|Year : 2012 | Volume
| Issue : 2 | Page : 93-95
Late preterms: A vulnerable group needing due attention
Milind M Jambagi, Suhail Ahmed Ambi, NS Mahantashetti
Department of Pediatrics, J N Medical College, Nehru Nagar, Belgaum, Karnataka, India
|Date of Web Publication||1-Oct-2012|
N S Mahantashetti
J N Medical College, Nehru Nagar, Belgaum-590 010, Karnataka
Source of Support: None, Conflict of Interest: None
"Late preterms may be apparently normal but a vulnerable group of preterm infants needing due attention both by the Obstetricians and Pediatricians. Late preterms like any other preterms are vulnerable to complications such as Respiratory Distress Syndrome (RDS) and other complications seen in a preterm infant. The American Congress of Obstetricians and Gynecologists guidelines recommend administration of antenatal corticosteroids in a mother in premature labor only up to the gestational age of 34 weeks. This is a case report of a preterm baby with a gestational age of 35 weeks which presented with RDS. We are hereby reporting this case to draw attention of the Obstetricians and Pediatricians toward this entity of 'Late Preterm' to provide better care to them and obtain better outcomes."
Keywords: Antenatal Corticosteroids, late preterm, near term, preterm, respiratory distress syndrome
|How to cite this article:|
Jambagi MM, Ambi SA, Mahantashetti N S. Late preterms: A vulnerable group needing due attention. J Sci Soc 2012;39:93-5
| Introduction|| |
The American Academy of Pediatrics and the American College of Obstetricians and Gynecologists define a "preterm" as one who is born before the end of the 37 th week (259 th day) of gestation, from the first day of the last menstrual period. But there is no consensus for defining "near term". Many descriptive terms have been used to describe the preterms widely ranging in gestational-age groups between 33 weeks and term, like-"marginally preterm", "moderately preterm", "minimally preterm," and "mildly preterm". As per the recommendations of a panel of experts suggested by the National Institute of Child Health and Human Development of the National Institutes of Health in the USA an apparently normal but vulnerable group of preterms was described as "late preterm" designating " infants born between the gestational ages of 34 weeks and 0/7 days through 36 weeks and 6/7 days (239 th -259 th day)". 
The panel also suggested that the phrase "Near Term" is misleading and conveys an impression that these infants are "almost term", resulting in under-estimation of risk and less-diligent evaluation, monitoring and follow-up. Several factors were considered in recommending the gestational age of 34 0/7 to 36 6/7 weeks to define as late preterm.  In obstetric view, 34 completed weeks is a maturational milestone for the fetus. But compared with the term infants, those born between 34 th and 37 th week of gestation have higher rates of morbidity and mortality. Because there is no such thing as a normal preterm infant, "late preterm" conveys the sense of vulnerability of these infants better than the phrase "near term".
Today, late preterms need greater attention due to the magnitude of the health problems they pose. The rate of preterm births in the US increased from 9.1% in 1981 to 12.3% in 2003, an increase of 31%, most of which was due to increase in the proportion of late preterms.  Late preterm births have increased from 7.33% in 1990 to 9.04% in 2007. Categorically, the rate of late preterm births accounts for three quarters of all preterms (<37 weeks) in the US.
The increase in the rate of late preterm deliveries is due to:
Late preterms are vulnerable as they are prone to develop following complications: 
- More women delivering at later years of age;
- Multiple births;
- Medically indicated preterm deliveries due to-prolonged premature rupture of membranes (PPROM), pregnancy-induced hypertension, placental abruption, infection, IUGR;
- Increased demand for Assisted Reproductive Technologies (ART); and
- Increased rate of multiple gestations.
Hence, the obstetric and neonatal care at late preterm gestations presents many challenges to the health care team. The obstetrician has to weigh the risks and benefits of immediate delivery against expectant management of preterm gestation. ,, A pediatrician has the challenging task to care of a preterm infant who maybe seemingly healthy but is at higher risk than term infant for several neonatal morbidities, higher readmission rates, and higher neonatal and postneonatal mortality rates.
- Respiratory distress syndrome (RDS) and transient tachypnea of newborn (TTN) due to lack of clearance of lung fluid and relative deficiency of surfactant, lack of labor and related hormonal changes in C-section:
- Hyperbilirubinemia; and
- Feeding difficulties-As deglutition, peristaltic functions, and sphincter controls are less mature.
In one study it was found that, of the above named complications RDS is very common in the late preterm infants. Hence, considering the vulnerability and need for greater attention toward the health issues of late preterms we are hereby reporting a case of " Respiratory Distress Syndrome in a Late Preterm".
| Case Report|| |
A 20-year-old primigravida delivered a female baby weighing 2.2 kg after 35 weeks of gestation by emergency caesarean section due to meconium-stained liquor. At birth, the baby was thick meconium-stained and did not cry immediately after birth with heart rate <40/min, no spontaneous respiratory efforts and cyanosis. Baby was meconium cleared, intubated, and resuscitated with Ambu bag ventilation. After 7-8 min of bag and endotracheal tube (ET) ventilation the baby started to have minimal spontaneous respiratory efforts and heart rate of >100/min.
