How Do I Calculate Mid-Parental Height and Other Growth Parameters?

Patient Presentation
A 5-year-old male came to clinic for his health supervision visit. His father was concerned because he seemed “short” to him and wanted to know how tall he would be when he grew up. Otherwise there were no concerns. His father was 5 foot 9 inches and his mother was 5 foot 3 inches tall. His father said that both parents went through puberty “at the normal times.” The boys’ growth chart showed him to be growing at the 10-25% for height and 50% for weight. The family history showed diabetes and stroke.

The pertinent physical exam showed a happy boy with a weight of 18 kg (50th %) and height of 106 cm (25%) and a BMI of 16 (50%). He was Tanner stage 1 and had a normal examination. The diagnosis of a healthy normally growing boy was made. The resident seeing him knew there was a calculation for evaluating mid-parental height but didn’t know what it was. When she talked with the attending physician they reviewed the calculation and determined that his midparental height would be [paternal height of 69 inches + (maternal height of 63 inches + 5 inches or 68 inches )] / 2 or 68.5 inches. This calculated height also appeared to be consistent with his previous and current growth pattern and was communicated to the family.

Discussion
Parents and pediatric healthcare providers are very concerned with children’s growth as it is such an important marker of their health status. Healthcare providers know, but parents often need to be educated, that it is not the exact measurements but the change in height, weight or head circumference that is the most important determinant. Therefore knowing some basic growth parameters and their changes over time are extremely important for analyzing children’s growth patterns. Children that appear to not be following these general patterns may do so for many reasons such as prematurity, chronic illness, or genetic constitution. But children who are not following these general patterns need to be at a minimum monitored closely and an appropriate evaluation begun if they appear to continue to be deviating from the normal patterns or if the deviation is increasing.

Learning Point
Averages at Birth
Weight = 3.5 kg (7.7 pounds)
Head circumference = 35 cm (14 inches)
Length = 50 cm (20 inches)

Weight
Infant weight gain averages 30 grams/day for the first 3 months, then decreases to 10-20 grams/day for the first year
Infants double their birth weight by 6 months and triple by 12 month of age
Estimated Weight: [2 x(age in years)] + 10 = weight in kg
General averages of weight at:

    1 year = 10 kg (22 pounds)
    5 years = 20 kg (44 pounds)
    10 years = 30 kg (66 pounds)
    11-12 years = 36 kg (80 pounds to be able to move out of a car booster seat)

Underweight
Age <3 years = weight for length is <3rd percentile for age
Or
Age >2 years = BMI for age is <5th percentile for age

Overweight
Age 95th percentile for age
Or
Age >2 years = BMI for age is >95th percentile for age or BMI is >30 kg/m2

Height
General averages of height increase are:

    0-1 year = 10 inches/year (25 cm/year)
    1-2 years = 5 inches/year (12.5 cm/year)
    2 year-puberty = 2.5 inches/year (6.25 cm/year)

Calculation of Mid-Parental Height
This calculation corrects for the opposite gender parents height so that a mid-parental height can be calculated and evaluated on the appropriate gender growth chart
For boys: [paternal height + (maternal height + 5 inches or 13 centimeters)] / 2
For girls: [maternal height + (paternal height - 5 inches or 13 centimeters)] / 2

Head Circumference
General averages for head circumference increase are:

    0-3 months = 2 cm/month (average 3 month old is 41 cm)
    0-1 year = 1 cm/month (average 1 year old is 47 cm)
    > 1 year = only another 8 cm total (average adult is 55 cm)

Premature Infants
When evaluating growth in premature children, they should have prematurity corrected for until 2.5 years of age chronologically.
Some children may “catch-up” before this depending on many factors.

Questions for Further Discussion
1. How much weight and height should a normal school age child gain in a year?
2. At 2 years old, how can you tell what the high school graduation cap size will be?
3. What are the indications for an endocrinology evaluation for a child with abnormal growth patterns?
4. Explain the differences between constitutional growth delay and familial short stature?
5. Where can I find normal growth parameters for common genetic syndromes or non-U.S. populations?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Child Development and Growth Disorders.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Bacon GE, Spencer ML, Hopwood NJ, Kelch RP. A Practical Approach to Pediatric Endocrinology. Year Book Medical Publisher, Chicago, IL. 1990;62-96.

