Thyroid Function
Conditions
Keywords
iodine, thyroid, TSH, pregnancy, nutrition, diet
Brief summary
This is an observational study in pregnant mothers and their newborn babies. The rationale of the study is to examine early markers of the effects of iodine insufficiency during pregnancy on thyroid stimulating hormone (TSH) and thyroglobulin in mother and baby.
Detailed description
Iodine is a critical component of thyroid hormones, which are essential for normal growth, and brain development, most of the latter occurring during fetal life and in the first three years of life. Maternal dietary iodine is the sole source for fetuses and for exclusively breastfed infants. Recent evidence indicates that the UK female population is not iodine sufficient. Thus a significant proportion of UK pregnant women will also be insufficient in dietary iodine with potential harmful consequences for their babies. We wish to investigate the relationship between maternal iodine status (sufficient versus insufficient) in pregnancy, the mode of neonatal feeding (exclusively breast fed vs exclusively formula fed); and the effect this has on the functioning of the newborn baby's thyroid gland, with provision for later cognitive followup assessment. In order to do this, we will determine: i) the iodine status of the mother during pregnancy and in the immediate postnatal period (dietary and urinary) and the newborn infant (urinary), ii) the thyroid function of the mother (thyroid stimulating hormone, thyroglobulin, T4 in serum during pregnancy, and thyroid stimulating hormone and thyroglobulin in dried blood spots postpartum) and infant (thyroid stimulating hormone in dried blood spots collected during a routine procedure). Our hypothesis is that babies whose mothers are iodine insufficient will show higher levels of TSH and thyroglobulin than the babies of iodine sufficient mothers.
Interventions
Sponsors
Study design
Eligibility
Inclusion criteria
* Healthy pregnant women * Able to read, write and speak in English * Attending a Greater Glasgow and Clyde maternity unit
Exclusion criteria
* Abnormal pregnancies. * Mothers with known thyroid disorders. * Preterm infants (born before 37 completed weeks). * Multiple births. * Infants with postnatal problems such as infection or malformation.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| thyroid function of mothers (measurement of TSH and Tg) | up to 38 week gestation | measurement of TSH and Tg |
| thyroid function of infant (routine TSH measurement) | Day 4 of life | routine TSH measurement |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Iodine status of mothers (iodine intake and excretion) | up to 38 week gestation | iodine status defined by iodine intake and excretion |
| Iodine status of infant (iodine intake and excretion) | Day 4 of life | iodine status defined by iodine intake and excretion |
| Iodine level in hair and breastmilk | after birth | measurement of iodine in hair and breastmilk |
Countries
United Kingdom