Researchers at the Academic Unit of Obstetrics and Gynaecology, St Mary's Hospital, Manchester, UK, have found that late developers may run a higher risk of infection than sexually mature younger teens.
The study, which examined biological and hormonal markers of sexually transmitted infections among adolescents attending genitourinary medicine clinics, appears in the journal 'Sexually Transmitted Infections', and suggests sexual maturity, rather than age at first sex, seems to be a critical factor.
Dr Loretta Brabin and the team of researchers studied 127 young women from three sexual health clinics. All had started having periods within the preceding five years or were aged 17 years and under.
The young women were screened for genital infections, including chlamydia, wart virus (human papillomavirus or HPV), and bacterial vaginosis.
Almost two thirds of the young women tested positive for HPV, half of which were the high risk types associated with the development of cervical cancer.
Over half of those infected with HPV had at least one other infection. About one in four tested positive for chlamydia, which is associated with infertility.
Certain behaviour patterns were found to have had specific effects on particular infections.
A lower risk of chlamydial infection was associated with a recent new partner or use of a condom, while the use of emergency contraception doubled the risk.
Sex during a period was found to increase the risk of bacterial vaginosis. Smoking gave some protection against HPV, and sexual maturity had a significant impact on all three infections.
Young women, whose breasts were more developed, more sexually mature and who had infrequent menstrual cycle were significantly less likely to have any of the infections.
Girls who mature early, who start their periods before the age of 12, have higher oestrogen levels and this could help cut their infection risk. After taking into account age, number of sexual partners, and behavioural risk factors, young gynaecological age remains a strong predictor of the risk of infection.
The authors conclude that a sexually active 18 year old with late periods may be more susceptible to multiple infections than a sexually active 15 year old with early periods.
Dr Loretta Brabin, Academic Unit of Obstetrics and Gynaecology, St Mary's
Hospital, Manchester, UK
Tel: +44 (0)161 276 6388; Mobile: (0)7808 151 997
Email: [email protected]