This analysis included 856 women and 240 live birth singletons with the following outcomes: 44.04% clinical pregnancy rate, 35.63% live birth rate. There were 333 patients who were progesterone administered intramuscularly and 523 patients who were progesterone administered vaginally. Baseline demographics and characteristics were compared between patients with different progesterone regimens (Table 1). Among the 856 women, it did not reveal any significant difference for maternal age, BMI, whether there was at least one good quality embryo transferred, endometrium thickness at endometrium transform day, days of estrogen duration, E2, P, LH level at endometrium transform day between two groups. The proportion of patients with estradiol vaginally and orally delivered together in progesterone vaginally group was significantly higher than in progesterone intramuscularly group. Serum progesterone level at 14th day after embryo transfer was significantly higher in progesterone intramuscularly group than in progesterone vaginally group. No significant difference of live birth rate and clinical pregnancy rate was found between different progesterone regimens (Crude OR 1.181, 95CI% 0.895, 1.557, p = 0.282; Crude OR 1.170, 95%CI 0.879, 1.557, p = 0.239)(Table 2). Controlling for maternal age, BMI, the route of estrogen administration, whether estradiol duration was longer than 21 days, whether there was at least one good quality embryo transferred, progesterone administered regimen did not modify the odds of achieving live birth (Adjusted OR 1.128, 95%CI 0.842, 1.511, p = 0.420) or clinical pregnancy (Adjusted OR 1.144, 95%CI 0.863, 1.518, p = 0.349) (Table 2). Maternal age and at least one good quality embryo transferred were the only independent factors that increased the live birth rate and clinical pregnancy rate.
Table 1
Baseline demographics and cycle characteristics according to different progesterone routes
| Progesterone intramuscularly (N = 333) | Crinone vaginally (N = 523) | P |
Maternal age (y) | 30.46 ± 4.5 | 31.0 ± 4.5 | 0.051 |
BMI | 21.47 ± 3.1 | 21.22 ± 3.0 | 0.26 |
At least one good quality embryo | 294 | 451 | 0.383 |
Endometrium thickness at endometrium transform day (mm) | 9.0 (8.38, 9.63)(N = 320) | 8.9 (8.4, 9.4)(N = 508) | 0.355 |
Days of estradiol administration | | | |
>21 days | 24 | 36 | 0.856 |
≤21 days | 209 | 487 | |
Estrogen route | | | |
Orally and vaginally | 126 | 229 | 0.009 |
Orally only | 107 | 294 | |
E2 level at endometrium transform day (pmol/L) | 1374 (789.3, 3843.3) (N = 312) | 1342.5(822, 5291) (N = 479) | 0.340 |
P level at endometrium transform day (pmol/L) | 1.1 (0.68, 1.7)(N = 311) | 1.2(0.65, 1.85)(N = 477) | 0.663 |
LH level at endometrium transform day (pmol/L) | 8.8(4.78, 14.11)(N = 311) | 8.6(4.44, 14.72)(N = 477) | 0.561 |
P level at 14th day after embryo transfer (pmol/L) | 40.5(31.61, 57.57)(N = 262) | 14.95(8.29, 25.55)(N = 410) | < 0.001 |
Data are presented as mean±SD for continuous variables in formal distribution, median (first quartile, third quartile) for continuous variables in informal distribution. P values were assessed with the use of t tests or Wilcoxon rank sum tests or chi-square. |
Table 2
Clinical outcomes according to different progesterone routes
| Progesterone intramuscularly (N = 333) | Crinone vaginally (N = 523) | Crude OR (95%CI) | P | Adjusted OR (95%CI) | P |
Clinical pregnancy | 155(46.55) | 222(42.45) | 1.181 (0.895, 1.557) | 0.239 | 1.144(0.863, 1.518) a | 0.349 |
Live birth | 126(37.84) | 179(34.23) | 1.170(0.879, 1.557) | 0.282 | 1.128(0.842, 1.511) a | 0.420 |
a: adjusted for maternal age, BMI, transfer with at least one good quality embryo, estrogen regimen, whether estrogen administration days > 21. CI = confidence interval; OR = odds ratio. |
To further explore the progesterone regimen impact on birthweight and gestational age, a cohort of 240 live birth singletons from 856 patients was investigated. Neonatal outcomes stratified by the regimen of progesterone administered were presented in Table 3. Newborn gender, gestational age, mean birthweight, Z-scores, preterm delivery rate, SGA and LGA rate were not different across two groups (Table 3). In multivariate analyses (Table 3), the risk of preterm delivery (Adjusted OR 1.920, 95%CI 0.603, 6.11, p = 0.269), the risk of LGA (Adjusted OR 0.862, 95%CI 0.425, 1.749, p = 0.681), and SGA (Adjusted OR 0.227, 95%CI 0.027, 1.934, p = 0.175) were not significantly different between two groups after adjusting for maternal age, BMI, estradiol route, estrogen administration more than 21 days, transfer with at least one good quality embryo and newborn gender.
