<prompt> Most frequent site of tubal ectopic pregnancy isInterstitialIsthmicAmpullaInfundibulum  <response>: Nearly 95 percent of ectopic pregnancies are implanted in the various segments of the fallopian tube. The ampulla 70 percent is the most frequent site, followed by isthmic 12 percent, fimbrial 11 percent, and interstitial tubal pregnancies 2 percent.The remaining 5 percent of non-tubal ectopic pregnancies implant in the ovary, peritoneal cavity, cervix, or prior cesarean scarReference: Williams Obstetrics; 25th edition; Chapter 19; Ectopic pregnancy 