In 1996, the United States Food and Drug Administration published regulations requiring the addition of folic acid to enriched breads, cereals, flour and other grain products. It is important to note that during the first four weeks of pregnancy (when most women do not even realize that they are pregnant), adequate folate intake is essential for proper operation of the neurulation process. Therefore, women who could become pregnant are advised to eat foods fortified with folic acid or take supplements in addition to eating folate-rich foods to reduce the risks of serious birth defects.

In Canada, mandatory fortification of selected foods with folic acid has been shown to reduce the incidence of neural tube defects by 46%.

Women who may become pregnant are advised to get 400 micrograms of folic acid daily. Women who have previously given birth to a child with a neural tube defect may benefit from a supplement containing 4.0 mg/5.0 mg in the UK mg daily, following advice provided by their doctor.

There is neither a single cause of spina bifida nor any known way to prevent it entirely. However, dietary supplementation with folic acid has been shown to be helpful in reducing the incidence of spina bifida. Sources of folic acid include whole grains, fortified breakfast cereals, dried beans, leaf vegetables and fruits.

Folate fortification of enriched grain products has been mandatory in the United States since 1998. The U.S. Food and Drug Administration, Public Health Agency of Canada and UK recommended amount of folic acid for women of childbearing age and women planning to become pregnant is at least 0.4 mg/day of folic acid from at least three months before conception, and continued for the first 12 weeks of pregnancy.

Women who have already had a baby with spina bifida or other type of neural tube defect, or are taking anticonvulsant medication, should take a higher dose of 4–5 mg/day.

Certain mutations in the gene "VANGL1" have been linked with spina bifida in some families with a history of the condition.

Surgeons at Vanderbilt University, led by Joseph Bruner, attempted to close spina bifida in 4 human fetuses using a skin graft from the mother using a laparoscope. Four cases were performed before stopping the procedure - two of the four fetuses died.

- 1998 – N. Scott Adzick and team at The Children's Hospital of Philadelphia performed open fetal surgery for spina bifida in an early gestation fetus (22-week gestation fetus) with a successful outcome. Open fetal surgery for myelomeningocele involves surgically opening the pregnant mother's abdomen and uterus to operate on the fetus. The exposed fetal spinal cord is covered in layers with surrounding fetal tissue at mid-gestation (19–25 weeks) to protect it from further damage caused by prolonged exposure to amniotic fluid. Between 1998 and 2003, Dr. Adzick, and his colleagues in the Center for Fetal Diagnosis and Treatment at The Children's Hospital Of Philadelphia, performed prenatal spina bifida repair in 58 mothers and observed significant benefit in the babies.

Fetal surgery after 25 weeks has not shown benefit in subsequent studies.

Some genetic research has been conducted to determine the causes of anencephaly. It has been found that cartilage homeoprotein (CART1) is selectively expressed in chondrocytes (cartilage cells). The CART1 gene to chromosome 12q21.3–q22 has been mapped. Also, it has been found that mice homozygous for deficiency in the Cart1 gene manifested acrania and meroanencephaly, and prenatal treatment with folic acid will suppress acrania and meroanencephaly in the Cart1-deficient mutants.

Treatments of NTDs depends on the severity of the complication. No treatment is available for anencephaly and infants usually do not survive more than a few hours. Aggressive surgical management has improved survival and the functions of infants with spina bifida, meningoceles and mild myelomeningoceles. The success of surgery often depends on the amount of brain tissue involved in the encephalocele. The goal of treatment for NTDs is to allow the individual to achieve the highest level of function and independence. Fetal surgery in utero before 26 weeks gestation has been performed with some hope that there is benefit to the final outcome including a reduction in Arnold–Chiari malformation and thereby decreases the need for a ventriculoperitoneal shunt but the procedure is very high risk for both mother and baby and is considered extremely invasive with questions that the positive outcomes may be due to ascertainment bias and not true benefit. Further, this surgery is not a cure for all problems associated with a neural tube defect. Other areas of research include tissue engineering and stem cell therapy but this research has not been used in humans.

