No differences found of Small for Gestational Age (SGA) between Fresh Embryo Transfer (ET) babies and Spontaneously Conceived (SC) ones.

Context: There are increasing concerns that a disrupted endocrine environment may disturb the growth of the fetus. Assisted reproductive technology (ART) situates gamete/embryo in a supraphysiological estradiol (E2) environment and, thus, provides an ideal model to investigate this problem. Objective: Our objective was to investigate whether the maternal high-E2 environment in the first trimester increases the risks of low birth weight (LBW) and small-for-gestational-age (SGA) birth. Methods: In total, 8869 singletons born after fresh embryo transfer (ET) (n = 2610), frozen ET (n = 1039), and natural conception (NC) (n = 5220) and their mothers were included. Birth weight, LBW, SGA, and maternal serum E2 levels were investigated. Results: The mean serum E2 levels of women undergoing fresh ET at 4 and 8 weeks of gestation were significantly higher than those of the women undergoing frozen ET and the women with NC (P < .01). Serum E2 levels of women undergoing fresh ET at 4 and 8 weeks of gestation were positively correlated to those on the day of human chorionic gonadotropin (hCG) administration (r = 0.5 and r = 0.4, respectively; P < 0.01). The birth weight after fresh ET was significantly lower than that after frozen ET and NC (P < 0.01), with increased incidence of LBW and SGA (P < .05). Furthermore, in the fresh ET group, singletons of mothers with high E2 levels (≥10460 pmol/L on the day of hCG administration) had higher risks of LBW (P < .01) and SGA (P < .01) than those with low E2 levels, and maternal serum E2 level on the day of hCG administration negatively correlated with the birth weight (P < .01). Conclusions: The maternal high-E2 environment in the first trimester is correlated with increased risks of LBW and SGA. Evaluation of serum E2 before ET should be adopted to reduce the possibility of high E2 exposure to gamete/embryo.

Download Full-text

Endometrial thickness is associated with incidence of small-for-gestational-age infants in fresh in vitro fertilization–intracytoplasmic sperm injection and embryo transfer cycles

Fertility and Sterility ◽

10.1016/j.fertnstert.2019.12.014 ◽

2020 ◽

Vol 113 (4) ◽

pp. 745-752 ◽

Cited By ~ 2

Author(s):

Zizhen Guo ◽

Xinxin Xu ◽

Lin Zhang ◽

Liping Zhang ◽

Lei Yan ◽

...

Keyword(s):

In Vitro Fertilization ◽

Embryo Transfer ◽

Gestational Age ◽

Small For Gestational Age ◽

Intracytoplasmic Sperm Injection ◽

Endometrial Thickness ◽

Vitro Fertilization

Download Full-text

P–380 Differential concentrations of maternal and fetal hemopexin and α1-microglobulin in preeclampsia from IVF pregnancies depending on the presence of corpus luteum at embryo transfer

Human Reproduction ◽

10.1093/humrep/deab130.379 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

M L Boutet ◽

L Youssef ◽

L Erlandsson ◽

E Hansson ◽

D Manau ◽

...

Keyword(s):

