"NEONATAL AND LONG-TERM COMPLICATIONS OF MATERNAL HYPOTHYROIDISM
In addition to adverse obstetrical outcomes, maternal hypothyroidism is associated with adverse neonatal outcomes. As the fetus does not begin to produce its own thyroid hormones until approximately 12 weeks’ gestation,
it is solely dependent on maternal thyroxine (T4) during early gestation.9,10 After 12 weeks, thyroid hormone in the fetus continues to be partly supplied by the mother.11
Recently,Kooistra et al. studied 108 neonates born to mothers with serum free thyroxine (fT4) levels below the 10th percentile at 12 weeks’ gestation. Compared with control subjects, these infants had decreased neonatal behavioural assessment scores at three weeks of age.12 Pop et al. studied 220 healthy infants and found that having maternal serum fT4 levels below the 10th percentile at 12 weeks’ gestation was a significant risk for impaired psychomotor development at 10 months of age.13
A similar result was observed by Kasatkina et al.14 The finding of a low maternal serum fT4 level at five to nine weeks’ gestation correlated significantly with a lower coefficient of mental development (which is thought to represent neuropsychological development) at 6, 9, and 12 months of age.14
In a study of 63 cases with matched controls, mothers with low serum fT4 at 12 weeks’ gestation who continued to have low levels at weeks 24 and 32 were at risk of having a child with delays in mental and motor development at one and two years of age. This neurodevelopmental delay was even more profound when the mothers had a continuing decrease in serum fT4 as pregnancy progressed.15
Children born to women who were not treated for thyroid deficiency during pregnancy (as defined by increased serum TSH) had average IQ scores at seven to nine years of age that were 7 points lower than those of controls.16
Fortunately, treatment of maternal hypothyroidism decreases the risk of neurodevelopmental deficits in the offspring. The stage of development during which the lack of T4 in the fetus is most detrimental for neurodevelopment is thought to be the first trimester.17 However, Pop et al. showed that maternal treatment at a later stage in pregnancy is also beneficial for neonatal outcome. In this study, the offspring of women who had an ongoing increase in maternal serum fT4 from 12 to 32 weeks’ gestation showed neurodevelopment at one and two years of age that was not significantly different from that of controls.15
Other investigators have noted similar benefits with treatment of maternal hypothyroidism. The offspring of mothers who had correction of serum fT4 by week nine of gestation using L-T4 had the same level of neurodevelopment at one year of age as control subjects.14
Interestingly, Haddow et al. observed that even when pregnant women were insufficiently treated for hypothyroidism (based on serum TSH measurements), the IQ scores of their offspring were not significantly different from those of controls.16"
Excerpt from "Hypothyroidism in Pregnancy" - Marilyn Sutandar, MD, Facundo Garcia-Bournissen, MD, Gideon Koren, MD - The Motherisk Program, Division of Clinical Pharmacology and Toxicology, Hospital for Sick Children, University of Toronto, Toronto ON J Obstet Gynaecol Can 2007;29(4):354–356
So do you think my unborn child was harmed?
There are both positive and negative studies so no one could give you a definite answer on this. I would think positive thoughts. :)
Thank you so much. I have been so worried. Thanks again :-)
I have had numerous friends who found out they were hypo when they were pregnant. I went hyper in my first trimester with all my kids. All our kids are just fine, I am sure yours will be too. If it was that serious I am sure your doctor would have said so. One of my friends that it happened to was a dr. and she was never concerned. Good thoughts going your way.
Do you know how soon your friends started on the meds?
After the first trimester. Sometimes just being pregnant can mess with your thyroid hormones, especially in the first trimester. I would call your doctor for reassurance.
Ok thank you so much! I really appreciate it! :-)