Insufficiency of endogenous progesterone occurs in Luteal Phase Defect (LPD) which makes it difficult to maintain a functional secretory endometrium. Further, it also inhibits embryo growth and implantation. Data from 1960 indicated that 20 million pregnancies were exposed to Dydrogesterone in utero.LOTUS I and LOTUS II, the two major multicenter Phase III studies conducted on patients planning to undergo In Vitro Fertilization (IVF) with or without Intracytoplasmic Sperm Injection (ICSI), established Dydrogesterone to be non-inferior to micronized vaginal progesterone. This was confirmed by the existence of fetal heartbeats at 12 weeks of gestation. LPD can be treated by dispensing Progesterone orally, or vaginally combined with proportional estrogen and Gonadotropin-Releasing Hormone (GnRH) agonist drugs. Evidence suggests utilising Dydrogesterone in fresh IVF cycles and Luteal Phase Support (LPS) till 10–12 weeks. However, it may be stopped once β-hCG becomes positive or at the sight of a fetal heartbeat.Pant PR, Shrivastava U, Simkhada S et al. Luteal Phase Defect (LPD): A necessary tool in assisted reproductive techniques. Indian Journal of Obstetrics and Gynecology Research. 2021. https://www.ijogr.org/article-details/13371