Maternal–Fetal Relationship: I. Medical Aspects

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During the last decades of the twentieth century, perinatal medicine made tremendous advances in scientific knowledge and in the successful application of this knowledge toward improving pregnancy outcomes. These advances have also brought a dramatic change in medicine's conceptualization of the fetus. No longer is the fetus defined predominantly as a part of the pregnant woman, but rather as a distinct entity that can be the independent focus of diagnostic tests and individual therapies: "A second patient with many rights and privileges comparable to those previously achieved only after birth." It is the widely shared view of obstetricians that the fetus is a patient to whom they owe ethical duties. The purpose of this entry is to delineate the medical advances that have brought about this change in fetal identity and to discuss the impact of these changes on pregnant women and the obstetrical decision-making process.

Pregnancy and Maternal Health

Maternal morality in pregnancy fell dramatically in the United States from more than one in 200 in 1935 to 7.7 per 100,000 in 1999. Most of this reduction was accomplished earlier in this century through improved surgical techniques and increased access to safe blood products, antibiotics, intravenous fluids, and improved prenatal care.

Despite these improvements, pregnancy still poses the risk of serious illness and, in rare cases, death. It has been calculated that the risk of mortality in pregnant women is 179 times that of the risk of death among women using the safest method of birth control. The major causes of maternal death are hypertensive disorders of pregnancy, pulmonary embolism, uterine hemorrhage, and sepsis. The risks of pregnancy are proportional to the age of the pregnant woman and to her underlying state of health. Women with medical illness may note worsening of their disease during pregnancy, sometimes with serious long-term consequences. But even women who begin a pregnancy in excellent health may find themselves suddenly confronting the morbidity and mortality risks associated with cesarean section (nearly 25% of all U.S. deliveries in 2000), postpartum hemorrhage (4–8% of all deliveries), or pre-eclampsia (a pregnancyrelated condition that can lead to seizures, strokes or death in the pregnant woman) (5% of all pregnancies).

Pregnant women may experience preterm labor (U.S. incidence was 11.9% in 2001), the development of premature contractions that if not stopped can result in delivery of the fetus before adequate development has occurred. Preterm delivery poses significant risk of disability and death for the fetus. While preterm labor itself does not pose a health risk to the pregnant woman, many of the treatments recommended for its treatment have significant maternal side effects. The three drugs commonly used to treat (attempt to stop) preterm labor have serious side effects ranging from nausea, vomiting, dizziness, flushing, tremor, and jitteriness to life-threatening risks of pulmonary edema (fluid in the lungs), alterations in blood chemistries (hypokalemia, hyperglycemia), heart rate abnormalities (tachycardia, arrhythmias), hypotension, respiratory depression, and cardiac arrest.

For all women, pregnancy is a complex physiologic process; almost every organ system undergoes adaptation to support the maternal-fetal unit. It is important to appreciate the range of symptoms experienced by many pregnant women due to these physiologic changes. These include nausea, vomiting, fatigue, syncope (fainting), round ligament pelvic pain, backache, heartburn, hemorrhoids, constipation, urinary frequency, carpal tunnel syndrome (numbness and tingling of the hands), pedal edema, and sciatica (hip and leg nerve pain). Thus, while pregnancy is described as a normal physiologic process, it is not without common discomforts and the potential for serious illness. Most pregnant women willingly assume these sacrifices for their developing fetus.

Pregnancy and Fetal Therapies

Perinatal technologies have benefited the fetus by increasing the understanding of normal fetal development as well as improving prenatal diagnostic capabilities and therapeutic interventions. The fetus can be visualized with ultrasound, its well-being assessed with fetal heart-rate monitoring, and its diseases diagnosed with chorionic villus sampling, amniocentesis, and fetal blood sampling. Increases in diagnostic capabilities have been accompanied by the development of techniques to treat the fetus directly in utero. Our increasing ability to act on behalf of the fetus has made its claims to our care more compelling.

