Low maternal serum oestriol and chorionic gonadotropin in the prediction of adverse pregnancy outcome

Pregnancy outcome for women with very low levels of maternal serum unconjugated estriol on second-trimester screening

OBJECTIVE

Our purpose was to assess pregnancy outcome for women whose second-trimester triple screen results revealed very low unconjugated estriol levels.

STUDY DESIGN

Of 44,146 women screened for alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol, a group of women with isolated very low unconjugated estriol levels were selected as the study group. Pregnancy outcome was obtained by contacting the referring physicians.

RESULTS

During the study period 62 women had unconjugated estriol levels at or below the sensitivity of the assay. Fetal death was the most common explanation, accounting for 37.1% of cases. Six cases of early death followed uneventful prenatal visits. Eighteen women had unexplained very low unconjugated estriol levels. Of these 18, four cases of placental sulfatase deficiency were diagnosed. Sixteen of these 18 women gave birth to male infants (p = 0.03).

CONCLUSION

A very low unconjugated estriol level in the second trimester is associated with increased risk for early death and placental sulfatase deficiency.

Prenatal detection of X-linked ichthyosis by maternal serum screening for Down syndrome

Maternal serum unconjugated oestriol (uE3) was measured in 15,375 pregnancies during 2 years of second-trimester risk assessment for Down syndrome using biochemical markers. Very low levels of uE3 (< 0.1 MOM) were detected in 22 serum samples (0.14 per cent). Very low uE3 was associated with an adverse outcome in 13 pregnancies including fetal death and miscarriage (N = 11) anencephaly (N = 1), and Meckel-Gruber syndrome (N = 1). Dry scales on the skin appeared in the first year of life in four boys. From dermatological diagnosis, prenatal uE3 levels, and pedigree analysis, it is concluded that at least 5 in approximately 7500 male births in the study population are affected by steroid sulphatase deficiency, which is the biochemical defect in X-linked ichthyosis. Very low uE3 levels in the second trimester are indicative of this disease in pregnancies with normal ultrasound findings.