Is the wrong question being asked in infertility research?

Cleavage-stage or blastocyst-stage embryo biopsy has no impact on growth and health in children up to 2 years of age

BACKGROUND

Studies show conflicting results on neonatal outcomes following embryo biopsy for PGT, primarily due to small sample sizes and/or heterogeneity in the timing of embryo biopsy (day 3; EBD3 or day 5/6; EBD5) and type of embryo transfer. Even fewer data exist on the impact on children's health beyond the neonatal period. This study aimed to explore outcomes in children born after EBD3 or EBD5 followed by fresh (FRESH) or frozen-thawed embryo transfer (FET).

METHODS

This single-centre cohort study compared birth data of 630 children after EBD3, of 222 EBD5 and of 1532 after non-biopsied embryo transfers performed between 2014 and 2018. Follow-up data on growth were available for 426, 131 and 662 children, respectively.

RESULTS

Embryo biopsy, either at EBD3 or EBD5 in FET and FRESH cycles did not negatively affect anthropometry at birth, infancy or childhood compared to outcomes in non-biopsied FET and FRESH cycles. While there was no adverse effect of the timing of embryo biopsy (EBD3 versus EBD5), children born after EBD3 followed by FET had larger sizes at birth, but not thereafter, than children born after EBD3 followed by FRESH. Reassuringly, weight and height gain, proportions of major congenital malformations, developmental problems, hospital admissions and surgical interventions were similar between comparison groups.

CONCLUSION

Our study indicated that neither EBD3 nor EBD5 followed by FRESH or FET had a negative impact on anthropometry and on health outcomes up to 2 years of age.

Reproduction as a window to future health in women

Cultivating awareness for reproduction as a window to future health presents an opportunity for early identification and modification of risk factors that can affect both individual and population-level morbidity and mortality. Infertility could serve as both a window into future health as well as a pathway to future pathology. The underlying mechanisms of infertility may share common pathways with long-term risk for health and well-being. Making this identification early in the disease process may improve opportunities for intervention, and deepen our understanding of long-term risk. Additionally, fertility treatments may increase individual risk. Only by making these associations and designing studies to understand how disease and treatment risk impact health can we truly fulfill our goal of building healthy families. The aim of this review is to discuss the short-term impact of fertility challenges and treatment, long-term associations of infertility with morbidity and mortality, and the role of parity in modifying these risk associations.

Assisted Reproductive Technology or Infertility: What underlies adverse outcomes? Lessons from the Massachusetts Outcome Study of Assisted Reproductive Technology

Numerous studies have demonstrated that assisted reproductive technology (ART: defined here as including only in vitro fertilization and related technologies) is associated with increased adverse pregnancy, neonatal, and childhood developmental outcomes, even in singletons. The comparison group for many had often been a fertile population that conceived without assistance. The Massachusetts Outcome Study of Assisted Reproductive Technology (MOSART) was initiated to define a subfertile population with which to compare ART outcomes. Over more than 10 years, we have used the MOSART database to study pregnancy abnormalities and delivery complications but also to evaluate ongoing health of women, infants, and children. This article will review studies from MOSART in the context of how they compare with those of other investigations. We will present MOSART studies that identified the influence of ART and subfertility/infertility on adverse pregnancy (pregnancy hypertensive disorder, gestational diabetes, placental abnormality) and delivery (preterm birth, low birthweight) outcomes as well as on maternal and child hospitalizations. We will provide evidence that although subfertility/infertility increases the risk of adverse outcomes, there is additional risk associated with the use of ART. Studies exploring the contribution of placental abnormalities as one factor adding to this increased ART-associated risk will be described.

Pregnancy outcomes among women with endometriosis and fibroids: registry linkage study in Massachusetts

BACKGROUND

Endometriosis and uterine fibroids are common gynecologic conditions associated with a greater risk for infertility. Previous research has suggested that these conditions are associated with adverse pregnancy outcomes, potentially because of increased utilization of fertility treatments.

OBJECTIVE

Our objective was to investigate whether women with a history of endometriosis or fibroids had a greater risk for adverse pregnancy outcomes and whether this risk varied by infertility history and fertility treatment utilization.

STUDY DESIGN

Deliveries (2013-2017) recorded in Massachusetts' vital records were linked to assisted reproductive technology data, hospital stays, and all-payer claims database. We identified endometriosis and fibroids diagnoses via the all-payer claims database before index delivery. Adjusted relative risks for pregnancy complications were modeled using generalized estimating equations with a log link and Poisson distribution. The influence of subfertility or infertility and assisted reproductive technology was also investigated.

RESULTS

Among 91,825 deliveries, 1560 women had endometriosis and 4212 had fibroids. Approximately 30% of women with endometriosis and 26% of women with fibroids experienced subfertility or infertility without utilizing assisted reproductive technology, and 34% of women with endometriosis and 21% of women with fibroids utilized assisted reproductive technology for the index delivery. Women with a history of endometriosis or fibroids were at a greater risk for pregnancy-induced hypertension, preeclampsia, or eclampsia (endometriosis relative risk, 1.17; fibroids relative risk, 1.08), placental abnormalities (endometriosis relative risk, 1.65; fibroids relative risk, 1.38), and cesarean delivery (endometriosis relative risk, 1.22; fibroids relative risk, 1.17) than women with no history of those conditions. Neonates born to women with a history of endometriosis or fibroids were also at a greater risk for preterm birth (endometriosis relative risk, 1.24; fibroids relative risk, 1.17). Associations between fibroids and low birthweight varied by fertility status or assisted reproductive technology (P homogeneity=.01) and were stronger among noninfertile women.

CONCLUSION

Endometriosis or fibroids increased the risk for adverse pregnancy outcomes, possibly warranting differential screening or treatment.

Fertility treatments and the risk of preterm birth among women with subfertility: a linked-data retrospective cohort study

Background

In vitro fertilization (IVF) births contribute to a considerable proportion of preterm birth (PTB) each year. However, there is no formal surveillance of adverse perinatal outcomes for less invasive fertility treatments. The study objective was to describe associations between fertility treatment (in vitro fertilization, intrauterine insemination, usually with ovulation drugs (IUI), or ovulation drugs alone) and preterm birth, compared to no treatment in subfertile women.

Methods

The Fertility Experiences Study (FES) is a retrospective cohort study conducted at the University of Utah between April 2010 and September 2012. Women with a history of primary subfertility self-reported treatment data via survey and interviews. Participant data were linked to birth certificates and fetal death records to asses for perinatal outcomes, particularly preterm birth.

