important factor in newborn mortality
Complications increases as BW decreases
Resuscitation rate of those less than 1500g is 80%
macrosomia NBW VLBW ELBW
1. AGA ( appropriate for gestational age)
Infants with birth weight for their gestational age that falls between the 10th and 90th centiles.
2. SGA ( small for gestational age)
Infants with birth weight for their gestational age that falls below the 10th centiles.
3. LGA ( large for gestational age)
Infants with birth weight for their gestational age that falls above the 90th centiles.
Point A represents a premature infant. Point B indicates an infant of similar birth weight who is mature but small for gestational age. Weight for gestational age chart
Characteristic and nursing care of neonate An infant’s intrauterine to extrauterine transition requires many biochemical and physiologic changes. Many of a newborn’s special problems are related to poor adaptation due to asphyxia, premature birth, life-threatening congenital anomalies, or adverse effects of delivery .
Features in appearance of normal term neonate and preterm neonate pink ， well-nurished ， Less fine-hair term Dark-red,edema ， transparent ， more fine-hair preterm Skin
ear soft ear stick to the skull, poor figuration preterm Good ear figuration, well-developed cartilage term
preterm Under-developed, no testes in the sac genitalia （ male ） term Well-developed, testes decend
preterm the labia majora don’t cover the labia minus term the labia majora cover the labium minus; genitalia （ female ）
preterm Shallow and less Sole markings term Obvious, over all the sole
Respiratory system Fetal lung development
Filled with fluid
Surfactant synthesis : begins at 24-28w, peak at 35w
Establishment of breathing after birth
opening of the alveoli by mechanical,chemical,thermal, sensory stimuli
Characteristics of Newborn respirations
1. 30-60 rate
2. shallow and irregular
3. 5-15 second periods of apnea
Abnormal findings: retractions, grunting, nasal flaring, 20 sec or more apnea; abnormal rate
Circulatory system Transitional Physiology
Increased aortic pressure and decreased venous pressure
Increased systemic pressure and decreased pulmonary artery pressure.
Closure of the foramen ovale: occurs due to increased pressure in the left atrium.
Closure of the ductus arteriosus.
Closure of the ductus venosus
Circulatory system Characteristics of cardiac function in newborn Heart rate: ranges from 120 to 160 per minute. Heart murmur:
Murmurs are usually produced by turbulent blood flow.
90% of all murmurs are transient and not associated with anomalies.
Usually involve incomplete closure of the ductus arteriosis or foramen ovale.
Heart size: The heart of the newborn infant often seems large with respect to the size of the chest when measured by adult standards. Blood pressure: from 46 to 80 mmHg(systolic)
Urinary system Renal function: does not meet the standards of later life GFR(glomerular filtration rate): is lower, about one fourth to one half of that in an adult. Urine often contains protein in small amounts. . Urine may contain an abundance of urates which may give the diaper a pink stain during the first week of life. The ability to dilute urine is good. but the time taken to reach the maximal ability is relatively long , so newborns are apt to become water overloaded . Urine pH ranges from 5 to 7, specific gravity ranges from 1.006 to 1.020. The first urination occurs within 24 hrs. It ranges from 4 to 6 times/day in the first day and 20 times or so /day in later days of the neonatal period.
Hemotological system Blood volume: ranges from 80 to 100 ml/kg . Hemoglobin: ranges around 15~22g/dL. RBC: RBCs range from 5000 to 7000 thousand/mm 3 . WBC: Leukocyte number may be about 18000/ mm 3 or so at birth, and generally increase in number for the first 24 hrs with relative neutrophilia . Counts as high as 25000 to 35000/ mm 3 may be encountered. After the first few days (5 days or so ) the white cell count is likely to be below 14000/ mm 3 with characteristically relative lymphocytosis of infancy and early childhood.
Alimentary system The first stool will generally be passed within 12 hr of life and consists of meconium. Meconium stools begin to be replaced by transitional stools on the third or fourth day with the establishment of milk feeding. Typical milk stool follows after an interval of 3 or 4 days. The frequency of stools in newborn infants averages 3 to 5 times a day by the end of the first week. It is unusual for an infant to have as many as 6 or 7 stools after the 2 nd day. The first feeding should be at 6 hrs of postnatal age for a full term baby, 12 hrs for a premature body.