There is no cure or standard treatment for anencephaly and the prognosis for patients is death. Most anencephalic fetuses do not survive birth, accounting for 55% of non-aborted cases. Infants that are not stillborn will usually die within a few hours or days after birth from cardiorespiratory arrest.

Four recorded cases of anencephalic children surviving for longer periods of time are Stephanie Keene (better known as Baby K) of Falls Church, Virginia, USA, who lived for 2 years 174 days; Vitoria de Cristo, born in Brazil in January 2010 and surviving until July 17, 2012; Nickolas Coke of Pueblo, Colorado, USA, who lived for 3 years and 11 months, and died October 31, 2012; and Angela Morales, from Providence, Rhode Island, who live for 3 years and 9 months, and died December 16 2017.

In almost all cases, anencephalic infants are not aggressively resuscitated because there is no chance of the infant's ever achieving a conscious existence. Instead, the usual clinical practice is to offer hydration, nutrition, and comfort measures and to "let nature take its course". Artificial ventilation, surgery (to fix any co-existing congenital defects), and drug therapy (such as antibiotics) are usually regarded as futile efforts. Some clinicians and medical ethicists view even the provision of nutrition and hydration as medically futile.

It is recommended that women who may become pregnant take 400 micrograms of folic acid daily.

Animal studies have shown that administration of the drugs vinblastine, streptonigrin, triparano, sulfonamide, tetracycline, antihistamines, and antitumor agents to pregnant mothers have resulted in offspring born with iniencephaly. The drug clomiphene, a drug commonly used for ovulation stimulation in fertility treatments, has also been seen to be associated with iniencephaly.

Pregnant mothers are advised to take folic acid supplements to reduce risk of iniencephaly by up to 70%. Pregnant mothers are also advised not to take antiepileptic drugs, diuretics, antihistamines, and sulfa drugs, all of which have been associated with increased risk for neural tube defects.

Currently, the only effective treatment for encephaloceles is reparative surgery, generally performed during infancy. The extent to which it can be corrected depends on the location and size of the encephaloceles; however, large protrusions can be removed without causing major disability. Surgery repositions the bulging area back into the skull, removes the protrusions, and corrects the deformities, typically relieving pressure that can delay normal brain development. Occasionally, shunts are placed to drain excess cerebrospinal fluid from the brain.

The goals of treatment include:

- closure of open skin defects to prevent infection and desiccation of brain tissue

- removal of nonfunctional extracranial cerebral tissue with water-tight closure of the dura

- total craniofacial reconstruction with particular emphasis on avoiding the long-nose deformity (nasal elongation that results from depression of the cribiform plate and nasal placode). Without proper management, the long-nose deformity can be more obvious after repair.

Probably, the most well-known teratogenic drug is thalidomide. It was developed near the end of the 1950s by Chemie Grűnenthal as a sleep inducing aid and antiemetic. Because of its ability to prevent nausea it was prescribed for pregnant women in almost 50 countries worldwide between 1956–1962. Until William McBride published the study leading to its withdrawal from the market at 1961, about 8- 10 000 severely malformed children were born. The most typical disorder induced by thalidomide were reductional deformities of the long bones of the extremities. Phocomelia otherwise a rare deformity, which therefore helped to recognise the teratogenic effect of the new drug. Among other malformations caused by thalidomide were those of ears, eyes, brain, kidney, heart, digestive and respiratory tract. 40% of the prenatally affected children died soon after birth. As thalidomide is used today as a treatment for multiple myeloma and leprosy, several births of affected children were described in spite of the strictly required use of contraception among female patients treated by it.

