<prompt> For evaluating a case of recurrent spontaneous aboion, which of the following investigation is unwanted?HysteroscopyTesting for Antiphospholipid antibodiesTesting for TORCH infectionsThyroid function tests.  <response>: TORCH infections is not a cause of recurrent spontaneous aboion. Recurrent spontaneous aboion is defined as 3 or more consecutive pregnancy losses at 20 weeks or less or with fetal weights less than 500 grams. Causes and investigations includes : Chromosomal abnormalities: karyotypic evaluation of both parents Genital tract anatomical abnormalities : three-dimensional sonography, hysteroscopy Autoimmune Factors like SLE: antiphospholipid antibodies Alloimmune Factors Inherited Thrombophilias Endocrinological factors like progesterone deficiency, PCOS, diabetes mellitus, hypothyroidism Ref: Williams Obstetrics, 23e chapter 9. 