An infant death is one that takes place at a time between birth and what age?
An infant death is one that takes place at a time between birth and what age?
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A. 3 months
B. 6 months
C. 12 months
D. 24 months
The perinatal mortality rate (per 1000 total births) is calculated by adding the number of neonatal deaths to which of the following?
A. number of stillbirths
B. number of infant deaths
C. spontaneous abortions
D. all of the above
Reference:
Obstetrics in Broad Perspective: Introduction
In the 10th edition of Williams Obstetrics, Eastman described the word obstetrics as being derived from the Latin obstetrix, meaning midwife. The word also is connected with the verb obstare—to stand by or in front of. The rationale for this derivation is that the midwife stood by or in front of the parturient. It is intriguing to consider that the derivation of obstetrics may have its origins in the evolution of the human species. To do so, we examine the thought-provoking observations of Rosenberg and Trevathan (2002). Their hypothesis dwells on two characteristics that set humans apart from other mammals, that is, that humans are the only mammals that walk on two legs, and that for body size, we have the largest brains. Also, unlike the females of other mammalian species, including other primates, women routinely seek assistance when they give birth.
Rosenberg and Trevathan (2002) propose that women's need for birthing assistance may be the result of this evolved bipedalism and large brain. The challenge of birth for many primates, and especially for humans, is that the size of the newborn's head is very close to the size of the passage through which it must travel. The series of rotations described in Chapter 17 that the human fetus must undergo during childbirth are thought to be related to the evolution of upright locomotion as well as the larger brain. Because of pelvic changes necessary to accommodate bipedalism, the human fetus must negotiate a birth canal that is not constant in cross-section. The pelvic inlet, where the fetus begins its transit, is widest from side to side. Midway through the pelvis, however, the orientation shifts 90 degrees and the widest dimension of the pelvis is from anterior to posterior. This change in pelvic dimensions means that the fetus must negotiate a series of turns as it passes through the birth canal so that its largest dimensions—the head and shoulders—are always aligned with the widest dimension of the birth canal. As a consequence of this rotation, human fetuses predominantly assume the occiput anterior position at delivery. In contrast, occiput posterior delivery is characteristic for nonhuman primates with smaller brains and correspondingly smaller head size. For example, in monkeys, the neonate is born looking up into its mother's face, which makes it possible for the mother to reach down and guide the newborn out of the birth canal. She can also wipe mucus from the baby's face to assist its breathing.
Thus, Rosenberg and Trevathan (2002) propose that human parturients require assistance because they cannot mechanically manage delivery of the occiput anterior vertex without help. They suggest that the triple challenge of a big-brained neonate, a maternal pelvis designed for walking upright, and a rotational delivery in which the infant emerges facing backward were natural selection pressures that favored humans seeking assistance—hence, obstetrics.
In the broader sense, obstetrics is concerned with reproduction of the society of humans. The specialty aims to promote health and well-being as the branch of medicine that is concerned with pregnancy, labor, and the puerperium in both normal and abnormal circumstances. The importance of obstetrics is attested to by the observation that maternal and neonatal outcomes are universally used as an index of the quality of health and life in human society. With this in mind, we provide a synopsis of the current state of maternal and newborn health in the United States. Following this is a perspective on some of the forces affecting obstetrics in these early years of the 21st century.
Vital Statistics
The vital statistics of the United States are collected and published through a decentralized, cooperative system (Tolson and colleagues, 1991). Responsibility for the registration of births, deaths, fetal deaths, marriages, divorces, annulments, and induced terminations of pregnancy is vested in the individual states and certain separate governmental entities. The system comprises 57 registration areas: each state, the District of Columbia, New York City, American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the Virgin Islands.
The first standard certificates for the registration of live births and deaths were developed in 1900. An act of Congress in 1902 established the Bureau of the Census to develop a system for the annual collection of vital statistics. The overall objective was to develop and maintain a system for registration that is uniform in such matters as forms, procedures, and statistical methodology. The Bureau retained the authority for producing national vital statistics until 1946, when the function was transferred to the United States Public Health Service. It is presently assigned to the Division of Vital Statistics of the National Center for Health Statistics (NCHS). The standard certificate of live birth was substantially revised in 1989 to include much more information on medical and lifestyle risk factors and also obstetrical care practices. Currently, more than 99 percent of births in the United States are registered.
The NCHS is part of the Centers for Disease Control and Prevention (CDC). Its function is to collaborate with colleagues in state vital statistics offices to revise the certificates of live birth and fetal death. This process generally is carried out every 10 to 15 years. Revisions were initiated in some states in 2003, and full implementation in all states will begin in phases over several years. The 2003 revision focuses on fundamental changes in the way the data are collected to accomplish greater accuracy. Changes also include a format conducive to electronic processing, to collect more explicit parental demographic data, and to improve selection of information regarding antepartum and intrapartum complications. Some examples of new data to be collected include that related to uterine rupture, blood transfusion, and pregnancy resulting from infertility treatment.
