Abortion surveillance--United States, 1989

Since 1980, the number of legal induced abortions reported to CDC has remained stable, varying each year by < 5%. In 1989, 1,396,658 abortions were reported--a 1.9% increase from 1988. The abortion ratio for 1989 was 346 legal induced abortions/1,000 live births, and the abortion rate was 24/1,000 women ages 15-44 years. The abortion ratio was highest for black women and women of other minority racial groups and for women < 15 years of age. Overall, women undergoing abortions tended to be young, white, and unmarried; to have had no previous live births; and to be having the procedure for the first time. Approximately half of all abortions were performed before the eighth week of gestation, and 87% were before the thirteenth week of gestation. Younger women tended to obtain abortions later in pregnancy than older women. This report also includes newly reported abortion-related deaths for 1986 and 1987, as well as an update on abortion-related deaths for the period 1978-1985. Ten deaths in 1986 and six deaths in 1987 were associated with legal induced abortion. The case-fatality rate in 1986 was 0.8 abortion-related deaths/100,000 legal induced abortions and 0.4/100,000 in 1987.

Abortion surveillance, United States, 1984-1985

Since 1983, the number of legal abortions reported to CDC increased by 5% to 1,333,521 in 1984; in 1985, that number decreased by less than 1% to 1,328,570. The national abortion rate was the same for both years-24 per 1,000 females ages 15-44 years. The abortion ratio for 1984 was 364 legally induced abortions per 1,000 live births; the ratio for 1985 was 354 per 1,000. Abortion ratios were higher among women of black and other minority races and among women younger than 15 years of age. Women undergoing legally induced abortions tended 1) to be young, white, and unmarried, 2) to have had no previous live births, and 3) to be having the procedure for the first time. Curettage was the procedure used in 96% of the reported cases. Eleven deaths were associated with legally induced abortions in 1984, and six in 1985. The case-fatality rate in 1985 was 0.5 deaths per 100,000 legally induced abortions, down from the 0.8 per 100,000 reported in 1983 and 1984. Overall, since 1980, the numbers and rates of abortion have had only slight year-to-year fluctuations. The steady increase in the percentage of repeat abortions since 1972 reflects the ongoing availability of legal abortions. Since the beginning of CDC's abortion mortality surveillance, the number of deaths related to legal abortions has decreased 75%, from 24 deaths in 1972 to six deaths in 1985.

Analysis of surveillance data with Poisson regression: a case study

One way to examine the ability of a statistical technique to detect changes in surveillance data is to analyse data sets with known changes and observe how accurately these changes can be detected. The elimination of restrictions on legal abortions should have reduced mortality associated with abortions, particularly mortality associated with illegal abortions. The sensitivity of Poisson regression to detect changes in abortion associated mortality from 1962 to 1984 was assessed for the entire United States of America and for specific states. Although it is clear that this change occurred using data from the entire United States, only the largest of the individual state data sets examined (370 events over 23 years) consistently demonstrated the expected pattern. Inconsistent patterns were found in data sets from two states with between one-fourth and one-half this number of events. The legal change was not detected at all in three states with a small number of events (1 event per year or less). From this case study, a minimum of two or three events per year seems to be necessary before Poisson regression can detect outliers. Comparisons of the four tests used suggest that tests based on model deviance are superior to tests based on comparison of observed and expected number of events.

[Reproductive mortality in Switzerland between 1952 and 1982]

Reproductive mortality includes mortality attributable to pregnancy and childbirth and its sequelae, termination of pregnancy and contraception. The latter is mainly due to an increase of cardiovascular diseases in oral contraceptive users. An estimate of reproductive mortality in Switzerland is based on available figures on cardiovascular mortality, smoking and use of oral contraceptives. The reproductive mortality has been steadily declining since 1952 in the age group of 15-34, a stagnation of this risk can be observed for women over 35 since 1962. Theoretically this stagnation might be due to the use of oral contraceptives and an increase in smoking.

