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Maternal Pregnancy Complications


Hypothyroidism is characterized by a slowing down of basal metabolism and often an increase in thyroid size (goiter).

Hypothyroidism affects about 1 in 100 women and its frequency increases with age.

If the mother is not treated during pregnancy, there may be serious consequences for the unborn baby, including the possibility of intellectual development delays since thyroid hormones are necessary for the proper development of the fetal brain.


The causes of hypothyroidism are diverse:

  • Autoimmune disease
  • Inflammation of the thyroid gland
  • Treatment for cancer
  • Treatment for hyperthyroidism (radioactive iodine)
  • Medication
  • Congenital abnormalities 


True hypothyroidism causes the following symptoms:

  • Lack of energy
  • Excessive weight gain
  • Cold intolerance
  • Dry skin
  • Hair loss
  • Constipation

Tests and procedures

Your doctor will prescribe regular blood tests to determine your thyroid stimulating hormone (TSH) level and adjust medication according to the results.

Treatment and follow-up care

Hypothyroidism is corrected by a medication called Synthroid®.

If hypothyroidism was known prior to pregnancy, a dose increase of 25% (approximately 2 tablets per week) is required from the beginning of pregnancy.

Treatment continues during the three trimesters of pregnancy. A joint follow-up appointment is provided by the Obstetrics and Gynecology Internal Medicine Clinic and the Fetal-Maternal Medicine Clinic.

Resources and useful links

  • Adèle Pillitteri. Maternal & Child Health Nursing : Care of the Childbearing & Childrearing Family, 5e édition, Toronto : Wolters Kluwer, 2006, p. 376.
  • www.doctissimo.fr
  • Patricia Ladewig et coll., Soins infirmiers en périnatalité, 4e édition, Montréal : ERPI, 2010, p. 359.
Page by

Josée Normandeau, inf. clinicienne, Dre Kateri Lévesque et Dre Lucie Morin

About this page
Updated on 1/25/2021
Created on 12/19/2017
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