Nervous system Head: is relatively large, i.e. from 10 to 12% of body weight . Spinal cord: relatively long. The end of it reaches the level of the third or forth lumbar vertebra . Physiological reflex: There are some physiological reflexes which appear at birth, then disappear at 4 months of life.
neonate sucks on the finger place a finger in the neonate’s mouth Sucking neonate makes walking motions with both feet hold the neonate in an upright position and touch one foot lightly to a flat surface (such as the bed) stepping neonate turns the head toward the stimulus, opens the mouth and searches for the stimulus touch a finger to the neonate’s cheek or the corner of mouth. Rooting neonate grasps the finger place a finger in the neonates palm Grasp Neonate extends and abducts all extremities bilaterally and symmetrically Suddenly but gently drop the neonate s head backward (relative to the trunk) Moro NORMAL RESPONSES TESTING METHOD REFLEX
Moro Suddenly but gently drop the neonate s head backward (relative to the trunk) Neonate extends and abducts all extremities bilaterally and symmetrically
Grasp place a finger in the neonates palm neonate grasps the finger
Rooting touch a finger to the neonate’s cheek or the corner of mouth. neonate turns the head toward the stimulus, opens the mouth and searches for the stimulus
Sucking place a finger in the neonate’s mouth neonate sucks on the finger
stepping hold the neonate in an upright position and touch one foot lightly to a flat surface (such as the bed) neonate makes walking motions with both feet
Immune system Normal or slightly higher level of IgG is due to active transfer from the mother to fetus via the placenta, but IgM and IgA are low (they cannot pass through the placenta); therefore the newborns are at high risk for gram negative bacterial infection . T lymphocyte functions are somewhat reduced in newborn infants. White blood cells display low function in killing microorganisms.
BCG vaccinations in all population at high risk of tuberculosis infection
HBV vaccination as soon as possible where perinatal infections are common
Normal temperature: 36.5–37.5°C
Hypothermia: < 36.5°C -- Significant contribution to deaths in low birth weight infants and preterm newborns
Stabilization period: 1st 6–12 hours after birth
The body temperature is likely to be influenced by the environmental temperature.
Neutral environmental temperature: the environmental temperature at which the core temperature of the infant at
rest is between 36.7 and 37.3°C and oxygen consumption and caloric utilization are lowest
Temperature control for newborn infants is important to avoid the excess stress which hypo- or hyperthermia imposes on a newborn. To provide a neutral thermal environment, the incubator temperature should be kept at the temperatures shown in the followingtables.
Skin At birth the infant is generally covered with vernix caseosa , a cheesy - white substance adherent to the skin. It is helpful for protecting the baby against infections, and should not be taken off. Keeping the skin of the baby clean is very important because it is apt to be infected.
Umbilical cord After the ligation of the umbilical cord, it comes off from 1 to 7 days of postnatal age. It has to be prevented against contamination and be kept it from bleeding .
Water metabolism Water may contribute up to 75% of body weight (40% extracellular). During the first few days there are a loss of fluid leading to about 6% loss of body weight (physiologic) and usually do not exceed 10%. Insensible water loss is about 40ml/100cal.
Requirments for calories and fluid of neonate
Associated with GA, BW and health condition
day 1 day 2 day 3
calorie fluid calorie fluid calorie fluid
Full term 60 － 80 60 － 80 100 － 120 80 － 100 120 － 150 110 － 150
High risk neonates The term designates infants who should be under close observation by experienced physicians and nurses.
Neonatal Intensive Care Unit, (NICU) The special medical unit which take special care for those high risk babies with modern medical equipments and techniques such as purified air ward, resuscitation technique, mechanical ventilator, color Doppler mapping, radiated heater and so on.
Problems Preemies May face
Air sacs in the lungs not able to stay open due to lack of surfactant in the lungs
Lung damage due to long term respiratory problems
Incomplete lung development
Apnea (stop breathing) 50% of babies born at or before 30 weeks will have this problem
Patent ductus arteriosus
Congenital heart defects
Infection of the intestinal tract
Bleeding in the brain
Poor muscle tone
Characteristics of Pre Term Infant
Little body fat
Little scalp hair
Weak body tone
Treatment of the Pre term Infant
Need special care in Neonatal Intensive Care Unit
Oxygen by mask or ventilator
Feedings by NG tube
Several physiological states of the newborn
Physiologic jaundice Mild jaundice may occur in most newborns, this is due to the immaturity of the baby's liver, which leads to a slow processing of bilirubin. It generally appears at 2 to 4 days of age and disappears by 1 to 2 weeks of age. The appearance of visible jaundice before 48 hrs , or a serum concentration of bilirubin exceeding 12 mg/dL at any time of neonatal period are considered to be abnormal. For premature infants, the serum bilirubin concentration exceeding 15 mg/dL is abnormal.
Pseudomenstration Vaginal bleeding may occur at the age of 5 to 7 days in some newborn girls and lasts for 1 to 2 days. Placentally transmitted and withdrawn maternal hormones are responsible for temporary vaginal bleeding.
Enlargement of the breasts Enlargement of the breasts, and production of milk may occur at the age of 3 to 5 days in some newborn boys or girls. This stops at the postnatal age of 2 to 3 weeks. This is also caused by transmission and withdraw of maternal hormones. This no requires management.