A newborn is examined in the delivery room shortly after being born vaginally to a 38-year-old woman. The mother had intermittent prenatal care, and the pregnancy was complicated by bipolar disorder and chronic hypertension. Interview of the mother reveals pressured and tangential speech. She states, "I take my prescribed meds when I remember," and then adds, "I have a good memory, and I took the meds most of the time throughout the pregnancy." She claims to have smoked cigarettes occasionally but then changes the subject when asked if other substances were used during pregnancy. Examination of the neonate shows a nondysmorphic face and a mass overlying the lower spine that is covered with a patch of hair. Which of the following maternal interventions could have most likely prevented this neonate's abnormalities?

Question

A newborn is examined in the delivery room shortly after being born vaginally to a 38-year-old woman.  The mother had intermittent prenatal care, and the pregnancy was complicated by bipolar disorder and chronic hypertension.  Interview of the mother reveals pressured and tangential speech.  She states, "I take my prescribed meds when I remember," and then adds, "I have a good memory, and I took the meds most of the time throughout the pregnancy."  She claims to have smoked cigarettes occasionally but then changes the subject when asked if other substances were used during pregnancy.  Examination of the neonate shows a nondysmorphic face and a mass overlying the lower spine that is covered with a patch of hair.  Which of the following maternal interventions could have most likely prevented this neonate's abnormalities?

Quizplus · Accepted Answer

11ec160b_3749_b022_9249_b9fc225d6139_MD0001_00 Midline fusion of neural folds creates the neural tube during the third week of fetal life. The neural tube is a structure that is connected to the amniotic cavity by openings at the ends known as anterior and posterior neuropores. Failure of neuropore closure by 4 weeks gestation leads to neural tube defects (NTDs). Anterior NTDs include anencephaly (absence of the forebrain) and encephalocele (protrusion of neural tissue through the cranial defect). Posterior NTDs include spina bifida occulta, meningocele, and meningomyelocele. Meningocele and meningomyelocele present as a cystic mass at the lower spine that is covered with skin and sometimes a tuft of hair (seen in this patient). A meningocele consists of spinal meninges that protrude through the vertebral arch defect. A meningomyelocele has portions of the spinal cord or cauda equina within the protruding meningeal sac. Folate (vitamin B₉) supplementation reduces risk of NTDs and is recommended for all women of childbearing age because the neural tube develops during the time when most women are unaware of their pregnancy. Prenatal valproate use for bipolar disorder (likely in this patient) or epilepsy is associated with a 10- to 20-fold increased risk of NTDs due to impaired folate metabolism. Other risk factors include maternal use of folate antagonists (eg, methotrexate, trimethoprim-sulfamethoxazole). (Choice A) Antenatal steroid therapy (eg, betamethasone) reduces the incidence of neonatal respiratory distress syndrome in premature infants. It does not reduce the risk of NTDs. (Choice B) Although chronic alcohol consumption can result in folate deficiency (and therefore NTDs), it is more commonly associated with fetal alcohol syndrome. However, fetal alcohol syndrome is unlikely in the absence of short palpebral fissures, a thin vermilion border, and a smooth philtrum. (Choice C) Lithium and valproate are first-line drugs for acute mania. If valproate cannot be substituted by another drug to control a mood or epilepsy disorder, the lowest effective dose should be prescribed during pregnancy. Lithium use in pregnancy is also not recommended due to its association with increased incidence of Ebstein anomaly. (Choices D and E) Uncontrolled hypertension and tobacco use can cause fetal growth restriction, premature delivery, and placental abruption. Tobacco use, hypertension, and antihypertensive medications are not associated with NTDs. Educational objective: Failure of neural tube closure at 4 weeks gestation results in neural tube defects (NTDs). First trimester use of valproate is a significant risk factor for NTDs, but periconceptional folate (vitamin B₉) supplementation reduces this risk. __________ References: Effects and safety of periconceptional oral folate supplementation for preventing birth defects (http://www.ncbi.nlm.nih.gov/pubmed/26662928)

A Newborn Is Examined in the Delivery Room Shortly After