Fetal alcohol spectrum disorder

Fetal alcohol spectrum disorders are a group of conditions that can occur in a person who is exposed to alcohol during gestation. In the United States FASD affects 1 in 20 Americans, but is highly misdiagnosed and underdiagnosed.
The several forms of the condition are: fetal alcohol syndrome, partial fetal alcohol syndrome, alcohol-related neurodevelopmental disorder, and neurobehavioral disorder associated with prenatal alcohol exposure. Other terms used are fetal alcohol effects, partial fetal alcohol effects, alcohol-related birth defects, and static encephalopathy, but these terms have fallen out of favor and are no longer considered part of the spectrum.
Not all infants exposed to alcohol in utero will have detectable FASD or pregnancy complications. The risk of FASD increases with the amount consumed, the frequency of consumption, and the longer duration of alcohol consumption during pregnancy, particularly binge drinking. The variance seen in outcomes of alcohol consumption during pregnancy is poorly understood. Diagnosis is based on an assessment of growth, facial features, central nervous system, and alcohol exposure by a multidisciplinary team of professionals. The main criteria for diagnosis of FASD are nervous system damage and alcohol exposure, with FAS including congenital malformations of the lips and growth deficiency. FASD is often misdiagnosed as or comorbid with ADHD.
Almost all experts recommend that the mother abstain from alcohol use during pregnancy to prevent FASDs. As the woman may not become aware that she has conceived until several weeks into the pregnancy, it is also recommended to abstain while attempting to become pregnant. Although the condition has no known cure, treatment can improve outcomes. Treatment needs vary but include psychoactive medications, behavioral interventions, tailored accommodations, case management, and public resources.
Globally, 1 in 10 women drinks alcohol during pregnancy, and the prevalence of having any FASD disorder is estimated to be at least 1 in 20. The rates of alcohol use, FAS, and FASD are likely to be underestimated because of the difficulty in making the diagnosis and the reluctance of clinicians to label children and mothers. Authorities recommend abstinence to avoid real risks, while critics argue that zero-tolerance policies are scientifically questionable moral panics that stigmatize women.

Signs and symptoms

The key signs of fetal alcohol syndrome required for diagnosis include:

Growth deficiency or failure to thrive: slow fetal growth low birth weight or height, small head circumference
Congenital malformations of lips: short palpebral fissure lengths, smooth philtrum, and thin upper lip.
Nervous system damage: Clinically significant structural neurological, or functional impairment

Popova et al. identified 428 ICD-10 conditions as co-occurring in individuals with FAS. Excluding conditions used in FAS diagnosis, co-occurring conditions with 50% prevalence or greater include:

Conduct disorder, behavioral problems, disruptive behavior, or impulsivity
Developmental language disorder
Hearing loss
Visual impairment, including blindness or astigmatism
Developmental delay, cognitive disorder, or mental deficiency
Premature birth
Substance dependence
Congenital malformation of retina
Congenital fusion of cervical vertebrae or cervical spine fusion
Attention deficit hyperactivity disorder or otherwise impaired attention
Small eye openings, or an abnormally increased distance between the eyes, or both

Other FASD conditions are partial expressions of FAS, where the central nervous system shows clinical deficits. In these other FASD conditions, an individual may be at greater risk for adverse outcomes because brain damage is present without associated visual cues of poor growth or the "FAS face" that might ordinarily trigger an FASD evaluation. Such individuals may be misdiagnosed with primary mental health disorders such as ADHD or oppositional defiance disorder without appreciation that brain damage is the underlying cause of these disorders, which requires a different treatment paradigm than typical mental health disorders. While other FASD conditions may not yet be included as an ICD or DSM-IV-TR diagnosis, they nonetheless pose significant impairment in functional behavior because of underlying brain damage. Many indications of fetal alcohol spectrum disorders are developmental. Therefore, although a child may appear 'normal' at birth, intellectual disabilities caused by alcohol before birth may not appear until the child begins school.
More broadly, alcohol use during pregnancy is also associated with:

Intellectual disability, both in overall IQ measurements and in many functional tests
Fetal mortality, such as spontaneous abortion, stillbirth, and sudden infant death syndrome
Domestic violence and potential harm to the infant
Sleep and sucking problems as a baby
Heart: A heart murmur that frequently disappears by one year of age. Ventricular septal defect, atrial septal defect, tetralogy of Fallot, coarctation of the aorta, or cardiac rhythm dysfunction.
Bones: Joint anomalies including abnormal position and function, altered palmar crease patterns, small distal phalanges, and small fifth fingernails.
Kidneys: Horseshoe, aplastic, dysplastic, or hypoplastic kidneys.
Eyes: Strabismus, optic nerve hypoplasia.
Cleft lip with or without a cleft palate: Alcohol is known to be a folic acid antagonist, and a baby's palate and lip develop during the first trimester of the pregnancy. Heavy alcohol consumption and binge drinking during this time have been linked to orofacial cleft.
Occasional problems: ptosis of the eyelid, microphthalmia, webbed neck, short neck, radioulnar synostosis, spina bifida, and hydrocephalus.

