1. IntroductionAnthropometry is the method for assessing the corpulence, proportions and composition of the human body [1] . It is of great interest in public health and in clinical decisions because body dimensions, whatever the age, reflect the overall state of health and well-being of individuals and populations. Thus, for newborns, the anthropometric study is an essential research tool for studying the determinants and early consequences of insufficient or excessive fetal growth [2] [3] . According to the World Health Organization (WHO), body size at birth reflects the duration of gestation and the speed of fetal growth [1] . The rate of fetal growth will be influenced by both maternal and paternal factors [2] [4] . However, it must be recognized that any population has its own characteristics, determined by racial, ethnic, geographic, nutritional and socio-economic factors [5] [6] [7] [8] .
As a result, numerous studies have been able to demonstrate that the anthropometric parameters of the newborn at birth vary from one region to another, from one population to another. In the United States of America, Neggers et al. in 1995 in Alabama through an anthropometric study of 1205 full-term births at the University Hospital of Alabama found an average weight of 3272 grams (g), an average head circumference (BW) of 34.1 centimeters (cm), a thoracic perimeter (PT) of 33 centimeters (cm), an upper arm circumference (MUAC) of 10.8 centimeters (cm) [9] . On the European continent, in 2018 in Turkey the results of Betul et al. following an anthropometric study on 476 newborns of gestational age between 37 and 38 weeks were: average weight: 3238 g, average head circumference: 34.9 cm, average thoracic perimeter: 33 cm [10] . In Asia Chao et al. in 2018 during a study carried out on 51 full-term births at the neonatology department of the Xian Jiaoton university center found an average weight of 3260 g, average head circumference of 34 cm [11] . Within the African continent, disparities have also been observed. In Sub-Saharan Africa, Ndiaye et al., in Senegal in 2003 reported an average weight of 3120 g +/− 405 g, an average height of 49.2 cm +/− 2 cm, an average head circumference of 34.3 cm +/− 1.2 cm, the average thoracic circumference of 32.4 cm +/− 1.8 cm after a study carried out on a population of 300 newborns of gestational age between 37 weeks and 42 weeks of amenorrhea [12] . In Ouagadougou in 2005, after a study of 2162 full-term newborns, Ye et al. revealed an average weight of 2888.7 g, an average height of 49.1 cm, and the average head circumference was 33.9 cm, the average thoracic circumference of 32.0 cm, and an average upper arm circumference of 10.7 cm [13] . In Cameroon, Tietche et al. in 1994 on a population of 902 full-term Cameroonian newborns in an urban environment found an average weight of 3229 g, an average height of 49.0cm, an average head circumference of 34.7 cm, an average upper arm circumference of 10.6 cm, an average thoracic circumference of 33.0 cm [14] .
Given the variability of said parameters and the age of the data in our environment, multicenter studies were therefore necessary; hence the interest of our research.
2. Material and Methods2.1. Type, Location and Period of StudyWe conducted a multicenter prospective cross-sectional study with analytical aims in certain hospitals in the city of Douala, notably the Laquintinie Hospital of Douala, the General Hospital of Douala, the Deido District Hospital, the Nylon District Hospital, Bonassama District Hospital over a period of 04 months from January 13, 2020 to April 18, 2020.
2.2. Study PopulationOur target population consisted of all newborns from the hospitals in our study, born alive, at term during the recruitment period (January 2020-April 2020), with a single-fetal pregnancy.
2.3. Inclusion CriteriaAny newborn born alive during the recruitment period in the above-mentioned hospitals, vaginally or by cesarean section, seen in the first 24 hours of life from a single-fetal pregnancy of gestational age was included. Between 37 completed weeks and 41 weeks of amenorrhea + 6 days of which the mother had given her consent. A total of 1146 newborn were sreened and 305 finally included.
2.4. Non-Inclusion CriteriaNewly eligible people whose mothers did not consent to the study.
2.5. Exclusion CriteriaExcluded were:
- Newborns whose term was unclear.
- Newborns with congenital malformations or signs of embryo-foetopathy.
2.6. SamplingWe carried out non-exhaustive consecutive sampling.
2.7. ProcedureAdministrative process
We obtained authorization (Ethical Clearance No. 2144) from the institutional ethics committee of the University of Douala as well as research authorizations in the various hospitals.
Data collection procedure
In order to determine the fetal anthropometric profile, a questionnaire was developed for this purpose. Mothers were interviewed upon admission to the maternity ward or within 48 hours of giving birth.
It included the variables.
· Obstetric monitoring
- The date of the last period
- The term of the pregnancy which was calculated in weeks of amenorrhea from the date of the last period (by questioning the mother/pregnancy logbook) with the Naegle formula (gestational age = date of the last period + 7 days − 3 months) or from the ultrasound in the first trimester (before the 14th week). In the event of discrepancy between the two estimates, the gestational age calculated from the date of the first trimester ultrasound was used.