Legal abortion mortality and general anesthesia

Legal abortion-related mortality as reported to the Centers for Disease Control declined eightfold between 1972 and 1981. However, the causes of legal abortion mortality have changed over time. We reviewed all legal abortion-related deaths that occurred between 1972 and 1985 in the United States. We found that, although the absolute number of legal abortion-related deaths caused by general anesthesia complications did not increase, the proportion of such deaths increased significantly, from 7.7% between 1972 and 1975 to 29.4% between 1980 and 1985. Women who died of general anesthesia complications did not differ by age, presence of preexisting medical conditions, or type of facility from women who died of other causes. However, the proportion of deaths from general anesthesia complications was significantly higher among women of black and other races, women obtaining abortions during the first trimester, and women obtaining abortions in the Northeast. Our results indicate that at least 23 of the 27 deaths were due to hypoventilation and/or loss of airway resulting in hypoxia. Persons administering general anesthesia for abortion must be skilled in airway management as well as the provision of general anesthesia.

Legal abortion mortality in the United States: 1972 to 1982

Between 1972 and 1982, 186 women died as a result of legal abortion in the United States. The overall death rate resulting from legal abortion dropped nearly fivefold, from 4.1 per 100,000 abortions in 1972 to 0.8 in 1982. Women who were older, black, of high parity, and had abortions at a later gestational age were at increased risk of death throughout the 11 years of surveillance. During this period, the death rate decreased for abortions at all stages of gestation; the greatest decrease was with abortions performed during the second trimester. For the entire interval, mortality rates were highest for abortions performed by hysterotomy or hysterectomy and lowest for abortions performed by curettage. Before 1977, the most common causes of abortion-related death were infection, hemorrhage, and general anesthesia complications, respectively. Thereafter, hemorrhage became the most common cause of abortion-related death, followed in number by general anesthesia complications. Our findings suggest that there has been a marked decrease in septic legal abortion deaths, but potentially preventable deaths from general anesthesia and hemorrhage remain an important concern. Use of general anesthetics during first-trimester abortions should be carefully reviewed.

Cluster of abortion deaths at a single facility

This report describes a cluster of four abortion-related deaths at a single facility from 1979 to 1983. The deaths followed curettage abortions at eight to 18 weeks' gestation. One death was attributed to a prolapsed mitral valve, and one was attributed to spontaneous ventricular fibrillation. Two deaths, which occurred within three weeks of each other, were caused by hemorrhage from uterine perforation. The person who allegedly performed the last two abortions was not licensed to practice medicine, nor was he under the supervision of a licensed physician. The estimated death-to-case rate at this facility (57 per 100,000 abortions) is significantly higher than the national rate (1.2 per 100,000 abortions, P less than .001). To prevent such situations, prompt treatment of abortion complications and community-based surveillance of serious morbidity should be performed.

Deaths due to sexually transmitted diseases. The forgotten component of reproductive mortality

Reproductive mortality has three principal components: deaths related to pregnancy, contraception, and sexually transmitted diseases (STDs). The last component is usually overlooked. In 1955, deaths due to STDs constituted a minimum of 32% of all reproductive mortality in the United States; in 1965 and 1975, the percentages were 32% and 20%, respectively. Pelvic inflammatory disease and syphilis account for most deaths due to STDs. In 1979, the mortality rate due to pelvic inflammatory disease was 0.29 deaths per 100,000 women aged 15 to 44 years; the corresponding figure for syphilis was 0.17. If cervical cancer is viewed as an STD, then deaths due to this cause alone (approximately 6,800 per year) would far outnumber deaths due to all other reproductive causes combined. Surveillance of reproductive mortality in the United States should be expanded to encompass deaths due to STDs.

Trends in induced legal abortion morbidity and mortality

Abortion mortality in the USA experienced an eight-fold decline between 1972 and 1981, with the greatest decline occurring after 1975. The risk for all groups of women declined, but the decline was greater for some groups than for others. When both changing risk for a given characteristic and changing prevalence of that characteristic were examined, it appears that the declining mortality rates are largely due to a downward shift in the gestational ages at which abortions are obtained and the increased use of D&E for abortions at 12 gestational weeks or later. Although morbidity data analogous to the mortality data are not available, analysis of morbidity trends from three large multicentre prospective studies between 1970 and 1978 suggests that morbidity may not have declined quite as rapidly as mortality. The morbidity data, as well as giving information on cause-specific abortion mortality in the USA, showing dramatic declines for such causes as infection and pulmonary embolus, suggest that improved medical management of complications has contributed to declining abortion mortality in the USA.

