Vanquishing multiple pregnancy in in vitro fertilization in the United States-a 25-year endeavor

Mitigating multiples, less is more: examining trends in multifetal gestation rates with assisted reproductive technology

PURPOSE

Multifetal gestation (MFG) is much more common in pregnancies that utilize assisted reproductive technologies (ART). We assessed how these rates have changed over the previous decade and the impact on live birth rates (LBR).

METHODS

This retrospective cohort study uses the National Summary Reports of the Society for Assisted Reproductive Technology (SART) from 2014 to 2020. Data points included only autologous cycles. The data were divided into five age groups as reported in the database: < 35, 35-37, 38-40, 41-42, and > 42 years old. Descriptive statistics and a two-tailed T-test were used to determine the trends and statistical significance (p < 0.05).

RESULTS

Rates of twin births decreased substantially from 2014 to 2020 for autologous embryo transfers across all age groups and diagnoses. Surprisingly, the overall LBR for autologous IVF cycles decreased at similar rates from 2014 to 2020 in all age groups. The mean number of embryos transferred has dramatically reduced, especially across age groups < 42.

CONCLUSION

Rates of twin and higher-level gestations have decreased substantially over the past decade; the effect correlates with the increased utilization of eSET and PGT. The cause of infertility did not significantly impact the rate of MFG.

In Vitro Fertilization and Adverse Pregnancy Outcomes in the Elective Single Embryo Transfer Era

OBJECTIVE

Our objective was to estimate the association between in vitro fertilization (IVF) pregnancy and adverse pregnancy outcomes during delivery hospital admission in a contemporary, nation-wide cohort of births in the United States.

STUDY DESIGN

This retrospective, population-based cohort study used the National Inpatient Sample database to identify patients discharged from the hospital following delivery from 2014 to 2019. IVF pregnancies were identified using the International Classification of Disease-Revision 9/10 codes. Crude and adjusted odds ratios of preterm birth and other clinically significant adverse pregnancy outcomes were evaluated using multivariable logistic regression models. Trends in preterm birth and multiple pregnancy were estimated over the study period. The contribution of multiple pregnancy to preterm birth in IVF pregnancy was estimated in a mediation analysis.

RESULTS

Among 4,451,667 delivery-related discharges, IVF pregnancies were associated with 3.25 times the odds of preterm birth (95% confidence interval [CI]: 3.05-3.46, p < 0.001) compared with non-IVF pregnancy deliveries. Odds of preterm birth in IVF pregnancy delivery discharges decreased over the study period (p-value for linear trend = 0.009). The proportion of multiple pregnancies decreased in IVF pregnancy delivery discharges but remained stable in non-IVF pregnancy deliveries. The proportion of the adjusted effect of IVF pregnancy on preterm birth mediated through multiple pregnancy was 67.6% (95% CI: 62.6-72.7%).

CONCLUSION

While the odds of adverse pregnancy outcomes are increased compared with non-IVF pregnancies, the odds of preterm birth and multiple gestation have decreased among IVF pregnancies in the United States.

KEY POINTS

· Pregnancies conceived by in vitro fertilization (IVF) are at significantly higher risk of multiple gestation, preterm birth, and other pregnancy complications.. · Recent guidelines for artificial reproductive treatments recommend single-embryo transfer in IVF.. · Using population-wide data, we demonstrate a significant gradual decline in the rates of preterm birth and other pregnancy complications following IVF in the last decade, mostly mediated by a reduction in multiple pregnancies..

Iatrogenic and demographic determinants of the national plural birth increase

OBJECTIVE

To study the contribution of ovulation induction and ovarian stimulation, in vitro fertilization (IVF), and unassisted conception to the increase in national plural births in the United States, a significant contributor to adverse maternal and infant health outcomes.

DESIGN

National and IVF-assisted plural birth data were derived from the Centers for Disease Control and Prevention's National Vital Statistics System (1967-2021, after introduction of Clomiphene Citrate in the United States) and the National Assisted Reproductive Technology Surveillance System (1997-2021), respectively.

SETTING

Not applicable.

PATIENT(S)

Not applicable.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

In addition to IVF-assisted plural births, the contributions of unassisted conception to plural births among women aged <35 and ≥35 years were estimated using plural birth rates from 1949-1966 and a Bayesian logistic model with race and age as independent variables. The contribution of ovulation induction and ovarian stimulation was estimated as the difference between national plural births and IVF-assisted and unassisted counterparts.