Prenatal technologies designed to benefit the fetus range from the simple to the complex, with differing risks and benefits for both the pregnant woman and her fetus. The most commonly used technology with the intention of improving fetal outcome is electronic fetal monitoring (EFM). EFM was introduced in the United States in the early 1970s with the promise that it would enable early detection of fetal hypoxia in labor and alert the physician to perform an immediate delivery, preventing the serious consequences of oxygen deprivation, including brain damage and stillbirth. Its use rapidly expanded from high-risk pregnancies to all pregnancies; in 1996, it was estimated that three-fourths of all U.S. pregnancies were monitored. Unfortunately, the wide acceptance of this technology occurred before adequate studies had been done to assess its efficacy and safety. There have been numerous randomized and controlled trials of EFM that have been unable to demonstrate a decrease in intrapartum fetal death or better newborn health in low-risk pregnancies. However, the use of EFM was shown to double the C-section (cesarean section) rate for the indication of fetal distress, thus exposing more women to the increased morbidity and mortality risks of C-section without the promised fetal benefit.

Other technologies include internal monitoring, used almost exclusively in high-risk situations, and telemetry monitoring, which uses radio waves and is non-invasive. Internal monitoring can cause fetal injury and infection to both the mother and baby.

A C-section entails a greater risk of maternal morbidity and mortality than does a vaginal delivery. The mortality rate associated with C-section is between two and four times that associated with a vaginal delivery. Maternal morbidity is also more frequent and usually more severe with a C-section. The common causes of morbidity associated with C-sections are infection, injury to the urinary tract, risk of placenta accreta (where the placenta attaches to the incision in a subsequent pregnancy) and hemorrhage with the possible risk of transfusion. Even an uncomplicated C-section requires a much longer recovery period for the mother at a time when she is experiencing increased physical and emotional demands.

The simplest fetal therapies are medications given to a pregnant woman for the benefit of her fetus. A well-accepted treatment of a woman who develops mild diabetes during pregnancy is to give her insulin until delivery. This practice benefits the fetus by preventing its excessive growth and associated birth trauma and by avoiding the potential neonatal difficulties of an infant of a diabetic mother. While insulin is not essential for the pregnant woman's health, it may be beneficial by reducing her risk of C-section delivery and the potential harms of a mildly elevated glucose to her own organ systems. Digoxin is a medication administered to pregnant women for the benefit of a fetus with cardiac arrhythmia. Unlike insulin, digoxin offers no benefit to the health of the pregnant woman. The risks to the pregnant woman of ingesting insulin or digoxin are minimal if administered appropriately. In summary, these pharmacologic fetal therapies confer benefit upon the fetus and are minimally invasive; one offers some benefit for the pregnant woman; the other solely benefits the fetus.

An accepted but more invasive therapy of sole benefit to the fetus is a fetal blood transfusion for isoimmunization from Rh disease (a condition in which the immune system of the pregnant woman destroys the blood cells of the fetus resulting in fetal death if severe and untreated). The most common technique is cordocentesis, in which a needle is placed through the maternal abdominal and uterine wall into the umbilical blood vessel for the purpose of transfusing blood into the fetus. This technique is not without its risks for both the fetus and the pregnant woman. This procedure poses a 2 percent chance of fetal death. It also increases the risk of fetal bradycardia (a dangerous lowering of the heart rate), a condition that mandates an emergency C-section for the safety of the fetus. All the maternal risks of C-section delineated above are increased in an emergency C-section, with the addition of the increased risk of death from general anesthesia. Cordocentesis is an example of an accepted fetal therapy that is potentially beneficial for the fetus and invasive for the pregnant woman, with significant risks to her in complicated cases.

The most invasive fetal therapy is in utero fetal surgery. While these procedures are still uncommon, some successes have occurred. One example is the surgical removal of a lung mass in the fetus. The rationale for the surgery is that without prenatal removal, the fetal lungs will be unable to grow sufficiently to support survival after birth. Intrautrine shunt therapy for hydrocephalus (abnormal amounts of brain fluid causing brain damage and enlargement of the head) is an experimental surgical procedure. Another, more controversial surgery involves fetal surgery to fuse the spinal hole caused by myelomeningocele (spina bifida). Because spina bifida is not a life-threatening disease, some ethicists and physicians have called the procedure into question. In 2003 the National Institute of Child Health and Human Development began a study of prenatal and postnamtal closure of myelomeningocele to determine the long-term benefits.

