This is another older study (1986) showing the effects of abortion on teenagers. 

Acute and Long Term Consequences of Adolescents Who Choose Abortions
Frank Biro, M.D.; Linda Wildey, MSN; Paula Hillard, M.D.; Jerome Rauh, M.D.

Psychosocial Consequences
The issue of unwanted pregnancy among teenagers has received widespread national attention (eg. Time, 9 Dec 1985). This paper will examine the process by which a teenager decides to continue or terminate the pregnancy as well as the acute and long-term medical and psychosocial sequelae of abortion at adolescence.

The majority of adolescent pregnancies are unintended. In 1981, there were 1,343,200 pregnancies among women under 20 years of age. In the same year, there were 448,570 legal abortions for women under the age of 20. (1) Legal abortion [has] a serious complication rate of 0.4% (2)...

The highest abortion rate of any group is in the 18-19 year-old age group (61.8 per 1000)...Adolescents are less likely than older women to approve of abortion...the experience of the procedure itself is considered by many teens to be stressful and associated with feelings of guilt, depression, and a sense of isolation (6,8,9) These feelings are especially negative with abortifacient instillations (6) in which the teenager undergoes labor and delivers a dead fetus, often in isolation.

Parental involvement with the adolescent who undergoes an abortion has a mixed influence, although the younger teen does better with parental support. The negative consequences are short-term and are mitigated with support from the partner before, during, and after the procedure. (9)

When compared to adult women, adolescents tend to obtain abortions at later gestational ages, and younger adolescents delay more than other teens.
This is especially significant when one considers that the medical complications of abortion increase with the gestational age.

...If the adolescent feels pressured by her family to terminate her pregnancy, she is also at higher risk for psychological sequelae (11) and repeat pregnancy soon after abortion (13) Teens who have obtained abortions are more effective contraceptors (17,18)

Medical Risks
The two primary factors that influence the morbidity of an abortion include gestational age at time of the procedure and abortion technique,  which is related to gestational age (19).

Other factors affecting the potential risks include the choice of anesthetic. Use of general anesthesia for abortions at 12 weeks of gestation or less is associated with a 2- to 4-fold increased risk of death from abortion (22) although there was no statistically significant difference in the rate of major complications (23)  Local anesthesia for second trimester curettage is associated with a lower risk of morbidity than general anesthesia (24)

Specific Complications
Abortion complications can be divided into immediate (occurring or developing within 3 hours of the procedure), delayed (after 3 Hours and up to 28 days), and late (occurring past 28 days) (25). The Centers for Disease Control's (CDC) definition of serious complication includes:
1) fever of 38 degrees C for 3 or more days; 2) unintended major surgical procedures; 3) transfusions; or 4) death.

An immediate complication is hemorrhage. Transfusion requirements are low, with rates of 0.06 per 100 first trimester suction procedures, 0.19 per 100 second trimester curettage, and 0.96 to 1.53 per 100 instillation procedures (25).

General anesthetic for first and second trimester curettage procedures is associated with higher rates of hemorrhage (23) Uterine perforation is reported to occur in only 0.9 cases per 1000 abortions (21). Treatment for perforation may range from no treatment other than observation to laparotomy for intra-abdominal bleeding.

Injury or trauma to the cervix has been reported to occur in 1.03 per 100 first tirmester curettage procedures (21).  The extent of cervical injury may range from minor tenaculum tears requiring no treatment to major lacerations from dilators that may injure the uterus or tuerine blood vessels.

Concern has been raised that mechanically dilating the cervix will result in injury to the internal cervical os with resultant risk of cervical incompetence. In an effort to prevent these problems, many physicians are now using laminaria or synthetic osmotic dilators...

Instillation procedures may rarely lead to the complication of a cervicovaginal fistula if cervical dilation does not occur and strong uterine contractions force the fetus to be expelled through a posterior sacculation of the cervix. A number of problems have been associated with instillation abortion procedures, and the type of complication is related to the abortifacient used. Morbidity is increased with hypertonic saline instillation. Amniotic fluid, clot, or air embolism occur rarely enough that no reliable incidence figures are available.