RESULT(S)

From 1967-2021, the national twin birth rate increased 1.7-fold to a 2014 high (33.9/1,000 live births), then declined to 31.2/1,000 live births; the triplet and higher order birth rate increased 6.7-fold to a 1998 high (1.9/1,000 live births), then declined to 0.8/1,000 live births. In 2021, the contribution of unassisted conception among women aged <35 years to the national plural births was 56.1%, followed by ovulation induction and ovarian stimulation (19.5%), unassisted conception among women aged ≥35 years (16.8%), and IVF (7.6%). During 2009-2021, the contribution of ovulation induction and ovarian stimulation has remained stable, the contribution of unassisted conception among women aged <35 and ≥35 years has increased, and the contribution of IVF has decreased.

CONCLUSION(S)

Ovulation induction and ovarian stimulation are leading iatrogenic contributors to plural births. They are, therefore, targets for intervention to reduce the adverse maternal and infant health outcomes associated with plural births. Maternal age of ≥35 years is a significant contributor to the national plural birth increase.

Long-term health risk of offspring born from assisted reproductive technologies

Since the world's first in vitro fertilization baby was born in 1978, there have been more than 8 million children conceived through assisted reproductive technologies (ART) worldwide, and a significant proportion of them have reached puberty or young adulthood. Many studies have found that ART increases the risk of adverse perinatal outcomes, including preterm birth, low birth weight, small size for gestational age, perinatal mortality, and congenital anomalies. However, data regarding the long-term outcomes of ART offspring are limited. According to the developmental origins of health and disease theory, adverse environments during early life stages may induce adaptive changes and subsequently result in an increased risk of diseases in later life. Increasing evidence also suggests that ART offspring are predisposed to an increased risk of non-communicable diseases, such as malignancies, asthma, obesity, metabolic syndrome, diabetes, cardiovascular diseases, and neurodevelopmental and psychiatric disorders. In this review, we summarize the risks for long-term health in ART offspring, discuss the underlying mechanisms, including underlying parental infertility, epigenetic alterations, non-physiological hormone levels, and placental dysfunction, and propose potential strategies to optimize the management of ART and health care of parents and children to eliminate the associated risks. Further ongoing follow-up and research are warranted to determine the effects of ART on the long-term health of ART offspring in later life.

The role of acupuncture in women with advanced reproductive age undergoing in vitro fertilization-embryo transfer: A randomized controlled trial and follicular fluid metabolomics study

BACKGROUND

The objective of this study was to determine the efficacy of acupuncture on the outcome of in vitro fertilization (IVF) in elderly infertile patients with kidney qi deficiency, and to explore its possible mechanism from the perspective of pseudo-targeted metabolomics of follicular fluid.

METHODS

Sixty cases of elderly women undergoing IVF were sampled and randomly divided into 2 equal groups: the treatment and the elderly control (HA) group. In the treatment group, routine ovulation induction combined with acupuncture treatment was used. Routine ovulation induction combined with sham acupuncture was used in the HA group. Reproductive outcomes of the 2 groups were compared. The follicular fluid of patients obtained on the day of oocyte retrieval was analyzed by the ultra-high-performance liquid chromatography-mass spectrometry analysis system.

RESULTS

Compared with the HA group, the score of kidney qi deficiency syndrome in the treatment group was significantly decreased, and the 2 PN fertilization rate, high-quality embryo rate and cumulative pregnancy rate were significantly increased (P < .05). Through the identification of target metabolites, 3 metabolic pathways were found to be closely related to the developmental potential of oocytes, namely: Retinol metabolism pathway; Glycine, serine, and threonine metabolism pathway; Glycerophospholipid metabolism pathway.

CONCLUSION

From our findings, acupuncture can improve the quality of oocytes thus bettering the outcome of IVF-assisted pregnancy in elderly patients with kidney qi deficiency.

TRIAL REGISTRATION

ChiCTR1800018329.

Assisted reproductive technology: what are the cardiovascular risks for women?

INTRODUCTION

Infertility affects 15% of women of reproductive age in the United States. The use of assisted reproductive technology (ART) has been rising globally, as well as a growing recognition of reproductive factors that increase risk for cardiovascular disease (CVD).

AREAS COVERED

Women with infertility who use ART are more likely to have established CVD risk factors, such as obesity, dyslipidemia, hypertension, and diabetes. They are also more likely to experience adverse pregnancy outcomes, which are associated with both peripartum and long-term cardiovascular complications. ART may lead to increased cardiometabolic demands due to ovarian stimulation, pregnancy itself, and higher rates of multifetal gestation. Preeclampsia risk appears greater with frozen rather than fresh embryo transfers.

