Menstrual Patterns in the First Gynecological Year: A Systematic Review

Area of Science:

• Reproductive endocrinology
• Adolescent gynecology

Background:

• Understanding normal menstrual cycles in the first gynecological year (GY1) is crucial for adolescents and clinicians.
• Limited high-quality evidence exists on menstrual and ovulatory patterns during this transitional phase.

Purpose of the Study:

• To systematically summarize published literature on menstrual and ovulatory patterns in adolescents during their first gynecological year.
• To provide evidence-based insights into the diversity and characteristics of early adolescent reproductive health.

Main Methods:

• Systematic literature search of multiple electronic databases (MEDLINE, Embase, Web of Science, etc.) from inception to 2018.
• Inclusion of studies detailing menstrual cycles, symptoms, or validated ovulatory data in healthy adolescents in GY1.
• Independent screening, data extraction, and quality assessment by two authors.

Main Results:

• Twenty-two studies with over 2000 adolescents were analyzed.
• Mean cycle length varied (32–61 days) and decreased over GY1; mean menses length was 4.9–5.4 days.
• Ovulatory cycle prevalence ranged from 0–45% and increased throughout GY1, though definitions used were often subovulatory.

Conclusions:

• Menstrual and ovulatory patterns in GY1 are highly variable and immature compared to adults.
• Irregular cycles, dysmenorrhea, and ovulation are common during this transitional period.
• Advocacy for safe sexual practices and accessible medical management is essential for adolescents in GY1.