Results

A total 487 birth certificates and 3 fetal death records were linked as first births for study participants who completed questionnaires. Among linked births, 19% had a PTB. After adjustment for maternal age, paternal age, maternal education, annual income, religious affiliation, female or male fertility diagnosis, and duration of subfertility, the odds ratios and 95% confidence intervals (CI) for PTB were 2.17 (CI 0.99, 4.75) for births conceived using ovulation drugs, 3.17 (CI 1.4, 7.19) for neonates conceived using IUI and 4.24 (CI 2.05, 8.77) for neonates conceived by IVF, compared to women with subfertility who used no treatment during the month of conception. A reported diagnosis of female factor infertility increased the adjusted odds of having a PTB 2.99 (CI 1.5, 5.97). Duration of pregnancy attempt was not independently associated with PTB. In restricting analyses to singleton gestation, odds ratios were not significant for any type of treatment.

Conclusion

IVF, IUI, and ovulation drugs were all associated with a higher incidence of preterm birth and low birth weight, predominantly related to multiple gestation births.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12978-022-01363-4.

Infertility treatments such as in vitro fertilization are associated with preterm birth, but less is known about how other less invasive treatments contribute to preterm birth. This study compares different types of fertility treatments and rates of preterm birth with women who are also struggling with infertility but did not use fertility treatments at the time of their pregnancy. 490 women were recruited at the University of Utah between 2010 and 2012. Participants were asked to complete a survey and were linked to birth certificate and fetal death certificate data. Women who used in vitro fertilization were 4.24 times more likely to have a preterm birth than those who used no treatment. Use of intrauterine insemination were 3.17 times more likely to have a preterm birth than those who used no treatment at time of conception. Ovulation stimulating drugs were 2.17 times more likely to have a preterm birth. Having female factor infertility was also associated with higher odds of having preterm birth. For those who are having trouble conceiving, trying less invasive treatments to achieve pregnancy might reduce their risk of preterm birth.

Hospitalizations up to 8 years following delivery in assisted reproductive technology-treated and subfertile women

OBJECTIVE

To investigate hospitalizations up to 8 years after live birth among women who used assisted reproductive technology (ART) or who were subfertile compared with women who conceived naturally.

DESIGN

Retrospective cohort.

SETTING

Deliveries among privately insured women aged ≥18 years between 2004 and 2017 from Massachusetts state vital records were linked to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System and hospital observational/inpatient stays.

PATIENT(S)

We compared patients with ART, medically assisted reproduction (MAR), and unassisted subfertile (USF) delivery with those with fertile delivery.

INTERVENTION(S)

NA.

MAIN OUTCOME MEASURE(S)

Postdelivery hospitalization information was derived from the International Classification of Diseases codes for discharges and combined by type. The relative risks and 95% confidence intervals (CIs) of hospitalization for up to the first 8 years postdelivery were modeled.

RESULT(S)

Among 492,515 deliveries, 5.6% used ART, 1.6% used MAR, and 1.8% were USF. Compared with fertile deliveries, deliveries that used ART or MAR or were USF were more likely to have hospital utilization (inpatient or observational stay) for any reason for up to 8 years of follow-up (USF, adjusted relative risk [aRR], 1.18 [95% CI, 1.12-1.25]; MAR, aRR, 1.20 [1.13-1.27]; and ART, aRR, 1.29 [1.25-1.34]). Assisted reproductive technology deliveries had an increased risk of hospitalization for conditions of the cardiovascular system (aRR, 1.31 [95% CI, 1.20-1.41]), overweight/obesity (aRR, 1.30 [1.17-1.44]), diabetes (aRR, 1.25 [1.05-1.49]), reproductive tract (aRR, 1.62 [1.47-1.79]), digestive tract (aRR, 1.39 [1.30-1.49]), thyroid (aRR, 2.02 [1.80-2.26]), respiratory system (aRR, 1.13 [1.03-1.24]), and cancer (aRR, 1.40 [1.18-1.65]) up to 8 years after delivery. Deliveries with MAR and subfertility had similar patterns of hospitalization as ART deliveries.

CONCLUSION(S)

Women who conceived through fertility treatment or experienced subfertility were at increased risk of subsequent hospitalization resulting from a variety of chronic and acute conditions.

Placental pathology of term singleton live births conceived with fresh embryo transfer compared with those conceived without assisted reproductive technology

OBJECTIVE

To compare placental pathology from term singleton live births conceived with fresh embryo transfer vs. those conceived without assisted reproductive technology (ART).

DESIGN

Retrospective cohort study.

SETTING

Academic fertility center.

PATIENT(S)

Women with a term singleton live birth who conceived after fresh autologous in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) cycles (ART group) and those who conceived without ART.

INTERVENTION(S)

An experienced placental pathologist categorized placental pathology as anatomic, inflammatory, or vascular. Patient characteristics were compared by chi-squared tests, Student's t-test, or nonparametric tests. Multivariate logistic regression models were used to compare placental pathology between pregnancies conceived with and without ART.

MAIN OUTCOME MEASURE(S)

Incidence of anatomic, inflammatory, and vascular placental pathology.

RESULT(S)

There was a higher incidence of placental pathology in the ART group (n = 511) than in the non-ART group (n = 121), specifically anatomic (adjusted odds ratio [aOR] 2.50, 95% confidence interval [CI] 1.42-4.40) and vascular (aOR 2.00, 95% CI 1.13-3.53) pathology. These findings were driven primarily by the significantly higher odds of anatomic (aOR 2.97, 95% CI 1.55-5.66) and vascular (aOR 1.98, 95% CI 1.04-3.75) pathology observed in ICSI pregnancies. Single blastocyst transfers remained associated with increased anatomic pathology (ART: aOR 4.89, 95% CI 2.28-10.49; ICSI: aOR 3.38, 95% CI 1.49-7.71).

CONCLUSION(S)

Fresh embryo transfer is associated with increased anatomic and vascular placental pathology in term singleton live births compared with conception without ART. This finding should be investigated prospectively in a larger cohort of patients.

Infertility treatment and the risk of small for gestational age births: a population-based study in the United States

Objective

To evaluate the association between infertility treatments and small for gestational age (SGA) births.

Design

Cross-sectional study.

Setting

United States, 2015–2019.

Patient(s)

Women (n = 16,836,228) who delivered nonmalformed, singleton live births (24–44 weeks’ gestation).

Intervention(s)

Any infertility treatment, including assisted reproductive technology (ART) and prescribed fertility-enhancing medications.

