The phrase "a trimester was" is correct and usable in written English.
It can be used when referring to a specific trimester in the past, often in educational or medical contexts.
Example: "A trimester was completed successfully, and the students were eager to see their results."
Alternatives: "one trimester was" or "a term was".
A repeat urine sample, collected from a subset of women, in each trimester would have given a better estimate of usual intake for the group (by correcting for intraindividual variation and adjusting the intake distribution to the mean) (56); unfortunately, repeat measures within a trimester were not available.
She noted that the discovery of birth defects, which often occurs in the second trimester, was a common reason for later abortions.
Thankfully, my second trimester was a joy.
You may think pregnancy is going to be exhausting, but for me and many others, the second trimester was a breeze.
In the current study, the third trimester was a risk of IgG sero-positivity, as demonstrated by univariate analysis.
Based on simple linear regression analysis, a unit increment in trimester was associated with 3.46 μg/dl decline in serum zinc level (t = 5.682, 0.000).
The corresponding impact of one SD increase in loge maternal whole blood during the first trimester was a 2.4-point decrease in the 24-month MDI.
In addition, we also found that low hemoglobin concentration in the first trimester was a risk of LBW and SGA, which has not been reported in the previous review.
The Cox regression analysis in a study in South Africa revealed that late antenatal attendance (≥28 weeks gestation) when compared to attendance during the first trimester, was a predictor for LTF in children [ 1].
In Cox regression analysis, late antenatal attendance (≥ 28 weeks gestation) relative to attending in the first trimester was a predictor for infant LTFU (adjusted hazards ratio = 2.3; 95% CI: 1.0 to 5.1; p = 0.044).