Definitions
The uniform use of standard definitions is encouraged by the World Health Organization as well as the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists (2002). Such uniformity allows comparison of data not only between states or regions of the country, but also between countries. It is recommended that United States statistics include all fetuses and neonates born weighing at least 500 g, whether alive or dead. It must be clarified, however, that the states are not uniform in their definition of fetal death. For example, 28 states stipulate that fetal deaths beginning at 20 weeks' gestation should be recorded, eight states report all products of conception as fetal deaths, and still others use birthweights of 350 g, 400 g, or 500 g or greater to identify fetal deaths.
Definitions recommended by the NCHS and the CDC are as follows.
In 1987, the CDC collaborated with the Maternal Mortality Special Interest Group of the American College of Obstetricians and Gynecologists, the Association of Vital Records and Health Statistics, and state and local health departments to initiate the National Pregnancy Mortality Surveillance System. Two new terms were introduced.
- Perinatal period. The period after birth of an infant weighing 500 g or more and ending at 28 completed days after birth. When perinatal rates are based on gestational age, rather than birthweight, it is recommended that the perinatal period be defined as commencing at 20 weeks.
- Birth. The complete expulsion or extraction from the mother of a fetus, irrespective of whether the umbilical cord has been cut or the placenta is attached. Fetuses weighing less than 500 g are usually not considered as births, but rather are termed abortuses for purposes of vital statistics.
- Birthweight. The weight of a neonate determined immediately after delivery or as soon thereafter as feasible. It should be expressed to the nearest gram.
- Birth rate. The number of live births per 1000 population.
- Fertility rate. The number of live births per 1000 females aged 15 through 44 years.
- Live birth. The term used to record a birth whenever the newborn at or sometime after birth breathes spontaneously, or shows any other sign of life such as a heartbeat or definite spontaneous movement of voluntary muscles. Heartbeats are to be distinguished from transient cardiac contractions, and respirations are to be distinguished from fleeting respiratory efforts or gasps.
- Stillbirth or fetal death. The absence of signs of life at or after birth.
- Neonatal death.Early neonatal death refers to death of a liveborn neonate during the first 7 days after birth. Late neonatal death refers to death after 7 days but before 29 days.
- Stillbirth rate or fetal death rate. The number of stillborn neonates per 1000 neonates born, including live births and stillbirths.
- Neonatal mortality rate. The number of neonatal deaths per 1000 live births.
- Perinatal mortality rate. The number of stillbirths plus neonatal deaths per 1000 total births.
- Infant death. All deaths of liveborn infants from birth through 12 months of age.
- Infant mortality rate. The number of infant deaths per 1000 live births.
- Low-birthweight. A newborn whose weight is less than 2500 g.
- Very-low-birthweight. A newborn whose weight is less than 1500 g.
- Extremely-low-birthweight. A newborn whose weight is less than 1000 g.
- Term neonate. A neonate born anytime after 37 completed weeks of gestation and up until 42 completed weeks of gestation (260 to 294 days).
- Preterm neonate. A neonate born before 37 completed weeks (the 259th day).
- Postterm neonate. A neonate born anytime after completion of the 42nd week, beginning with day 295.
- Abortus. A fetus or embryo removed or expelled from the uterus during the first half of gestation—20 weeks or less—and weighing less than 500 g.
- Induced termination of pregnancy. The purposeful interruption of an intrauterine pregnancy with the intention other than to produce a liveborn neonate, and which does not result in a live birth. This definition excludes retention of products of conception following fetal death.
- Direct maternal death. The death of the mother resulting from obstetrical complications of pregnancy, labor, or the puerperium, and from interventions, omissions, incorrect treatment, or a chain of events resulting from any of these factors. An example is maternal death from exsanguination after uterine rupture.
- Indirect maternal death. A maternal death not directly due to an obstetrical cause, but resulting from previously existing disease, or a disease that developed during pregnancy, labor, or the puerperium, but which was aggravated by maternal physiological adaptation to pregnancy. An example is maternal death from complications of mitral valve stenosis.
- Nonmaternal death. Death of the mother resulting from accidental or incidental causes not related to pregnancy. An example is death from an automobile accident or concurrent malignancy.
- Maternal mortality ratio. The number of maternal deaths that result from the reproductive process per 100,000 live births. Used more commonly, but less accurately, are the terms maternal mortality rate or maternal death rate. The term ratio is more accurate because it includes in the numerator the number of deaths regardless of pregnancy outcome—for example, live births, stillbirths, ectopic pregnancies—while the denominator includes the number of live births.
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- Pregnancy-associated death. The death of any woman, from any cause, while pregnant or within 1 calendar year of termination of pregnancy, regardless of the duration and the site of pregnancy.
- Pregnancy-related death. A pregnancy-associated death resulting from (1) complications of the pregnancy itself, (2) the chain of events initiated by the pregnancy that led to death, or (3) aggravation of an unrelated condition by the physiological or pharmacological effects of the pregnancy that subsequently caused death.
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Of the following, what is the number of deaths per 1000 births occurring during the first 28 days of
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