Xiaoyu Cheng, Yanning Yang, Yaxiao Chen, Meiqing Xie
This case illustrates that pulsatile GnRH therapy can be an effective and physiological approach for achieving pregnancy in women with IHH. Although based on a single case, the favorable outcome achieved within a short treatment duration supports considering this modality as one of the treatment options for fertility induction in appropriately selected patients. In the absence of genetic confirmation and given the overlap with functional hypothalamic amenorrhea, the diagnosis is best regarded as consistent with, rather than definitive for, congenital IHH.
BACKGROUND: Idiopathic hypogonadotropic hypogonadism (IHH) is a rare endocrine disorder characterized by deficient gonadotropin-releasing hormone (GnRH) secretion or action, resulting in delayed puberty and infertility. Its clinical distinction from functional hypothalamic amenorrhea can be challenging because of overlapping features. Pulsatile GnRH therapy offers a physiological approach to fertility induction in affected women; although pregnancies following this treatment have been reported previously, detailed longitudinal documentation from diagnosis through pregnancy and delivery in women with IHH remains valuable for clinical education.
CASE PRESENTATION: We present a 27-year-old nulligravid woman with clinical and biochemical features consistent with normosmic IHH who presented with primary amenorrhea and absent secondary sexual characteristics since adolescence. Evaluation revealed markedly suppressed gonadotropins (FSH 0.41 IU/L, LH 0.10 IU/L) with undetectable estradiol, normal pituitary magnetic resonance imaging, and a 46,XX karyotype. Normosmia distinguished this case from Kallmann syndrome. Following six months of hormone replacement therapy with regular withdrawal bleeding, the patient initiated pulsatile subcutaneous GnRH therapy (10 μg every 90 minutes) for fertility induction. Natural conception following pulsatile GnRH therapy occurred within two months of treatment initiation. The pregnancy progressed uneventfully with appropriate β-hCG doubling and normal ultrasonographic development. GnRH pump therapy was maintained until 12 weeks of gestation to support early pregnancy. The patient subsequently delivered a healthy term infant.
CONCLUSION: This case illustrates that pulsatile GnRH therapy can be an effective and physiological approach for achieving pregnancy in women with IHH. Although based on a single case, the favorable outcome achieved within a short treatment duration supports considering this modality as one of the treatment options for fertility induction in appropriately selected patients. In the absence of genetic confirmation and given the overlap with functional hypothalamic amenorrhea, the diagnosis is best regarded as consistent with, rather than definitive for, congenital IHH.