Morbidity and mortality from second-trimester abortions

The comparative safety of methods used to perform second-trimester abortion is an important public health concern. Morbidity and mortality studies have indicated that dilation and evacuation (D&E) is safer than instillation abortion, which is safer than hysterotomy and hysterectomy. In the third phase of the Joint Program for the Study of Abortion, the adjusted relative risk of serious complications associated with the intraamniotic instillation of urea and prostaglandin F2 alpha (the safest abortifacient regimen) was 1.9 times that associated with D&E (95% confidence interval, 1.2-3.1). An analysis of abortion mortality in the United States from 1972 to 1981 revealed a death-to-case rate of 4.9 per 100,000 abortions associated with D&E, 9.6 with instillation methods and over 60 with hysterotomy and hysterectomy. Little information exists concerning potential late sequelae of second-trimester abortion. D&E appears to be the safest method of second-trimester abortion available in the United States.

Legalized abortion: the Singapore experience

Abortion has been legal since 1970 in Singapore. This report traces the events leading to the liberalization of abortion laws and examines women's changing attitudes toward abortion, in Singapore. The method of abortion practiced by obstetricians, postabortal sterilization, and the effect of legalized abortion on the incidence of illegal abortion in the country are also examined.

Maternal deaths related to abortions in Sweden, 1931-1980

Deaths related to abortion accounted for 20% of all maternal mortality in Sweden during the period 1931-80. The risk of dying as a consequence of abortion, per 100,000 pregnancies, declined with a factor of 160 during the study period. Three main reasons for the improvement are discussed. The introduction of antibiotics reduced mortality due to illegal abortions, but during the 1950s and 1960s sepsis and air embolism resulting from illegal abortion still accounted for the bulk of the abortional mortality. Liberal legislation and abortional practice subsequently eliminated illegal abortions, and resulted in a more accurate and favorable statistical distribution of abortions by pregnancy week. This together with new technology reduced the legal abortions mortality rate to one-fiftieth over the last 30 years even though the number of legal abortions increased 7-fold.

Fatal hemorrhage from legal abortion in the United States

Deaths from hemorrhage associated with legal induced abortion should not occur. Yet hemorrhage was the third most frequent cause of death from legal abortion in the United States between 1972 and 1979. This study was undertaken to document the scope of the problem, to identify risk factors for fatal hemorrhage and to recommend ways of preventing these deaths. Deaths were identified through the CDC's nationwide surveillance of deaths from abortions; information on numbers and characteristics of women having legal abortions was obtained from CDC and the Alan Guttmacher Institute. Twenty-four women died from hemorrhage after legal abortion in the United States from 1972 to 1979, for a death-to-case rate of 0.3 deaths per 100,000 abortions (95 per cent confidence interval 0.2 to 0.5). Women who died from hemorrhage were significantly older than those who died from other causes (27.6 versus 24.4 years; p less than 0.05). Documented uterine perforation or rupture was far more frequent among women who died from hemorrhage than those who died from other causes (71 versus 8 per cent; p less than 0.001). Women who sustained uterine perforation or rupture were over 1,000 times more likely to die from hemorrhage than those who did not. Deaths from hemorrhage can be eliminated by preventing uterine trauma during abortion and by rapidly diagnosing and treating hemorrhage if it occurs.

Mortality from abortion and childbirth. Are the statistics biased?

Critics have challenged previous comparisons of mortality from legal abortion and childbirth for containing biases in the crude data that spuriously favor the safety of abortion. To evaluate this concern, we reviewed the sources of mortality data on which these comparisons are based and examined the completeness of abortion mortality statistics, the completeness of childbirth mortality statistics, and the accuracy of the denominators for both these events. We found the evidence to be consistent in two directions: (1) abortion deaths appear to be more completely ascertained than childbirth deaths; (2) use of different denominator estimates has relatively little impact on the comparison. From this evidence, we conclude that the crude data are biased in a direction that overestimates the abortion risks for the women relative to the risks of childbearing.

Mortality from abortion and childbirth. Are the populations comparable?

Critics have challenged previous comparisons of mortality from legal abortion and childbirth for contrasting population groups with different clinical characteristics. They allege that most women dying from abortion were young, white, and healthy, while those dying from childbirth had serious underlying conditions. To address this question, we calculated standardized abortion and childbirth mortality rates between 1972 and 1978. We also adjusted independently for preexisting medical conditions. These adjustments for demographic and health differences between the two populations actually widened the difference in the mortality risk between abortion and childbirth. Thus, between 1972 and 1978, women were about seven times more likely to die from childbirth than from legal abortion, with the gap increasing in the more recent years.