E-Library - Information At Your Fingertips: Printer Friendly 39 of 48 http://elibrary.judiciary.gov.ph/thebookshelf/showdocsfriendly/1/63027 woman's body.[54] In females, egg cells are produced through ovulation. Ovulation is a complex biological process characterized and defined by periods of elevated hormone production.[55] Every month, the pituitary gland[56] releases a follicle stimulating hormone that promotes the growth of several ovarian follicles. These ovarian follicles each contain an immature egg cell. As these ovarian follicles grow, estrogen is released into the blood stream. Once the level of estrogen peaks, the pituitary gland produces a surge of luteinizing hormones that would signal the most mature follicle to release the egg cell into the fallopian tube.[57] Although sperm cells have an average lifespan of three (3) to five (5) days within which to travel through the female's reproductive tract, there must be an available egg cell for fertilization to occur.[58] Contraceptives such as Implanon and Implanon NXT (Implanon) work specifically to prevent fertilization. Implanon is a hormone-releasing subdermal implant that contains a progestin hormone called "etonogestrel."[59] It was first launched in Indonesia in 1998 and is now registered in approximately 80 countries.[60] The implant is a small flexible plastic rod that is inserted under the woman's non-dominant upper arm.[61] Considered as a highly effective[62] and convenient method of contraception, Implanon can provide protection for up to three (3) years.[63] While there are some reports of pregnancies among users, these appear to have been caused by the implant's incorrect insertion.[64] The non-abortifacience of Implanon can be explained by its primary mechanism of action. First, it inhibits the surge of luteinizing hormones. This prevents the ovaries from releasing an egg cell into the fallopian tube. Second, Implanon thickens the cervical mucus, which hinders the passage of sperm cells into the uterus.[65] Implanon may also prevent "endometrial proliferation,"[66] the process in which the lining of the uterus thickens. This would make the uterus unsuitable to support a fertilized egg in the unlikely event that fertilization occurs.[67] Implanon makes it impossible for the sperm cell to unite with an egg cell. Hence, it cannot be considered as an abortifacient. This is consistent with Section 4 (a) of the RH Law. Another point of clarification is the typographical error found in the fallo of the ponencia. The ponente, in adopting a portion of Justice Mariano C. Del Castillo's Concurring Opinion[68] in Imbong v. Ochoa, had inadvertently equated the term conception with fertilization. It bears stressing that this Court, in Imbong v. Ochoa, recognized that the question on when life begins is both a scientific and medical issue that can only be decided upon proper hearing and evidence.[69] The ponente in Imbong, who is also the ponente in this case, clarified that the notion that life begins at fertilization was his 4/21/2020, 9:19 AM