Diffusion Weighted Imaging

Among the sequences added according to the clinical question, Diffusion Weighted Imaging (DWI), MR imaging with weighted sequence in diffusion provides functional information and qualitative and quantitative analysis at the microscopic level of the diffusion of water molecules within the placenta allowing the clinician to explore the tissue microarchitecture in a non-invasive way. The contrast of the image depends on the microscopic and random movement of the water protons that can be altered in different pathological processes [24]. The diffusion sequence is generally performed last as it involves the application of powerful gradients that cause a dephasing and a subsequent rapid rephasing of the spins causing a stimulation in the fetuses that are often agitated [25].

( Figura 2 ).

Among the sequences added according to the clinical question, Diffusion Weighted Imaging (DWI) (Fig. 2), MR imaging with weighted sequence in diffusion provides functional information and qualitative and quantitative analysis at the microscopic level of the diffusion of water molecules within the placenta allowing the clinician to explore the tissue microarchitecture in a non-invasive way. The contrast of the image depends on the microscopic and random movement of the water protons that can be altered in different pathological processes [24]. The diffusion sequence is generally performed last as it involves the application of powerful gradients that cause a dephasing and a subsequent rapid rephasing of the spins causing a stimulation in the fetuses that are often agitated [25].

TTTS typically affects the health of identical twins dramatically. Prematurity and neurodevelopmental impairment affect both the donor and recipient twins;  cardiovascular failure and obstruction of the right ventricular outflow tract are typical complications of recipients, possibly resulting in long-term morbidity [26]. Some of the common complications associated with Twin-Twin Transfusion Syndrome include:

• Donor twin anemia
• Recipient twin heart failure caused by the heart pumping excessive levels of blood
• Recipient twin brain defects, heart problems, and digestive or respiratory health issues
• Preterm labor caused by pregnancy induction or ruptured membranes
• Donor twin compromised fetal development
• Recipient twin health issues caused by excessive amniotic fluid that leads to premature membrane rupture
• Heart damage (recipient twins may develop progressive biventricular hypertrophy and diastolic dysfunction, in addition to poor right ventricular systolic function, possibly leading to functional right ventricular outflow tract obstruction and pulmonic stenosis)
• Brain damage
• Fetal death

Moreover, most pregnancies involving TTTS never go to full-term. Because of that, many of these premature births share the same complications and long-term effects as other premature babies that include[27, 28]:

• Stunted physical development
• Learning disabilities
• Compromised communication skills
• Asthma and other respiratory problems
• Bronchopulmonary dysplasia (BPD), a chronic lung disease caused by abnormal growth or inflammation.
• Hearing loss
• Vision problems including retinopathy
• Dental issues caused by delayed tooth growth that may result in crooked teeth or tooth discoloration
• Increased risk of developing ADHD (Attention Deficit-Hyperactivity Disorder)
• Increased potential risk of SIDS (Sudden Infant Death Syndrome)
• Increased risk of developing chronic diseases including diabetes, hypertension, or heart disease

Because of the increased risk of preterm birth, administering steroids for fetal maturation ought to be weighed at 24 to 33 6/7 weeks, particularly in pregnancies complicated by stage III TTTS, and those undergoing invasive interventions. Two treatment options are currently available for TTTS treatment: amniocentesis aimed at draining excess amniotic fluid from the recipient twin, which reduces amniotic fluid levels in order to help improve blood circulation and laser surgery, through the insertion of a thin, fiber-optic scope through the mother's abdominal wall, through the wall of the uterus and into the amniotic cavity of the recipient twin [29]. The blood vessels on the placental surface are thus examined directly with the scope, and the abnormal vascular connections between the twins can be spotted and eliminated through a laser beam. Only those vessels that go from one twin to the other are coagulated by the laser beam. The normal blood vessels that help nourish each twin are left intact. Laser photocoagulation of placental anastomoses is the recognized treatment of choice for Stages II–IV TTTS [30]. Upon completion of the laser procedure, an amnioreduction (i.e. removal of excess amniotic fluid) is carried out, in order to lower the risk of early labor and help make the pregnancy less demanding. Survival of at least one fetus following laser surgery is currently > 90%:  the increased use of interventions such as laser coagulation of the intertwin anastomoses (laser therapy) has resulted in significantly improved survival rates for both twins (69.5%) as well [31]. Nonetheless, the neurodevelopmental outcomes for survivors are as yet not fully understood. Prior to laser therapy, at least one in five survivors of TTTS had serious adverse neurodevelopmental outcomes (usually cerebral palsy). Neurological impairment among survivors following laser surgery is currently estimated to range from 4 to 31%, although long-term follow-up data are still limited [32]. Scientific evidence exists proving the superiority of fetoscopic laser ablation over serial amnioreductions regarding survival and neurological outcome for stages II-IV TTTS [33]. However, the optimal management of stage I is still undetermined and currently debated. Survival rates after fetoscopic laser surgery have sharply risen over the past 25 years. High volume centers report up to 70% double survival and at least one survivor in >90%. Long-term neurodevelopmental impairment occurs in about 10% of children after laser surgery [34].