· Progress of childbirth
- Delivery routes
- Indications if cesarean section
· Anthropometric profile of the newborn
- Sex
-Apgar
- Caput succedaneum
- Anthropometric parameters: the parameters studied were: weight in grams, height in centimeters, upper arm, thoracic and cranial perimeters in centimeters.
The anthropometric measurements of the newborn were taken at birth in the delivery room or within 24 hours after birth in hospital (except weight):
- Weight was measured in grams using baby scales from different hospitals. Newborns were weighed naked directly at birth. We delicately placed the newborn in supine position on the tared scale covered with a fine wipe. The value obtained once the newborn was stable on the scale was noted.
- The height of the newborn was measured with a horizontal measuring rod graduated in centimeters, the newborn being naked lying on his back, along the measuring rod. She was taken with the help of the mother. It was placed behind the fixed part of the measuring board against which the baby's head was positioned. We stood on the side of the movable part of the measuring board on which the feet were resting. The child's legs were extended thanks to light pressure on the knees without hurting the child, then the movable base of the height chart was slid against the flat soles of the feet, the toes turned upwards and we noted the size value.
- The cranial, thoracic and brachial perimeters were measured to the nearest centimeter, using a non-extensible tape measure: For the cranial perimeter, we carefully placed the tape measure around the head, choosing the point where the circumference is largest corresponding to the greatest occipito-frontal diameter, that is to say a width of one or two fingers above the eyebrow on the forehead and the most prominent point at the back of the head. The chest circumference was measured by applying the measuring tape around the newborn’s thorax through an imaginary line passing through the most prominent point of the chest, in most cases at the level of the nipples. Finally, the upper arm circumference was measured at the level of the newborn's left arm midway between the acromion and the olecranon.
The team in charge of the anthropometric measurements consisted of 5 peoplefrom a Gynecologist and university professor, two pediatric hospital practitioners and lecturers and a 7th year medical student tutored in this task.
The data recorded on the forms were entered consecutively into a digital database created for this purpose and the entered forms stored in a binder.
This thus prevented a risk of duplication or confusion.
5. Ethical ConsiderationsOur study was previously submitted for approval to the institutional ethics committee of the University of Douala, and obtained ethical clearance allowing us to conduct our study. Study authorization was also obtained from the administrative services of the hospitals in our study.
Parents of eligible newborns were clearly informed by the information sheet.
We carried out our study in strict compliance with the fundamental principles of medical research: the principle of the interest and benefit of research, the principle of the safety of research, confidentiality, and justice.
During our study period, 305 full-term newborns were included, divided into 172 boys and 133 girls (Figure 1) with a sex ratio of 1.3.
In our sample, 3 out of ten women gave birth had a gestational age of between 38 and 39 weeks of amenorrhea. The average gestational age was 39.2 weeks ± 1.21 with a median of 39.2 weeks (Figure 2) and the greatest number of births was recorded between 38 - 39 weeks of amenorrhea for all sexes combined (Table 1).
Table 1. Distribution of newborns according to sex and gestational age.
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6. Basic Information about Newborns6.1. The Weight of NewbornsThe overall average weight in our series was 3305.4 grams with extremes of 1840 grams and 5220 grams. The average weight was higher in newborn males (3368.8 grams vs 3222.3 grams) and it increased with gestational age. The weight of boys was higher regardless of gestational age.
A statistically significant difference was found between the weight of boys and girls between the 40th and 41st weeks of amenorrhea (p = 0.039) (Table 2).
We found a statistically significant difference between the means of weight, height, head circumference, upper arm circumference and thoracic circumference between girls and boys (Table 3).
6.2. The Size of the NewbornsThe average height in our series was 49.8 centimeters with extremes of 41 and 56 centimeters. The average height was higher among newborn males (50.0 centimeters vs. 49.6 centimeters). Depending on the gestational age, the average size increased between the 37th and the 41st week then decreased after the 41st week. A statistically significant difference was found between the height of girls and boys between the 40th and 41st weeks (p = 0.006) (Table 4).
6.3. The Head Circumference of NewbornsThe overall average head circumference in our sample was 34.6 centimeters with extremes of 30 and 38 centimeters and a median value of 35 centimeters. It was higher in newborn males (34.8 centimeters vs 34.2 centimeters), remained higher regardless of gestational age.
We found a statistically significant difference between the head circumference of boys and girls between the 40th and 41st weeks (p = 0.039) (Table 5).
6.4. Upper Arm Circumference of NewbornsThe overall mean upper arm circumference in our sample was 11.3 centimeters with extremes of 8 and 14 centimeters and a median value of 11 centimeters. The average upper arm circumference was higher in male newborns (11.4 centimeters vs. 11.2 centimeters).
