Thyroid Function in Pregnant Women from a West-African Population

Abstract

Thyroid dysfunction is frequent in pregnant women and is often associated with an increased risk of adverse maternal and fetal outcome. In the present work, thyroid function of pregnant women from Benin republic was studied. Two hundred forty (240) pregnant women, without thyroid disease history, have been included in the study. A blood sample was drawn for measurement of TSH, free T3 and free T4 serum levels. From the first to the third trimester, plasma levels of free T3 and free T4 decreased when plasma levels of TSH increased. Using recommendations of the 2011 American Thyroid Association (ATA) guidelines, thyroid dysfunction was observed in 24.17% of subjects. Hypothyroidism was present in 22.50% of subjects with 19.17% of subclinical hypothyroidism, 0.83% of overt hypothyroidism and 2.50% of hypothyroxinemia and hyperthyroidism was observed in 1.67% of subjects. An increase from 15.52% to 28.07% was observed in the frequency of hypothyroidism from the first to the third trimester of pregnancy. When an upper cut-off value of 4 mU/L was used for TSH, as recommended in the 2017 ATA guidelines, prevalence of thyroid disorders was 14.58% with 12.91% of hypothyroidism but no hypothyroidism was observed in women in the first trimester of pregnancy. A rise in hypothyroidism frequency was observed when pregnant women age increased. Hypothyroidism was very common in pregnant women in Benin. To allow accurate assessment of thyroid status in pregnant women in Benin, pregnancy specific range for plasma level of TSH and thyroid hormones should be established.

Assessment of thyroid function in pregnant women attending Suez Canal University Hospitals

“…19 In the current study, we had found that there was no statistically significant relationship between development of thyroid disorders and age of women, nor gravidity status nor the trimester. This comes in contrary with Awede et al, 15 who observed positive relationship between hypothyroidism with age, trimester and number of gravidity. This may be due to the difference in the sample size, population characteristics.…”

“…Another study in Africa comparing the prevalence of thyroid functions in pregnancy using 2011ATA guidelines and 2017 ATA guidelines. In a study by Awede et al, 15 Two hundred and forty (240) pregnant women were included in the study. It showed that Thyroid dysfunction was present in 24.17% of the pregnant women.…”

Assessment of Thyroid Function in Pregnant Females Attending Suez Canal University Hospital

“…In this case, thyroid disorders were present in 14.58% of pregnant women. The frequency of subclinical hypothyroidism, overt hypothyroidism, hypothyroxinemia and hyperthyroidism were respectively 9.58%, 0.42%, 2.91% and 1.67% [15] . In this study, similar comparison was done and revealed that the prevalence of thyroid dysfunction according to 2011 ATA reference ranges was 49% (39% SCH, 6% OH, 4% isolated hypothyroxinemia), while according to 2017 ATA reference ranges was 23% (13% SCH, 3% OH and 7% isolated hypothyroxinemia).…”

“…This comes in contrary with Awede et al who observed positive relationship between hypothyroidism with age, trimester and number of gravidity. This may be due to the difference in the sample size, population characteristics [15] .…”

Study on thyroid function test in pregnancy in a tertiary care hospital

“…Aboelroose AA reported overall incidence of thyroid disorders in low risk pregnant women was 49 % and 23 % as per 2011 ATA guidelines and 2017 ATA guidelines respectively [9]. Whereas, Awede B et al conducted study over 240 pregnant women and found thyroid dysfunction was present in 24.17 % and 14.58 % according to 2011 ATA guidelines and 2017 ATA guidelines respectively [10]. Wang W et al in a multicenter cohort study among 2899 pregnant women in China, who did not use trimester specific reference ranges as recommended by ATA found prevalence of thyroid dysfunction of 10.2 % [11].…”