In all maternal-fetal surgeries, the pregnant woman must undergo a major abdominal operation and take medications to prevent the preterm labor that might be caused by the surgery. The surgery entails the usual risks associated with a C-section but at a higher rate because of the type of uterine incision, the thickness of the uterine wall, and the need for general anesthesia. Because of the type of uterine incision necessary for this fetal surgery, the woman must have a C-section in this pregnancy, even if her fetus is stillborn, as well as in all future pregnancies.

Neonatal Advances and Obstetrical Decision Making

Simultaneous advances in neonatology have had a significant impact on obstetrical knowledge and care. The gestational age at which survival is possible in the modern intensive care nursery has been pushed back continuously over the past few decades to the age of twenty-four to twenty-five weeks (fifteen to sixteen weeks premature). Many fetuses/babies who in the past would have been considered nonviable now survive and develop normally. However, the cost of this success is measured in hundreds of thousands of dollars per premature infant and in the potential for severe lifelong impairments.

This improved neonatal survival has had two significant influences on the perspective of obstetrical providers. Most have seen or participated in the care of very premature babies; thus fetuses in utero from twenty-four weeks on possess a very concrete human image for those who care for them. In addition, the possibility of survival beginning at twenty-four gestational weeks creates an argument for aggressive obstetrical management at earlier and earlier stages of pregnancy. The lower the gestational age at birth and the lower the birth weight, the lower the chance of survival and the higher the risk of severe physical and mental impairment. Between twenty-four to twenty-eight weeks the likelihood of survival increases from 20 percent to 90 percent, with a 20 percent incidence of severe neonatal impairment in the survivors. Complicating this situation is the inaccuracy of techniques to estimate gestational age and fetal weight. The inability to predict with certainty before birth either the survival or the likelihood of impairment creates legitimate divergent perspectives on what to do in individual pregnancies and ensures difficult decision making for obstetricians and pregnant women.

Formerly, a woman who developed preterm labor at twenty-five weeks would have been allowed to deliver vaginally and comforted regarding the certain death of her baby. Today, that pregnant woman will be faced with the option and probable recommendation that the fetus be monitored in labor and delivered by C-section if needed for fetal benefit. A C-section at this gestational age is riskier for her than one at term and because the type of uterine incision required commits her to C-section delivery of future pregnancies. The chance of the infant's survival is between 30 and 50 percent depending on its weight (which is difficult to predict prior to delivery). If the infant does survive, there will be a significant chance of neurologic or physical impairment. Some women will choose to take any risk for a slim possibility of fetal benefit, and accept aggressive obstetrical management. Other women decide that the risk of C-section in this and future pregnancies combined with the potential suffering for their premature infant is not worth the slight chance of being able to take home a normal or mildly impaired child. They choose to let "nature take its course," and hope that their next pregnancy will be free of complications. For the obstetrician faced with this clinical dilemma, the uncertainty of prognosis (this fetus might do well), the availability of technologic intervention (C-section), the desire to do something, and the legal fear of doing nothing may prompt him or her to advocate intervention as the baby's only hope. This is a persuasive argument for most pregnant women, especially if alternatives are not presented as legitimate.

The beneficial effects of fetal therapies and neonatal advances are impressive when successful: Babies previously at high risk of stillbirth, birth trauma, hypoxia, and neonatal death now have a greater chance of being born safely and having a near normal development. However, some babies who would have died now survive but with significant handicaps and at a significant cost to the physical, emotional, and financial well-being of the mother, her child, and her family. Some therapies are recommended with hope of fetal benefit but without good scientific evidence and with known maternal risks of death and morbidity. Pregnant women must be able to choose the best medical option based upon accurate scientific knowledge and an honest appraisal of the uncertainties involved in medical science.

Pregnancy and Fetal Development

Increased understanding of fetal development has allowed identification of environmental factors that can promote or impair the development of a healthy fetus. The placenta was once felt to operate as a barrier allowing only those substances beneficial to the fetus to pass. Now it is known that the placenta is an efficient transporter of many substances to the fetus, regardless of their toxicity, including both therapeutic and recreational drugs. Media coverage has focused on the rising incidence of crack cocaine use by pregnant women. It has been estimated that 11 percent of pregnant women use an illegal drug during their pregnancies and that 75 percent of these women use cocaine. While there are methodologic shortcomings in the studies of cocaine's effect on pregnancy, many serious sequelae of using this drug have been suggested, including an increased spontaneous abortion rate; suspected cardiac, genitourinary, facial, and limb abnormalities (though these may be alcohol-related); growth retardation; and in utero strokes. Obstetrical complications include preterm delivery, abruption (placental separation), and fetal distress. Newborns who have been exposed to cocaine in utero experience withdrawal symptoms, making them more irritable and less able to bond with caregivers. Many believe that cocaine-exposed babies will be more likely to experience learning disabilities, though some research has shown that there is no difference in learning scores between cocaine-exposed children and other children at age 4.