Grover G. Nutritional Needs in Pediatrics a Primary Care Approach, Berkowitz CD, ed. W.B. Saunders Co., Philadelphia, PA. 1996;35-36.

Custer JW, Rau RE. The Harriet Lane Handbook. 18th. Edit. Elsevier/Mosby Publications: Philadelphia, PA. 2009:285, 561-576.

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    5. Patients and their families are counseled and educated.
    8. Health care services aimed at preventing health problems or maintaining health are provided.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
    15. Information technology to manage information, access on-line medical information and support the healthcare professional’s own education is used.
    16. Learning of students and other health care professionals is facilitated.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • If I Had To, How Would I Use Anti-Venom?

    Patient Presentation
    A 7-year-old male was playing with a large box that had been in the yard undisturbed for several days.
    He was kicking and moving the box when he noticed a small snake at the opening. He ran away and called his parents.
    His father, using gloves, moved the box to the edge of the yard and when the box tipped over several small snakes and a large snake with a copper-colored body and triangular shaped head emerged and slithered into a marshy area nearby.
    The father who was a general pediatrician realized that he and his son had been very lucky in not being bitten, probably by a copperhead. Later he realized that he did not know how to use snake anti-venom and decided to do a PUBMED and general Internet search. He found several references to answer his question.

    Discussion
    In the United States there were 3264 snake bites reported to the American Association of Poison Control Centers in 2007.
    Bites and envenomations were the 13th most common substances involved in human exposures as reported by the same group.
    There are basically two types of venomous snakes in the U.S.:

    • Family – Crotalidae
      • Pit Vipers – copperheads, rattlesnake, cottonmouth, sidewinder
      • About 98-99% of all envenomations
      • Occur more in warmer months but can occur at any time
      • Bite reactions:
        • Extensive local reaction with severe pain and extensive regional swelling that can occur in as little as 10-30 minutes.
        • Coagulation disorders may follow such as epistaxis, purpura, hemolysis or disseminated intravascular coagulation occurring in 30 minutes-48 hours.
        • Shock can also be seen at the same time as the coagulation disorders.
        • Necrosis occurs after 6 hours and needs appropriate wound care.
    • Family Elapidae
      • Coral snakes
      • Along with imported venomous snakes = ~1-2% of all envenomations
      • Bite reactions:
        • Neurological syndromes move the patient toward respiratory paralysis and coma are seen.
        • Hypotension, myosis, hypersalivation, increased sweating, dysphagia and dyspnea can be seen along with paraesthesia and paresia. This can occur in the first 10-30 minutes.
        • Later, 30 minutes-5 hours, patients will have ptosis, trismus, respiratory paralysis and shock.

    Learning Point
    About 20-50% of snake bites have no envenomation. If an envenomation occurs, the severity depends on many factors, especially snake factors such as the quantity of venom injected. The bite site is important (head and neck are more dangerous), as are the size and weight of the individual with children being more seriously affected. Fang marks may not be seen, or there may be fang marks, scratch marks, vesicles or hemorrhagic blebs seen. Measuring the distance between the fang marks can give a general idea of the size of the snake.

    Initial treatment is rest, immobilization with the affected part below the heart and transportation to a hospital. If no envenomation appears to have occurred then patients are usually watched for 6-12 hours. Laboratory testing especially for respiratory status (blood gas) and coagulations disorders is necessary and needs to be re-evaluated at regular intervals. Anti-venom is the treatment for snake bites where envenomation has occurred. There are two types of antivenom: horse-derived and ovine-derived. Horse antivenom can cause allergic reactions including anaphylaxis. Ovine-derived appears to have fewer side effects. One study of ovine antivenom used for rattlesnake evenomations in children showed it was safe and seemed to be effective. Anti-venom is NOT give on a weight basis but is given on a vial basis. Children may require more anti-venom than a similar bite in an adult. Poison control experts can provide guidance for health care providers treating evenomations. Poison control centers are available nationally by calling toll free at 1-800-222-1222.

