PREGNYL
Clinical safety rating
cautionComprehensive clinical and safety monograph for PREGNYL (PREGNYL).
Comprehensive clinical and safety monograph for PREGNYL (PREGNYL).
FDA: Treatment of prepubertal cryptorchidismFDA: Induction of ovulation and pregnancy in anovulatory infertile womenOff-label: Hypogonadotropic hypogonadism in malesOff-label: Assisted reproductive technology (ART) protocols
Human chorionic gonadotropin (hCG) acts as a luteinizing hormone (LH) agonist, binding to LH receptors in the gonads, stimulating testosterone production in males and ovulation in females.
| Metabolism | Primarily renal metabolism and excretion; limited hepatic metabolism. |
| Excretion | Renal: 10-20% as unchanged drug; hepatic metabolism to inactive metabolites; fecal excretion negligible (<5%) |
| Half-life | Terminal elimination half-life: 23–24 hours; clinically, supports daily or every-other-day dosing; peak effect may lag due to prolonged absorption |
| Protein binding | ~80% bound primarily to albumin; minor binding to sex hormone-binding globulin (SHBG) |
| Volume of Distribution | 0.5–0.7 L/kg; moderately distributed into extracellular fluid; penetrates gonadal tissues |
| Bioavailability | Intramuscular: ~100%; Subcutaneous: comparable (~95-100%); Oral: <5% (not used) |
| Onset of Action | Intramuscular: 2–4 hours (increased serum estrogen/progesterone); Subcutaneous: similar |
| Duration of Action | IM: 36–48 hours (sufficient for ovulation triggering); effects on luteal phase support last up to 72 hours |
| Molecular Weight | 38000 |
Intramuscular injection: 5,000-10,000 IU once weekly for 4-9 weeks for ovulation induction; 1,000-2,000 IU three times weekly for spermatogenesis.
| Dosage form | INJECTABLE |
| Renal impairment | No specific guidelines; use with caution in severe renal impairment (CrCl <30 mL/min) due to limited data. |
| Liver impairment | No specific guidelines for Child-Pugh; use with caution in severe hepatic impairment. |
| Pediatric use | Not indicated for prepubertal children; for delayed puberty in males: 1,000-2,000 IU intramuscularly 2-3 times weekly for 3-6 months. |
| Geriatric use | No specific recommendations; use lowest effective dose due to potential increased sensitivity and comorbidities. |
| 1st trimester | Human chorionic gonadotropin (hCG) is used for fertility. No evidence of teratogenicity from therapeutic use; however, it is not indicated during pregnancy as it would not be effective. |
| 2nd trimester | Not indicated during pregnancy; therapeutic use is for ovulation induction prior to conception. If inadvertently used during pregnancy, no known harm. |
| 3rd trimester | Not indicated during pregnancy; no data available for use in third trimester. |
Clinical note
Comprehensive clinical and safety monograph for PREGNYL (PREGNYL).
| Placental transfer | hCG is a large glycoprotein (MW ~38,000 Da) and does not cross the placenta in significant amounts after exogenous administration. Endogenous hCG is produced by the placenta during pregnancy. |
| Breastfeeding | hCG is not likely to pass into breast milk in significant amounts due to its large molecular weight. However, it is not indicated during breastfeeding as it is used for fertility treatment. Caution is advised, but no adverse effects reported in nursing infants. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | Pregny (hCG) is not indicated for use during pregnancy. hCG is used to induce ovulation and is not continued after conception. In animal studies, high doses have shown fetal abnormalities, but human data are insufficient. First trimester: No direct fetal risk from therapeutic use as it is discontinued before implantation. Second/Third trimester: Not used. Overall, classified as FDA Pregnancy Category X for ovulation induction (contraindicated in pregnancy) but no teratogenic risk if discontinued before conception. |
| Fetal Monitoring | During ovulation induction: monitoring of ovarian response via ultrasound and serum estradiol levels to prevent ovarian hyperstimulation syndrome (OHSS). If pregnancy occurs: standard prenatal care. No specific fetal monitoring required beyond routine pregnancy surveillance. |
| Fertility Effects | Pregny is used to induce ovulation in anovulatory women, thereby restoring fertility. It carries a risk of multiple gestation (twins, etc.) and ovarian hyperstimulation syndrome. It does not impair fertility; rather, it is therapeutic for infertility. However, repeated use may lead to ovarian enlargement or cyst formation. |
■ FDA Black Box Warning
No FDA black box warning.
| Serious Effects |
Hypersensitivity to hCG or any excipientsSex hormone-dependent neoplasms (e.g., ovarian, breast, uterine, testicular)Active thromboembolic disordersUncontrolled thyroid or adrenal dysfunctionAbnormal uterine bleeding of unknown cause
| Precautions | Ovarian hyperstimulation syndrome (OHSS) in women, Arterial thromboembolism, Precocious puberty in males, Fluid retention, Ovarian enlargement or cyst rupture |
| Food/Dietary | No known clinically significant food interactions. Maintain usual diet unless advised otherwise by physician. |
| Clinical Pearls | Pregnyl (hCG) is used to trigger final follicular maturation and ovulation in assisted reproduction. Monitor for ovarian hyperstimulation syndrome (OHSS); consider withholding hCG if estradiol >4000 pg/mL or >20 follicles per ovary. Administer exactly 36 hours before oocyte retrieval. Intramuscular injection into gluteal muscle; rotate sites if repeated doses. |
| Patient Advice | Use Pregnyl exactly as prescribed to trigger ovulation; timing is critical for egg retrieval. · Report severe pelvic pain, bloating, nausea, or rapid weight gain (possible OHSS) immediately. · Avoid pregnancy tests during treatment as hCG may cause false positive. · May cause injection site pain or swelling; apply warm compress if needed. · Do not discontinue without consulting your fertility specialist. |
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