Context: The human fetal adrenal (HFA) is an integral component of the fetoplacental unit and important for the maintenance of pregnancy. Low kisspeptin levels during pregnancy are associated with miscarriage, and kisspeptin and its receptor are expressed in the HFA. However, the role of kisspeptin in fetal adrenal function remains unknown.
Objective: To determine the role of kisspeptin in the developing HFA.
Design: Experiments using H295R and primary HFA cells as in vitro models of the fetal adrenal. Association of plasma kisspeptin levels with HFA size in a longitudinal clinical study.
Setting: Academic research center and tertiary fetal medicine unit.
Participants: Thirty-three healthy pregnant women were recruited at their 12-week routine antenatal ultrasound scan.
Main outcome measures: The spatiotemporal expression of Kiss1R in the HFA. The production of dehydroepiandrosterone sulfate (DHEAS) from HFA cells after kisspeptin treatment, alone or in combination with adrenocorticotropic hormone or corticotropin-releasing hormone. Fetal adrenal volume (FAV) and kisspeptin levels at four antenatal visits (∼20, 28, 34, and 38 weeks' gestation).
Results: Expression of Kiss1R was present in the HFA from 8 weeks after conception to term and was shown in the inner fetal zone. Kisspeptin significantly increased DHEAS production in H295R and second-trimester HFA cells. Serial measurements of kisspeptin confirmed a correlation with FAV growth in the second trimester, independent of sex or estimated fetal weight.
Conclusions: Kisspeptin plays a key role in the regulation of the HFA and thus the fetoplacental unit, particularly in the second trimester of pregnancy.