724 citations,
April 2004 in “Lancet Oncology” Chemotherapy in the first trimester of pregnancy is risky, but in the second and third trimesters, it's generally safe with careful drug selection and timing.
19 citations,
March 2021 in “Experimental and Therapeutic Medicine” Isotretinoin can cause serious birth defects and needs careful use, especially in pregnant women.
4 citations,
September 2014 in “Elsevier eBooks” Use some skin medications with caution during pregnancy; avoid strong steroids, certain eczema treatments, and systemic retinoids, but many topical treatments and nasal sprays are safe.
343 citations,
December 2008 in “Endocrine Reviews” Metformin helps with menstrual cycles and insulin levels in PCOS but is less effective for hair growth, diabetes prevention, and weight loss, and may improve fertility and reduce diabetes risk.
171 citations,
October 1990 in “Alcoholism/Alcoholism, clinical and experimental research” The document concludes that the exact way alcohol causes harm to fetal development is unknown, but it significantly affects nutrient transport to the fetus and a safe level of alcohol during pregnancy is not determined.