As mentioned before, roughly ten percent of identical twins (and other identical multiple babies) develop TTTS. Typically, at least one monozygotic twin is affected when the fetus disproportionately shares a monochorionic placenta. In many cases, restricted nutrients to one twin might result in abnormal growth or death. Any failure or delay to diagnose TTTS or treat the syndrome properly may result in medical malpractice lawsuits being filed [35].

Litigation stemming from negligence

Doctors may be held financially liable under tort law statutes if their actions were negligent and they failed to accurately diagnose fetal conditions. Doctors, in fact, might not have carried out the proper tests, identified symptoms or followed up on early indicators that something was wrong including:

• There was an identifiable difference between each fetus' umbilical cord size
• There were obvious differences in amniotic fluid and amniotic sac size
• The size of each baby was significantly different

The provable failure to either test for or properly follow up on and treat the above-mentioned signs may indicate negligence. Case law analysis revolving around five instances of relevant TTTS litigation are laid out in Table 2.

Table 2: Relevant case law involving TTTS (Sources: Justia, Lexis, Leagle spanning 2000-2020)

Conclusions

As many instances of TTTS-related lawsuits show, medical malpractice may contribute to injuries sustained by a child as a result of the negligent handling or treatment of TTTS or a failure to timely diagnose the condition. Obstetricians, gynecologists or other physicians in charge of choosing and providing the most suitable forms of treatment for pregnant women are held to a high standard of care when it comes to the health and safety of mothers and fetuses alike. When a woman is pregnant with more than one identical fetus, her treating physician should be vigilant in performing certain tests aimed at determining whether the pregnancy may be complicated by TTTS. Any failure on the part of doctors to conduct these tests may form the basis of a medical malpractice claim if the tests could have prevented TTTS-related injuries. Medical malpractice law applies when a medical professional fails to use the level of care that a reasonably prudent medical professional would have used in the same or similar circumstances, thereby causing injuries or even death to the patient. It is important to note that the onus is on the plaintiff to establish malpractice in any case, and each of the following elements must be determined by a preponderance of the evidence; however, particularly under tort law statutes, compliance with cautionary measures must be proven by doctors. Such patterns may be summed up as:

• Provided that the defendant medical professional owed the patient a duty of care, then.
• The defendant doctor failed to live up to the duty of care owed to the patient; and
• The defendant medical professional’s breach was a direct and proximate cause of the patient’s injury, i.e. a causal relationship can be proven.

In addition to stressing the essential nature of a properly developed informed consent process and individually tailored patient assessment of risk factors, it cannot be overlooked that a court of law, particularly in tort law, will likely tend to hold professionals and facilities liable (thus concluding that malpractice stemming from negligence has occurred, rather than mere unavoidable complications) if any inconsistencies are found in the informed consent documentation and patient records. Furthermore, the role of clinical Practice Guidelines play is twofold when it comes to medical malpractice claims. They can in fact be brought up as a defensive value, i.e. exculpatory evidence in legal proceedings by a health professional or as inculpatory evidence by plaintiff patients damaged by an alleged standard of care breach [42]. Determining whether such a breach actually occurred is as essential as it is complicated [43], in medical malpractice claims. Overall, any failure to adhere to surgical safety protocols, clinical Practice Guidelines and best practices, and to properly produce documentation reflecting such adherence, will most likely result in courts ruling against healthcare providers and facilities. To that end, it is of utmost importance to devise sets of standardized, clearly defined guidelines and best practices, both for the sake of patients and to shield healthcare professionals from adverse court decisions. There is no denying, in fact, that medical malpractice entails substantially higher direct as well as indirect health care costs, such as high insurance premiums, hefty expenses for compensatory damages, litigation fees, “defensive medicine” practices. Virtually all TTTS-related litigation herein outlined has stemmed from a failure to put in place diagnostic measures in a timely fashion.  Lastly, hospital protocols and policies are themselves key elements in keeping professionals and facilities from being subjected to malpractice allegations and lawsuits. It is in fact worth noting that in some instances, a hospital or other employer may also be liable for a medical professional’s negligence and ensuing malpractice-related damages sustained by patients, under the legal concept of “vicarious liability”. Liability also may be established when the hospital is found to have been negligent in adopting policies and procedures for the care and treatment of TTTS patients or mismanaged the process of hiring, training, screening, monitoring, or retaining a negligent professional.