Main Outcome Measure(s)

Small for gestational age birth, defined as sex-specific birth weight <10% for gestational age. Associations between SGA and infertility treatment were derived from Poisson regression with robust variance. Risk ratios (RR) and 95% confidence intervals (CI) were derived after adjusting for confounders. In a sensitivity analysis, we corrected for nondifferential exposure misclassification and unmeasured confounding biases.

Result(s)

Subsequently, 1.4% (n = 231,177) of pregnancies resulted from infertility treatments (0.8% ART and 0.6% fertility-enhancing medications). Of these, SGA births occurred in 9.4% (n = 21,771) and 11.9% (n = 1,755,925) of pregnancies conceived with infertility treatment and naturally conceived pregnancies, respectively (adjusted RR, 1.07; 95% CI, 1.06, 1.08). However, after correction for misclassification bias and unmeasured confounding, infertility treatment was associated with a 27% reduced risk of SGA (bias-corrected RR, 0.73; 95% CI, 0.53, 0.85). Similar trends were seen for analyses stratified by exposure to ART and fertility-enhancing medications, as well as for SGA <5th and <3rd percentiles.

Conclusion(s)

Exposure to infertility treatment is associated with a reduced risk of SGA births. These findings, which are contrary to some published reports, may reflect changes in the modern practice of infertility care, maternal lifestyle, and compliance with prenatal care within the infertile population. Until these findings are corroborated, the associations must be cautiously interpreted.

Obstetric outcomes in pregnancies resulting from in vitro fertilization are not different in fertile, sterilized women compared to infertile women: A Society for Assisted Reproductive Technology database analysis

OBJECTIVE

To compare obstetric and neonatal outcomes resulting from assisted reproductive technology in couples with a history of female sterilization to couples with other infertility diagnoses.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

Fresh, nondonor cycles excluding gestational surrogacy from 2004 to 2013 in the United States.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Preterm birth rates and low birth weight rates from in vitro fertilization (IVF) pregnancies in couples with infertility and in couples with prior tubal ligation as their sole indication for IVF.

RESULT(S)

The mean ages of fertile women (N = 8,478) and infertile women (N = 371,488) were 35.3 and 34.6 years, respectively. Of the singletons born to parous women (N = 26,463), the incidence of preterm birth was not significantly different in fertile, sterilized couples compared to infertile couples (13.7% vs. 12.0%). The incidence of low birth weight among term singletons was also not significantly different between fertile couples compared to infertile couples (3.5% vs. 3.2%).

CONCLUSION(S)

Fertile couples have similar preterm birth and low birth weight rates after IVF compared to infertile couples. This suggests that differences in perinatal outcomes may be due to assisted reproductive technology procedures rather than infertility itself.

Association between infertility and all-cause mortality: analysis of US claims data

BACKGROUND

The consequences of an infertility diagnosis extend beyond the pursuit of family building, because women with infertility also face increased risks for severe maternal morbidity, cancer, and chronic disease.

OBJECTIVE

This study aimed to examine the association between female infertility and all-cause mortality.

STUDY DESIGN

This retrospective analysis compared 72,786 women with infertility, identified in the Optum Clinformatics Datamart from 2003 to 2019 by infertility diagnosis, testing, and treatment codes, with 3,845,790 women without infertility seeking routine gynecologic care. The baseline comorbidities were assessed using the presence of ≥1 metabolic syndrome diagnoses and the Charlson Comorbidity Index. The primary outcome, which was all-cause mortality, was identified by linkage to the Social Security Administration Death Master File outcomes and medical claims. The association between infertility and mortality was examined using a Cox proportional hazard regression by adjusting for age, hypertension, hyperlipidemia, type II diabetes, year of evaluation, smoking, number of visits per year, nulliparity, obesity, region of the country, and race.

RESULTS

Among 16,473,458 person-years of follow-ups, 13,934 women died. Women with infertility had a 32% higher relative risk for death from any cause (0.42% vs 0.35%, adjusted hazard ratio, 1.32; 95% confidence interval, 1.18-1.48) than women without infertility. The mean follow-up time per patient was 4.0±3.7 years vs 4.2±3.8 years for women with and without infertility, respectively. When stratified by age of <35 or ≥35 years or baseline medical comorbidity, the association between infertility and mortality remained. Women with infertility who delivered a child during the follow-up period faced a similar increased risk for mortality than the overall infertile group. Finally, receiving fertility treatment was not associated with a higher risk for death than receiving an infertility diagnosis or testing alone.

CONCLUSION

Although the absolute risk for death was low in both groups, women with infertility faced a higher relative risk for mortality than women without infertility. The association remained across all age, race and ethnicity groups, morbidities, and delivery strata. Importantly, infertility treatment was not associated with an increased risk for death. These findings reinforce the disease burden associated with infertility and its potential for long-term sequelae.

DNA methylation differences at birth after conception through ART

STUDY QUESTION

Is there a relation between ART and DNA methylation (DNAm) patterns in cord blood, including any differences between IVF and ICSI?

SUMMARY ANSWER

DNAm at 19 CpGs was associated with conception via ART, with no difference found between IVF and ICSI.

WHAT IS KNOWN ALREADY

Prior studies on either IVF or ICSI show conflicting outcomes, as both widespread effects on DNAm and highly localized associations have been reported. No study on both IVF and ICSI and genome-wide neonatal DNAm has been performed.

STUDY DESIGN, SIZE, DURATION

This was a cross-sectional study comprising 87 infants conceived with IVF or ICSI and 70 conceived following medically unassisted conception. The requirement for inclusion in the study was an understanding of the Swedish language and exclusion was the use of donor gametes.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were from the UppstART study, which was recruited from fertility and reproductive health clinics, and the Born into Life cohort, which is recruited from the larger LifeGene study. We measured DNAm from DNA extracted from cord blood collected at birth using a micro-array (450k array). Group differences in DNAm at individual CpG dinucleotides (CpGs) were determined using robust linear models and post-hoc Tukey’s tests.

MAIN RESULTS AND THE ROLE OF CHANCE

We found no association of ART conception with global methylation levels, imprinted loci and meta-stable epialleles. In contrast, we identify 19 CpGs at which DNAm was associated with being conceived via ART (effect estimates: 0.5–4.9%, P_FDR < 0.05), but no difference was found between IVF and ICSI. The associated CpGs map to genes related to brain function/development or genes connected to the plethora of conditions linked to subfertility, but functional annotation did not point to any likely functional consequences.