Depending on gestational age, the mean upper arm circumference increased with gestational age and was higher in male newborns regardless of gestational age.
At all these different gestational ages, there was no significant difference between the upper arm circumference of boys and girls (Table 6).
6.5. The Chest Circumference of NewbornsThe overall mean chest circumference in our sample was 32.8 centimeters with extremes of 27 and 38 centimeters and a median value of 33 centimeters.
Depending on gestational age, the mean chest circumference increased with gestational age and was higher in male newborns regardless of gestational age (Table 7).
At all these different gestational ages, there was no significant difference between the chest circumference of boys and girls.
We also studied the distribution in percentiles of these parameters within the study population in order to identify the threshold values defining small for gestational age (< 10th percentile) and normal for gestational age (between the 10th and 90th percentile) and large for gestational age (> 90th percentile).
In our study population we reported a 3rd percentile at 2380 grams, a 10th percentile at 2656 grams, a 90th percentile at 3966 grams and a 97th percentile at 4351 grams (Table 8).
By sex, the percentile distribution of weight was higher among male newborns (Table 9).
- Regarding the size of newborns, in our sample, we found a 3rd percentile at 45 centimeters, a 10th percentile at 48 centimeters, a 90th percentile at 52 centimeters, a 97th percentile at 54 centimeters.
- Depending on sex, the distribution in percentiles of height was higher in male newborns for the 3rd and 97th percentiles but the 10th and 90th percentiles had the same values for all sexes combined (Table 10).
- The head circumference of newborns:
Overall, we had a 3rd percentile at 32 centimeters, a 10th percentile at 33 centimeters, a 90th percentile at 36 centimeters, a 97th percentile at 38 centimeters.
Depending on sex, the distribution in percentiles of head circumference was higher in female newborns for the 3rd percentile. For the 10th, 90th and 97th percentile the distribution was higher among newborn males (Table 11).
- The upper arm circumference of newborns:
We had a 3rd percentile at 09 centimeters, a 10th percentile at 10 centimeters, a 90th percentile at 13 centimeters, a 97th percentile at 13 centimeters.
Depending on sex, the distribution in percentiles of mid-upper arm circumference is higher in male newborns for the 3rd and 90th percentiles but the 10th and 97th percentiles had the same values for all sexes combined (Table 12).
- The chest circumference of newborns:
In our series, we found a 3rd percentile at 29 centimeters, a 10th percentile at 30 centimeters, a 90th percentile at 35 centimeters and a 97th percentile at 36 centimeters.
Depending on sex, the distribution in percentiles of chest circumference is higher in male newborns for the 10th, 90th percentile and 97th percentile but the 3rd percentile had the same value for all sexes combined (Table 13).
Table 2. Distribution of average weights according to gestational age and sex.
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Table 3. Average anthropometric parameters at birth.
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Table 4. Distribution of average height according to gestational age and sex.
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Table 5. Distribution of average head circumference according to gestational age and sex.
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Table 6. Distribution of average upper arm circumference according to gestational age and sex.
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Table 7. Distribution of average chest circumference according to gestational age and sex.
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Table 8. Percentile distribution of anthropometric parameters.
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Table 9. Percentile distribution of weight by sex.
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Table 10. Percentile distribution of height by sex.
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Table 11. Percentile distribution of head circumference by sex.
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Table 12. Percentile distribution of upper arm circumference by sex.
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Table 13. Percentile distribution of height by sex.
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6.6. Anthropometric Profile of the NewbornOur investigation focused on 172 boys (56.3%) and 133 girls (43.6%), i.e. a sex ratio of 1.3, far from the findings in the literature, such as Fengqing et al, whose sex ratio was 1.06 with, however, like us, a male predominance. More specifically, depending on the continent, a sex ratio of 1.04 in America, 1.075 in Central Asia, 1.054 in Europe and 1.03 in sub-Saharan Africa was reported, thus matching our results [15] .
6.7. Weight of NewbornsThe overall average weight in our series was 3305 grams.
Considering the findings of other authors both from the same geographical area and elsewhere, our weight reference was dichotomous; this data is complex and integrates the individual genetic constitution of the parents and hence the fusion product of their procreation including racial, ethnic, geographical, nutritional and socio-economic factors; hence this disparity compared to the findings of other authors on this theme [16] .
If similarity or superposition there is with Yihua et al. in China (3374 grams) [17] , Jerbi et al. in Tunisia (3278.2 grams) [18] Neggers et al. (3272 grams) [9] , our finding was however higher than those of Tieche et al. (3229 grams) in Yaoundé [14] Ashraf et al. in Qatar (3185 grams) Adimora et al. in Nigeria (3170 grams) [15] , Ndiaye et al. in Senegal (3120 grams) [12] .
