Maternal Autoimmune Thyroid Disease and Fetal Thyroxin
|Pregnancy Complicated by Hyperthyroidism Hypothyroidism in Pregnancy|
|Study Design:||Observational Model: Case Control
Time Perspective: Prospective
|Official Title:||Fetal Thyroid Hormones Concentration In Hyperthyroid or Hypothyroid Pregnant Women|
- Fetal free thyroxin [ Time Frame: 24th to 32nd week of gestation ]
- fetal ultrasound parameters [ Time Frame: 24th to 32nd week of gestation ]at the same time as fetal free thyroxin sampling
- maternal antithyroid antibodies [ Time Frame: 24th to 32nd week of gestation ]sampled at the same time as the fetal free thyroxin
- dose of maternal antithyroid medication (ATD) [ Time Frame: 24th to 32nd week of gestation ]recorded at the same time as the fetal sampling for free thyroxin
|Study Start Date:||January 2001|
|Study Completion Date:||June 2011|
|Primary Completion Date:||March 2011 (Final data collection date for primary outcome measure)|
Hyperthyroid pregnant women
hyperthyroidism diagnosed and treated by an endocrinologist, based on clinical and laboratory tests and ultrasound thyroid examination.
Hypothyroid pregnant women
hypothyroidism diagnosed and treated by an endocrinologist, based on clinical and laboratory tests and ultrasound thyroid examination
Healthy pregnant women
uncomplicated pregnancies in healthy women, older then 35 years, directed for cordocentesis due to age, because of missed karyotyping in previous period of pregnancy
Maternal hyperthyroidism in pregnancy is complicated with hypertension, preeclampsia, heart failure, thyroid storm, preterm labor and stillbirth, while the fetus suffers from intrauterine growth retardation (IUGR), goiter; neonatal prematurity and low birth weight.
Maternal hypothyroidism is seen in 2 % of pregnancies. Risks are higher for preeclampsia, postpartum hemorrhage, miscarriage, stillbirth, preterm birth and lower IQ score.
Thyroid stimulating hormone (TSH) receptor antibodies, antithyroid drugs and iodine pass to the fetus. So the fetus may also become a patient. Monitoring fetal growth, fetal heart rate (tachycardia is a late sign of fetal hyperthyroidism), bone maturation and the size of the fetal thyroid by ultrasound are important parameters for the assessment of transfer of hyperthyroidism from mother to the fetus
Patients follow up:
After inclusion into the study, thyroid function tests (fT4, TSH), and auto-antibodies assessment (anti TPO, TRAK) were performed once every two months in mothers with AITD, and from the 24th week of gestation monthly. Treatment was adjusted accordingly. Ultrasound for fetal size, morphology and fetal heart rate (FHR) was performed once in two months, and from the 24th week of gestation, monthly. The fetal biophysical profile score was determined weekly from the 30th week of gestation. The single centre design was chosen: all fetal sonograms were performed by the same gynecologist. Cardiotocography was performed once weekly from the 30th week of gestation.
Fetal and maternal free thyroxin (fT4) and TSH, thyroid antibodies in mothers and fetal ultrasound (fetal size, morphology and fetal heart rate) were determined at the same time, once, from 22nd to 33rd weeks of gestation.
Procedure: Cordocentesis (Cordocentesis is a highly specialized prenatal test in which a fetal blood sample is removed from the umbilical cord and tested for genetic problems, hormones or infections. Cordocentesis can be done at 18 weeks of pregnancy or later). Fetal fT4 and TSH were measured from cord blood samples. Healthy pregnant subjects were directed for cordocentesis for karyotype analysis due to age (missed previous procedures for karyotyping).
The diagnosis of fetal hypo or hyperthyroidism was established taking into account fT4 concentrations according to the nomograms Thorpee-Beeston et al., 1996, 1991.
When fetal hyperthyroidism is diagnosed, antithyroid drugs given to the mother are administered or adjusted. When fetal hypothyroidism is diagnosed, then the possibility of intraamniotic thyroxin application is discussed with the mother.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01528904
|Clinic for Gynecology and Obstetrics|
|Belgrade, Serbia, 11000|
|Principal Investigator:||Svetlana Spremovic-Radjenovic, MD PhD||Medical School of the University of Belgrade|