Vitamin A, or retinol, is the sole vitamin which is embryotoxic even in a therapeutic dose, for example in multivitamins, because its metabolite, the retinoic acid, plays an important role as a signal molecule in the development of several tisues and organs. Its natural precursor, the β-carotene, is considered safe, whereas the consumption of animal liver can lead to malformation, as the liver stores lipophile vitamins, including retinol. Isotretinoin (13-cis-retinoic-acid; brand name Roaccutane), vitamine A analog, which is often used to treat severe acne, is such a strong teratogen that just a single dose taken by a pregnant woman (even transdermally) may result in serious birth defects. Because of this effect, most countries have systems in place to ensure that it is not given to pregnant women, and that the patient is aware of how important it is to prevent pregnancy during and at least one month after treatment. Medical guidelines also suggest that pregnant women should limit vitamin A intake to about 700 μg/day, as it has teratogenic potential when consumed in excess. Vitamine A and similar substances can induce spontaneous abortions, premature births, defects of eyes (microphthalmia), ears, thymus, face deformities, neurological (hydrocephalus, microcephalia) and cardiovascular defects, as well as mental retardation.

Tetracycline, an antibiotic, should never be prescribed to women in the reproductive age or children, because of its negative impact on bone mineralization and teeth mineralization. The "tetracycline teeth" have brown or grey colour as a result of a defective development of both the dentine and the enamel of teeth.

Several anticonvulsants are known to be highly teratogenic. Phenytoin, also known as diphenylhydantoin, along with carbamazepine is responsible for the fetal hydantoin syndrome, which may typically include broad nose base, cleft lip and/or palate, microcephalia, nails and fingers hypoplasia, intrauterine growth restriction and mental retardation. Trimethadione taken during pregnancy is responsible for the fetal trimethadione syndrome, characterized by craniofacial, cardiovascular, renal and spine malformations, along with a delay in mental and physical development. Valproate has anti-folate effects, leading to neural tube closure-related defects such as spina bifida. Lower IQ and autism have recently also been reported as a result of intrauterine valproate exposure.

Hormonal contraception is considered as harmless for the embryo. Peterka and Novotná do however state that syntethic progestines used to prevent miscarriage in the past frequently caused masculinization of the outer reproductive organs of female newborns due to their androgenic activity. Diethylstilbestrol is a synthetic estrogen used from the 1940s to 1971 when the prenatal exposition has been linked to the clear-cell adenocarcinoma of the vagina. Following studies showed elevated risks for other tumors and congenital malformations of the sex organs for both sexes.

All cytostatics are strong teratogens, abortion is usually recommended when pregnancy is found during or before chemotherapy. Aminopterin, a cytostatic drug with anti-folate effect, was used during the 1950s and 1960s to induce therapeutic abortions. In some cases the abortion didn´t happen, but the newborns suffered a fetal aminopterin syndrome consisting of growth retardation, craniosynostosis, hydrocephalus, facial dismorphities, mental retardation and/or leg defomities

Substances whose toxicity can cause congenital disorders are called "teratogens", and include certain pharmaceutical and recreational drugs in pregnancy as well as many environmental toxins in pregnancy.

A review published in 2010 identified 6 main teratogenic mechanisms associated with medication use: folate antagonism, neural crest cell disruption, endocrine disruption, oxidative stress, vascular disruption and specific receptor- or enzyme-mediated teratogenesis.

It is estimated that 10% of all birth defects are caused by prenatal exposure to a teratogenic agent. These exposures include, but are not limited to, medication or drug exposures, maternal infections and diseases, and environmental and occupational exposures. Paternal smoking use has also been linked to an increased risk of birth defects and childhood cancer for the offspring, where the paternal germline undergoes oxidative damage due to cigarette use. Teratogen-caused birth defects are potentially preventable. Studies have shown that nearly 50% of pregnant women have been exposed to at least one medication during gestation. During pregnancy, a female can also be exposed to teratogens from the contaminated clothing or toxins within the seminal fluid of a partner. An additional study found that of 200 individuals referred for genetic counseling for a teratogenic exposure, 52% were exposed to more than one potential teratogen.