LIMITATIONS, REASONS FOR CAUTION

We measured DNAm in cord blood and not at later ages or in other tissues. Given the number of tests performed, our study power is limited and the findings need to be replicated in an independent study.

WIDER IMPLICATIONS OF THE FINDINGS

We find that ART is associated with DNAm differences in cord blood when compared to non-ART samples, but these differences are limited in number and effect size and have unknown functional consequences in adult blood. We did not find indications of differences between IVF and ICSI.

STUDY FUNDING/COMPETING INTEREST(S)

E.W.T. was supported by a VENI grant from the Netherlands Organization for Scientific Research (91617128) and JPI-H2020 Joint Programming Initiative a Healthy Diet for a Healthy Life (JPI HDHL) under proposal number 655 (PREcisE Project) through ZonMw (529051023). Financial support was provided from the European Union’s Seventh Framework Program IDEAL (259679), the Swedish Research Council (K2011-69X-21871-01-6, 2011-3060, 2015-02434 and 2018-02640) and the Strategic Research Program in Epidemiology Young Scholar Awards, Karolinska Institute (to A.N.I.) and through the Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM) framework grant no 340-2013-5867, grants provided by the Stockholm County Council (ALF-projects), the Strategic Research Program in Epidemiology at Karolinska Institutet and the Swedish Heart-Lung Foundation and Danderyd University Hospital (Stockholm, Sweden). The funders had no role in study design, data collection, analysis, decision to publish or preparation of the manuscript. The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Influence of Placental Abnormalities and Pregnancy-Induced Hypertension in Prematurity Associated with Various Assisted Reproductive Technology Techniques

OBJECTIVE

Assisted reproductive technology (ART)-treated women exhibit increased risk of premature delivery compared to fertile women. We evaluated whether ART treatment modalities increase prematurity and whether placental abnormalities and pregnancy-induced hypertensive (PIH) disorders mediate these risks.

METHOD(S)

This retrospective study of ART-treated and fertile deliveries (2004-2017) used an ART-cycle database linked to Massachusetts birth certificates and hospital discharges. Outcomes of late preterm birth (LPTB: 34-36 weeks gestation) and early preterm birth (EPTB: <34 weeks gestation) were compared with term deliveries (≥37 weeks gestation) in ART-treated (linked to the ART database) and fertile (no indicators of infertility or ART) deliveries. ART treatments with autologous oocyte, donor oocyte, fresh or frozen embryo transfer (FET), intracytoplasmic sperm injection (ICSI) and no-ICSI were separately compared to the fertile group. Adjusted odds ratios (AOR) were calculated with multivariable logistic regression: placental abnormalities or PIH were quantified in the pathway as mediators.

RESULTS

There were 218,320 deliveries: 204,438 fertile and 13,882 ART-treated. All treatment types increased prematurity (AOR 1.31-1.58, LPTB; AOR 1.34-1.48, EPTB). Placental abnormalities mediated in approximately 22% and 38% of the association with LPTB and EPTB, respectively. PIH mediated 25% and 33% of the association with LPTB and EPTB in FET and donor oocyte cycles, more than other treatments (<10% LPTB and <13% EPTB).

CONCLUSIONS

ART-treatment and all ART modalities increased LPTB and EPTB when compared with fertile deliveries. Placental abnormalities modestly mediated associations approximately equally, while PIH was a stronger mediator in FET and donor oocyte cycles. Reasons for differences require exploration.

Optimizing the control group for evaluating ART outcomes: can outpatient claims data yield a better control group?

Purpose

We previously developed a subfertile comparison group with which to compare outcomes of assisted reproductive technology (ART) treatment. In this study, we evaluated whether insurance claims data in the Massachusetts All Payers Claims Database (APCD) defined a more appropriate comparison group.

Methods

We used Massachusetts vital records of women who delivered between 2013 and 2017 on whom APCD data were available. ART deliveries were those linked to a national ART database. Deliveries were subfertile if fertility treatment was marked on the birth certificate, had prior hospitalization with ICD code for infertility, or prior fertility treatment. An infertile group included women with an APCD outpatient or inpatient ICD 9/10 infertility code prior to delivery. Fertile deliveries were none of the above. Demographics, health risks, and obstetric outcomes were compared among groups. Multivariable generalized estimating equations were used to calculate adjusted relative risk (aRR) and 95% confidence intervals (CI).

Results

There were 70,726 fertile, 4,763 subfertile, 11,970 infertile, and 7,689 ART-treated deliveries. Only 3,297 deliveries were identified as both subfertile and infertile. Both subfertile and infertile were older, and had more education, chronic hypertension, and diabetes than the fertile group and less than the ART-treated group. Prematurity (aRR = 1.15–1.17) and birthweight (aRR = 1.10–1.21) were increased in all groups compared with the fertile group.

Conclusion

Although the APCD allowed identification of more women than the previously defined subfertile categorization and allowed us to remove previously unidentified infertile women from the fertile group, it is not clear that it offered a clinically significantly improved comparison group.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10815-021-02111-6.

Preconception Evaluation Before In Vitro Fertilization

Importance

Infertility poses a substantial public health problem for women of reproductive age, in the United States and globally. Infertility can be overcome with a variety of emerging assisted reproductive technologies (ARTs). In vitro fertilization (IVF) currently represents the most commonly utilized method of ART and is typically associated with the highest clinical pregnancy rate and live birth rate compared with other infertility treatment options. However, proper preconception evaluation and counseling is paramount for optimizing IVF and pregnancy outcomes.

Objective

This article aims to outline current guidelines and recommendations for comprehensive preconception evaluation before initiation of IVF.

Evidence Acquisition

Articles were obtained from PubMed, ACOG committee opinions 781 and 762, and relevant textbook chapters.

Results

A variety of recommendations and best practices exist for optimally managing patients seeking IVF. Special attention must be paid to the workup of certain patient populations, such as those with age older than 35 years, uterine abnormalities, comorbidities (especially hypertension, diabetes, and thrombophilias), and obesity. In addition, many lifestyle factors must be addressed before IVF initiation, such as smoking, illicit drug use, and inadequate nutrition. Preconception counseling and expectation management is key to optimizing pregnancy outcome.

Conclusion and Relevance

A myriad of patient and environmental factors impact the potential success rates of IVF in treating infertility. Providers must be equipped to provide data-driven, patient-centered counseling before initiation of IVF.

Early Autism Spectrum Disorders in Children Born to Fertile, Subfertile, and ART-Treated Women

INTRODUCTION

We examined the prevalence of autism spectrum disorders (ASDs) in Massachusetts (MA) comparing children born via assisted reproductive technology (ART) and children born to women with indicators of subfertility but no ART (Subfertile), to children born to women with neither ART nor indicators of subfertility (Fertile). We assessed the direct, indirect, and total effects of ART and subfertility on ASD among singletons.

