Relationship Between Posterior Fontanelle with Gestational Age

In this study we have measured size and area of posterior fontanelle and have studied its relations with gestational age in human fetuses. This study is aimed to provide a range of normal posterior fontanelle dimensions and to provide base for further research in Asian population on morphology of posterior fontanelle and see if there exists any significant difference when compared to European & African studies. For this fifty fetuses were arranged in 5 groups according to their gestational age. Mean posterior fontanelle size and area of each group is measured. After statistical calculations it was observed that posterior fontanelle size and area both vary significantly with gestational age. Key-words: fetus, Posterior Fontanelle, Change in size Corresponding Author: Dr. Nema Usman , Lecturer Dept. Anatomy, J.N.Medical College ,A.M.U, Aligarh,202002, email : [email protected] , [email protected] INTRODUCTION: Developmental anatomy is one of the sub-disciplines of anatomy which has attained great significance in the research field. Embryogenesis has been extensively explored but the literature relating to organogenesis appears relatively sparse and inadequate. Fetal research is gaining importance due to usage of invasive and non-invasive procedures in fetal defect correction. Cudithy has performed cranial ultrasonography via posterior fontanelle to obtain middle sagittal views of cerebellum. Anderson obtained normal brain anatomy by posterior fontanelle ultrasonography. Pooh revolutionized the ultrasonographic technique by using trans-vaginal power doppler to obtain angiography. Faix studied fontanelle size in black and white newborn infants. Philip studied fontanelle size and epiphyaeal ossification in neonatal twins discordant by weight. Tan 6 studied large fontanelles in newborns.Philip studied fetal growth retardation by femurs and fontanelles. Adeyemo and Omotade studied variations in fontanelle diameter with gestational age. Places in the skull of newborn infants, where contact between bones does not occur and the sutures are wide areas of fibrous tissue are known as fontanelles or fonticulli. Anatomically there are at least six fontanelles in a fetal skull: an anterior, a posterior, two mastoid and two sphenoidal fontanelles Posterior fontanelle is triangular in shape . It is present at the junction of lambdoid and sagittal, sutures and its time of closure is 2-3 months after Birth Wull observed the widely opened posterior fontanelle as one of the most important finding in cases of congenital hypothyroidism during neonatal screening. In this study we will measure size and area of posterior fontanelle and study its relations with gestational age in fetuses. Cephalic indices in Indians are known to vary from those of Europeans. In such situations, a study on Indian specimens seems relevant. Posterior fontanelle is considered because it is, important clinically, has proper shape making the measurements feasible and has support of previous literature. Present study is conducted with following aims1.To provide a range of normal posterior fontanelle dimensions. 2. To find out the alterations in morphogenesis with gestational age. 3.To determine the pattern of growth. 4. To collect the informations about the relative growth. MATERIAL AND METHODS: Fifty fetuses from museum of department of anatomy in SRMS IMS Bareilly was used for study. Fetuses selected for study were without any obvious congenital anomaly. They were preserved museum specimens. They were preserved since many years. Parameter Relationship Between Posterior Fontanelle with Gestational Age NJIRM 2011; Vol. 2(2).April-June-Special eISSN: 0975-9840 pISSN: 2230 9969 P ag e5 4 used for assessment of gestational age is fetal foot length. Fair correlation between foot length and gestational age was documented For the purpose of study fetuses were divided into 5 groups : GROUP GESTATIONAL AGE NUMBER OF FETUSES A Upto 16 weeks 6 B 16-20 weeks 14 C 21-25 weeks 11 D 26-30 weeks 12 E More than 30 weeks 7 Following parameters were measured: Fetal Foot Length (in mm), Head Circumference (HC) (in mm), Posterior Fontanelle Size (PFS)Maximum fontanelle length in sagittal section and Posterior Fontanelle Area (PFA)-Area of triangle is taken as PFA. Method for measuring PFA is shown in figure below RESULTS: Result is tabulated in following table Table 1: POSTERIOR FONTANELLE SIZE(PFS): GROUP MEAN PFS (IN MM) S.D. PERCENT CHANGE #