Strengths and limitations
Our present work has some strength of note. Firstly, we adjusted more
variables to ensure that the result was more reliable. Secondly, proper
statistical methods and sensitivity analysis ensure structural
stability. Thirdly, the study included solely ovulatory women to cleanly
analyze the impact of both types of endometrial preparation. Last but
not least, we only included women in the first cycle of FET, thus
avoiding bias from multiple cycles.
Several limitations are associated with the present study warrant
mention. Firstly, the type of endometrial preparation was chosen by the
treating physician’s preference and this may introduce a potential bias.
Secondly, this was a retrospective study and could not investigate other
confounders, including exercises, nutritional supplements and diets.
Thirdly, we could not compare the incidence of preeclampsia and
placental dysfunction in pregnancies after NC and AC, since these data
were not collected in our dataset.