Alcohol is a well-known danger to the developing fetus. Fetal alcohol syndrome has been identified in the offspring of women who consumed excessive alcohol during their pregnancy; it is defined by a triad of symptoms: gross physical retardation; central nervous system dysfunction, including mental retardation; and characteristic facial abnormalities. Fetal alcohol effects are more common; they include cardiac, genitourinary, skeletal, and muscular anomalies; hypoxia; irritability; and hyperactivity. While excessive alcohol use during pregnancy has clearly been documented to cause significant fetal harm, no minimum safe level of consumption has been established. Many experts have recommended total abstinence from alcohol during pregnancy as the only way to avoid all possible harm.

Smoking has significant effects on pregnancy outcome. Approximately 30 percent of U.S. women of childbearing age smoke. Cigarette smoking results in reductions in birthweight, length, and head circumference. It has been estimated that between 20 and 40 percent of all low birthweight births in the United States can be attributed directly to smoking. Smoking has also been associated with higher rates of spontaneous abortion, preterm birth, perinatal mortality, and deficits in later physical, intellectual, and emotional development. A comparison of the known perinatal dangers of alcohol, smoking, and cocaine consumption illustrates that the legal substances a pregnant women may ingest are no less medically harmful than the illegal ones.

Public policy aimed at improving perinatal outcomes by reducing the use of fetotoxic substances by pregnant women must be grounded in medical knowledge. Recreational drug use by most pregnant women is an addiction; they do not consume the drug to harm the fetus but to satisfy an acute physical or psychological need. To address the problem of addiction, comprehensive and supportive programs designed to enlist the individual in her own recovery are necessary. There have been documented successes in programs that emphasize early identification of women at risk for substance abuse and that utilize comprehensive education, prenatal care, psychological intervention, and social services. However, there are very few substance abuse programs available to pregnant women. In one notable case of criminal prosecution of a woman for drug use during her pregnancy, the accused woman had sought drug treatment during her pregnancy without success.

Punitive approaches to addictive disease are generally ineffective. They have the potential to drive the addicted individual away from the very care that could be beneficial. Because the developing fetus is so vulnerable to uterine exposure to toxins, it is critical that pregnant women not be deterred from care. Prenatal care alone, in the presence of continuing drug use, can improve perinatal outcome for the drug-exposed fetus.

Obstetrical Decision Making

While a pregnant woman and her fetus may be conceptualized as two independent patients, they are in fact intimately interdependent, and actions taken to benefit one may pose a risk to the other. A pregnant woman may suffer from a serious illness that requires a treatment that will itself pose risk to her fetus; premature delivery to improve maternal health and chemotherapy for maternal cancer are two examples. Alternatively, treatment for the benefit of the fetus (C-section delivery, treatment of preterm labor, fetal surgery) may pose a risk to the pregnant woman. In addition, a medical treatment for presumed fetal benefit may interfere with the nonmedical needs of the pregnant woman.

These situations have been described by many as maternal-fetal conflict when they more accurately might be described as maternal-physician conflict. When an obstetrician agrees with the pregnant woman's choice and underlying values, no conflict ensues, even in the presence of potential fetal risk. The disagreement that does occur often is based on differing views of what is beneficial for the pregnant woman and her fetus and what are acceptable maternal risks to achieve obstetrical goals.

Obstetricians have a predominant focus on the current pregnancy. Appropriately, they emphasize the medical health of their patient and the fetus, give expert advice to improve pregnancy outcome, and urge women to follow this advice as a priority in their lives. However, medical recommendations are at times influenced by the fear of malpractice, research interests, a reluctance to give up, and a provider's own personal values.