    Questions for Further Discussion
    1. How do you treat scorpion bites?
    2. What spiders are commonly poisonous and how are they treated?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Animal Bites

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Medicine Sans Frontieres. Snake Bites. Clinical Guidelines Diagnosis and Treatment Manual. 2007:272-274.

    Bronstein, AC, Spyker, DA, Cantilena JR, LR, Green, JL, Rumack, BH. and Heard, SE.2007 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 25th
    Annual Report,Clinical Toxicology, 2008;46:10,927 — 1057.

    ACGME Competencies Highlighted by Case

  • Patient Care
    6. Information technology to support patient care decisions and patient education is used.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.

  • Practice Based Learning and Improvement
    12. Evidence from scientific studies related to the patients’ health problems is located, appraised and assimilated.
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.
    15. Information technology to manage information, access on-line medical information and support the healthcare professional’s own education is used.

  • Interpersonal and Communication Skills
    17. A therapeutic and ethically sound relationship with patients is created and sustained.
    18. Using effective nonverbal, explanatory, questioning, and writing skills, the healthcare professional uses effective listening skills and elicits and provides information.
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • What Are the Complications of Cardiothoracic Surgery?

    Patient Presentation
    A term female infant with prenatally diagnosed left congenital diaphragmatic hernia was born by normal spontaneous vaginal delivery.
    She developed respiratory distress at the time of birth that was treated with nasopharyngeal continuous positive airway pressure.
    On day of life 4 she underwent a repairlater of a Bochdalek-type congenital diaphragmatic hernia with opening of the left chest cavity. The procedure went well. On day of life 5, she had a chest x-ray that revealed some atelectesis.
    She was intubated on day of life 6 for increased tachypnea and work of breathing.

    A few hours her pertinent physical exam showed an intubated infant with a clean surgical scar. Her respiratory rate was 84, heart rate was in the 150-180s with normal blood pressure. She had a weight of 3450 grams that was increased from a birth weight of 3260 grams.
    Her heart examination had a normal S1, S2 with no murmur. Her lung examination revealed decreased breath sounds on the left relative to the right side which had been equal prior.
    She had some paradoxical breathing. The rest of her examination was normal.

    The laboratory evaluation of a complete blood count, C-reactive protein and blood cultures were eventually normal. The radiologic evaluation of a chest radiograph showed a large left pleural effusion with a shift of the heart to the right side with no bowel gas in the chest. Thoracentesis revealed increased triglycerides and lymphocytes in the fluid.

    The diagnosis of a chylothorax was made. A chest tube was placed for drainage and the infant was placed on formula containing medium chain fatty acids.
    She stabilized and was doing well 2 days later.

    Case Image
    Figure 78 – AP radiographs of the chest taken immediately after a left-sided congenital diaphragmatic hernia repair (above) and then 2 days later (below). The radiograph taken immediately post-operatively shows the hypoplastic left lung bud in the apex of the lung, and there is no pleural fluid. The radiograph taken 2 days later shows interval near-total opacification of the left hemithorax secondary to development of a large left pleural effusion. The aerated lung bud in the apex of the left lung is faintly seen. There is slight mediastinal shift to the right and the diaphragmatic hernia has not recurred.

    Discussion
    Congenital diaphragmatic hernia (CDH) occurs in 1 / 2000-3000 live births.
    Its overall mortality has been hard to determine as many infants die in-utero or just after birth before transfer for surgical care.
    One study found that ~61% of fetuses with CDH are live born. Many of these fetuses had other congenital anomalies.
    Mortality after live birth is ~ 40-62%.

    There are 3 major types of CDH:

    • Bochdalek hernia which occurs posterolaterally
    • Morgagni hernia which occurs anteriorly
    • Hiatus hernia

    Left sided Bochdalek hernias are the most common (85%). Treatment currently includes fetal surgical repair, post-natal surgical repair and critical care.