Corpus Luteum ◽

Embryo Transfer ◽

Gestational Age ◽

Assisted Reproductive Technologies ◽

Reproductive Technologies ◽

Oocyte Donation ◽

Severe Preeclampsia ◽

Fresh Embryo Transfer ◽

Gestational Age At Birth ◽

Age At Birth

Abstract Study question Does the presence of corpus luteum (CL) in in vitro fertilization (IVF) treatments affect maternal and fetal concentrations of hemopexin and α1-microglobulin in preeclampsia? Summary answer Decreased hemopexin and increased α1-microglobulin levels in maternal and fetal blood in IVF pregnancies with absence of CL particularly in pregnancies complicated by preeclampsia. What is known already: Pregnancies after frozen embryo transfer (FET) in programmed cycles have higher rates of hypertensive disorders of pregnancy, suggesting a link between the absence of CL in programmed cycles and adverse maternal outcomes.Cardiovascular function is impaired early in pregnancy in women conceiving by IVF treatments in the absence of CL.Plasma relaxin–2, a potent vasodilator and stimulus of decidualization, has been reported to be undetectable in a non-CL cohort, but markedly elevated in a multiple-CL cohort through pregnancy.Hemopexin and α1-microglobulin act as scavengers that eliminate free heme-groups responsible for hemoglobin-induced oxidative stress known to contribute to preeclampsia development. Study design, size, duration A case-control study of 160 singleton pregnancies recruited from 2016 to 2020, including 54 spontaneous pregnancies from fertile couples, 50 conceived by IVF following fresh embryo transfer (ET) and FET in natural cycle (presence of CL) and 56 IVF after fresh oocyte-donation or FET in programmed cycles (absence of CL). Pregnancies were subclassified according to the presence of preeclampsia in uncomplicated, preeclampsia and severe preeclampsia cases. Participants/materials, setting, methods IVF pregnancies were recruited from a single Assisted Reproduction Center, ensuring homogeneity in IVF stimulation protocols, endometrial preparation, laboratory procedures and embryo culture conditions. Spontaneous pregnancies from fertile couples were randomly selected from our general population and matched to IVF by gestational age at birth. Hemopexin and α1-microglobulin concentrations were measured by ELISA in maternal and cord plasma collected at delivery. All comparisons were adjusted for age, ethnicity, prematurity, birthweight centile, oocyte-donation and FET cycles. Main results and the role of chance Parental ethnicity, body mass index, exposure to aspirin and corticoids during pregnancy, mean gestational age at birth and birthweight were similar in all study groups. While maternal hemopexin levels were lower in treatments without CL, the IVF group with one or several CL showed significantly increased hemopexin concentrations, both in uncomplicated and preeclampsia cases (uncomplicated: spontaneous conceptions median 1520 ug/ml [interquartile range 1054–1746], IVF with CL 1554 [1315–1778], IVF without CL 1401 [1130–1750]; Preeclampsia: spontaneous conceptions 1362 [1121–1667], IVF with CL 1372 [403–2558], IVF without CL 1215 [971–1498]). Maternal α1-microglobulin was significantly higher in the absence of CL in severe preeclamptic cases as compared to spontaneous pregnancies and IVF with CL (spontaneous conceptions median 23 ug/ml [interquantile range 20–24], IVF with CL 24 [24–26], IVF without CL 26 [25–28]). The cord blood profiles were identical to the maternal for both biomarkers. Overall, and in line with previous studies, preeclamptic pregnancies independently of the mode of conception, showed decreased concentrations of hemopexin and increased concentrations of α1-microglobulin both in maternal and fetal plasma, with more pronounced changes in severe preeclampsia cases. Limitations, reasons for caution Infertility factors contribution to the outcome cannot be unraveled from the assisted reproductive technologies procedure itself as we have only included spontaneous pregnancies from fertile couples. Adjustments for oocyte-donation and FET modalities were performed due to the higher proportion of these features in the ET in programmed cycles group. Wider implications of the findings: These findings acknowledge physiological differences between pregnancies following ET in stimulated and natural versus programmed cycles, supporting the hypothesis that the CL activity could influence perinatal results. This approach to perinatal outcomes in IVF patients could lead to changes in ET protocols in order to develop a CL if possible. Trial registration number Not applicable

Download Full-text

P–395 Obstetric and perinatal outcomes of pregnancies resulting from fresh versus frozen embryo transfer – a sibling cohort

Human Reproduction ◽

10.1093/humrep/deab130.394 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

H Gane. Herman ◽

Y Mizrachi ◽

A Shevac. Alon ◽

Y Farhadian ◽

O Gluck ◽

...

Keyword(s):

Embryo Transfer ◽

Gestational Age ◽

Small For Gestational Age ◽

Linear Regression Analysis ◽

Perinatal Outcomes ◽

Frozen Embryo Transfer ◽

Adverse Outcomes ◽

Obstetric Outcomes ◽

Multivariate Linear Regression Analysis ◽

Fresh Transfer

Abstract Study question We aimed to compare obstetric and perinatal outcomes between pregnancies conceived by in vitro fertilization (IVF) with fresh embryo transfer and frozen embryo transfer (FET) in the same women. Summary answer IVF pregnancies following fresh and FET entailed the same obstetric and perinatal outcomes, when compared in the same women. What is known already: There seems to be a difference in adverse outcomes between pregnancies following fresh and FET, as fresh transfer has repeatedly been associated with a higher risk of preterm birth and small for gestational age neonates, and the FET with preeclampsia and large for gestational age neonates. The overall lower incidence of adverse obstetric outcomes in FET may relate to the transfer of an embryo to a uterine environment in the setting of more physiological estradiol level but may also relate to patient characteristics which allow for freezing and subsequent transfer. Study design, size, duration This was a retrospective cohort of 214 deliveries during a 13-year period. Participants/materials, setting, methods The study was performed in a tertiary hospital. The cohort included live singleton deliveries (>24 weeks of gestation) and excluded pregnancies following egg donation. Each fresh transfer IVF pregnancy was matched to a FET pregnancy by the same woman (1:1 ratio). Main results and the role of chance A total of 107 fresh transfer pregnancies were matched to 107 FET pregnancies, in the same women. Mean maternal age was lower in the fresh transfer group compared to the FET group (30.4 vs. 32.5 years, p < 0.001), as was body mass index (BMI) (p = 0.001). A higher rate of nulliparity was noted in fresh transfer pregnancies (64.5% vs. 12.1%, p < 0.001). Mean birthweight was higher in the FET group (3160 vs. 3081 grams, respectively, p < 0.001), although the rates of low birth weight and small for gestational age neonates did not differ between the groups. Preterm deliveries occurred in 10.3% and 9.3% of fresh transfer and FET pregnancies respectively, p = 0.79. On multivariate linear regression analysis, the type of embryo transfer - FET or fresh - was not independently associated with birthweight, after adjustment for women’s age, nulliparity and BMI. Limitations, reasons for caution The study relied on coding in patient files, and thus certain data were missing for analysis, such as paternal identity. In addition, women included had at least two successful IVF pregnancies, and at least one cycle in which embryo freezing was performed. This may confer a selection bias. Wider implications of the findings: Our study of sibling deliveries after fresh and FET, points to a similar prognosis for the main obstetric and perinatal outcomes. This adds to current research which points to similar development of children following fresh and FET and is reassuring for clinicians consulting patients who are eligible for both options. Trial registration number Not applicable

