Last updated on Jun 22nd, 2021 at 04:48 pm

Hypothyroidism in pregnancy

We all know that pregnancy is a time of change, but many don’t know that changes in the hormonal level can have serious health implications.

During pregnancy, women typically produce a lower level of thyroid-stimulating hormone (TSH) than normal (0.4-4.0 milli-international units per litre). However, should this level rise above 2.5-3 milli-international units per litre, it causes hypothyroidism or a mildly underactive thyroid and can spell misfortune for excited moms-to-be.

This week, Mayo Clinic researchers report that one of those results could be pregnancy loss.

The risks of having a mildly underactive thyroid

“A recent analysis of 18 studies showed that pregnant women with untreated subclinical hypothyroidism are at higher risk for pregnancy loss, placental abruption, premature rupture of membranes, and neonatal death,” says Spyridoula Maraka, M.D., an endocrinologist and lead author of the study.

Subscribe to our Free Daily All4Women Newsletter to enter

“It seemed likely that treating subclinical hypothyroidism would reduce the chance of these deadly occurrences. But we know that treatment brings other risks, so we wanted to find the point at which benefits outweighed risks.”

Pregnant women with untreated subclinical hypothyroidism are at higher risk for pregnancy loss, placental abruption, premature rupture of membranes, and neonatal death

Over 5 000 pregnant women included in study

Dr Maraka and her team examined the health information of 5 405 pregnant women diagnosed with subclinical hypothyroidism.

Of these, 843 women, with an average pretreatment TSH concentration of 4.8 milli-international units per litre, were treated with thyroid hormone. The remaining 4 562, with an average pretreatment TSH concentration of 3.3 milli-international units per litre, were not treated.

Compared with the untreated group, treated women were 38 percent less likely to experience pregnancy loss. However, they were more likely to have a preterm delivery, experience gestational diabetes or preeclampsia.

Is it best left alone?

“Our findings lead us to believe that overtreatment could be possible,” says Juan Brito Campana, M.B.B.S., a Mayo Clinic endocrinologist and study co-author. “If the TSH levels are in that 2.5-4.0 [milli-international units per litre] range, it may be best to leave subclinical hypothyroidism untreated.”

The results and recommendations in this study seem somewhat prophetic. On 6 January 2017, the American Thyroid Association published updated care guidelines with treatment recommendations for women experiencing thyroid disease during pregnancy.

Source: Mayo Clinic via Sciencedaily.com

While All4Women endeavours to ensure health articles are based on scientific research, health articles should not be considered as a replacement for professional medical advice. Should you have concerns related to this content, it is advised that you discuss them with your personal healthcare provider.