METHODS

This study included 10,147 ART, 8072 Subfertile and 441,898 Fertile MA resident births from the MA Outcome Study of ART (MOSART) database linked with Early Intervention program participation data. ART included fresh in vitro fertilization (IVF), fresh intracytoplasmic sperm injection (ICSI), and frozen embryo transfer. We estimated the prevalence of ASD by fertility group. We used logistic regression to assess the natural direct effect (NDE), natural indirect effect (NIE) through preterm birth, and total effects of each fertility group on ASD.

RESULTS

The NDE indicated that, compared to the Fertile group, the odds of ASD were not statistically higher in the ART (OR_NDE 1.07; 95% CI 0.88-1.30), Subfertile (OR_NDE 1.11; 95% CI 0.89-1.38), IVF (OR_NDE 0.91; 95% CI 0.68-1.22), or ICSI (OR_NDE 1.13; 95% CI 0.84-1.51) groups, even if the rate of preterm birth was the same across all groups. The total effect (product of NDE and NIE) was not significant for ART (OR_{Total Effect} 1.08; 95% CI 0.89-1.30), Subfertile (OR_{Total Effect} 1.11; 95% CI 0.89-1.38), IVF (OR_{Total Effect} 0.92; 95% CI 0.69-1.23), or ICSI (OR_{Total Effect} 1.13; 95% CI 0.84-1.52).

CONCLUSION

Compared to children born to Fertile women, children born to ART, ICSI, or IVF, or Subfertile women are not at increased risk of receiving an ASD diagnosis.

Adverse Pregnancy Outcomes in Endometriosis - Myths and Realities

PURPOSE OF REVIEW

There is increasing interest in the long-term health and comorbid conditions associated with endometriosis for both women and neonates. The purpose of this review was to synthesize and discuss the current state of the literature investigating endometriosis and risk of adverse pregnancy outcomes.

RECENT FINDINGS

Methodologic considerations for studying endometriosis and adverse pregnancy outcomes include complexities regarding the comparison population, endometriosis definition, sample size, residual confounding, and interactions. The current research on endometriosis and adverse pregnancy outcomes should be interpreted cautiously. To date, evidence suggests that endometriosis may be associated with higher risk of ectopic pregnancy, placenta previa, preterm birth, and cesarean section. While an association with miscarriage and stillbirth has been consistently observed, the relative risk was small.

SUMMARY

Pregnant women with endometriosis may be at higher risk for certain adverse pregnancy outcomes and may therefore benefit from additional monitoring. However, additional research is needed to confirm these associations and should focus on ensuring studies have internal and external validity, as well as, investigate the potential for differences in endometriosis phenotypes. Moreover, future research should focus on understanding potential mechanisms of association and better understanding how early interventions, through increased monitoring or screening during pregnancy, may improve outcomes.

Maternal and Fetal Risk Associated With Assisted Reproductive Technology

Infertility is a disease that affects up to 15.5% of reproductive-aged couples. Until the birth of the first neonate born from in vitro fertilization (IVF) in 1978, many infertile couples did not have an opportunity to conceive a biological child. Over the past 40 years, access to and effectiveness of IVF have increased; currently 1.7% of births in the United States result from IVF. As with any medical intervention, potential risk exists. In the case of IVF, both maternal risks (ovarian stimulation, oocyte retrieval, and subsequent pregnancy) and fetal risks that vary based on maternal age and fetal number must be considered. Importantly, risk quantification varies by comparison group, which is typically either spontaneous conception in a fertile couple or assisted non-IVF conception in an infertile couple. It must also be considered compared with the alternative of not undergoing IVF, which may mean not having a biological child. Although increased compared with spontaneous conception, absolute maternal-fetal-assisted reproductive technology risks are low and can be minimized by optimizing ovarian stimulation and transferring a single embryo. In this article, we aim to summarize maternal and fetal risk associated with use of assisted reproductive technology. The review focuses on ovarian stimulation and procedural risks as well as adverse perinatal outcomes among resultant singleton and twin pregnancies in young women and women of advanced maternal age.

Hospitalization before and after delivery in fertile, subfertile, and ART-treated women

PURPOSE

Pre-pregnancy and post-delivery hospitalizations were compared as markers for health among women who conceived using assisted reproductive technology (ART), non-ART medically assisted reproduction (MAR), no treatment (unassisted subfertile), and who were fertile.

METHODS

We analyzed hospital discharge data linked to Massachusetts birth certificates from 2004 to 2013 within 5 years prior to pregnancy and 8-365 days post-delivery. ART deliveries were linked from a national ART database; MAR deliveries had fertility treatment but not ART; unassisted subfertile women had subfertility but no ART or MAR; and fertile women had none of these. Prevalence of diagnoses during hospitalization was quantified. Multivariable logistic regression models with fertile deliveries as reference were adjusted for maternal age, race, education, year, and plurality (post-delivery only) with results reported as adjusted odds ratios (AORs) and 95% confidence intervals (CI).

RESULTS

Of 170,605 privately insured, primiparous deliveries, 10,458 were ART, 3005 MAR, 1365 unassisted subfertile, and 155,777 fertile. Pre-pregnancy hospitalization occurred in 6.8% and post-delivery in 2.8% of fertile women. Subfertile groups had more pre-pregnancy hospitalizations (AOR, 95% CI: 1.84, 1.72-1.96 ART; 1.41, 1.24-1.60 MAR; 3.02, 2.62-3.47 unassisted subfertile) with endometriosis, reproductive organ disease, ectopic pregnancy/miscarriage, and disorders of menstruation, ovulation, and genital tract being common. Post-delivery hospitalizations were significantly more frequent in the ART (AOR 1.19, 95% CI 1.05-1.34) and unassisted subfertile (1.59, 1.23-2.07) groups with more digestive tract disorders, thyroid problems, and other grouped chronic disease conditions.

CONCLUSIONS

Greater likelihood of hospitalization in the ART, MAR, and unassisted subfertile groups is largely explained by admissions for conditions associated with subfertility.

