Taste changes across pregnancy

We examined taste intensity and preference in 46 pregnant and 41 healthy female controls enrolled in the Yale Pregnancy Study (J. Rodin, PI). Pregnant females were tested non-pregnant (non-pg) and during the first, second and third trimesters; controls, at corresponding time intervals. Subjects rated intensity of and preference for a three-member concentration series of NaCl, sucrose, citric acid (CA), and quinine hydrochloride (QHCl) on a labeled line ('nothing' at the left, 'extremely' at 80%). Variance differences between groups were tested with the F distribution (p < 0.05). Controls had significantly greater variance among overall intensity ratings than pregnant females, most pronounced for QHCl. Controls did not have highest variance among overall hedonic ratings, but did have highest variance for sweet and QHCl ratings. Within pregnancy analyses were tested with the Friedman two-way ANOVA. Significant intensity changes occurred for moderate NaCl and QHCL concentrations (p < 0.005). For NaCl, intensity fell from non-pg and first trimester to second and third trimesters. For QHCl, intensity rose from non-pg to first trimester, and fell from first to second and third trimesters. In the hedonic ratings, significant changes occurred for top concentrations of NaCl (p < 0.05) and 0.001 M CA (p < 0.001), and moderate QHCl (p < 0.005). NaCl preference rose from non-pg to third trimester. Preference for CA fell from non-pg to first trimester and then rose from first to second and third trimesters. QHCl became less disliked from non-pg and first trimester to third trimester.

taste intensity and hedonic variance in controls may associate with menstrual hormone fluctuations. Pregnant women were aligned in pregnancy stage which may explain the lower variance. Taste intensity and hedonic changes across pregnancy could serve to support healthy pregnancy outcomes: increases in bitter intensity in first trimester to protect against ingesting poisons; changes in NaCl, sour and bitter preference later in pregnancy to support ingesting a varied diet.