Periconceptional maternal body mass index and the impact on post-implantation (sex-specific) embryonic growth and morphological development

Objective: Women with obesity have an increased risk of pregnancy complications. Although complications generally present in the second and third trimester of pregnancy, most of them develop in the periconception period. Moreover, fetal sex also impacts pregnancy course and outcome. Therefore, our aim is to study (sex-specific) associations between periconceptional maternal body mass index (BMI) and embryonic growth and morphological development. Methods: A total of 884 women with singleton pregnancies were selected from the Rotterdam Periconception Cohort, comprising 15 women with underweight, 483 with normal weight, 231 with overweight and 155 with obesity. Longitudinal three-dimensional ultrasound examinations were performed at 7, 9, and 11 weeks of gestation for offline measurements of crown-rump length (CRL), embryonic volume (EV), and Carnegie stages. Analyses were adjusted for maternal age, parity, ethnicity, education, and periconceptional lifestyle. Results: A negative trend was observed for embryos of women with obesity (βEV −0.03, p = 0.086), whereas embryonic growth and developmental trajectories in women with overweight were comparable to those with normal weight. Maternal underweight was associated with faster morphological development (βCarnegie 0.78, p = 0.004). After stratification for fetal sex, it was demonstrated that female embryos of underweight women grow and morphologically develop faster than those of normal weight women (βEV 0.13, p = 0.008; βCarnegie 1.39, p < 0.001), whereas female embryos of women with obesity grow slower (βEV −0.05, p = 0.027). Conclusion: We found that periconceptional maternal underweight is associated with faster embryonic growth, especially in females. In contrast, female embryos of women with obesity grow slower than female embryos of women with normal weight. This may be the result of altered female adaptation to the postnatal environment. Future research should focus on strategies for optimizing preconceptional maternal weight, to reduce BMI-related pregnancy complications and improve the health of future generations

The impact of IVF culture medium on post-implantation embryonic growth and development with emphasis on sex specificity: the Rotterdam Periconceptional Cohort

Research question: Are there (sex-specific) differences in first-trimester embryonic growth and morphological development between two culture media used for IVF and intracytoplasmic sperm injection (ICSI) treatment? Design: A total of 835 singleton pregnancies from a prospective hospital-based cohort study were included, of which 153 conceived after IVF/ICSI treatment with Vitrolife G-1™ PLUS culture medium, 252 after culture in SAGE 1-Step™ and 430 were naturally conceived. Longitudinal three-dimensional ultrasound examinations were performed at 7, 9 and 11 weeks of gestation for offline biometric (crown rump length, CRL), volumetric (embryonic volume) and morphological (Carnegie stage) measurements. Results: Embryos cultured in SAGE 1-Step grew faster than those cultured in Vitrolife G-1 PLUS (betaEV 0.030 3√ml [95% CI 0.008–0.052], P = 0.007). After stratification for fetal sex, male embryos cultured in SAGE 1-Step demonstrated faster growth than those cultured in Vitrolife G-1 PLUS (betaEV 0.048 3√ml [95% CI 0.015–0.081], P = 0.005). When compared with naturally conceived embryos, those cultured in SAGE 1-Step grew faster (betaEV 0.040 3√ml [95% CI 0.012–0.069], P = 0.005). This association was most pronounced in male embryos (betaEV 0.078 3√ml [95% CI 0.035–0.120], P < 0.001). Conclusions: This study shows that SAGE 1-Step culture medium accelerates embryonic growth trajectories compared with Vitrolife G-1 PLUS and naturally conceived pregnancies, especially in male embryos. Further research should focus on the impact of culture media on postnatal development and the susceptibility to non-communicable diseases

A higher preconceptional paternal body mass index influences fertilization rate and preimplantation embryo development