Epigenetically regulated imprinted gene expression associated with IVF and infertility: possible influence of prenatal stress and depression

PURPOSE

Despite the growing body of research implying an impact of in vitro fertilization (IVF) on imprinted genes and epigenetics, few studies have examined the effects of underlying subfertility or prenatal stress on epigenetics, particularly in terms of their role in determining infant birthweights. Both subfertility and prenatal stressors have been found to impact epigenetics and may be confounding the effect of IVF on epigenetics and imprinted genes. Like IVF, both of these exposures-infertility and prenatal stressors-have been associated with lower infant birthweights. The placenta, and specifically epigenetically regulated placental imprinted genes, provides an ideal but understudied mechanism for evaluating the relationship between underlying genetics, environmental exposures, and birthweight.

METHODS AND RESULTS

In this review, we discuss the impacts of IVF and infertility on birthweight, epigenetic mechanisms and genomic imprinting, and the role of these mechanisms in the IVF population and discuss the role and importance of the placenta in infant development. We then highlight recent work on the relationships between infertility, IVF, and prenatal stressors in terms of placental imprinting.

CONCLUSIONS

In combination, the studies discussed, as well as two recent projects of our own on placental imprinted gene expression, suggest that lower birthweights in IVF infants are secondary to a combination of exposures including the infertility and prenatal stress that couples undergoing IVF are experiencing. The work highlighted herein emphasizes the need for appropriate control populations that take infertility into account and also for consideration of prenatal psychosocial stressors as confounders and causes of variation in IVF infant outcomes.

Care plans for women pregnant using assisted reproductive technologies: a systematic review

Background

Between 1 and 5% of children in industrialized countries are conceived through Assisted Reproductive Technologies (ART). As infertility and the use of ART may be associated with adverse perinatal outcomes, care plans specific to these pregnancies are needed. We conducted a systematic review to examine the existing care plans specific to women pregnant following Assisted Reproductive Technologies (ART).

Methods

MEDLINE, Embase and the Cochrane Library were searched by a senior information specialist. The population of interest included women becoming pregnant with ART (e.g., Intra-Uterine Insemination, In Vitro Fertilization (IVF), Intracytoplasmic Sperm Injection (ICSI), and surrogacy). All proposed care plans were sought that pertained to any aspect of care during pregnancy and delivery. Only Clinical Practice Guidelines (CPGs) addressing the recommendations and plans for the care of ART pregnant women were included. The search was restricted to the publication dates 2007 to June 12, 2017 when the search was run. The search was not restricted by language, however only English and French language guidelines were considered for inclusion.

Results

After screening 2078 citations, a total of ten CPGs were included. The following key clinical messages were prevalent: (1) although there was no supporting evidence, antenatal care for ART pregnancies should be provided by specialist with knowledge in obstetrics; (2) high-order multiple pregnancies are the greatest risk of ART and selective reduction options should be discussed; (3) there is some evidence of increased risk of congenital abnormalities and prenatal genetic and anatomic screening is recommended, especially in IVF-ICSI pregnancies; (4) due to a lack of or conflicting evidence, treatment of venous thromboembolism, antithrombotic therapy, treatment for hypothyroidism, and women with positive thyroid antibodies is recommended to be the same as in spontaneous pregnancies; and lastly (5) since an increased level of distress is a recognized feature in these pregnancies, psychosocial care and counselling should be considered.

Conclusions

There is a lack of CPGs specific to ART pregnancies. While we identified a small number of recommendations for ART pregnancies, specific interventions and models of care aiming at decreasing adverse maternal and perinatal outcomes following ART should be developed, implemented, and evaluated.

Electronic supplementary material

The online version of this article (10.1186/s12978-019-0667-z) contains supplementary material, which is available to authorized users.

Risk of prematurity and infant morbidity and mortality by maternal fertility status and plurality

PURPOSE

To evaluate the risk of prematurity and infant mortality by maternal fertility status, and for in vitro fertilization (IVF) pregnancies, by oocyte source and embryo state combinations.

METHODS

Women in 14 States who had IVF-conceived live births during 2004-13 were linked to their infant's birth and death certificates; a 10:1 sample of non-IVF births was selected for comparison; those with an indication of infertility treatment on the birth certificate were categorized as subfertile, all others were categorized as fertile. Risks were modeled separately for the fertile/subfertile/IVF (autologous-fresh only) group and for the IVF group by oocyte source-embryo state combinations, using logistic regression, and reported as adjusted odds ratios (AORs) and 95% confidence intervals (CI).

RESULTS

The study population included 2,474,195 pregnancies. Placental complications (placenta previa, abruptio placenta, and other excessive bleeding) and prematurity were both increased with pregestational and gestational diabetes and hypertension, among subfertile and IVF groups, and in IVF pregnancies using donor oocytes. Both subfertile and IVF pregnancies were at risk for prematurity and NICU admission; IVF infants were also at risk for small-for-gestation birthweight, and subfertile infants had greater risks for neonatal and infant death. Within the IVF group, pregnancies with donor oocytes and/or thawed embryos were at greater risk of large-for-gestation birthweight, and pregnancies with thawed embryos were at greater risk of neonatal and infant death.

CONCLUSIONS

Prematurity was associated with placental complications, diabetes and hypertension, subfertility and IVF groups, and in IVF pregnancies, donor oocytes and/or thawed embryos.

Birth outcomes of singleton vaginal deliveries to ART-treated, subfertile, and fertile primiparous women

PURPOSE

To determine whether differences in birth outcomes among assisted reproductive technology (ART)-treated, subfertile, and fertile women exist in primiparous women with, singleton, vaginal deliveries.

METHODS

Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) data were linked to Massachusetts vital records and hospital discharges for deliveries between July 2004 and December 2010. Primiparous women with in-state vaginal deliveries, adequate prenatal care, and singleton birth at ≥ 20 weeks (n = 117,779) were classified as ART-treated (linked to ART data from SART CORS, n = 3138); subfertile (not ART-treated but with indicators of subfertility, n = 1507); or fertile (neither ART-treated nor subfertile, n = 113,134). Outcomes of prematurity (< 37 weeks), low birthweight (< 2500 g), perinatal death (death at ≥ 20 weeks to ≤ 7 days), and maternal prolonged length of hospital stay (LOS > 3 days) were compared using multivariable logistic regression.

RESULTS

Compared to fertile, higher odds were found for prematurity among ART-treated (adjusted odds ratio [AOR] 1.40, 95% confidence interval [CI] 1.25-1.50) and subfertile (AOR 1.25, 95% CI 1.03-1.50) women, low birthweight among ART-treated (AOR 1.41, 95% CI 1.23-1.62) and subfertile (AOR 1.40, 95% CI 1.15-1.71) women, perinatal death among subfertile (AOR 2.64, 95% CI 1.72-4.05), and prolonged LOS among ART-treated (AOR 1.33, 95% CI 1.19-1.48) women. Differences remained despite stratification by young age and absence of pregnancy/delivery complications.

