Maarit Niinimäki, MD PhD, Department of O&G, University Hospital of Oulu, Finland
Pregnancies among teenagers, mostly unplanned, offer a special challenge to family planning. Vast majority, about 80%, of teenage pregnancies are unintended (Guttmacher Institute Report 2010). In 2009 9.5% of all abortions were performed for girls <18 years in UK. Also in Finland teenage abortions are relatively common. In the youngest age group (15-19 years) the abortion rates were higher than in the whole population (12.8 vs. 8.8/1000 women in the same age) in 2009.
Despite the widespread use of medical abortion, data concerning the safety and feasibility of medical abortion among adolescents is scarce. A small prospective study found medical abortion to be highly effective and well tolerated among minors aged 14 to 17 years in duration of gestation 56 days maximum (Phelps 2001).
The present study aimed to compare the incidence and risk factors for adverse events among adolescents and adult women. The study was based on the national registry-based cohort in which all the medical abortions during 2000-2006, 27.030 women, were included. The duration of gestation was 5 to 20 weeks. The cohort was divided into two subgroups; adolescent < 18 years (n=3024) and adults ≥ 18 years of age (n=24.006). The categories for adverse events were: I hemorrhage, II post-abortal infections, III incomplete abortions, IV injuries or other reasons for surgical operation, V thromboembolic disease, VI psychiatric morbidity and VII death. The classification was based on that reported in the Joint Study of the Royal College of General Practitioners and the Royal College of Obstetricians and Gynaecologists and modified for the present study. Codes for interventions and diagnoses (ICD-10) found in a national Hospital Registry were linked with the abortion registry. For 2004-2006, individual data on STDs (Chlamydia trachomatis and gonorrhea) in this cohort was also available. The screening for Chlamydia infections has been recommended in the national guidelines for termination of pregnancy.
The overall number of adverse events was higher in adult cohort. Also the incidence of hemorrhage, incomplete abortion and surgical evacuation was significantly higher among adults. The incidence of infections was similar in the cohorts. However, adolescents had more psychiatric morbidity. In subanalysis of primigravid women, the overall rate of adverse events and hemorrhage was higher in cohort of adult women. The risk factors for adverse events (e.g. age, duration of gestation) were mostly similar in the two cohorts.
In 2004-2006, the incidence of STD was significantly higher among adolescents (5.7% vs. 3.7%). No difference in the rate of post-abortal infections emerged between the two cohorts among women positive in the preabortal STD-screening. Also, positive preabortal STD screening had no effect on rate of postaboral infections when compared to STD-negative women in the whole cohort.
In conclusion, we find that the rate of adverse events and complications following medical abortion in adolescents is similar or lower than that seen among adult women. Thus medical abortion is not to be evaded as a method among adolescents once the decision of termination of pregnancy has made. In addition, based on these data, preabortal screening for STDs (“screen and treat”) seems to be a feasible strategy in all women.