First-trimester maternal serum progesterone in aneuploid pregnancies.
BACKGROUND
First-trimester maternal serum screening for Down syndrome (DS) can be improved by the use of additional serum markers. We examined whether progesterone (P), synthesized by placenta, might be a first-trimester maternal serum marker for fetal DS.


METHODS
P was quantified in first-trimester maternal serum from 42 DS, six trisomy 18 and two trisomy 13 pregnancies and 115 controls. Log-regression of P versus gestational age in days was used to convert P concentrations into multiples of the median (MoM).


RESULTS
The P concentrations in controls increased with gestational age (p = 9.5 x 10(-7)). The log10MoM P distribution in DS pregnancies was not significantly different from that in controls. However, from day 58-67, the log10MoM P was elevated in DS pregnancies (n = 10) with a mean (SD) of 0.1040 (0.0956), compared to a mean (SD) of - 0.0109 (0.1661) in controls (n = 24) (p = 0.05). Five out of six trisomy 18 and both trisomy 13 pregnancies had a P MoM < 1.


CONCLUSIONS
P is not a useful marker for DS in first trimester, except perhaps in a narrow gestational age window from day 58 to 67. P is a trisomy 18/13 marker.
Christiansen
Michael
M
Department of Clinical Biochemistry, Statens Serum Institut, Copenhagen, Denmark. mic@ssi.dk
Sørensen
Tina Lindvig
TL
Larsen
Severin Olesen
SO
Nørgaard-Pedersen
Bent
B
D000328:Adult; D000782:Aneuploidy; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004314:Down Syndrome / Q000097:blood / Q000175:diagnosis; D005260:Female; D006801:Humans; D009035:Mothers; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000235:genetics; D011261:Pregnancy Trimester, First / Q000097:blood*; D011296:Prenatal Diagnosis / Q000379:methods; D011374:Progesterone / Q000097:blood*
D015415:Biomarkers; D011374:Progesterone