CONCLUSIONS

Greater odds of prematurity and low birthweight in ART-treated and subfertile, and perinatal death in subfertile deliveries are evident among singleton vaginal deliveries. The data suggest that even low-risk pregnancies to ART-treated and subfertile women be managed for adverse outcomes.

Parental health status and infant outcomes: Upstate KIDS Study

OBJECTIVE

To assess parental health status inclusive of infertility and infant outcomes.

DESIGN

Birth cohort with cross-sectional analysis of parental health status and infant outcomes.

SETTING

Not applicable.

PATIENT(S)

Parents (n = 4,886) and infants (n = 5,845) participating in the Upstate KIDS birth cohort.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Infertility was defined as [1] sexually active without contraception for 1+ years without pregnancy, [2] ever requiring ≥12 months to become pregnant, and [3] requiring ≥12 months for index pregnancy. Multivariable linear regression with generalized estimating equations estimated the change (β coefficient and 95% confidence interval [CI]) in infant outcomes (gestation, birthweight, length, head circumference, ponderal index) and relative to each disease, including infertility after adjusting for age, body mass index, and infertility treatment.

RESULT(S)

Prevalence of parental chronic diseases ranged from <1% to 19%, and 21% to 54% for infertility. Maternal hypertension was negatively associated with gestation (β, -0.64; 95% CI, -1.03, -0.25) and birthweight (-151.98; -262.30, -41.67) as was asthma and birthweight (-75.01; -130.40, -19.62). Maternal kidney disease was associated with smaller head circumference (-1.09; -2.17, -0.01), whereas paternal autoimmune disease was associated with larger head circumference (0.87; 0.15, 1.60). Infertility was negatively associated with birthweight (-62.18; -103.78, -20.58), length (-0.33; -0.60, -0.06), and head circumference (-0.35; -0.67, -0.03).

CONCLUSION(S)

Infertility was significantly associated with reduced infant size even after accounting for infertility treatment, although the magnitude of reduction varied by definition of infertility. Absence of pregnancy within a year of being at risk may be informative about health.

Adverse pregnancy, birth, and infant outcomes in twins: effects of maternal fertility status and infant gender combinations; the Massachusetts Outcomes Study of Assisted Reproductive Technology

BACKGROUND

It is unknown whether the risk of adverse outcomes in twin pregnancies among subfertile women, conceived with and without in vitro fertilization, differs from those conceived spontaneously.

OBJECTIVE

We sought to evaluate the effects of fertility status on adverse perinatal outcomes in twin pregnancies on a population basis.

STUDY DESIGN

All twin live births of ≥22 weeks' gestation and ≥350 g birthweight to Massachusetts resident women in 2004 through 2010 were linked to hospital discharge records, vital records, and in vitro fertilization cycles. Women were categorized by their fertility status as in vitro fertilization, subfertile, or fertile, and by twin pair genders (all, like, unlike). Women whose births linked to in vitro fertilization cycles were classified as in vitro fertilization; those with indicators of subfertility but without in vitro fertilization treatment were classified as subfertile; all others were classified as fertile. Risks of 6 adverse pregnancy outcomes (gestational diabetes, pregnancy hypertension, uterine bleeding, placental complications [placenta abruptio, placenta previa, and vasa previa], prenatal hospitalizations, and primary cesarean) and 9 adverse infant outcomes (very low birthweight, low birthweight, small-for-gestation birthweight, large-for-gestation birthweight, very preterm [<32 weeks], preterm, birth defects, neonatal death, and infant death) were modeled by fertility status with the fertile group as reference, using multivariate log binomial regression and reported as adjusted relative risk ratios and 95% confidence intervals.

RESULTS

The study population included 10,352 women with twin pregnancies (6090 fertile, 724 subfertile, and 3538 in vitro fertilization). Among all twins, the risks for all 6 adverse pregnancy outcomes were significantly increased for the subfertile and in vitro fertilization groups, with highest risks for uterine bleeding (adjusted relative risk ratios, 1.92 and 2.58, respectively) and placental complications (adjusted relative risk ratios, 2.07 and 1.83, respectively). Among all twins, the risks for those born to subfertile women were significantly increased for very preterm birth and neonatal and infant death (adjusted relative risk ratios, 1.36, 1.89, and 1.87, respectively). Risks were significantly increased among in vitro fertilization twins for very preterm birth, preterm birth, and birth defects (adjusted relative risk ratios, 1.28, 1.07, and 1.26, respectively).

CONCLUSION

Risks of all maternal and most infant adverse outcomes were increased for subfertile and in vitro fertilization twins. Among all twins, the highest risks were for uterine bleeding and placental complications for the subfertile and in vitro fertilization groups, and neonatal and infant death in the subfertile group. These findings provide further evidence supporting single embryo transfer and more cautious use of ovulation induction.

Pregnancy and birth outcomes in couples with infertility with and without assisted reproductive technology: with an emphasis on US population-based studies