Background: Obesity is a worldwide problem affecting the health of millions of people throughout the life course. Studies reveal that obesity impairs sperm parameters and epigenetics, potentially influencing embryonic development. Objective: To investigate the association between preconceptional paternal body mass index (BMI) and embryo morphokinetics using a time-lapse incubator and in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) outcomes. Materials and methods: Participants were recruited from a tertiary hospital in this prospective periconceptional cohort study. A total of 211 men were included: 86 with normal weight (BMI < 25.0), 94 overweight (BMI 25–29.9), and 41 obese (BMI ≥ 30). These men were part of a couple that underwent IVF/ICSI treatment with ejaculated sperm after which 757 embryos were cultured in a time-lapse incubator. The main outcome parameters consisted of fertilization rate, embryo developmental morphokinetics, embryo quality assessed by a time-lapse prediction algorithm (KIDScore), and live birth rate. Results: A higher paternal BMI was associated with faster development of the preimplantation embryo, especially during the first cleavage divisions (t2: −0.11 h (p = 0.05) and t3: −0.19 h (p = 0.01)). Embryo quality using the KIDScore was not altered. The linear regression analysis, after adjustment for confounders (paternal age, ethnicity, smoking, alcohol use, education, total motile sperm count, and maternal age and BMI), showed an inverse association between paternal BMI and fertilization rate (effect estimate: −0.01 (p = 0.002)), but not with the live birth rate. Discussion and conclusion: Our data demonstrate that a higher preconceptional paternal BMI is associated with a reduced fertilization rate in IVF/ICSI treatment. Our findings underline the importance of a healthy paternal weight during the preconception period

Using the embryo-uterus statistical model to predict pregnancy chances by using cleavage stage morphokinetics and female age: two centre-specific prediction models and mutual validation

BACKGROUND: The predictive capability of time-lapse monitoring (TLM) selection algorithms is influenced by patient characteristics, type and quality of data included in the analysis and the used statistical methods. Previous studies excluded DET cycles of which only one embryo implanted, introducing bias into the data. Therefore, we wanted to develop a TLM prediction model that is able to predict pregnancy chances after both single- and double embryo transfer (SET and DET). METHODS: This is a retrospective study of couples (n = 1770) undergoing an in vitro fertilization cycle at the Erasmus MC, University Medical Centre Rotterdam (clinic A) or the Reinier de Graaf Hospital (clinic B). This resulted in 2058 transferred embryos with time-lapse and pregnancy outcome information. For each dataset a prediction model was established by using the Embryo-Uterus statistical model with the number of gestational sacs as the outcome variable. This process was followed by cross-validation. RESULTS: Prediction model A (based on data of clinic A) included female age, t3-t2 and t5-t4, and model B (clinic B) included female age, t2, t3-t2 and t5-t4. Internal validation showed overfitting of model A (calibration slope 0.765 and area under the curve (AUC) 0.60), and minor overfitting of model B (slope 0.915 and AUC 0.65). External validation showed that model A was capable of predicting pregnancy in the dataset of clinic B with an AUC of 0.65 (95% CI: 0.61-0.69; slope 1.223, 95% CI: 0.903-1.561). Model B was less accurate in predicting pregnancy in the dataset of clinic A (AUC 0.60, 95% CI: 0.56-0.65; slope 0.671, 95% CI: 0.422-0.939). CONCLUSION: Our study demonstrates a novel approach to the development of a TLM prediction model by applying the EU statistical model. With further development and validation in clinical practice, our prediction model approach can aid in embryo selection and decision making for SET or DET

Prenatal growth trajectories and birth outcomes after frozen–thawed extended culture embryo transfer and fresh embryo transfer: the Rotterdam Periconception Cohort