A pregnant woman's values may differ from those of her providers and she may place a different value on the physician's medically based goals. Like other adults, a pregnant woman must and does make decisions about her prenatal activity within the broader context of her life. Her obligation to her fetus is sometimes weighed against her obligations to her other children, her parents, her partner, or others with whom she has a special relationship. Her decision may be influenced by religious or other strongly held personal beliefs.

Some have argued that pregnant women should be forced to undergo certain treatments if the benefit to the fetus would be substantial and the risk to the woman would be minimal or low. Medical uncertainty and medical practice make this a difficult policy to administer rationally or fairly. As delineated above, perinatal medicine is limited by diagnostic and prognostic uncertainty. This is best illustrated by a legal case in which a judge ordered a woman to undergo a forced C-section. In seeking the court order, the obstetrician testified that without delivery by C-section, the fetus had a 99 percent chance of dying and the pregnant woman had a 50 percent chance of mortality. However, the pregnant woman fled the court's jurisdiction and had an uneventful vaginal delivery. The ability to predict fetal distress in labor is frequently inaccurate. Because of this uncertainty, a policy of enforcing obstetrical recommendations would allow obstetricians to make the wrong decisions sometimes but would never allow a pregnant woman to be wrong or right about decisions that profoundly affect her life.

The problem of precisely defining fetal risk is matched by the complex task of delineating what constitutes an acceptable risk of harm for the mother. Risks, no matter how small in the medical context, may take on a different meaning within the context of an individual's life. The small risk of maternal death from a C-section may be very significant to a single woman who is the sole supporter of her children. Bed rest for the prevention of preterm labor may mean the loss of work and health insurance for her whole family. A Jehovah's Witness who is forced to receive blood may believe she is condemned to eternal damnation and may undergo significant stress or rejection within her religious community.

If obstetricians are given the authority to force pregnant women to follow their recommendations, this force may be used in a very arbitrary way. Not only is there variation in obstetrical diagnostic and prognostic accuracy, there are obstetrical debates about the appropriate management of various conditions. The medical justifications in the reported cases of requests for court-ordered C-sections have included breech presentation, prior C-section, and rupture of membranes for twenty-four hours without signs of febrile morbidity. Many obstetricians would disagree with each of these indications for C-section. Furthermore, the women who have been subjected to court orders have been shown to be more likely subjects of other forms of discrimination. In one study of forced C-sections, 81 percent of the women belonged to a minority group and 24 percent did not use English as their first language, and all requests for the court orders involved women who received care at a teaching hospital or who were receiving public assistance.

If the use of force by doctors against pregnant women were to be legitimized, it would have negative implications for their therapeutic relationship. The relationship would become less cooperative and supportive and more adversarial; compromise in situations of disagreement would become less and less possible. Under these circumstances of care, some women might lie about their behaviors or symptoms, fearing that their obstetrician would use this information to force upon them unacceptable treatment. Others might avoid prenatal care completely. The adversarial climate created by the use of force would decrease the effectiveness of obstetricians in improving maternal and fetal health.


Perinatal advances have dramatically improved the perinatal survival and well-being of fetuses/babies, fulfilling the obstetrical goals of prenatal providers and the personal goals of pregnant women. Increased understanding of the developing fetus and improved technologies have given the fetus an enhanced human identity and status as a direct patient of the obstetrician. The new therapeutic options with their maternal risks have created difficult ethical decisions for the pregnant woman and her obstetrician. A discussion regarding the legitimate use of force against pregnant women for fetal benefit has begun. The resolution of this debate must take into account the implications of the uncertainty inherent in medicine, the maternal risks associated with fetal therapies, the inevitable influence of an obstetrician's personal values upon his or her medical recommendations, the harmful influence of force in any therapeutic relationship, and the ethical and constitutional rights of all parties, including pregnant women.

nancy milliken (1995)


SEE ALSO: Abortion; Alcohol and Other Drugs in a Public Health Context; Alcoholism; Care; Compassionate Love; Embryo and Fetus; Feminism; Fetal Research; Genetic Screening and Testing: Public Health Context; Infants; Mental Health, Meaning of Mental Health; Mental Illness; Professional-Patient Relationship;Women, Historical and Cross-Cultural Perspectives; and other Maternal-Fetal Relationship subentries


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Maternal–Fetal Relationship: I. Medical Aspects

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