Compressed progression of puberty in South Indian Girls between 1981 and 1998

INTRODUCTION

A silent change is occurring in the rate of sexual maturation of girls in Chennai, South India. Tracking the secular trends in the pubertal development is important for the social and health needs of adolescents.

Menarche happens to be one end of the “goal post.” Before menarche occurs, there are signals (sexual maturity ratings [SMR]) in real time to judge, counsel, and set the limits of normalcy of development. This narrative is about applying Tanner’s stages of SMR to the South Indian girls of Chennai from affluent families. Paucity of information from South India merits this study’s contribution.

MATERIAL AND METHODS

In the year 1981, an all-girls matriculation school located in the heart of the city of Chennai requested a school health check-up. This private school drew students whose parents belonged to the higher economic status. These recruits could pay the school fees of about Rs. 500/month, which at that period of time, was considered high.

Again in the year 1998, another all-girls private matriculation school requested a health check-up for their students. This school was about 10 km from the school surveyed in 1981. The students paid school fees of about Rs. 2000/month. The ability to pay the higher school fees bracket for their female ward was considered a measure of parental financial status. The children studying in fee-paying schools (adjusted for the per-capita income of the family) were taken as a criterion for deciding their high socioeconomic status.

Consent for the survey was obtained from the parents by the school authorities as was appropriate at the time. As per the instructions from the principal investigator (Vedavati Subramanyam), the need to change into a dressing gown before examination was clearly explained and agreed to by all concerned parties. Surveyors were all women, each team consisting of three Senior House Officers and a Registrar (all women pediatricians) – a different team was formed for each survey. They were trained by the principal investigator (VS). Inter-observer difference was kept as low as was possible. The principal investigator personally attended both the surveys.

Girls between the ages of 8 and 15 years were included in the analysis. Girls below the age of 8 years and above the age of 15 years were excluded. Girls with physical abnormalities and chronic diseases such as cardiac, pulmonary, renal, and inborn disorders were excluded. Girls whose data were incomplete and those who declined SMR evaluation were also excluded. A survey done in the year 1981 was designated as Group I and that of the year 1998 as Group II. Then, the data were entered into Microsoft Excel. Analysis of the studied parameters was carried out using the Statistical Package for the Social Sciences 16.0 (Windows 2001). Data were preserved manually from 1981 to 1998 by VS.

The LMS method summarizes the changing distribution by three curves representing the median (M), coefficient of variation (S) and skewness (L). LMSchartmaker is a program to fit smooth centile curves to reference data using the LMS method. LMSchartmaker was used to compute the percentile of ages at which Tanner’s stage was reached. Student t-test and Chi-square test were used as appropriate to compare the variables among the groups.

Data collected during the surveys included anthropometry (height and weight), SMRs, and age at menarche. The assessments of SMR – breast stage and pubic hair – were classified into one of the five stages described by Marshall and Tanner.^[1]

The author would like to emphasize that the day of menarche is considered a “landmark day” in the life of a south Indian girl which is remembered for life. This information had much accuracy and was ascertained by the surveyor from the girls who had attained menarche. Information regarding the age was also obtained from the school records and was rechecked for each student. Age in months was converted to decimal by dividing the completed months by twelve, and the age at menarche was recalculated.

RESULTS

There were 1976 girls included in 1981 – G1 group and 1520 girls in the year 1998 – G2 group. There were no exclusions in G1. In G2 , 69 recruits were excluded.

Descriptive analysis of Group 1 and Group 2 data is represented in Tables 1 and 2, respectively.

Consolidated representation of parameters Sexual Maturity Rating (SMR), menarche and Thelarche - menarche Interval are shown in Table 3.

For comparison, a study from North India (2013) is included as shown in Table 3.

Thelarche-menarche interval has also shortened from 1.5 years to 0.9 years as per Table 3. B2-B4 interval was 3.7 years and 2.8 years in 1981 and 1998 respectively. P2-P4 interval was 3.2 years in I981 and 2.1 years in1998 as shown in Table 4.

Thelarche-Menarche interval has also shortened from 1.5 years to 0.9 years as per Table 5.

Menarcheal age is also reduced from 12.4 years to 12.1 years [Figure 1].

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Figure 1:

Comparison of attainment of menarche in Groups I and II.

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Decrease in menarcheal age at the rate of 1.7 months per decade as it is evident from Figure 1.

DISCUSSION

This narrative is about the stages of puberty in South Indian girls in the years 1981 and 1998.

Variations in the SMRs, its onset, progress, and offset have been reported in the western literature^[1-3] and Indian literature.^[4-9]

A point to note is that menarcheal age has also decreased as seen in other studies^[10] [Figure 1]. Menarcheal age is influenced by genetic and environmental factors.

Understandably, it is not an easy proposal to collect SMRs virtually. Awareness of the velocity of the progress of SMRs will help a clinician to make a reasonable guess regarding the time interval left for the menarche to occur. A Caveat is that local data are more helpful.

The reasons for this study, the author would like to offer:

1. Ranges of normalcy could be anywhere between 20^th and 80^th percentile. They include the early and late bloomers at the extremes of ages

2. In office practice, once sexual maturity signs start appearing, parents anticipate menarche to occur in the course of time. They want to know when it is likely to happen. For personal and social reasons, a girl child needs to be protected and guided in activities such as sports, media exposure, and participation in camp activities

3. Chronological age and body image need to match. If they do not, emotional setbacks can occur

4. An optimum guideline thus becomes the need of the hour.

This study has attempted to provide a time frame for the SMR’s progress before menarche.

To the best of the author’s knowledge, this is the first report from South India.

We submit the following information:

1. Sexual maturity in girls occurs in a short period of 1 year to 1.5 years

2. To study the time interval, it is best to do a longitudinal study. The feasibility of such a manner of study is questionable in these times^[8]

3. Therefore, cross-sectional studies have come to stay

4. The correct date of birth and date of menarche are crucial for evaluation. This study to a large extent has both these parameters effectively correct

5. The cultural practice of celebrating the first menarcheal date in South Indian families is etched in the child’s memory

6. Age at various Tanner stages is taken in this study as of the date of the survey

7. Interestingly, data analysis revealed that the time taken to move from breast stage II (B2) to breast stage IV (B4) and from pubic hair stage II (PH2) to pubic hair stage 4 (PH4) has shortened between the two study groups [Tables 1 and 2]

8. Menarcheal age is reduced from 12.4 years in 1981 to 12.1 years in 1998 [Figure 1]^[10]

9. It is reasonable to conclude that the sexual maturity of girls in South India is compressed in time [Tables 1-3]

10. Thelarche-menarche interval has reduced from 1.2 years to 0.9 years as against the North Indian Study which mentions the interval to be 1.5–2 years [Tables 4 and 5].

This has social consequences. This research reiterates the aim that there is a compression of the progression of puberty in indian girls between 1981 and 1998.

CONCLUSION

Sexual maturity of girls in South India is now compressed in time.