Hyperreactio luteinalis, a rare cause of hyperthyroidism in pregnancy

Hyperreactio luteinalis associated with fetal hyperandrogenism and cystic hygroma

A 23‐year‐old woman with a gestational age of 17 weeks presented with abdominal pain. The ultrasound showed maternal hyperreactio luteinalis with fetal cystic hygroma. After termination of pregnancy, the female fetus showed masculinization features with muscular hypertrophy. The hyperreactio luteinalis regressed under hormonal suppression therapy.

Hyperreactio luteinalis can develop in spontaneous pregnancies with normal gonadotropin levels. Resolution with conservative therapy is the rule in most cases. This abnormality was accompanied with fetal cystic hygroma in two documented cases.

Testosterone serum levels are not predictive of maternal virilization in hyperreactio luteinalis

Background

Elevated concentrations of circulating testosterone are present in hyperreactio luteinalis (HL), a pregnancy-specific, self-limited condition. HL is associated with maternal virilization in about 30% of cases. The correlation between testosterone levels and maternal virilization has not yet been quantified. Our aim was to identify a testosterone cut-off level which may allow to predict maternal virilization.

Methods

A literature research was performed. Publications were chosen if serum testosterone concentrations and presence or absence of maternal virilization was mentioned. Additionally, we report serial levels of steroids analyzed by Liquid chromatography–tandem mass spectrometry (LC–MS/MS) in one case of HL managed at our institution.

Results

In all, 31 cases fulfilled the search criteria. We found significant overlap between testosterone levels in asymptomatic women and women with signs of virilization (range 6.2–37.3 nmol/l and 13.7–197.5 nmol/l, respectively). The method applied for testosterone analysis was mentioned in three reports only. Peak serum testosterone concentration in our case was 120.3 nmol/l.

Conclusion

From the available data, maternal virilization in HL cannot be predicted by the level of circulating testosterone. However, comparability of results is hampered by the analytical methods applied. LC–MS/MS should preferably be used for reporting concentrations of circulating testosterone.