Biochemical Pregnancies

There is little information in the literature about biochemical pregnancies (BP). However, BPs (a pregnancy which regresses prior to imaging with ultrasound) are a major problem in IVF and recurrent miscarriage clinics. The incidence of between 13% and 22% of pregnancies may be confounded as today’s sensitive pregnancy tests may detect endometrial, pituitary, or phantom hCG. Additionally, a false-positive result may follow extaneous hCG administered in an assisted reproductive technology (ART) cycle. Hence the authors have suggested a rising hCG level at two consecutive tests as a definition, and that one raised hCG level should be known as a raised isolated hCG level. The etiology remains unclear. Embryonic aneuploidy, thinned endometrium, sperm defects, and defective angiogenesis have been suggested. Additionally, a number of biochemical pregnancies are early ectopic pregnancies which fail to develop further. The authors treat recurrent BPs as recurrent pregnancy loss (RPL). However, treatment to prevent further BPs is empiric with no evidence in the literture. The authors use hCG supplementation to enhance implantation. These results show a non-significant improvement in the subsequent live birth rate. Intra-venous immunoglobulin (IVIg) has been administered to 20 patients with >5 biochemical pregnancies, 50% terminated as live births. If a biochemical pregnancy becomes persistent, and hCG levels fail to fall, methotrexate may be required as in early ectopic pregnancies.