    Learning Point
    Cardiothoracic surgical repairs are critical for treatment of CDH and other congenital heart disease or congenital malformations. These surgeries themselves have their own associated mortalities and morbidities.
    The European Association for Cardiothoracic Surgery and The Society of Thoracic Surgeons and other groups published a comprehensive listing of more than 2800 definitions of cardiothoracic surgical complications.

    Below is a condensation of this vast listing:

    • Arrhythmias requiring drug treatment, defibrillation, cardioversion, or pacemaker
    • Cardiac
      • Cardiac arrest, dysfunction or failure
      • Endocarditis
      • Pericardial effusion
      • Pulmonary hypertension
      • Pulmonary hypertensive crisis
      • Pulmonary vein obstruction
      • Systemic vein obstruction
    • General
      • Death
      • Readmission
      • Multiple organ system failure
    • Neurological
      • Neurological deficit – transient or persistent
      • Paralyzed diaphragm
      • Peripheral nerve injury
      • Seizure
      • Spinal cord injury
      • Stroke
      • Vocal cord dysfunction
    • Operative/Procedures
      • Bleeding requiring re-operation
      • Sternum left open – planned or unplanned
      • Unplanned cardiac re-operation or interventional procedure
      • Mechanical support utilization
    • Pulmonary
      • Chylothorax
      • Pleural effusion requiring drainage
      • Pneumonia
      • Pneumothorax
      • Respiratory insufficiency requiring mechanical ventilation for > 7 Days, reintubation or tracheostomy
    • Renal failure requiring dialysis
    • Sepsis
    • Wound
      • Infection – superficial, deep, mediastinitis
      • Dehiscence
    • Other complications not listed in the exhaustive listing

    Questions for Further Discussion
    1. What are the potential complications of fetal surgeries?
    2. How do various specialties work with parents of in-utero fetuses with potential congenital anomalies to plan prenatal and post-natal treatment in your region?
    3. What surgical procedures are being performed using robotic surgery?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for these topics: Hernia and Birth Defects.

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Jacobs JP. Introduction – Databases and the assessment of complications associated with the treatment of patients with congenital cardiac disease.
    Cardiology in the Young, 2008;18 (S2);1-37.

    Part IV – the dictionary of definitions of complications associated with the treatment of patients with congenital cardiac disease.
    Cardiology in the Young, 2008;18 (S2);282-530.

    Steinhorn RH. Congenital Diaphragmatic Hernia. eMedicine.
    Available from the Internet at http://emedicine.medscape.com/article/978118-overview (rev. 7/9/2009, cited 7/22/09).

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • What Forms of Vitamin K Exist?

    Patient Presentation
    A 4-day-old full-term female came to clinic for her health supervision visit.
    She was breastfeeding well for a total of 15-25 minutes every 2.5 – 3.0 hours with multiple bowel movements and urinations per day. Her parents were concerned because she was slightly jaundiced. She was sleeping well and was usually easily arousable. The past medical history showed a full-term normal spontaneous vaginal delivery after an 18 hour labor and delivery. Apgars were 8 and 9. She went home after 48 hours and had had regular newborn care with the exception of the parents refusing Vitamin K injection. Documentation revealed several conversations about this with the family and she had received a dose of oral Vitamin K in the first 24 hours of life, with the plan to repeat the dose at 5-7 days and again at 4 weeks.

    The family history was non-contributory and was negative for bleeding problems and hepatobiliary problems. The review of systems was negative. The pertinent physical exam showed a quietly alert female with mild jaundice of the face and normal vital signs. Her weight was 3345 grams which was decreased from 3360 grams at discharge and decreased from a birth weight of 3390 grams. She had mild icterus of her skin and had no bruising. The rest of her examination was normal.

    The diagnosis of a healthy newborn with very mild jaundice was made. As the family was leaving, the parents asked the physician for a prescription for more Vitamin K as they said they had not received a prescription. The physician wrote a prescription and had thought that it would be filled at the hospital pharmacy since they had compounded the medication previously. An outside pharmacy called the physician stating that there was no oral form of Vitamin K currently available, only an intravenous or injectable form. The physician asked the outside pharmacy to have the family return to the hospital pharmacy who was able to compound the Vitamin K into a suspension using a Vitamin K tablet.

