Endometrial biopsy with a Pipelle catheter was studied as an alternative to D&C and found inferior (Barnhart, 2003b; Ries, 2000). By comparison, frozen section of curettage fragments to identiY products of conception is accurate in more than 90 percent of cases (Barak, 2005; Li, 2014b).
Direct visualization of the fallopian tubes and pelvis by laparoscopy ofers a reliable diagnosis in most cases of suspected
FIGURE 19-6 Techniques to identiy hemoperitoneum. A.Transvaginal sonography of an anechoic fluid collection (arrow) in the retrouterine cul-de-sac. B. Culdocentesis: with a 16-to 18-gauge spinal needle attached to a syringe, the cul-de-sac is entered through the posterior vaginal fornix as upward traction is applied to the cervix with a tenaculum. (B, Reproduced with permission from Gala RB: Ectopic pregnancy. In Hofman BL, Schorge JO, Bradshaw KD, et al: Williams Gynecology, 3rd ed. New York, McGraw-Hili Education, 2016.) ectopic pregnancy. This also permits a ready transition to definitive operative therapy, which is discussed on page 378.
Medical therapy traditionally involves the antimetabolite methotrexate (MTX). This drug is a folic acid antagonist. It tightly binds to dihydrofolate reductase, blocking the reduction of dihydrofolate to tetrahydrofolate, which is the active form of folic acid. As a result, de novo purine and pyrimidine synthesis is halted, which leads to arrested DNA, RNA, and protein synthesis. Thus, MTX is highly efective against rapidly proliferating tissue such as trophoblast. Overall, ectopic tubal pregnancy resolution rates approximate 90 percent with its use. The drawbacks, however, are that bone marrow, gastrointestinal mucosa, and respiratory epithelium can also be harmed. It is directly toxic to hepatocytes and is renally excreted. MTX is also a potent teratogen, and MTX embryopathy is notable for craniofacial and skeletal abnormalities and fetal-growth restriction (N urmohamed, 201i1). In addition, MTX is excreted into breast milk and may accumulate in neonatal tissues and interfere with neonatal cellular metabolism (American Academy of Pediatrics, 2001; Briggs, 2015). Based on all these findings, a list of contraindications and pre therapy laboratory testing is found in Table
TABLE 19-1. Medical Treatment Protocols for Ectopic Pregnancy
Sensitivity to MTX Tubal rupture Breastfeeding One dose; repeat if necessary
Days 1 (baseline), 4, and 7 If seru m �-hCG level does not decline by 15% from day 4 to day 7 Less than 15% decline during
Up to four doses of both drugs until serum �-hCG declines by 15% 1 mg/kg, days 1,s3,5, and 7 0.1 mg/kg days 2, 4, 6, and 8 Days 1 (baseline), 3, 5, and 7
If serum �-hCG level declines < 15%, give additional dose; repeat serum �-hCG in 48 hours and compare with previous value; maximum four doses
Once 15% decline achieved, then weekly serum �-hCG levels until undetectable
Intrauterine pregnancy Immunodeficiency Peptic ulcer disease Hepatic, renal, or hematologic dysfunction Active pulmonary disease