Clinics in obstetrics and gynaecology最新文献

No nation desirous of reducing its growth rate to 1% or less can expect to do so without the widespread use of abortion. This observational study, based on the experience of 116 of the world's largest countries, supports the contention that abortion is essential to any national population growth control effort. The principal findings are: Except for a few countries with ageing populations and very high contraceptive prevalence rates, developed countries will need to maintain abortion rates generally in the range of 201-500 abortions per 1000 live births if they are to maintain growth rates at levels below 1%. The current rate in the USA is 426 abortions per 1000 live births. Developing countries, on the other hand, are faced with a different and more difficult set of circumstances that require even greater reliance on abortion. No developing nation wanting to reduce its growth to less than 1% can expect to do so without the widespread use of abortion, generally at a rate greater than 500 abortions per 1000 live births. Widespread availability of abortion is a necessary but not sufficient condition to achieve growth rates below 1%. A high contraceptive prevalence is essential as well in order to achieve growth rates below 1%. A high contraceptive prevalence is a necessary but not sufficient condition to achieve population growth rates below 1%. A high rate of abortion (generally 201-500 or more abortions per 1000 live births in the developed and greater than 500 abortions per 1000 live births in the developing countries) is essential to achieve growth rates below 1%. The different and more difficult set of circumstances faced by developing countries that will necessitate even higher abortion rates than developed countries includes a young population with resultant rapidly growing numbers of young fertile women, poor contraceptive use-effectiveness, low prevalence of contraception, and poor or non-existent systems for providing contraceptives. These data show that high death rates of infants and children can moderate population growth rates--a most undesirable solution. The data in this report suggest that actual alternatives are high death rates of infants and children or widespread use of contraception and abortion. African nations tend to have the very lowest abortion rates and the very highest infant and child death rates. To avoid a world with deteriorating social, economic and political stability, with the concomitant loss of personal and national security, we must ensure that safe abortion is made available to all who wish to use this service.

Abortion is a universal phenomenon, occurring throughout recorded history and at all levels of societal organization. Techniques are highly varied, as are the circumstances under which it is practised. The status of and attitudes towards abortion in Western civilization are variable and have, in most cases, been changing. As of 1982, 10% and 18% of the world's population respectively, lived in countries where abortion was totally prohibited or where it was permitted only to save the mother's life. In the USA, various national surveys indicate liberalization of public attitudes towards pregnancy termination between 1965 and the years immediately following the Roe v. Wade Supreme Court decision (1973) which legalized abortion. More recent polls demonstrate little attitudinal change since 1972-1973: between 80% and 90% of Americans approve of abortion in the case of poor health, a seriously defective fetus, or rape, and between 40% and 50% indicate approval for all other reasons as well. Only 10% of the American population would like to see abortion prohibited under all circumstances. Sociodemographic analyses indicate that individuals who disapprove of abortion differ from those who approve of its availability in that they are more likely to be Roman Catholic or fundamentalist Protestant; are, in general, more strongly committed to organized religion; are on the traditional/conservative end of the spectrum with regard to women's role in life, premarital sex, sex education and civil liberties; and tend to have achieved a relatively low educational level. 'Pro-life' and 'pro-choice' activists tend to be women who are completely different from one another in sociodemographic characteristics and in overall values, particularly as these relate to traditional versus modern female roles.

The impact of abortion on subsequent fecundity has been extensively studied, especially since abortion was legalized in Eastern Europe during the 1950s and 1960s and in Western Europe and the USA during the 1960s and 1970s. A review of this literature reveals a number of consistent findings. First, women who choose to have their first pregnancy terminated are at no increased risk of failing to conceive at a later date. Exceptions include abortions complicated by infection leading to pelvic inflammatory disease (PID). However, this combination of factors occurs very infrequently. Second, women whose first pregnancy is terminated by vacuum aspiration are at no increased risk of subsequent ectopic pregnancy. Exceptions may be women whose abortion is complicated by pre-existing C. trachomatis and others who experience post-abortion infection leading to PID. Third, women whose first pregnancy is terminated by vacuum aspiration are at no increased risk of subsequent mid-trimester spontaneous abortion, preterm delivery or low birthweight, when compared with women who are pregnant for the first time. Fourth, women whose first pregnancy is terminated by D&C may have an increased risk of subsequent ectopic pregnancy, mid-trimester spontaneous abortion and low birthweight. Fifth, more research is needed before it is clear whether multiple induced abortions carry an increased risk of adverse pregnancy outcomes. Finally, too little is known about fecundity following mid-trimester abortion procedures to state definitively that they carry no increased risk of adverse outcomes. However, studies to date suggest that instillation procedures carry little, if any, excess risk. Risks related to dilation and evacuation, if any, may be related to the method and extent of cervical dilation.

Women who have major medical complications, such as cardiovascular conditions leading to cardiac, renal, or cerebral impairment, which interfere with their lifestyle or who have fetuses with major malformations or chromosomal abnormalities are eligible for pregnancy terminations before the fetus has reached a viable stage. Any method for uterine evacuation may be offered at any time if the woman's life is threatened or if the fetal chromosomal abnormality (e.g. triploidy) or malformation is considered to be definitely incompatible with life. Such malformations would include bilateral renal agenesis, anencephaly, lethal forms of chondrodysplasia, holoprosencephaly, and severe pulmonary hypoplasia. Prostaglandin vaginal suppository therapy is the primary method for cervical dilation and induction of uterine contractions at most perinatal centres. This therapy is particularly useful when a fetal abnormality is suspected, since the fetus is usually delivered intact for gross and histological evaluation. Postmortem findings are helpful to the parents and other family members for future childbearing and family history. Disadvantages of such therapy include side-effects from the medication, prolonged labour discomfort, and delivery of a viable rather than stillborn infant. A surgical dilation and evacuation of the uterus may be undertaken between 12 and 20 weeks' gestation for women with prior uterine surgery, contraindication to prostaglandin use, no future childbearing being desired, and a fetus having a known lethal chromosomal abnormality (e.g. trisomy 13 or 18). This form of therapy is rapid, less painful, and fetal blood and tissue may be gathered for analysis although complete morphological examination of the fetus is not possible. Instillation of hypertonic saline or urea is no longer widely used for pregnancy termination, although intra-amniotic urea may be used adjunctively. Prolonged instillation-to-evacuation times and potential metabolic concerns are limitations. This therapy may be particularly useful when a stillborn infant is desired or when prior prostaglandin therapy has been unsuccessful. Abdominal operations such as hysterectomy or hysterotomy are also unnecessary unless there is an accompanying gynaecological complication or unless other pregnancy termination methods have been unsuccessful or unavailable. Women experiencing mid-gestation pregnancy terminations undergo a grief process which involves disbelief, sadness, guilt, anger and acceptance before and after the pregnancy termination. This is common and understandable. Parental counselling is recommended both before the procedure and several weeks thereafter.