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Recurrent Pregnancy Loss And Hypothyroidism

Author information

Wani R *, Shah Y **, Jalvee R ***, Shah S ****
(* Additional Professor, ** Assistant Honorary, *** Assistant Professor, **** Senior Registrar, Department of Obstetrics & Gynecology, H.B.T. Medical College & Dr R.N. Cooper Municipal Hospital, Mumbai, India)

Abstract

Recurrent pregnancy loss (RPL) may be defined as three consecutive pregnancy losses prior to 20 weeks. The reported incidence of RPL is 1-2%.[1] The causes of RPL include genetic abnormalities (2 – 5 %), anatomic (10 – 15 %), autoimmune (20 %), endocrine (17 – 20 %), unexplained (17 – 20 %). Endocrine factors which are implicated are luteal phase defect, polycystic ovarian disease, diabetes mellitus and thyroid disease. 
Hypothyroidism complicates up to 3% of pregnancies, 0.3- 0.5 % is overt and 2 - 2.5 % is subclinical.[2] We present a case report of recurrent pregnancy loss due to uncontrolled hypothyroidism with successful obstetrical outcome.

Introduction

Hypothyroidism is diagnosed by noting a high TSH associated with subnormal T4 concentration. Subclinical hypothyroidism (SCH)  is present when the TSH is high but the T4 level is in the normal range. It is the most common form of hypothyroidism in pregnancy. It is usually due to progressive destruction of the thyroid gland. Overt and subclinical hypothyroidism is associated with poor maternal and fetal outcomes, if ignored in the preconception and antenatal period.[3] Obstetrical outcomes observed are infertility, spontaneous abortions, anemia in pregnancy, preeclampsia, abruption, and postpartum hemorrhage. Fetal  outcomes include preterm delivery, low birth weight, respiratory distress.[4] It is also implicated as a preventable cause of mental retardation in neonates.

Case Report

A 32 year old fourth gravida with previous intrauterine fetal death and 2 spontaneous abortions came for the first time at 9 months of gestation with physical appearances as below and with a pulse rate of 60/ minute and blood pressure of 120/ 70 mm Hg . She was irritable, had a hoarse voice with dry myxematous skin changes. Her face was puffy, with periorbital edema and non pitting pedal edema, but no neck swelling. ECG showed low QRS voltages with widespread T- wave inversions.


Figure 1. Facial features and skin changes.

On abdominal examination uterine size corresponded to 34 weeks with regular fetal heart sounds. She had been seen at a private clinic earlier where ultrasonography at 34 weeks had shown gestational age of 30 weeks with estimated baby weight of 1.5 kg, and color Doppler done was suggestive of early fetoplacental insufficiency. Laboratory investigations had shown a high TSH level of 21.24 µIU/ l.  Her free T3 was 4.41 pg/ml, free T4 26.61 pmol/ l (both low) but she had not been started on any medications.  
With endocrine reference we started her on tablet thyroxine 75 µg/ day and 150 µg on weekends before breakfast. She was advised to repeat TSH levels after 4 weeks, at which time her tests showed free T3 of 2.53 pg/ ml, T4 of 1.14 ng/ dl and TSH of 14.31 µIU/ l. 
An endocrine review was done and the dosage was increased to 100 µg / day and 150 µg on weekends and levels were again repeated after 4 weeks. She opted for outpatient treatment and after 4 weeks her free T3 was 4.01 pg/ ml, free T4 was 1.18 ng/ dl and TSH was 10.44 µIU/ ml. Patient came to our emergency ward in labor at 41 weeks of gestation. She underwent emergency LSCS in view of non-reassuring NST at 41 weeks of gestation. Intra-operatively there was scanty liquor (clear). She delivered a male weighing 1.9 kg with Apgar of 8/10 at 1 minute and 9/10 at 5 minutes. 
Baby was admitted in NICU in view of small for gestational age and low birth weight with large ears and protruding tongue. His TSH on day 3 was 2.6 µ IU/l. In the postpartum period, the patient was continued on 100 µg of  tablet thyroxine and after 6 weeks her TSH was 2.67 µ IU/l.


Figure 2: SGA with hypothyroid features.

Discussion

Subclinical hypothyroidism is defined as TSH > 3mIU/ l but < 10 mIU/l with normal FT3 and  FT4. Overt hypothyroidism includes a TSH > 10 mIU/l with low FT4  levels. Treatment includes levothyroxine which is a stereoisomer of physiologic thyroxine which can be started as soon as diagnosis is made. 
Although universal screening is not recommended (ACOG), the indications for screening include presence of goiter or thyroid nodules, history  of thyroid surgery, infertility, previous history of neck radiation, thyroid dysfunction in the postpartum period, previous birth of infant with thyroid and other autoimmune chronic conditions like type 1 diabetes mellitus. [5]
This case had bad obstetric history and clinical features of overt hypothyroidism but unfortunately had not been screened till late third trimester when growth restriction had already set in. The current recommendations suggest to use laboratory-specific and trimester-specific reference ranges in pregnancy. When not available, aim to maintain the TSH between 0.3 -3 mIU/ l and check TSH in every trimester. [6]

Conclusion

Uncontrolled overt and subclinical hypothyroidism if neglected lead to poor perinatal outcomes, and timely diagnosis and treatment is essential. We believe that offering at least one TSH test at the booking visit especially in those with risk factors will improve obstetric outcomes.

References
  1. Stephenson MD. Frequency of factors associated with habitual abortion in 197 couples. Fertil Steril. 1996; 66(1): 24-29. 
  2. Neale DM, Cootauco AC, Burrow G. Thyroid disease in pregnancy. Clin Perinatol. 2007; 34(4): 543-557, v-vi.
  3. Glinoer D,  Soto MF,  Bourdoux P,  Lejeune B,  Delange F,  Lemone M, et al. Pregnancy in patients with mild  thyroid  abnormalities: maternal and neonatal repercussions. J Clin Endocrinol Metab. 1991; 73(2): 421-427. 
  4. Davis LE, Leveno KJ, Cunningham FG. Hypothyroidism complicating pregnancy. Obstet Gynecol. 1988; 72(1): 108-112. 
  5. ACOG Practice Bulletin Number 148: Thyroid disease in pregnancy. Obstet Gynecol. 2015; 125: 996–1005.
  6. Stagnaro-Green A, Abalovich M, Alexander E, Azizi F, Mestman J, Negro R, et al. Guidelines of the American Thyroid Association for the diagnosis and management of thyroid disease during pregnancy and postpartum. Thyroid. 2011; 21:1081-1125.
Citation

Wani R, Shah Y, Jalvee R, Shah S. Recurrent Pregnancy Loss And Hypothyroidism. JPGO 2016. Volume 3 No. 8. Available from: http://www.jpgo.org/2016/08/recurrent-pregnancy-loss-and.html