Download Full-text

P–781 Birthweight is not affected by freezing process. Results from a quasi-experimental study using the Oocyte Donation Model

Human Reproduction ◽

10.1093/humrep/deab130.780 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

N Díaz ◽

J Llácer ◽

E Álvarez ◽

E Serrano ◽

J Ortiz ◽

...

Keyword(s):

Sample Size ◽

Embryo Transfer ◽

Gestational Age ◽

Endometrial Thickness ◽

Large For Gestational Age ◽

Freezing Process ◽

Fresh Embryo Transfer ◽

Term Birth ◽

Quasi Experimental ◽

Frozen Embryo Transfers

Abstract Study question Is the freezing process responsible to increase the birthweight or the incidence of Large for Gestational Age (LGA) in Frozen Embryo Transfers (FET)? Summary answer Neither the birthweight nor the LGA incidence were different in embryos that underwent the freezing-thawing process. What is known already Freezing-thawing constitutes one of the processes with a potential impact on the health of the newborn. Data coming from register-based studies and metaanalisis have found an increase in birthweight with a higher incidence of LGA in newborns coming from FET. This is a matter of concern since epigenetic alterations have been suggested to explain this finding casting doubts on future health during childhood and adulthood. Clarifying the safety of cryotechniques should be a priority taken into account that at present frozen embryo transfers outnumber fresh embryo transfers in IVF clinics. Study design, size, duration This retrospective cohort study evaluated 670 women oocyte recipients who underwent fresh (367 cycles) or frozen embryo transfer (303 cycles) at Instituto Bernabeu between July 2017 and March 2019. All recipients were prepared with substitutive cycle and received single blastocyst embryo transfers on day five. All of them at the same culture medium, resulting in a singleton live birth. Participants/materials, setting, methods 1637 patients were assessed for eligibility but 967 were excluded. The sample size has been calculated accepting an alpha risk of 5% and a beta risk of 20%. A sample size of 266 patients (133 per group) is required to detect a minimum mean difference of 275 grams with a standard deviation of 800 grams. Pearsońs Chi-square test (univariate) and binary logistic regression (multivariate for confounding factors) were used to analyze association between variables. Main results and the role of chance Maternal age (42.21 ± 4.45; 42.79 ± 3.83 p = 0.519), BMI (23.34 ± 3.69; 24.99 ± 15.52; p = 0.060), maternal parity (Nulliparous 81.5%; 85.5%; Multiparous 18.5%; 14.5% p = 0.177), gestational diabetes (4.9%; 4.3% p = 0.854), preeclampsia (2.7%; 5.6% p = 0.074), hypertensive disorders (3.3%; 2.3% p = 0.494), maternal smoking (10.8%; 13.0% p = 0.475), gestational age (38.96 ± 1.97; 38.77 ± 2.15; p = 0.207) and liveborn gender (Female 44.5%; 48.8%; Male 55.5%; 51.2%p=0.276) do not present statistically significant differences between fresh or frozen groups, respectively. However endometrial thickness was statistically signiticantly different in both groups (8.83mm ± 1.73 fresh; 8.57mm ± 1.59 frozen p = 0.035) The mean birthweight did not present statistically significant differences (3239.21 ± 550.43 fresh; 3224.56 ± 570.83 frozen p = 0.211). There were also no differences regarding macrosomy (7.1% fresh; 6.3% frozen p = 0.317), LGA (6.0% fresh; 6.7% frozen p = 0.866), pre-term birth (10.9% fresh; 9.0% frozen p = 0.988), very pre-term birth (0.8% fresh; 1.3% frozen p = 0.999), and extremely pre-term birth (0% fresh; 1.0% frozen p = 0.998). There were statistically significant differences regarding underweight (10.0% fresh; 7.0% frozen p = 0.020), but there were no differences in very low weight (0.6 fresh; 1.1% frozen p = 0.972) and SGA (1.9% fresh; 0.7% frozen p = 0.432). Limitations, reasons for caution Despite a quasi-experimental design, the synchronization in fresh embryo transfer drove to a longer preparation with a thicker endometrium. It’s not possible to rule-out the influence in the results of this parameter. Wider implications of the findings: As a hypothesis, the increase in birthweight and/or an abnormal placentation in FET could be explained by the endometrial preparation more than the freezing process. Studies must be planned in the future to explore the possibility of changes in the birthweight between embryos transferred in natural vs artificial endometrial preparations. Trial registration number Not applicable

Download Full-text