A live-born fetus is an undesired complication of second trimester abortion, which can be minimized through the use of ultrasonography to accurately assess gestational age and the use of fetocidal abortifacients.

Delayed Complications
Retained products of conception after an abortion procedure result in abnormal bleeding or uterine infection, and thus will necessitate repeat curettage.

Untreated cervical gonorrhea markedly increases the risk for postabortion infection, while the role of untreated cervical chlamydia has not been clarified. Prophylactic antibiotics such as tetracycline, which treats both gonorrhea and chlamydia, may reduce the risk of postabortion infection.

...Death related to an abortion procedure is particularly tragic in that women obtaining abortions are generally young and healthy...Abortion-related deaths reported to the CDC were 0.5 per 100,000 procedures (21)

...One recent study assessing abortion morbidity risk concluded that adolescents are more likely than older women to develop a postabortal endometritis (32). These authors also noted a trend toward a greater risk of cervical laceration, which had been shown in another study to be twice as likely to occur in women 17 years old and younger (33)...

Burkman's study (32) also demonstrated higher rates of positive cervical gonorrhea cultures and urinary tract infections among adolescents...

Prophylactic antibiotics for abortion procedures may therefore be of particular value in adolescents.
["Acute and Long-Term Consequences of Adolescents Who Choose Abortions", Biro, Wildey, Hillard, Rauh, Pediatric Annals 15: 10 October 1986]

References
1. Henshaw, SK, Binkins Nh, Blaine E et al. A portrait of American women who obtain abortions. Fam Plann Perspect 1985; 17(2): 90-96.
2. Joint Program for Study of Abortions III.
6. Perez-Reyes MG; Falk R. Follow-up after therapeutic abortion in early adolescence, Arch Gen Psychiatry, 1973, 28: 120-126.
8. Freeman EW: Influence of personality attributes on abortion experiences, Am Orthopsychiatry, 1977, 47(3): 503-513.
9. Robbins JM, deLamater JD: Support from significant others and loneliness following induced abortion. Soc Psychiatry 1985, 20:92-99.
11. Olson L: Social and psychological correlates of pregnancy resolution among adolescent women. Am J Orthopsychiatry 1980, 50(3): 432-455.
13. Lewis CC. A comparison of minors and adults - Pregnancy decisions. Am J Orthopsychiatry 1980, 50(3):446-453.
17. Abrams M: Birth control use by teenagers. J Adolesc Health Care 1985; 6: 196-200.
18. Cvejic H, Lippey I, Kinch RA, et al: Follow-up of 50 adolescent girls two years after abortion, CMA Journal 1977, 116: 44-46.
19. Cates W, Schulz KF, Grimes DA, et al: Effect of delay and method choice on the risk of abortion morbidity. Fam Plann Perspect 1977, (6): 266-276.
21. CDC, Abortion Surveillance 1981, issued November 1985.
22. Peterson HB, Grimes DA, CAtes W et al: Comparative risk of death from induced abortion at/under 12 weeks gestation performed with local vs. general anesthesia. Am J Obstet Gynecol 1981141: 763-768.
23. Grimes DA, Schulz KF, Cates W et al: Local vs. general anesthesia: Which is safer for performing suction curettage abortions. Am J Obstet Gynecol 1979, 135: 1030-1035.
24. MacKay HT, Schulz KF, Grimes DA: Safety of local vs. general anesthesia for second trimester dilation and evacuation abortion. Obstet Gynecol 1985; 66: 661-665.
25. Grimes DA, Cates W: Complications from Legally-induced abortions: A review. Obstet Gynecol Surv 1979, 34: 177-191.
32. Burkman RT, Atienze MF, King TM: Morbidity risks among young adolescnets undergoing elective abortion, Contraception 1984; 30: 99-105.
33. Schulz KF, Grimes DA, Cates W: Measures to prevent cervical injury during suction, curettage abortion. Lancet 1983; 5: 1182-1185.