Vitamin K antagonist embryofetopathy

What it is

From: Orphanet

Vitamin K antagonist embryofetopathy is characterized by a group of symptoms that may be observed in a fetus or newborn when the mother has taken oral vitamin K antagonists, such as warfarin during pregnancy. Vitamin K antagonists are anticoagulant drugs that provide efficient thromboprophylaxis and that can cross the placenta. 5-12 % of infants exposed to warfarin between 6-9 weeks gestation present nasal hypoplasia and skeletal abnormalities, including short limbs and digits (brachydactyly), and stippled epiphyses. Warfarin fetopathy with central nervous system abnormalities (hydrocephalus, intellectual disability, spasticity, and hypotonia) or ocular abnormalities (microphthalmia, cataract, optic atrophy), fetal loss, and stillbirth, occurs in infants exposed at later gestations. Additional features that have been reported after in utero warfarin exposure include facial dysmorphism (cleft lip and/or palate, malformed ears), choanal atresia or stenosis, aorta coarctation, situs inversus totalis, bilobed lungs, and ventral midline dysplasia.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Anteverted nares · Very frequent (99-80%)

Anteriorly-facing nostrils viewed with the head in the Frankfurt horizontal and the eyes of the observer level with the eyes of the subject. This gives the appearance of an upturned nose (upturned nasal tip).

Depressed nasal bridge · Very frequent (99-80%)

Posterior positioning of the nasal root in relation to the overall facial profile for age.

Epiphyseal stippling · Very frequent (99-80%)

The presence of abnormal punctate (speckled, dot-like) calcifications in one or more epiphyses.

Punctate vertebral calcifications · Very frequent (99-80%)

The presence of punctiform calcification of the bone of the vertebral bodies.

Short nose · Very frequent (99-80%)

Distance from nasion to subnasale more than two standard deviations below the mean, or alternatively, an apparently decreased length from the nasal root to the nasal tip.

Brachydactyly · Frequent (79-30%)

Digits that appear disproportionately short compared to the hand/foot. The word brachydactyly is used here to describe a series distinct patterns of shortened digits (brachydactyly types A-E). This is the sense used here.

Intellectual disability · Frequent (79-30%)

The term intellectual disability or intellectual developmental disorder is used to describe significantly sub-average intellectual and adaptive functioning based on clinical assessment and as measured by individually administered, appropriately normed, standardized and validated tests of intellectual functioning and adaptive behavior, with onset during the developmental period from infancy through adolescence.

Intrauterine growth retardation · Frequent (79-30%)

An abnormal restriction of fetal growth with fetal weight below the tenth percentile for gestational age.

Short distal phalanx of finger · Frequent (79-30%)

Short distance from the end of the finger to the most distal interphalangeal crease or the distal interphalangeal joint flexion point. That is, hypoplasia of one or more of the distal phalanx of finger.

Short neck · Frequent (79-30%)

Diminished length of the neck.

Respiratory insufficiency · Frequent (79-30%)

Abnormal cardiovascular system morphology · Occasional (29-5%)

Any structural anomaly of the heart and blood vessels.

Cataract · Occasional (29-5%)

A cataract is an opacity or clouding that develops in the crystalline lens of the eye or in its capsule.

Choanal atresia · Occasional (29-5%)

Absence or abnormal closure of the choana (the posterior nasal aperture). Most embryologists believe that posterior choanal atresia results from a failure of rupture between the 35th and 38th day of fetal life of the partition which separates the bucconasal or buccopharyngeal membranes. The resultant choanal atresia may be unilateral or bilateral, bony or membranous, complete or incomplete. In over 90 per cent of cases the obstruction is bony, while in the remainder it is membranous. The bony type of atresia is commonly located 1-2 mm. anterior to the posterior edge of the hard palate, and the osseous septum varies in thickness from 1 to 10 mm. In the membranous form of choanal atresia the obstruction usually occurs further posteriorly. In approximately one third of cases the atresia is bilateral.

Other findings in the same source

From: Orphanet

Additional reported features include Hearing impairment (Occasional (29-5%)); Hydrocephalus (Occasional (29-5%)); Hypertelorism (Occasional (29-5%)); Hypotonia (Occasional (29-5%)); Macroglossia (Occasional (29-5%)); Microtia (Occasional (29-5%)); Myelomeningocele (Occasional (29-5%)); Optic atrophy (Occasional (29-5%)); Proptosis (Occasional (29-5%)); Seizure (Occasional (29-5%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

Antenatal; Neonatal

Inheritance in the source

From: Orphanet

Not applicable

Which doctor should you see?

The suggested department for discussing Vitamin K antagonist embryofetopathy is Clinical Genetics, with a clinical geneticist as the relevant type of clinician. Paediatrician (children) or physician (adults), with clinical geneticist referral.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Does the exact genetic or chromosome finding explain the observed features?
• Would a genetic counsellor help the family understand the result?
• Which organ-specific assessments are appropriate for this particular diagnosis?

Treatment discussions and follow-up

The material gathered for this draft does not provide a complete condition-specific treatment pathway for Vitamin K antagonist embryofetopathy. That gap does not mean that treatment is unavailable. A clinician needs to establish the diagnosis and review current guidance before recommending medicines, procedures, rehabilitation or other support.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.