Prognosis is poor. Previous research suggested a 100% mortality rate for those with acrania. This disease is rare, occurring in 1 in 20,000 live births.

In order to better manage an acrania diagnosis, early detection is of extreme importance so that actions may be taken to help the mother and child. Families may choose either to terminate the pregnancy, or to carry the child to term. Acrania may cause a fetus to spontaneously abort before reaching term.

Rachischisis (Greek: "rhachis - ῥάχις" - spine, and "schisis - σχίσις" - split) is a developmental birth defect involving the neural tube. This anomaly occurs in utero, when the posterior neuropore of the neural tube fails to close by the 27th intrauterine day. As a consequence the vertebrae overlying the open portion of the spinal cord do not fully form and remain unfused and open, leaving the spinal cord exposed. Patients with rachischisis have motor and sensory deficits, chronic infections, and disturbances in bladder function. This defect often occurs with anencephaly.

Craniorachischisis is a variant of rachischisis that occurs when the entire spinal cord and brain are exposed - simultaneous complete rachischisis and anencephaly. It is incompatible with life; affected pregnancies often end in miscarriage or stillbirth. Infants born alive with craniorachischisis die soon after birth.

There are two problems that may occur during development that cause acrania.

Most human infants with diprosopus are stillborn. Known instances of humans with diprosopus surviving for longer than minutes to hours past birth are very rare; only a few are recorded. In 2002 and 2003, two living male infants with partial diprosopus were described in the medical literature in separate case reports. One infant was born with duplication of the nose and the cerebral frontal lobes, two widely spaced eyes, a small, underdeveloped central eye socket, and a large, asymmetric mouth. The other infant was born with duplication of the upper and lower jaw, two tongues ending in the same base, cleft palate, a slightly divided tip of the nose, and two widely spaced eyes, as well as absence of the corpus callosum, duplication of the pituitary gland and stalk, and abnormalities in the midbrain. Because they were born with a milder, partial form of diprosopus, both infants were considered candidates for surgical correction of their abnormal facial features.

Because the cause of facial clefts still is unclear, it is difficult to say what may prevent children being born with facial clefts. It seems that folic acid contributes to lowering the risk of a child being born with a facial cleft.

There are several options for treatment of mouth anomalies like Tessier cleft number 2-3-7 . These clefts are also seen in various syndromes like Treacher Collins syndrome and hemifacial microsomia, which makes the treatment much more complicated. In this case, treatment of mouth anomalies is a part of the treatment of the syndrome.

Usually babies with this malformation do not survive past birth. However, there have been cases of survival. As of 2004, there were only two reported living cases. Of these two, one was severely cognitively impaired and physically disabled. The status of the other was unreported. If the fetus progresses to full term, there is the risk that it will have head trauma from the pressure applied to the head while being delivered. A few other cases of acalvaria have been reported, which did not progress to birth. In addition to the lack skull cap, there were brain malformations present in each case, and all of the pregnancies were terminated either electively or the fetuses were spontaneously aborted.

Because this malformation is rare and there are extremely few individuals living with this condition, treatment is limited. Treatment consists of carefully managing the condition in a controlled manner. Proceeding with a bone graft when the child reaches school age is also recommended.

Because newborns can breathe only through their nose, the main goal of postnatal treatment is to establish a proper airway. Primary surgical treatment of FND can already be performed at the age of 6 months, but most surgeons wait for the children to reach the age of 6 to 8 years. This decision is made because then the neurocranium and orbits have developed to 90% of their eventual form. Furthermore, the dental placement in the jaw has been finalized around this age.

Structural nasal deformities are corrected during or shortly after the facial bipartition surgery. In this procedure, bone grafts are used to reconstruct the nasal bridge. However, a second procedure is often needed after the development of the nose has been finalized (at the age of 14 years or even later).