Research question: Are there differences in prenatal growth trajectories and birth outcomes between singleton pregnancies conceived after IVF treatment with frozen–thawed extended culture embryo transfer at day 5, fresh embryo transfer at day 3 or naturally conceived pregnancies? Design: From a prospective hospital-based cohort, 859 singleton pregnancies were selected, including 133 conceived after IVF with frozen–thawed embryo transfer, 276 after fresh embryo transfer, and 450 naturally conceived pregnancies. Longitudinal 3D ultrasound scans were performed at 7, 9 and 11 weeks of gestation for offline crown–rump length (CRL) and embryonic volume measurements. Second trimester estimated fetal weight was based on growth parameters obtained during the routine fetal anomaly scan at 20 weeks of gestation. Birth outcome data were collected from medical records. Results: No differences regarding embryonic growth trajectories were observed between frozen–thawed and fresh embryo transfer. Birthweight percentiles after fresh embryo transfer were lower than after frozen–thawed embryo transfer (38.0 versus 48.0; P = 0.046, respectively). The prevalence of non-iatrogenic preterm birth (PTB) was significantly lower in pregnancies resulting from fresh embryo transfer compared with frozen–thawed embryo transfer (4.7% versus 10.9%; P = 0.026, respectively). Compared with naturally conceived pregnancies, birthweight percentiles and percentage of non-iatrogenic PTB were significantly lower in pregnancies after fresh embryo transfer and gestational age at birth was significantly higher. Conclusions: This study shows that embryonic growth is comparable between singleton pregnancies conceived after fresh and frozen–thawed embryo transfer. The lower relative birthweight and PTB rate in pregnancies after fresh embryo transfer than after frozen–thawed embryo transfer and naturally conceived pregnancies warrants further investigation

Higher preconceptional maternal body mass index is associated with faster early preimplantation embryonic development

Background: Overweight and obesity affect millions of people globally, which has also serious implications for reproduction. For example, treatment outcomes after in vitro fertilisation (IVF) are worse in women with a high body mass index (BMI). However, th

The influence of frozen-thawed and fresh embryo transfer on utero-placental (vascular) development

STUDY QUESTION: Does frozen-thawed or fresh embryo transfer (ET) influence utero-placental (vascular) development, when studied using three-dimensional (3D) ultrasound and virtual reality imaging techniques?  SUMMARY ANSWER: In the first trimester, placental developmental parameters, that is, placental volume (PV) and utero-placental vascular volume (uPVV), were comparable between pregnancies resulting from frozen-thawe

The Impact of Culture Medium on Morphokinetics of Cleavage Stage Embryos : An Observational Study

To study the impact of culture media on preimplantation morphokinetics used for predicting clinical outcomes. All IVF and ICSI cycles performed between 2012 and 2017 with time-lapse information available were included. In November 2014, culture medium was changed from Vitrolife G-1 PLUS to SAGE 1-Step. Each embryo was retrospectively assigned a morphokinetic-based KIDScore for prediction of implantation. Clinical outcomes were retrieved from medical records. Linear mixed models were used to study differences in morphokinetic parameters, a proportional odds model for KIDScore ranking and logistic regression for differences in clinical outcomes. All analyses were adjusted for patient and treatment characteristics. In 253 (63.1%) cycles, embryos (n = 671) were cultured in Vitrolife, and in 148 (36.9%) cycles, embryos (n = 517) were cultured in SAGE. All cleavage divisions occurred earlier for SAGE embryos than for Vitrolife embryos (2-cell: -2.28 (95%CI: -3.66, -0.89), 3-cell: -2.34 (95%CI: -4.00, -0.64), 4-cell: -2.41 (95%CI: -4.11, -0.71), 5-cell: -2.54 (95%CI: -4.90, -0.18), 6-cell: -3.58 (95%CI: -6.08, -1.08), 7-cell: -5.62 (95%CI: -8.80, -2.45) and 8-cell: -5.32 (95%CI: -9.21, -1.42) hours, respectively). Significantly more embryos cultured in SAGE classified for the highest KIDScore compared to embryos cultured in Vitrolife (p < 0.001). No differences were observed in clinical outcomes. Our results demonstrate an impact of culture medium on preimplantation embryo developmental kinetics, which affects classification within the KIDScore algorithm, while pregnancy outcomes were comparable between the groups. This study underscores the need to include the type of culture medium in the development of morphokinetic-based embryo selection tools