Infertility, defined as the inability to conceive within 1 year of unprotected intercourse, affects an estimated 80 million individuals worldwide, or 10-15% of couples of reproductive age. Assisted reproductive technology includes all infertility treatments to achieve conception; in vitro fertilization is the process by which an oocyte is fertilized by semen outside the body; non-in vitro fertilization assisted reproductive technology treatments include ovulation induction, artificial insemination, and intrauterine insemination. Use of assisted reproductive technology has risen steadily in the United States during the past 2 decades due to several reasons, including childbearing at older maternal ages and increasing insurance coverage. The number of in vitro fertilization cycles in the United States has nearly doubled from 2000 through 2013 and currently 1.7% of all live births in the United States are the result of this technology. Since the birth of the first child from in vitro fertilization >35 years ago, >5 million babies have been born from in vitro fertilization, half within the past 6 years. It is estimated that 1% of singletons, 19% of twins, and 25% of triplet or higher multiples are due to in vitro fertilization, and 4%, 21%, and 52%, respectively, are due to non-in vitro fertilization assisted reproductive technology. Higher plurality at birth results in a >10-fold increase in the risks for prematurity and low birthweight in twins vs singletons (adjusted odds ratio, 11.84; 95% confidence interval, 10.56-13.27 and adjusted odds ratio, 10.68; 95% confidence interval, 9.45-12.08, respectively). The use of donor oocytes is associated with increased risks for pregnancy-induced hypertension (adjusted odds ratio, 1.43; 95% confidence interval, 1.14-1.78) and prematurity (adjusted odds ratio, 1.43; 95% confidence interval, 1.11-1.83). The use of thawed embryos is associated with higher risks for pregnancy-induced hypertension (adjusted odds ratio, 1.30; 95% confidence interval, 1.08-1.57) and large-for-gestation birthweight (adjusted odds ratio, 1.74; 95% confidence interval, 1.45-2.08). Among singletons, in vitro fertilization is associated with increased risk of severe maternal morbidity compared with fertile deliveries (vaginal: adjusted odds ratio, 2.27; 95% confidence interval, 1.78-2.88; cesarean: adjusted odds ratio, 1.67; 95% confidence interval, 1.40-1.98, respectively) and subfertile deliveries (vaginal: adjusted odds ratio, 1.97; 95% confidence interval, 1.30-3.00; cesarean: adjusted odds ratio, 1.75; 95% confidence interval, 1.30-2.35, respectively). Among twins, cesarean in vitro fertilization deliveries have significantly greater severe maternal morbidity compared to cesarean fertile deliveries (adjusted odds ratio, 1.48; 95% confidence interval, 1.14-1.93). Subfertility, with or without in vitro fertilization or non-in vitro fertilization infertility treatments to achieve a pregnancy, is associated with increased risks of adverse maternal and perinatal outcomes. The major risk from in vitro fertilization treatments of multiple births (and the associated excess of perinatal morbidity) has been reduced over time, with fewer and better-quality embryos being transferred.

Pregnancy, birth, and infant outcomes by maternal fertility status: the Massachusetts Outcomes Study of Assisted Reproductive Technology

BACKGROUND

Births to subfertile women, with and without infertility treatment, have been reported to have lower birthweights and shorter gestations, even when limited to singletons. It is unknown whether these decrements are due to parental characteristics or aspects of infertility treatment.

OBJECTIVE

The objective of the study was to evaluate the effect of maternal fertility status on the risk of pregnancy, birth, and infant complications.

STUDY DESIGN

All singleton live births of ≥22 weeks' gestation and ≥350 g birthweight to Massachusetts resident women in 2004-2010 were linked to hospital discharge and vital records. Women were categorized by their fertility status as in vitro fertilization, subfertile, or fertile. Women whose births linked to in vitro fertilization cycles from the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System were classified as in vitro fertilization. Women with indicators of subfertility but not treated with in vitro fertilization were classified as subfertile. Women without indicators of subfertility or in vitro fertilization treatment were classified as fertile. Risks of 15 adverse outcomes (gestational diabetes, pregnancy hypertension, antenatal bleeding, placental complications [placenta abruptio and placenta previa], prenatal hospitalizations, primary cesarean delivery, very low birthweight [<1500 g], low birthweight [<2500 g], small-for-gestation birthweight [z-score ≤-1.28], large-for-gestation birthweight [z-score ≥1.28], very preterm [<32 weeks], preterm [<37 weeks], birth defects, neonatal death [0-27 days], and infant death [0-364 days of life]) were modeled by fertility status with the fertile group as reference and the subfertile group as reference, using multivariate log binomial regression and reported as adjusted risk ratios and 95% confidence intervals.

RESULTS

The study population included 459,623 women (441,420 fertile, 8054 subfertile, and 10,149 in vitro fertilization). Women in the subfertile and in vitro fertilization groups were older than their fertile counterparts. Risks for 6 of 6 pregnancy outcomes and 6 of 9 infant outcomes were increased for the subfertile group, and 5 of 6 pregnancy outcomes and 7 of 9 infant outcomes were increased for the in vitro fertilization group. For 4 of the 6 pregnancy outcomes (uterine bleeding, placental complications, prenatal hospitalizations, and primary cesarean) and 2 of the infant outcomes (low birthweight and preterm) the risk was greater in the in vitro fertilization group, with nonoverlapping confidence intervals to the subfertile group, indicating a substantially higher risk among in vitro fertilization-treated women. The highest risks for the in vitro fertilization women were uterine bleeding (adjusted risk ratio, 3.80; 95% confidence interval, 3.31-4.36) and placental complications (adjusted risk ratio, 2.81; 95% confidence interval, 2.57-3.08), and for in vitro fertilization infants, very preterm birth (adjusted risk ratio, 2.13; 95% confidence interval, 1.80-2.52), and very low birthweight (adjusted risk ratio, 2.15; 95% confidence interval, 1.80-2.56). With subfertile women as reference, risks for the in vitro fertilization group were significantly increased for uterine bleeding, placental complications, prenatal hospitalizations, primary cesarean delivery, low and very low birthweight, and preterm and very preterm birth.

CONCLUSION

These analyses indicate that, compared with fertile women, subfertile and in vitro fertilization-treated women tend to be older, have more preexisting chronic conditions, and are at higher risk for adverse pregnancy outcomes, particularly uterine bleeding and placental complications. The greater risk in in vitro fertilization-treated women may reflect more severe infertility, more extensive underlying pathology, or other unfavorable factors not measured in this study.

Placental imprinting variation associated with assisted reproductive technologies and subfertility

Infertility affects one in 6 couples in developed nations, resulting in an increasing use of assisted reproductive technologies (ART). Both ART and subfertility appear to be linked to lower birth weight outcomes, setting infants up for poor long-term health. Prenatal growth is, in part, regulated via epigenetically-controlled imprinted genes in the placenta. Although differences in DNA methylation between ART and control infants have been found, it remains unclear whether these differences are due to the ART procedures or to the underlying parental subfertility and how these methylation differences affect imprinted gene expression. In this study, we examined the expression of 108 imprinted genes in placental tissues from infants born to subfertile parents (n = 79), matched naturally-conceived controls (n = 158), and infants conceived using in vitro fertilization (IVF, n = 18). Forty-five genes were identified as having significantly different expression between the subfertile infants and controls, whereas no significant differences were identified between the IVF and control groups. The expression of 4 genes-IGF2, NAPIL5, PAX8-AS1, and TUBGCP5-was significantly downregulated in the IVF compared with the subfertile group. Three of the 45 genes significantly dysregulated between subfertile and control placentae-GRB10, NDN, and CD44 -were found to have a significant positive correlation between expression and birth weight. Methylation levels for these 3 genes and 4 others-MKRN3, WRB, DHCR24, and CYR61-were significantly correlated with expression. Our findings indicate that epigenetic differences in placentas resulting from IVF pregnancies may be related to the underlying subfertility in parents using IVF rather than the IVF procedure itself.