Secondary rhinoplasty is based mainly on a nasal augmentation, since it has been proven better to add tissue to the nose than to remove tissue. This is caused by the minimal capacity of contraction of the nasal skin after surgery.

In rhinoplasty, the use of autografts (tissue from the same person as the surgery is performed on) is preferred. However, this is often made impossible by the relative damage done by previous surgery. In those cases, bone tissue from the skull or the ribs is used. However, this may give rise to serious complications such as fractures, resorption of the bone, or a flattened nasofacial angle.

To prevent these complications, an implant made out of alloplastic material could be considered. Implants take less surgery time, are limitlessly available and may have more favorable characteristics than autografts. However, possible risks are rejection, infection, migration of the implant, or unpredictable changes in the physical appearance in the long term.

At the age of skeletal maturity, orthognathic surgery may be needed because of the often hypoplastic maxilla. Skeletal maturity is usually reached around the age of 13 to 16. Orthognathic surgery engages in diagnosing and treating disorders of the face and teeth- and jaw position.

Cephalic disorders (from the Greek word "κεφάλι", meaning "head") are congenital conditions that stem from damage to, or abnormal development of, the budding nervous system. Cephalic means "head" or "head end of the body."

Cephalic disorders are not necessarily caused by a single factor, but may be influenced by hereditary or genetic conditions, nutritional deficiencies, or by environmental exposures during pregnancy, such as medication taken by the mother, maternal infection, or exposure to radiation. Some cephalic disorders occur when the cranial sutures (the fibrous joints that connect the bones of the skull) join prematurely. Most cephalic disorders are caused by a disturbance that occurs very early in the development of the fetal nervous system.

The human nervous system develops from a small, specialized plate of cells on the surface of the embryo. Early in development, this plate of cells forms the neural tube, a narrow sheath that closes between the third and fourth weeks of pregnancy to form the brain and spinal cord of the embryo. Four main processes are responsible for the development of the nervous system: cell proliferation, the process in which nerve cells divide to form new generations of cells; cell migration, the process in which nerve cells move from their place of origin to the place where they will remain for life; cell differentiation, the process during which cells acquire individual characteristics; and cell death, a natural process in which cells die.

Damage to the developing nervous system is a major cause of chronic, disabling disorders and, sometimes, death in infants, children, and even adults. The degree to which damage to the developing nervous system harms the mind and body varies enormously. Many disabilities are mild enough to allow those afflicted to eventually function independently in society. Others are not. Some infants, children, and adults die, others remain totally disabled, and an even larger population is partially disabled, functioning well below normal capacity throughout life.

The National Institute of Neurological Disorders and Stroke (NINDS) is currently "conducting and supporting research on normal and abnormal brain and nervous system development."

Diprosopus often occurs in combination with other congenital disorders, particularly anencephaly, neural tube defect and cardiac malformations. When present, the brain may show abnormalities ranging from partial to complete duplication of brain structures, and/or underdevelopment of brain tissues.

Until recently, the medical literature did not indicate a connection among many genetic disorders, both genetic syndromes and genetic diseases, that are now being found to be related. As a result of new genetic research, some of these are, in fact, highly related in their root cause despite the widely varying set of medical symptoms that are clinically visible in the disorders. Exencephaly is one such disease that has recently been identified as part of an emerging class of diseases called cilopathies. The underlying cause may be a dysfunctional molecular mechanism in the primary cilia structures of the cell, organelles which are present in many cellular types throughout the human body. The cilia defects adversely affect "numerous critical developmental signaling pathways" essential to cellular development and thus offer a plausible hypothesis for the often multi-symptom nature of a large set of syndromes and diseases. Known ciliopathies include primary ciliary dyskinesia, Bardet–Biedl syndrome, polycystic kidney and liver disease, nephronophthisis, Alström syndrome, Meckel–Gruber syndrome and some forms of retinal degeneration.