FDA: hyperprolactinemic disorders Off‐label: infertility of pituitary origin; adjunct in the treatment of OHSS
Category B BNF: Bromocriptine: compatible with pregnancy Cabergoline: human data suggest low risk
Dopamine antagonists Antihypertensive drugs
Gonadotropins
Human gonadotropin analogues
FDA: ovarian stimulation and ovulation induction
Category X
None known
GnRH agonists
GnRH receptor agonists, desensitization with prolonged exposure
FDA: prevention of premature LH surge in women undergoing COS Off‐label: ovulation trigger in high responders
Category X
None known
GnRH antagonists
GnRH receptor blockers
FDA: prevention of premature LH surge in women undergoing COS Off‐label: treatment of OHSS
Category X
None known
hCG
LH analogue
FDA: ovulation induction in anovulatory women; follicular maturation in COS Off‐label: luteal phase support in IVF
Category X—intrauterine death
None known
hGH
IGF‐1 production
Off‐label: adjuvant therapy in low responders in IVF
Category B
None known
Intralipid infusions
Unclear—possible immune modulator
Off‐label: recurrent implantation failure / pregnancy loss
Category C BNF: compatible with pregnancy
Oxine
Intravenous immunoglobulin (IVIg)
Immune modulator
Off‐label: recurrent implantation failure / pregnancy loss
Category C BNF: compatible with pregnancy; no known embryo‐fetal risk
None known
Metformin
Various ‐ euglycemic
Off‐label: improvement of menstrual cycle regularity or hyperandrogenism in women with PCOS
Category B BNF: human data suggest low risk
Furosemide increases metformin concentration Nifedipine increases the absorption of metformin
Prednisolone
Various
Off‐label: treatment of APS
Category D BNF: increased risk of orofacial clefts
Anticoagulants CYP3A4 inducers and inhibitors NSAIDs
Progesterone
Sex steroid hormone
FDA: luteal phase support in ART
FDA category not assigned
None known
Sildenafil
Phosphodiesterase 5 inhibitor
Off‐label: female infertility with endometrial factor; increase endometrial thickness
Category B BNF: limited human data—animal data suggest low risk
Alpha blockers Anti‐hypertensives Nitrates CYP3A4 inhibitors (increase the concentration of sildenafil)
Tamoxifen
Selective estrogen receptor modulator
Off‐label: alternative to clomiphene in PCOS / women with thin endometrium in response to clomiphene
Category D BNF: contraindicated (fetal growth restriction, miscarriage and preterm birth)
Erythromycin Letrozole Nifedipine Rifampicin
ACE, angiotensin‐converting enzyme; APS, antiphospholipid syndrome; ART, assisted reproductive treatment; BNF, British National Formulary; COS, controlled ovarian stimulation; COX, cyclooxygenase; CYP, cytochrome P; FDA, Food and Drug Administration; GnRH, gonadotropin‐releasing hormone; hCG, human chorionic gonadotropin; hGH, human growth hormone; IGF, insulin‐like growth factor; IVF, in vitro; fertilization; LH, luteinizing hormone; NSAID, nonsteroidal anti‐inflammatory drug; OHSS, ovarian hyperstimulation syndrome; PCOS, polycystic ovary syndrome.
Key points
Challenge: Conventional and herbal drugs in patients undergoing ART.
Background:
Patients undergoing ART and pregnant women commonly take prescribed and/or over‐the‐counter medicinal products.
Drugs, whether medical or herbal, may have harmful effects on a pregnancy, ranging from miscarriage to developmental anomalies and fetal growth restriction.
Management:
Regularly reassess the need for medication in women trying to conceive or who become pregnant, and where possible consider nonpharmacological interventions.
Avoid drugs in the first trimester if possible.
Prescribe if the expected benefit outweighs the risks.
Prescribe drugs that have long been used in pregnancy with a good safety record over new or untested drugs.
Use the smallest effective dose for the shortest period of necessity.
Consult a pharmacist or teratology information service when in doubt about a drug’s most up‐to‐date safety profile in pregnancy.
Always involve women in decisions made about pharmacological interventions in pregnancy.
