Pulmonary hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS) is the lack of normal fetal development of the pulmonary parenchyma. The condition is characterized by a decreased number of alveoli Alveoli Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place. Acute Respiratory Distress Syndrome (ARDS) and bronchial generations. Oligohydramnios Oligohydramnios Oligohydramnios refers to amniotic fluid volume less than expected for the current gestational age. Oligohydramnios is diagnosed by ultrasound and defined as an amniotic fluid index (AFI) of ‰¤ 5 cm or a single deep pocket (SDP) of < 2 cm in the 2nd or 3rd trimester. Oligohydramnios is a notable cause, but conditions that restrict lung development or lead to fetal lung compression Compression Blunt Chest Trauma can also result in pulmonary hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS). A diagnosis of pulmonary hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS) can be suspected on prenatal ultrasound. Findings include reduced amniotic fluid Amniotic fluid A clear, yellowish liquid that envelopes the fetus inside the sac of amnion. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (amniocentesis). Placenta, Umbilical Cord, and Amniotic Cavity, congenital abnormalities Congenital Abnormalities Malformations of organs or body parts during development in utero. Omphalocele, and characteristic anatomical measurements. A more complete picture at birth points to the diagnosis based on clinical findings (respiratory distress, typical anomalies) and further evaluation (reduced lung volume on imaging). Treatment is focused on antenatal lung maturity and postnatal ventilatory support, with subsequent correction of associated causes and defects. Survival depends on the degree of lung underdevelopment.
Last updated: 22 Mar, 2021
Pulmonary hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS) is the insufficient or defective development of one or both lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy, resulting in underdeveloped or undeveloped pulmonary parenchyma with decreased alveoli Alveoli Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place. Acute Respiratory Distress Syndrome (ARDS) and airway Airway ABCDE Assessment branches.
Development of the
lungs
Lungs
Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2.
Lungs: Anatomy:
The respiratory system begins development by week 4 of gestation. The olfactory pit forms from the
ectoderm
Ectoderm
The outer of the three germ layers of an embryo.
Gastrulation and Neurulation, one of the structures to become the
nasal cavity
Nasal cavity
The proximal portion of the respiratory passages on either side of the nasal septum. Nasal cavities, extending from the nares to the nasopharynx, are lined with ciliated nasal mucosa.
Nose and Nasal Cavity: Anatomy. The laryngotracheal bud forms from the primitive
pharynx
Pharynx
The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking.
Pharynx: Anatomy. From this bud, the longitudinal
extension
Extension
Examination of the Upper Limbs becomes the tracheal and bronchial buds.
The process of
elongation
Elongation
Polymerase Chain Reaction (PCR) and branching of buds continues as conducting airways up to 16 weeks of gestation. Major maturation occurs by 24 weeks, with significant alveolar precursors developing and an increased amount of
surfactant
Surfactant
Substances and drugs that lower the surface tension of the mucoid layer lining the pulmonary alveoli.
Acute Respiratory Distress Syndrome (ARDS) produced. By 28 weeks of gestation, there usually will be enough mature
alveoli
Alveoli
Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.
Acute Respiratory Distress Syndrome (ARDS).
Mature structures of the lung: alveoli Alveoli Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place. Acute Respiratory Distress Syndrome (ARDS), bronchiole and pulmonary circulation Circulation The movement of the blood as it is pumped through the cardiovascular system. ABCDE Assessment
Image: “Bronchial anatomy” by Patrick J. Lynch. License: CC BY 2.5Multiple aspects of the impairment of fetal lung growth can lead to hypoplasia Hypoplasia Hypoplastic Left Heart Syndrome (HLHS).
A diagram of the Potter sequence potter sequence Potter sequence, which is due to severe oligohydramnios and the compressive effect of enlarged kidneys: positional limb deformities, craniofacial abnormalities, pulmonary hypoplasia, growth impairment, and feeding difficulties. Autosomal Recessive Polycystic Kidney Disease (ARPKD)
Image by Lecturio.
Potter sequence
potter sequence
Potter sequence, which is due to severe oligohydramnios and the compressive effect of enlarged kidneys: positional limb deformities, craniofacial abnormalities, pulmonary hypoplasia, growth impairment, and feeding difficulties.
Autosomal Recessive Polycystic Kidney Disease (ARPKD):
Pregnancy
Pregnancy
The status during which female mammals carry their developing young (embryos or fetuses) in utero before birth, beginning from fertilization to birth.
Pregnancy: Diagnosis, Physiology, and Care complicated by
oligohydramnios
Oligohydramnios
Oligohydramnios refers to amniotic fluid volume less than expected for the current gestational age. Oligohydramnios is diagnosed by ultrasound and defined as an amniotic fluid index (AFI) of ‰¤ 5 cm or a single deep pocket (SDP) of < 2 cm in the 2nd or 3rd trimester.
Oligohydramnios can lead to
newborn
Newborn
An infant during the first 28 days after birth.
Physical Examination of the Newborn abnormalities.
Images show Potter facies (
micrognathia
Micrognathia
Abnormally small jaw.
Pierre Robin Sequence,
low-set ears
Low-set ears
DiGeorge Syndrome, flattened nasal bridge, beaked
nose
Nose
The nose is the human body’s primary organ of smell and functions as part of the upper respiratory system. The nose may be best known for inhaling oxygen and exhaling carbon dioxide, but it also contributes to other important functions, such as tasting. The anatomy of the nose can be divided into the external nose and the nasal cavity.
Nose and Nasal Cavity: Anatomy). Limb deformities include persistently flexed and dislocated hip with bilateral clubbed
foot
Foot
The foot is the terminal portion of the lower limb, whose primary function is to bear weight and facilitate locomotion. The foot comprises 26 bones, including the tarsal bones, metatarsal bones, and phalanges. The bones of the foot form longitudinal and transverse arches and are supported by various muscles, ligaments, and tendons.
Foot: Anatomy. The
newborn
Newborn
An infant during the first 28 days after birth.
Physical Examination of the Newborn in the images also has an absent
right eye
Right Eye
Refractive Errors.
Pulmonary
hypoplasia
Hypoplasia
Hypoplastic Left Heart Syndrome (HLHS):
CT of the lung of a
neonate
Neonate
An infant during the first 28 days after birth.
Physical Examination of the Newborn with left lung
hypoplasia
Hypoplasia
Hypoplastic Left Heart Syndrome (HLHS)