|Year : 1985 | Volume
| Issue : 1 | Page : 37-39
Pupillary Membrane (a good criteria to assess gestational age of the new born)
KL Sethia, Anita Chahar, UK Satsangi, R Sahai
Department of Ophthalmology, S.P. Medical College, Bikaner, India
K L Sethia
Deptt. Of Ophthalmology, S.P. Medical College, Bikaner
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Sethia K L, Chahar A, Satsangi U K, Sahai R. Pupillary Membrane (a good criteria to assess gestational age of the new born). Indian J Ophthalmol 1985;33:37-9
|How to cite this URL:|
Sethia K L, Chahar A, Satsangi U K, Sahai R. Pupillary Membrane (a good criteria to assess gestational age of the new born). Indian J Ophthalmol [serial online] 1985 [cited 2020 May 30];33:37-9. Available from: http://www.ijo.in/text.asp?1985/33/1/37/27329
An ideal system for assessment of gestational age applicable to the masses should involve a system with use of minimum number of variables and should be least time consuming and disturbing to an ill or preterm baby. The present study was taken to evaluate the efficacy of assessment of gestational age by visualising pupillary membrane in new borns, and comparing it with other well known criteria for assessing the gestational age like L. M. P. (last menstrual period, birth weight and physical criteria, taking L.M.P. as a base value.
| Material and methods|| |
Total 320 new borns delivered mothers whose remembered their first day of last menstrual period (L.M.P.), were included in the present study. Examination was done within 24 hours of birth. Gestational age was assessed by different criteria namely L.M.P., weight of the new borns, physical criteria and pupillary membrane.
Nude new born wrapped in a sterile towel was weighed with the help of Detecto Scale Balance. Gestational age in weeks was determined with the help of intrauterine weight charts
Assessment of gestational age by physical criteria was done.
Examination of the pupillary membrane was done by hand slit lamp after dilating the pupil with phenylepherine 10%. An arbitrary grading of anterior vascular membrane was done according to Hittner et al to judge the gestational age of the new born in weeks.
| Observations|| |
The present study included 320 new borns, out of which 208 (65%) were males and 112 (35%) females. The new borns were divided into three groups namely-Premature 50 (16.63%), Mature 268 (83.75%) and Postmature 2 (0.62%) on the basis of L.M.P.
50 Pre-term babies, when assessed on the basis of weight, were further classified into three groups-Appropriate for date 38 (76%), Small for date 11 (22%) and Large for date 1(2%).
[Table - 1] shows mean age of the premature new borns by L.M.P., weight, physical signs, and pupillary membrane.
[Table - 2] shows comparison of estimated gestational age in premature by pupillary membrane with physical signs and weight.
Knowledge of gestational age of a new born enables the neonatologist to manage the case in a better way. Easiest way to know the gestational age is to calculate it from the date of last menstrual period (L.M.P.) of the mother but many of the mothers especially those belonging to the low educational and socio-economic status are rather vague about the L.M.P., The date may also be wrong or may not be available if the periods are irregular, if conception has occurred during lactational amenorrhoea or if the mother was on hormone therapy prior to conception. Inn cases of pre-marital conception, the period may be post-dated intentionally by the mother. Similarly it can be pre-dated in cases of medicolegal interest. The inaccuracy of information about L.M.P. iii determining gestational age can amount to about 20 to 30%, when we rely on mothers' memory. This inaccuracy is likely to be intensified in our country.
| Discussion|| |
Pre-maturity if considered by low birth weight alone, not only includes small full term infants but also excludes many premature infants. W.H.O. (1961) recommended that the concept of pre-maturity be replaced by that of low birth weight for all infants weighing less than 2500 gms. Morbidity and mortality definitely increased in low birth weight new borns but form two distinct classes :
(i) Low birth infants born before term, have a high incidence of respiratory distress syndrome (hyaline membrane disease).
(ii) Low birth weight infants, though born at terms, but have growth retardation due to placental insufficiency, are pre-disposed to the complications of foetal malnutrition.
These considerations compel one to be aware of gestational age and low birth weight as two independent parameters when treating new borns.
In the present study out of the total 320 new borns, 50 (15.63%) were pre-mature. This incidence of pre-maturity coincides with earlier studies in India,.
Reliance upon the weight alone for calculating gestational age often misleads the conclusion as few may not coincide with the exact gestational age, being large or small for date
Another conventional method of using physical criteria is too time consuming and disturbing for a sick pre-term baby and requires considerable exposure of the new born.
Hence, recently pupillary membrane created a new interest in the assessment of gestational age. It regresses in a specific manner between 27 to 34 weeks. Central arcade disappears first, then intermediate tier and lastly peripheral tier disappears. After 34 weeks these vessels are generally atrophied completely. Before 24 weeks cornea is too hazy to visualise pupillary membrane.
Taking L.M.P. as a base value, the mean gestational age when compared with pupillary membrane showed that it was coinciding in 96% cases. While with physical signs and weight method, it was coinciding in 76% and 80% cases respectively.
In this study p value less than 0.02 i.e. significant, was found between physical signs and pupillary membrane while between weight and pupillary membrane p value less than 0.005 i.e. highly significant, was found.
It was clear from our study that the pupillary membrane is a constant finding in the pre-term new borns and is easy and useful method to know their gestational age.
| Summary|| |
Examination of the anterior vascular capsule for assessment of gestational age should be adopted as an adjunct with other criteria as a routine procedure. It helps the clinician to clearly identify the various categories of the high risk pre-term infants so that optimum treatment can be promptly instituted. Besides it gives an opportunity to detect the congenital anomalies if any, at an early date.
| References|| |
Singh, M , Giri, S. K. and Ram Chandran K. 1974, Indian Ped., 11 : 475.
Perkin, J. M., Hey, E. N. and Clowes, J S. 1976, Arch. Dis. Childh, 51 :259.
Hittner, H. M., Hirsch, N. J. and Rudolph, A.J. 1677, J. Paed., 91 : 455.
Chikaramana, A. S., Majumdar, G. R. and Shah. A.P. 1969, Ind. Paed. 6 : 720.
Ghosh, L. V., Sen, M. and Chandra Sekar, S. C. 1944, Cited by Saigal S. and Srivastava, J. R., 1969 Ind. Paed. 6 ; 2.
Kalara, K., Kishore, N. and Dayal, R. S. 1976, Ind J. Paed. 34:73
[Table - 1], [Table - 2]