Second-Trimester Maternal Serum Markers in Twin Pregnancy with Complete Mole: Report of 2 Cases

Abstract

We present second-trimester serum marker levels in cases of twin pregnancy with complete hydatidiform mole and a coexistent fetus (CHMCF). Second-trimester inhibin A (InhA) levels have not been previously reported in such cases. Second-trimester maternal serum screening, alpha-fetoprotein (AFP), unconjugated estriol (uE3), human chorionic gonadotropin (hCG), and InhA measurements combined with maternal age to estimate a patient's risk of Down syndrome during pregnancy was performed as a routine prenatal test in 2 cases of CHMCF. Hospital records containing serum marker data, patient history, pathology reports, and pregnancy outcome were reviewed. In cases of CHMCF, maternal serum AFP and uE3 levels were similar to those of a normal singleton pregnancy, whereas hCG and InhA levels were markedly increased. Second-trimester maternal serum marker profiles in cases of CHMCF are a composite of normal singleton and molar tissue secretions. We have found, for the first time, that second-trimester InhA levels are markedly increased in these cases. Serum marker levels may be useful in diagnosis of CHMCF, prenatal counseling, and evaluation of risk for persistent trophoblastic disease.

Second trimester maternal serum triple screening marker levels in normal twin and singleton pregnancies

“…However, the majority of the studies were based on the singleton gestational age-specific model for DS screening. The association of maternal serum markers between normal twin and singleton pregnancies remains controversial (3,5). The aim of the present study was to evaluate the distributions of AFP, free-β-hCG and uE 3 during the second trimester of gestation and investigate whether these markers in normal twins were 2-fold those in singletons and whether the singleton gestational age-specific model for DS screening was feasible for twin pregnancies.…”

Partly Molar Pregnancies that are Not Partial Moles: Additional Possibilities and Implications

“…We read with interest in the April issue of Pediatric and Developmental Pathology two publications that addressed the issue of pregnancies in which a phenotypically normal fetus is present in association with apparent molar change of the placenta [1,2]. Thaker [1] listed three possibilities in this situation, namely dichorionic twin pregnancies with complete hydatidiform mole and associated co-twin, partial molar pregnancy, and placental mesenchymal dysplasia.…”

“…In the same issue, Lambert et al [2] described 2 pregnancies with structurally normal co-twin and coexisting complete hydatidiform mole in which they investigated second-trimester maternal serum biochemistry. In addition to the known increase in maternal serum human chorionic gonadotropin concentration, they reported that maternal serum inhibin concentrations in particular are increased in this situation.…”

“…It would be interesting, however, to know whether investigation of a larger series of these cases would demonstrate an association between maternal serum biochemistry results and subsequent pregnancy outcome because prenatal prediction of cases destined to develop persistent gestational trophoblastic disease remains poor. Although absent from the reference list of Lambert et al [2], it should be noted that the largest previously published series of almost 80 cases of histologically confirmed twin pregnancies complicated by complete hydatidiform mole clearly demonstrated that, although such pregnancies are at risk of a number of complications, the risk of persistent gestational trophoblastic disease is not significantly greater than that reported in an equivalent population of singleton complete hydatidiform moles and, further, is not affected by pregnancy management [5]. In such cases, therefore, parents should be counseled regarding the overall poor pregnancy outcome and risk of complications, but should they choose to continue the pregnancy, follow-up for persistent trophoblastic disease should use the same protocol as in singleton complete hydatidiform moles.…”

The Partly Molar Pregnancy that is Not a Partial Mole

“…cental disc and diploid chromosomes derived from both parents. Two examples of this latter situation are described in a report published in this issue of Pediatric and Developmental Pathology [4].…”