Like the findings of Djadou et al. in Togo, Yestea et al. in Spain, Huque et al. in Bangladesh, the average weight values were higher in newborn males (3368.8 grams vs 3222.3 grams) with a statistically significant difference [8] [19] [20] . Aly et al. cited a high level of serum type I C-terminal collagen propeptide (marker of fetal bone formation) in boys compared to girls to explain variations in weight according to sex [21] .
The cutoff values defining the 10th percentile and the 90th percentile in our study were 2656 grams and 3966 grams. Which differed from the data of Yé et al. [13] who found 2400 grams and 3350 grams or those of Ndiaye et al. which had 2600 grams and 3648 grams [12] . Once again these differences reflect the genetic potential and nutritional variations of populations.
6.8. Size of NewbornsThe average size of newborns was 49.8 centimeters, close to that reported by Tietche et al. (49 cm) [14] whose study took place in the same human mix because it was national, but higher than that of Djadou et al. in Togo (48.4 cm) [19] .
Apart from parental anthropometric characteristics which could be incriminated here, the measurement of height in newborns is subject to variations in posture and tone which, if left uncontrolled, could create measurement biases.
According to sex, in agreement with data from Senegal, Togo and Burkina Faso, male newborns had a higher average height: 50.0 centimeters vs. 49.6 centimeters. But the mechanisms by which sex influences height are poorly understood [12] [13] [19] .
Unlike Yestea et al. [22] who reported an increase in size with gestational age, in our series, the size of newborns decreased beyond the 41st week. The variations in size according to gestational age are still little studied today. Beyond the 41st week of amenorrhea, the occurrence of placental calcifications necessarily reduces maternal-fetal nutritional exchanges and therefore probably impacts growth; which, in our opinion, justifies our finding.
The threshold values for the 10th percentile and the 90th percentile in our study (48 centimeters and 52 centimeters) were higher than the thresholds reported in other African series [12] [13] .
6.9. The Head Circumference of NewbornsThe average head circumference of newborns (34.6 cm) was comparable to those of other authors, notably Tietche in Cameroon (34.7 cm) [14] Djadou et al. (34.2 cm) [19] Ashraf et al. (34.5 centimeters) [23] .
Depending on gender, most studies also reported a higher average head circumference in boys [12] [13] .
Like Yestea et al, we found that head circumference increased with gestational age in accordance with optimal brain growth [22] .
The threshold values for the 10th percentile and the 90th percentile in our study were (33 cm and 36 cm) superimposable to the thresholds reported by Ndiaye et al (32.8 cm and 35.9 cm) [12] .
6.10. Upper Arm Circumference of NewbornsThe average upper arm circumference of newborns was 11.3 centimeters. Long-term anthropometric studies involving mid-upper arm circumference are not numerous, but our data were close to the majority of studies identified; notably 10.6 cm for Tietche et al; 10.8 cm for Neggers et al. 10.7 cm for Yé et al. The slight disparities observed could be attributable to the measurement conditions [9] [13] [14] .
Depending on gender, similar to the results from Yé in Ouagadougou, the average upper arm circumference was higher in boys [13] .
The cutoff values for the 10th percentile and 90th percentile in our study were 10 cm and 13 cm. The 10th percentile had almost the same value in other African series that we consulted [12] [13] [19] .
6.11. Chest Circumference of NewbornsThe average chest circumference of newborns was 32.8 centimeters; it was superimposable to the average thoracic perimeter found in other studies (33 cm) [9] [10] [14] [19] .
Depending on gestational age and sex, we agree with the findings of Yestea et al. with an increase in thoracic circumference with gestational age and a higher value in boys [22] . This variation according to sex would be in agreement with corpulence in adulthood.
The cutoff values for the 10th percentile and 90th percentile in our study were 30 centimeters and 35 centimeters. Like the upper arm circumference, the 10th percentile tended to keep the same value in other African studies [12] [13] .
Cite this paperEssome, H., Ekoube, C.E., Nkwele, F.M., Betoko, R.C.M., Mboe, I.C.E., Ekono, M.R., Nyong, A.N., Tchounzou, R., Ilick, I.D.O., Iyawa, H., Bilkissou, M., Kondo, A.N., Yaneu, J.N., Akam, M.V.N., Ngouhouo, G.M., Toutou, G.T., Noubi, N., Koh, V.M. and Njamen, T.N. (2024) Draft of an Anthropometric Reference System for Full-Term Cameroonian Newborns: Prospective Study with Analytical Aim in the Maternity Wards of Douala. Open Journal of Obstetrics and Gynecology, 14, 435-450. https://doi.org/10.4236/ojog.2024.143038