    Discussion
    Vitamin K is critical for prevention of Vitamin K Deficiency Bleeding (VKDB) formerly known as hemorrhagic disease of the newborn. Dr. Charles Townsend first described this entity in 1894. Vitamin K is necessary for the synthesis of prothrombin and Factors VII, IX and X. Vitamin K stores are low at birth and also are low in breast milk.

    VKDB has 3 presentation variants:

      • Early
        • Bleeding occurs in first 24 hours.
        • Bleeding sites – intraabdominal, intracranial, intrathoracic, skin and subperiosteal
        • Generally occurs with mothers who are taking anticonvulsants, warfarin or anti-tuberculosis medications
        Classical
        • Bleeding occurs usually between day of life 1-7 days (especially at 2-5 days)
        • Bleeding sites – circumcision, gastrointestinal, intraabdominal, intracranial, intrathoracic, and skin
        • Incidence is 4.4-89 / 100,000 births without Vitamin K prophylaxis
        Late
        • Bleeding occurs usually between 2-12 weeks (peak 3-8 weeks)
        • Bleeding sites – intracranial, skin and gastrointestinal tract (up to 50% is intracranial)
        • Occurs often in breastfed babies without Vitamin K prophylaxis
        • Occurs in babies with unsuspected cholestatic liver disease who may have received Vitamin K. Bleeding may be the first indication of the problem
        • Incidence is 4.4-72 / 10,000 births without Vitamin K prophylaxis

    Vitamin K given close to birth helps to prevent all 3 variants. Vitamin K given IM generally prevents classical and late disease. Vitamin K given orally prevents classical but may not prevent late disease particularly if the baby is premature, breastfed or has liver disease. Internationally, there are different dosing regimens used, but basically babies with these risk factors need higher doses or more doses of Vitamin K.

    Learning Point
    In the United States currently there is only an intravenous/intramuscular/subcutaneous form of Vitamin K available. It is recommended by the American Academy of Pediatrics as it is the only one available and also because it treats both classical and late disease. In the future, it appears that an oral product will be licensed in the United States. Currently if an oral product is needed because of parental refusal of injectable Vitamin K, it must be compounded using a Vitamin K tablet. The tablet/compounded form is not as effective as the oral forms available in other counties as they are slightly different formulations. Also, as this tablet/compounded product is a suspension, there is also the additional problem that the Vitamin K may not actually be delivered as the suspended particles may fall to the bottom of the bottle, or stick to the sides of the bottle or syringe.

    Questions for Further Discussion
    1. Where can you get tablet/compounded Vitamin K in your community?
    2. If you were on the expert panel for the American Academy of Pediatrics and the oral form of Vitamin K became available, what dosing regimen would you advocate for?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for these topics: Vitamins and Bleeding Disorders.

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    American Academy of Pediatrics Policy Statement. Controversies Concerning Vitamin K and the Newborn. Pediatrics. 2003:112;191-192. Available from the Internet at: http://aappolicy.aappublications.org/cgi/content/full/pediatrics;112/1/191 (rev. 09/2006 cited 7/16/09).

    Auckland District Health Board. Newborn Services Clinical Guideline. Vitamin K prophylaxis and Vitamin K Deficiency Bleeding. Available from the Internet at: http://www.adhb.govt.nz/newborn/Guidelines/Blood/VitaminK.htm (rev. 7/16/09, cited 7/16/09).

    Shearer MJ. Vitamin K deficiency bleeding (VKDB) in early infancy. Blood Rev. 2009 Mar;23(2):49-59. Epub 2008 Sep 19.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Professionalism
    22. Sensitivity and responsiveness to patients’ culture, age, gender, and disabilities are demonstrated.

  • Systems Based Practice
    26. Partnering with health care managers and health care providers to assess, coordinate, and improve health care and how these activities can affect system performance are known.

    Author
    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital