Safe termination of pregnancy in the first and second trimester

Medical and surgical methods are available for both first- and second-trimester abortions. Over the years, evidence of the efficacy and complications of the various methods available has increased ( Table 1 ).

For women presenting at less than 7 weeks gestation, early surgical abortion is an appropriate method. This allows pre-abortion ultrasound confirmation of a viable intrauterine pregnancy, confirmation of products of conception at aspiration, and ultrasound confirmation of complete evacuation after the procedure. In such instances, products of conception need not necessarily be sent for histological examination . Surgical vacuum aspirations performed at less than 7 weeks gestation, however, are three times more likely to fail to remove the gestation sac than those performed between 7 and 12 weeks . Therefore, for women presenting at less than 7 weeks gestation, an alternative recommended technique should ideally be chosen.

Medical abortion may be considered at these earlier stages of pregnancy . Combined mifepristone with prostaglandin regimens are recommended . Mifepristone administered as a single 600 mg oral dose followed 36–48 h by a prostaglandin analogue, such as a gemeprost 1 mg, vaginally is recommended. Evidence from a randomised-controlled trial indicates that a dose of 200 mg mifepristone has similar efficacy compared with 400 mg or 600 mg. The conventional prostaglandin E1 analogue gemeprost is a 1 mg pessary used for mid-trimester abortion, and is effective for early medical abortion and cervical priming. A series of studies have also shown that misoprostol, an alternative E1 analogue, is also effective in all these contexts , and that misoprostol is also more effective if administered vaginally rather than orally . Side-effects such as vomiting and diarrhea were reported more frequently by the women who received oral misoprostol than by those who received vaginal misoprostol . Misoprostol is substantially less expensive than gemeprost, making it a more affordable option . In countries in which mifepristone is not available because of stringent government control, a misoprostol-only regimen can be used for first-trimester medical abortion. The regimen includes a loading dose of 800 mcg of misoprostol given vaginally, followed by three further doses of 400 mcg of misoprostol given at 3-hourly hourly intervals. With this dose schedule, medical abortion was achieved in 96% of women, with minimal side-effects, and was also accompanied by a significant drop in the mean and median serum beta human chorionic gonadotropin (hCG) levels 2 weeks after the abortion . Clinical assessment is key in determining the completeness of the medical abortion; beta-hCG and ultrasound can be used as supplements in confirming a successfully medically induced abortion, and both have been shown to be equally effective .

For women presenting between 7 and 14 weeks gestation, vacuum aspiration is an appropriate method, although individual specialists may prefer to offer medical abortion at gestation above 12 weeks. Products of conception removed in a confirmed viable intrauterine pregnancy need not necessarily be sent for histological examination. Evidence to date suggests that, compared with using general anaesthesia in surgical abortions, local anaesthesia seems to be safe, efficacious, and less expensive, with a relatively lower risk of complications such as haemorrhage, cervical injury, and uterine perforation . Both oral and vaginal routes of administration of misoprostol have been shown to be equally effective in pre-induction cervical ripening before first-trimester pregnancy termination . The method of choice at 12–14 weeks gestation varies according to the preferences and expertise of the clinician. Alternatively, medical abortion using mifepristone and prostaglandin is appropriate at all gestations after 12 weeks . Evidence also shows that medical abortion is effective for women presenting between 7 and 12 weeks, especially in the 7–9 weeks band .

Three general methods are available for second-trimester pregnancy termination: dilatation and evacuation; administration of systemic abortifacients; and intrauterine instillation of abortifacients. Dilatation and evacuation is the most common technique used for second-trimester pregnancy termination in the USA . It has the lowest maternal mortality rate of all second-trimester pregnancy termination procedures, and comparable morbidity to other second-trimester techniques . Compared with abortion induction by intravaginal prostaglandin suppositories, it had a lower frequency of blood transfusion, cervical laceration, retained products of conception, fever, vomiting, and diarrhoea . It also had less than one-half the major complication rate compared with intra-amniotic infusion techniques . Second-trimester evacuation requires dilatation of the cervix, and options include multiple osmotic dilators or prostaglandins. Anaesthetic options include conscious sedation, regional block, and general anaesthesia. A vacuum cannula can be used to remove the intrauterine contents, although extraction with forceps may be required after 16–17 weeks, as the intrauterine contents are too large to aspirate through the cannulas. It should be stressed, however, that dilatation and evacuation can only be undertaken by gynaecologists who have been trained in the technique, have the necessary instruments, and have a case-load sufficient to maintain their skills. For gynaecologists lacking the necessary expertise and case-load, medical abortion may be appropriate .

For women beyond 12 weeks gestation, medical abortion with mifepristone followed by prostaglandin has been shown to be safe and effective. This regimen has been shown to be associated with shorter induction–abortion intervals than methods using prostaglandin alone . In the event of non-availability of mifepristone, prostaglandin-only regimens may be used. Prostaglandin E2 analogues, such as dinoprostone (Prostin), can be administered as a 3 mg intravaginal pessary every 3–4 h, with a maximal exposure of 24 h. The mean time to abortion is 13–14 h, and 90% of women abort by 24 h . Misoprostol, a prostaglandin E1 analogue, is also commonly used as a single agent for second-trimester induced abortion in many parts of the world. A recommended regimen is the administration of 400 mcg misoprostol vaginally every 3–4 h, with a maximum of five doses . Randomised trials have shown that the vaginal route was more effective and had a shorter induction-to-delivery interval compared with the oral route . The induction-to-abortion interval has also been shown to be longer in women with hyperglycaemia and advanced gestational age . A randomised-controlled trial comparing vaginal misoprostol and intra-amniotic prostaglandins for mid-trimester termination of pregnancy has also shown that vaginal misoprostol resulted in a significantly shorter mean induction-to-abortion interval, although the successful abortion rates were not statistically significant . Surgical evacuation is not required routinely after mid-trimester medical abortion .

Intrauterine instillation of abortifacient agents is another method for second-trimester pregnancy termination. Hypertonic agents infused into the intra-amniotic cavity or extraovular space induce contractions, leading to evacuation of uterine contents. The major agents used are prostaglandin F2-alpha and hypertonic saline. This technique, however, has been largely superseded by the development of safe and effective systemic agents and operative techniques. Hysterotomy or hysterectomy is rarely indicated because of the increased risk, but may be required after failed medical abortion when dilatation and evacuation cannot be safely performed, such as in situations where there multiple obstructing myomas are present, with pelvis peritoneal malignancy or after an abdominal cerclage . Complications of abortions are presented in Table 2 .

Women should be informed that abortion is a safe procedure, for which major complications and mortality are rare at all gestations. Complications and risks, however, should be discussed with women in a way that can be understood . Estimated complication rates are 1–2 per 1000 abortions . Although the absolute risk of major complications is low, evidence shows that complications increase with increasing gestation . A Cochrane systematic review comparing surgical and medical methods of abortion in the first trimester identified no significant difference in complications between methods, although a comparison of surgical and medical methods of abortion after 13 weeks of gestation in a few small randomised-controlled trials and cohort studies suggests that medical abortion is associated with higher all-cause adverse events .

The effect of unsafe abortion

About 205 million pregnancies occur worldwide each year, and 42 million of these pregnancies end in abortion, of which about 20 million are considered ‘unsafe abortion’ . The World Health Organization (WHO) defines ‘safe abortion’ as an abortion in countries where abortion law is not restrictive (abortion is legally permitted for social or economic reasons, or without specification as to reason) or countries in which, despite formal law, safe abortion is broadly available . On the other hand, ‘unsafe abortion’ is carried out by people lacking the necessary skills or using hazardous techniques, in an environment that does not meet minimum medical standards, or both.

Unsafe abortion is carried out by both trained and untrained providers, or may be self-induced . The four major methodologies are listed in Table 3 .

It is estimated that 98% of these unsafe abortions occur in the developing world . Unsafe abortions can result in maternal morbidity and mortality. WHO has estimated that, as many as one-quarter to one-third of pregnancy-related deaths is due to complications of unsafe abortion procedures. One in four women undergoing an unsafe abortion will have a major complication . It is estimated that, in the developing world, 5 million women are admitted to hospitals for treatment of complications from induced abortions each year .

Among women hospitalised with abortion-related complications, the types of complications include renal failure, haemorrhage, infection, trauma, and anaemia. Haemorrhage is the most common complication of unsafe abortion, and may result in hypovolemic shock, coagulopathy, and death. It may be related to lacerations of the vagina, cervix, uterus or adnexal vasculature, or uterine infection, atony, or both. Infection related to unsafe abortion is caused by retained products of conception, trauma, and non-sterile techniques. If untreated or inappropriately treated, infection can lead to sepsis, septic shock, organ failure, disseminated intravascular coagulation, and future sterility. Insertion of a foreign body is a common cause of abortion-related trauma. In addition to injuries to the genital tract, perforation can result in trauma to the bowel and other internal organs. Ingestion of chemical agents can also cause trauma. Women who have used oral, parenteral, or local drugs or toxic substances for abortion induction or assistance may have a variety of presentations, including local damage to the vagina or signs of renal or liver toxicity.

Increasing access to misoprostol has altered the way in which women obtain abortions in many parts of the world, despite the lack of legal and safe access to abortion care . In Brazil, it has led to a significantly lower infection rate from unsafe abortion compared with traditional alternative methods . Drug quality, however, may pose a problem, as a variety of misoprostol products on the market do not meet international standards, are poorly stored, or are expired . One should also watch for manifestations of misoprostol toxicity, such as high fever, shaking chills, abdominal cramping, vomiting, diarrhoea, tremor, agitation, confusion, rhabdomyolysis, hypoxaemia, and hypotension . As misoprostol is rapidly absorbed, symptoms develop soon after ingestion, and treatment involves removing any remaining tablets from the vagina or in the stomach .

Factors that increase morbidity and mortality at the time of unsafe abortion include lack of provider skill, poor technique, unsanitary conditions for performing the procedure, lack of appropriate equipment, use of toxic substances, poor maternal health, increasing gestational age, and lack of access to post-abortion care .

Prevention of unsafe abortion is key and requires a multi-pronged approach ( Table 4 ) . Provision of contraception is key to improving maternal health. Increasing contraceptive use in developing countries has cut the number of maternal deaths by 40% over the past 20 years, merely by reducing the number of unintended pregnancies . In addition, the risk of prematurity and low birth weight doubles when conception occurs within 6 months of a previous birth, and children born within 2 years of an elder sibling are 60% more likely to die in infancy than are those born more than 2 years after their sibling . Abortion levels have also declined steadily with the increased use of modern contraceptives .

Expanded access to safe abortion is also critical. Liberalisation of abortion laws have resulted in increased access to safe abortion in Romania, where it was associated with a 50% fall in maternal mortality within a year . A decrease in abortion-related deaths also occurred in the USA from 40 per million births to 8 per million births over 6 years owing to the increased availability of legal abortion . In addition, the provision of high-quality post-abortion medical care and post-abortion family planning counselling and contraceptive services are also critical to the prevention of unsafe abortion.

The way forward

The provision of high-quality services for family planning and the elimination of unsafe abortion are two of the five priority aspects of reproductive and sexual health targeted in WHO’s first global strategy on reproductive health . The WHO’s strategy for accelerating progress rests on internationally agreed instruments and global consensus declarations on human rights, including (1) the rights of all persons to the highest attainable standard of health; (2) the basic rights of all couples and individuals to decide freely and responsibly the number, spacing and timing of their children, and to have the information and means to do so; and (3) the rights of women to have control over and decide freely and responsibly on, matters related to their sexuality, including sexual and reproductive health. To ensure that these rights are respected, policies, programmes and interventions must promote gender equality and give priority to poor and underserved population groups .

Several urgent actions are necessary to prevent unsafe abortion, including strengthening family planning services to prevent unintended pregnancies, and, to the extent allowed by law, ensuring that services are available and accessible as well as training health service providers in modern techniques and equipping them with appropriate drugs and supplies. Strengthening reproductive health services should also involve attention to violence against women. This is now being tackled in various countries, with the provision of emergency contraception, abortion, treatment of sexually transmitted infections and post-exposure prophylaxis for HIV infection after rape. A study by WHO has also estimated that reducing intimate partner violence by 50% could potentially reduce unintended pregnancy by 2–18% and abortion by 4.5–40% .