Table 3
Neonatal outcomes of singletons live birth according to different progesterone routes
All singletons | Progesterone intramuscularly (N = 95) | Crinone vaginally (N = 145) | P |
Newborn gender | | | | | |
Female | 45 | 71 | 0.809 |
Male | 50 | 74 | | | |
Gestational Age | | | | | |
32–36 | 7 | 7 | 0.411 |
>37 | 88 | 138 | | | |
Birth weight | 3349.19 ± 487.2 | 3365.58 ± 469.5 | 0.744 |
Z score | 0.357 ± 1.047 | 0.345 ± 1.023 | 0.928 |
| Progesterone intramuscularly (N = 95) | Crinone vaginally (N = 145) | Crude OR(95%CI) | P | Adjusted OR(95%CI) | P |
Preterm delivery | 7 | 7 | 1.568(0.532, 4.623) | 0.411 | 1.920(0.603, 6.110)a | 0.269 |
SGA | 1 | 6 | 0.246(0.029, 2.080) | 0.319 | 0.227(0.027, 1.934)a | 0.175 |
LGA | 14 | 27 | 0.819(0.410, 1.637) | 0.572 | 0.862(0.425, 1.749)a | 0.681 |
Data are presented as mean±SD for continuous variables in formal distribution. P values were assessed with the use of t tests or Wilcoxon rank sum tests or chi-square (Fisher’s exact tests as appropriate). a: adjusted for maternal age, BMI, transfer with at least one good quality embryo, estrogen regimen, whether estrogen administration days > 21, newborn gender. SGA stands for small for gestational age. LGA stands for large for gestational age. |
In order to investigate the circulating serum progesterone impact on newborn gestational weeks and birth weight, a cohort of 262 patients with progesterone intramuscularly and 77 live birth singletons was further investigated. We did not analysis vaginal progesterone cohort because systemic serum progesterone value was not the reflection of progesterone Crinone vaginally absorbed[13]. From the cohort, clinical and neonatal outcomes of patients with serum progesterone level > 41.82 pmol/L and ≤ 41.82 pmol/L at the 14th day after embryo transfer were presented in Table 4. 41.82 pmol/L was the median value of serum progesterone level at the Hcg test day for patients with progesterone intramuscularly administered. Patients with serum P level > 41.82 pmol/L demonstrated higher clinical pregnancy rate and live birth rate than patients with serum P level ≤ 41.82pmolL both in univariate analysis and multivariate analysis adjusting for maternal age, BMI, whether at least one good quality embryo was transfered, estrogen regimen, whether estrogen administration days > 21(Adjusted OR 1.670, 95%CI 1.005, 2.774, p = 0.048; Adjusted OR 1.690, 95%CI 1.002, 2.849, p = 0.049). While birthweight, Z-score, preterm delivery rate, LGA and SGA rate were not different between these two groups. Multivariate analysis was not performed for preterm delivery rate, LGA and SGA rate because the number in this category was too small.
Table 4
Reproductive and neonatal outcomes between P level > 41.82 pmol/L and P level ≤ 41.82 pmol/L groups when progesterone intramuscularly was used in HRT-FET cycles
| | P level > 41.82 pmol/L (N = 131) | P level ≤ 41.82 pmol/L (N = 131) | Crude OR (95%CI) | P | Adjusted OR (95%CI) | P |
Clinical Pregnancy | | 72(54.9) | 55(41.98) | 1.686(1.034, 2.940) | 0.036 | 1.670(1.005, 2.774)a | 0.048 |
Live Birth | | 59 (45.04) | 43(32.82) | 1.677(1.016, 2.769) | 0.043 | 1.690(1.002, 2.849)a | 0.049 |
Singletons Neonatal outcome | | P level > 41.82 pmol/L (N = 42) | P level ≤ 41.82 pmol/L (N = 35) | Crude OR (95%CI) | P |
Birthweight | | 3331.79 ± 421.19 | 3354.03 ± 643.51 | | | 0.861 |
Z score | | 0.2778 ± 0.9658 | 0.6248 ± 1.1147 | | | 0.153 |
Preterm delivery | | 2 | 5 | 0.391(0.074, 2.051) | 0.444 |
LGA | | 5 | 8 | 0.610(0.194, 1.917) | 0.393 |
SGA | | 1 | 0 | / | | / |
a: adjusted for maternal age, BMI, transfer with at least one good quality embryo, estrogen regimen, whether estrogen administration days > 21. SGA stands for small for gestational age. LGA stands for large for gestational age. |