The baby was shifted to our level-2 neonatal intensive care unit (NICU) for severe respiratory distress. On admission, the baby was found to have-grunting, severe respiratory distress, shock, and hypoglycemia (random blood sugar (RBS) of 37 mg/dl). According to the New Ballard Scoring System the infant was estimated to have a gestational age of about 34-35 weeks. Due to financial restraints the baby was managed supportively with Continuous Positive Airway Pressure (CPAP) for respiratory distress, IV fluids and inotropes for shock and hypoglycemia. With this, the child maintained a saturation of 90-95%, however, the distress continued and SPO2 started dipping after 6 hours. The chest radiograph of the baby at this time showed Hyaline Membrane Disease (HMD) with ground-glass appearance [Figure 1].
|Figure 1: Hyaline membrane disease with ground glass appearance on chest X-ray|
Click here to view
Due to financial restraints, the parents could not afford surfactant and ventilator therapy. As the baby continued to deteriorate and in view of grave prognosis the parents decided to discontinue the life supports after 24 hours.
| Discussion|| |
As reported in the above case RDS is a very common complication in late preterms like in the other preterm infants. RDS in late preterms is a life threatening complication, which may be caused due to various reasons as:
Thus the use of antenatal steroids even after 34 weeks till 36 weeks 6 days of gestation should now be practiced, which helps to improve the respiratory outcomes and reduces the chances of RDS in late preterms.
- Iatrogenic RDS due to: ,,
- Early delivery;
- CS as a mode of delivery; and
- Birth prior to the onset of labour.
- Low Lecithin/Sphingomyelin ratio in late-preterms. ,
- Low Surfactant protein A (SP-A).
- Residual lung fluid due to no squeezing of lungs in caesarean section, so less surfactant to alveolar surface. 
- Maturation and secretion of surfactant is enhanced by labor and triggered by B-adrenergic agents and prostaglandins, which lacks in Caesarean Section. ,,,
| Conclusion|| |
Late preterms are the great imposters and like the tip of an iceberg, which need greater attention and early recognition of their health issues with regular monitoring and evaluation. Precise estimation of gestational age is difficult and could pose a challenge to diagnose "Late Preterms", but studies have shown that the estimation of gestational age could be precise if regular ultrasound examinations had been done from early first trimester by which the accuracy of estimating the gestational age could be +/- 5 days of the exact age. This helps the health team to better manage a "Late Preterm" if such a delivery is anticipated and improves the immediate outcomes and subsequent late sequelae. It is recommended that, in a mother if a late preterm delivery (34 weeks to 36 weeks, 6 days) is anticipated, the use of antenatal steroids should be practiced routinely, which improves the respiratory outcome and reduces the chances of respiratory distress in them.
| References|| |
|1.||Engle WA. American Academy of Pediatrics, Committee on Fetus and Newborn. Age terminology during the perinatal period. Pediatrics 2004;114:1362-4. |
|2.||Raju TN, Higgins RD, Stark AR, Leveno KJ. Optimizing Care and Outcome for Late-Preterm (Near-Term) Infants: A Summary of the Workshop Sponsored by the National Institute of Child Health and Human Development. Pediatrics 2006;118:1207-14. |
|3.||National Center for Health Statistics. Public Use Data Tapes. Natality Data Set: 1992-2002. Hyattsville, MD: US Department of Health and Human Services, Centers for Disease Control and Prevention; 2005. |
|4.||Sibai BM. Preeclampsia as a cause of preterm and late preterm(near-term) births. Semin Perinatol 2006;30:16-9 |
|5.||Hankins GDV, Longo M. The role of stillbirth prevention andlate preterm (near-term) births. Semin Perinatol 2006;30:20-3. |
|6.||Hauth JC. Preterm labor and premature rupture of membranes: To deliver or not to deliver. Semin Perinatol 2006;30:98-102. |
|7.||Morrison JJ, Rennie JM, Milton PJ. Neonatal respiratorymorbidity and mode of delivery at term: influence of timing of elective caesarean section. Br J Obstet Gynaecol 1995;102:101-6. |
|8.||Parilla BV, Dooley SL, Jansen RD, Socol ML. Iatrogenic respiratory distress syndrome following elective repeat caesarean delivery. Obstet Gynecol 1993;81:392-5. |
|9.||Wax JR, Herson V, Carignan E, Mather J, Ingardia CJ. Contribution of elective delivery to severe respiratory distress at term. Am J Perinatol 2002;19:81-6. |
|10.||Callen P, Goldsworthy S, Graves L, Harvey D, Mellows H, Parkinson C. Mode of delivery and the lecithin/sphingomyelinratio. Br J Obstet Gynaecol 1979;86:965-8. |
|11.||Whittle MJ, Hill CM. Relation between the amniotic fluidlecithin/sphingomyelin ratio, fetal cord blood corticosteroidlevels and the duration of induced labour. Br J Obstet Gynaecol 1980;87:38-42. |
|12.||Lawson EE, Birdwell RL, Huang PS, Taeusch HW Jr. Augmentation of pulmonary surfactant secretion by lung expansion at birth. Pediatr Res 1979;13:611-4. |
|13.||Rooney SA, Gobran LI, Wai-Lee TS. Stimulation of surfactantproduction by oxytocin-induced labor in the rabbit. J Clin Invest1977;60:754-9. |
|14.||Marino PA, Rooney SA. The effect of labor on surfactant secretionin newborn rabbit lung slices. Biochim Biophys Acta 1981;664:389-96. |
|15.||McDonald JV Jr, Gonzales LW, Ballard PL, Pitha J, Roberts JM. Lung beta-adrenoreceptor blockade affects perinatal surfactant release but not lung water. J Appl Physiol 1986;1727-33. |
|16.||Roth-Kleiner M, Wagner BP, Bachmann D, Pfenninger J. Respiratory distress syndrome in near-term babies after caesarean section. Swiss Med Wkly 2003;133:283-8. |