Alcohol can also harm the fertility of women who are planning for pregnancy. Adverse effects of alcohol can lead to malnutrition, seizures, vomiting, and dehydration. The mother can suffer from anxiety and depression, which can result in child abuse/neglect. It has also been observed that when the pregnant mother withdraws from alcohol, its effects are visible on the infant as well. The baby remains in an irritated mood, cries frequently, does not sleep properly, weakening of sucking ability and increased hunger.
In 2019, a study found that individuals with FASD have a higher risk of hypertension independent of race/ethnicity and obesity.

Causes

Fetal alcohol spectrum disorders are caused by alcohol exposure during gestational development. If an individual was not exposed to alcohol before birth, they will not have FASD. However, not all infants exposed to alcohol in utero will have detectable FAS, FASD, or pregnancy complications.

Exposure limit

No safe level of fetal alcohol exposure has been established. Because alcohol is a known teratogen, it is considered unethical to do randomized controlled trials on pregnant women to determine the precise toxicity effects of alcohol. Among women who consume any quantity of alcohol during pregnancy, the risk of giving birth to a child with FASD is about 15%, and to a child with FAS about 1.5%. Drinking 2 standard drinks a day, or 6 standard drinks in a short time, carries a 4.3% risk of a FAS birth. Furthermore, alcohol-related congenital abnormalities occur at an incidence of roughly one out of 67 women who drink alcohol during pregnancy. Among those mothers who have an alcohol use disorder, an estimated one-third of their children have FAS. The variance seen in outcomes of alcohol consumption during pregnancy is poorly understood. Aggravating factors may include advanced maternal age, smoking, poor diet, genetics, and social risk factors.
The risk of FASD increases with the amount consumed, the frequency of consumption, and a longer duration of alcohol consumption during pregnancy. Blood alcohol concentration has been identified as a relevant factor. All forms of alcohol, such as beer, wine, and liquor, pose similar risk. Binge drinking increases the chances and severity of FASD to such an extent that Svetlana Popova has stated that "binge drinking is the direct cause of FAS or FASD". Small amounts of alcohol may not cause an abnormal appearance, however, small amounts of alcohol consumption while pregnant may cause behavioral problems and also increases the risk of miscarriage. Quasi-experimental studies provide moderately strong evidence that prenatal alcohol exposure causes detrimental cognitive outcomes, and some evidence of reduced birthweight, although no study was fully rated at low risk of bias and quantity of studies was limited.
The evidence is inconsistent and contradictory regarding the effects of low-to-moderate drinking, for example, less than 12 grams of ethanol per day. Many studies find no significant effect, but some find beneficial associations, and others find detrimental associations, even on the same outcomes. Summarizing studies by country shows some similarity in results, due to using the same data sources. The definition of low alcohol consumption varies significantly among studies and often fails to incorporate all aspects of timing, dose, and duration. Recall bias and socioeconomic and psychosocial factors have been controlled for in most studies, but it is likely that residual confounding due to missing factors and variation in methods still exists and is larger than any observed effects.

Paternal alcohol use

Fathers who consume alcohol before conception may contribute to FASD through long-term epigenetic modification of the father's sperm, but this has been challenged; evidence it can cause complete FAS is inconclusive.

Prevention and stigma

Almost all experts recommend that the mother abstain from alcohol use during pregnancy to prevent FASDs. A pregnant woman may not become aware that she has conceived until several weeks into the pregnancy, so it is also recommended to abstain from alcohol while attempting to become pregnant. The recommendations of abstaining from alcohol during pregnancy and while attempting to become have been made by the Surgeon General of the United States, the Centers for Disease Control, the American College of Obstetricians and Gynecologists, the American Academy of Pediatrics, the World Health Organization, the United Kingdom's National Institute for Health and Clinical Excellence, and many others. In the United States, federal legislation has required that warning labels be placed on all alcoholic beverage containers since 1988 under the Alcoholic Beverage Labeling Act.