Determination of Crown‐Rump length from fetal long bones: Humerus and femur

Abstract

Lengths of the ossified diaphysis of the humerus and femur were measured in 50 fetuses ranging from 65 to 290 mm Crown-Rump length. A significant correlation was found between the diaphyseal length and the CR length. No appreciable difference was noted in diaphyseal lengths of the humerus and femur i n fetuses of 85 mm CR length or below. Various growth phases were observed. The difference i n length of the femur and humerus is due to a comparative slow growth of the humerus during the later period of prenatal life. Diaphyseal growth rates of the humerus and femur are 0.18 mm and 0.21 m m respectively for every 1 mm increase in CR length. Regression coefficients for the lengths of the ossified shaft of the humerus and femur are 5.35 and 5.00 respectively. With the help of these coefficients, CR length of the fetus was estimated within a range of k 1 5 mm. From the estimated CR length, age of the fetus was determined with the help of a standard age and size curve with reasonable accuracy.Study of the correlation between linear growth of long bones and the CR (CrownRump) length of the fetus assumes importance in medicolegal practice, since the correlation can be used to estimate the age of the fetus from its available long bones.Growth of long bones during prenatal life has been studied in detail (Nishizuka, '26; Streeter, '49; Felts, '54). Radiographic studies on the prenatal ossification of human long bones recording the ratio of the lengths of the ossified shaft relative to the corresponding CR length have been undertaken (Bade, '00; Halonen, '29; ORahilly and Meyer, '56). Various phases of linear growth of long bones have been reported (Depreux and Fontaine, '51 ; Moss et al., '55) and a linear correlation between diaphyseal length and fetal height has been observed (Smith, '39; Saettle, '51; Olivier and Pineau, '60). Recently, Gray and Gardner ('69) and Gardner and Gray ('70) in their reports on the prenatal development of the humerus and femur published tables showing the lengths of the ossified shaft and the corresponding CR length in fetal specimens of 37 to 342 mm CR length. AM, J. PHYS. ANTHROP.. 36: 165-168.In the present study the lengths of the ossified diaphysis of the humerus and femur were measured in fetal specimens of 65 to 290 mm CR length and a formula derived to estimate the age of the fetus based on the correlation of the diaphyseal growth with the CR length. MATERIALS AND METHODSWe studied 50 apparently normal fetuses, 30 male and 20 female, delivered by normal women and having a CR length ranging from 65 to 290 mm. The CR length was measured, after fixation of fetuses i n 10% formaline for four to six months, with a specially prepared osteometric board to the exactness of 1 mm. Values were verified by recording several times. The limbs were detached and placed in 5% KOH solution at room temperature for about two weeks. After thorough washing in running tap water, the humerus and femur were dissected out and cleaned. The cartilaginous ends were removed gently. The remaining ossified ...

The growth of long bones in human embryological and fetal upper limbs and its relationship to other developmental patterns

“…In a study of 50 fetuses (CRL between 65 and 290 ram), Mehta and Singh (1972) suggested that measurements of the ossified regions of humerus and femur could be used to determine the CRL. Bagnall et al (1982), in a radiographic study of the growth of ossification centres in limb long bones of human fetuses from 8 to 24 weeks, observed that humeral growth appeared much more marked on the left side of the body, and suggested that some other factors, such as manual dominance, may be related to it.…”

“…Mehta and Singh (1972) concluded their investigation by suggesting that once the CRL could be estimated from the length of the ossified shafts of humerus and femur, the fetal age could be estimated with reasonable accuracy. Kelemen et al (1984) measured the length of 491 long bones derived from 193 human fetuses (developmental age from 7 to 22 weeks) and suggested a linear correlation between the fetal age (assessed by measuring the CRL) and the long bone length.…”

“…Nevertheless, some authors have proposed the assessment of fetal age on the basis of long bone measurement (Felts 1954;Moss et al 1955;Gardner and Gray 1969;Mehta and Singh 1972;Kelemen et al 1984;Kalifa et al 1989). The appearance of ossified skeletal tracts and their longitudinal measurements could be considered as significant because the skeleton maintains its integrity even in non-vital fetuses persisting in the uterus some days before expulsion.…”

Fetal age: Methods of estimation and effects of pathology

“…Another method uses long bone measurements first to estimate fetal body size; the estimated body size is then used to estimate fetal age (Mehta and Singh, 1972;Fazekas and Kósa, 1978). Although producing a point estimate of gestational age, this method results in a compounded error (Smith, 1996).…”

Ossification Centers of Human Femur

“…The total length of the femora, measured by a slide calliper under a stereomicroscope, ranged between 12.5 and 126 mm. Conceptual age was calculated by correlation with the menstrual age reported on the catalog of the collection and by morphometric parameters commonly reported in literature: biparietal diameter and/or length of the ossified shaft of long bones for the smaller samples [1,11,[12][13][14][15]. The femora (it was not possible to identify the sex of the specimens) did not show any detectable malformation.…”