Fetal heart rate tracing patterns associated with congenital hypothyroidism

Intrapartum cardiotocography in pregnancies with and without fetal CHD

OBJECTIVES

Congenital heart defects (CHD) are the most common inherited abnormalities. Intrapartum cardiotocography (CTG) is still considered a "gold standard" during labor. However, there is a lack of evidence regarding the interpretation of intrapartum CTG in fetuses with CHD. Therefore, the study aimed to compare intrapartum CTG in normal fetuses and fetuses with CHD and describe the association between CTG and neonatal outcomes.

METHODS

The present study is a retrospective analysis of the CTG of 395 fetuses. There were three study groups: Group 1: 185 pregnancies with a prenatal diagnosis of CHD, Group 2: 132 high-risk pregnancies without CHD, and Group 3: 78 low-risk pregnancies without CHD.

RESULTS

Abnormal CTG was present statistically OR=3.4 (95%CI: 1.61-6.95) more often in Group 1. The rate of the emergency CS was higher in this group OR=3 (95%CI: 1.3-3.1). Fetuses with CHD and abnormal CTG were more often scored ≤7 Apgar, with no difference in acidemia. The multivariate regression model for Group 1 does not show clinical differences between Apgar scores or CTG assessment in neonatal acidemia prediction.

CONCLUSIONS

CTG in fetuses with CHD should be interpreted individually according to the type of CHD and conduction abnormalities. Observed abnormalities in CTG are associated with the fetal heart defect itself. Preterm delivery and rapid cesarean delivery lead to a higher rate of neonatal complications. Health practitioners should consider this fact during decision-making regarding delivery in cases complicated with fetal cardiac problems.

Isolated Fetal Sinus Bradycardia as a First Sign of Congenital Hypopituitarism

We present a case of marked fetal sinus bradycardia as the sole presenting sign of congenital combined pituitary hormone deficiencies. Fetal sinus bradycardia < 120 beats/min was detected at 36 weeks of gestation during an otherwise uncomplicated pregnancy. Sinus bradycardia persisted after birth, and congenital hypothyroidism and growth hormone deficiencies were subsequently identified. Normal sinus rhythm was rapidly restored with hormone supplementation. Hypothyroidism and growth hormone deficiency should be considered in the differential diagnosis of unexplained perinatal sinus bradycardia because early diagnosis may help to avoid potential complications (ie, mental retardation, severe hypoglycemia, and growth anomaly).

Transient hypothyroidism in the newborn: to treat or not to treat

Transient congenital hypothyroidism (CH) refers to a temporary deficiency of thyroid hormone identified after birth, with low thyroxine (T4) and elevated thyrotropin (TSH), which later recovers to improved thyroxine production, typically in first few months of infancy. Approximately 17% to 40% of children diagnosed with CH by newborn screening (NBS) programs were later determined to have transient hypothyroidism. Causes of transient CH are prematurity, iodine deficiency, maternal thyrotropin receptor blocking antibodies, maternal intake of anti-thyroid drugs, maternal or neonatal iodine exposure, loss of function mutations and hepatic hemangiomas. The classic clinical symptoms and signs of CH are usually absent immediately after birth in vast majority of infants due to temporary protection from maternal thyroxine. NBS has been largely successful in preventing intellectual disability by early detection of CH by performing thyroid function tests in infants with abnormal screening results. In this review we present the evidence for decision making regarding treatment vs. withholding treatment in infants with transient CH and present a rational approach to identifying transient CH based on American Academy of Pediatrics (AAP) recommendation.

Intrapartum fetal heart rate patterns of trisomy 21 fetuses: A case-control study

BACKGROUND/AIM

To determine whether there are specific characteristic intrapartum heart rate patterns for fetuses with trisomy 21(T21).

BACKGROUND STUDY DESIGN/PATIENTS

Intrapartum fetal heart rate (FHR) tracings of T21 fetuses were compared to those of euploid fetuses in a retrospective, observational, matched, case-control study. The study group consisted of 42 fetuses with T21 and 42 matched euploid controls. Matching was designed to accommodate possible confounders. The sign test and McNemar's test were used for categorical variables. The paired t test was used for comparison between quantitative variables.

RESULTS

Intrapartum baseline FHR of fetuses with T21 was found to be slightly decreased compared to controls (122.5 vs 129.05 beats per minute, p=0.028). No differences were detected in the presence of periodic changes, or FHR variability between the groups.

CONCLUSION

When evaluating intrapartum FHR of fetuses with T21, decreased baseline FHR can be expected.