EXPERT OPINION

The use of ART and its association with long term CVD has not been well-studied. Future prospective and mechanistic studies investigating the association of ART and CVD risk may help determine causality. Nevertheless, CVD risk screening is critical pre-pregnancy and during pregnancy to reduce pregnancy complications that elevate future CVD risk. This also offers a window of opportunity to connect patients to longitudinal care for early management of cardiometabolic risk profile and initiation of preventive lifestyle and pharmacotherapy interventions tailored toward patient-specific risk factors.

Long-term cardiometabolic health in people born after assisted reproductive technology: a multi-cohort analysis

AIMS

To examine associations of assisted reproductive technology (ART) conception (vs. natural conception: NC) with offspring cardiometabolic health outcomes and whether these differ with age.

METHODS AND RESULTS

Differences in systolic (SBP) and diastolic blood pressure (DBP), heart rate (HR), lipids, and hyperglycaemic/insulin resistance markers were examined using multiple linear regression models in 14 population-based birth cohorts in Europe, Australia, and Singapore, and results were combined using meta-analysis. Change in cardiometabolic outcomes from 2 to 26 years was examined using trajectory modelling of four cohorts with repeated measures. 35 938 (654 ART) offspring were included in the meta-analysis. Mean age ranged from 13 months to 27.4 years but was <10 years in 11/14 cohorts. Meta-analysis found no statistical difference (ART minus NC) in SBP (-0.53 mmHg; 95% CI:-1.59 to 0.53), DBP (-0.24 mmHg; -0.83 to 0.35), or HR (0.02 beat/min; -0.91 to 0.94). Total cholesterol (2.59%; 0.10-5.07), HDL cholesterol (4.16%; 2.52-5.81), LDL cholesterol (4.95%; 0.47-9.43) were statistically significantly higher in ART-conceived vs. NC offspring. No statistical difference was seen for triglycerides (TG), glucose, insulin, and glycated haemoglobin. Long-term follow-up of 17 244 (244 ART) births identified statistically significant associations between ART and lower predicted SBP/DBP in childhood, and subtle trajectories to higher SBP and TG in young adulthood; however, most differences were not statistically significant.

CONCLUSION

These findings of small and statistically non-significant differences in offspring cardiometabolic outcomes should reassure people receiving ART. Longer-term follow-up is warranted to investigate changes over adulthood in the risks of hypertension, dyslipidaemia, and preclinical and clinical cardiovascular disease.

Ultralow Oxygen Tension (2%) Is Beneficial for Blastocyst Formation of In Vitro Human Low-Quality Embryo Culture

Objectives

To investigate whether a reduction in the O₂ tension from 5 to 2% during extended culture from day 3 onwards was beneficial to human blastocyst development in vitro.

Methods

We firstly identified 139 patients who had no low-quality embryos on day 3, and all the embryos were prolonged to culture on day 5 or 6. We mainly analyzed 188 patients receiving IVF/ICSI-ET for the first time, and no high-quality embryos were obtained on day 3 from January 2018 to December 2019. After transferred with one or two low-quality embryos, extended culture was performed under low O₂ (5%) or ultralow O₂ (2%) tension for surplus embryos. 296 embryos from 106 patients were continued to culture under 5% O₂ tension, and 214 embryos from 82 patients were continued to culture under 2% O₂ tension. Main outcomes compared were blastulation and high-quality blastulation rates.

Results

We observed no significant differences in the blastulation and high-quality blastulation rates for high-quality cleavage-stage embryos between 2% and 5% O₂ groups (p > 0.05). For low-quality cleavage-stage embryos, we observed that the 2% O₂ group showed a significantly higher blastulation (39.72 versus 31.08%; p = 0.043) rate than that in the 5% O₂ group. The high-quality blastocyst formation rate (10.75 versus 8.45%; p = 0.380) was comparable between the 2% and 5% O₂ groups. The blastulation rate reached 44.86% by culturing blastocysts an additional day under 2% O₂ tension which was significantly higher than that (32.09%) under 5% O₂ tension (p < 0.05).

Conclusion

A reduction in O₂ tension from 5 to 2% after day 3 might be beneficial to the patients with no high-quality embryos. Extended culture to day 7 under 2% O₂ tension increased the number of available blastocysts per IVF/ICSI cycle and was worth recommending especially for patients with few blastocysts.