Caesarean section in pregnancies conceived by assisted reproductive technology: a systematic review and meta-analysis

Surgical repair of post-cesarean vesicouterine fistula: A systematic review and a plea for prevention

BACKGROUND

Vesicouterine fistula (VUF) is a iatrogenic injury in the vast majority of cases. The worldwide increase of cesarean delivery rates is expected to lead to increased complications.

OBJECTIVES

To assess current evidence on VUF pathogenesis and surgical management.

SEARCH STRATEGY

Pubmed and Embase databases were searched from January 2000 to January 2023 using relevant key words.

SELECTION CRITERIA

Only original articles including either transabdominal or transvaginal surgical routes for post-cesarean VUF repair, in English language, were included.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the references for eligibility, data extraction, and assessment of methodologic quality. All available surgical outcomes were recorded.

MAIN RESULTS

Of the 1160 studies retrieved, 67 were selected for analysis. Most of these were case reports, case series, or observational cohort studies including a total of 284 patients. The majority (78.6%) of patients had more than one cesarean section, and approximately 10% of them experienced an overt bladder injury and/or uterine rupture at the time of cesarean delivery. The supratrigonal part of the bladder was most commonly involved (92.5%). The majority of patients (88.8%) underwent delayed VUF repair through laparotomy. Length of stay and blood loss were significantly less in patients treated via a minimally invasive approach (P < 0.001 and P = 0.02, respectively). Most patients had double-layer bladder repair and single-layer uterine repair. The overall success rate was 100% on first attempt for each independent combination of different surgical approaches and techniques. Live birth following VUF repair was reported in 23 patients.

CONCLUSIONS

Paying close attention to surgical details is crucial to reduce the incidence of this complication and recurrence rates. Double-layer bladder closure and delayed timing of repair of VUF are recommended.

Impact of time interval from cesarean delivery to frozen embryo transfer on reproductive and neonatal outcomes

OBJECTIVE

To evaluate differences in reproductive and neonatal outcomes on the basis of the time interval from cesarean delivery to subsequent frozen embryo transfer (FET).

DESIGN

Retrospective cohort.

SETTING

Multicenter fertility practice.

PATIENTS

Women undergoing autologous elective single embryo transfer FET after prior cesarean delivery.

INTERVENTION

Time from prior cesarean delivery to subsequent FET.

MAIN OUTCOME MEASURES

live birth (LB).

RESULTS

A total of 6,556 autologous elective single embryo transfer FET cycles were included. Frozen embryo transfer cycles were divided into eight groups on the basis of the time interval from prior cesarean delivery to subsequent FET in months. A secondary analysis was then performed with time as a continuous variable. The proportion of LBs did not differ significantly across all time interval groups and over continuous time (range: 40.0%-45.6%). The mean gestational age at the time of delivery did not significantly differ as the time between prior cesarean delivery and subsequent FET increased (range: 37.3-38.4). When time was evaluated continuously, the proportion of preterm births was higher with a shorter time between cesarean delivery and subsequent FET. The mean birth weight ranged from 3,181-3,470g, with a statistically significant increase over time. However, the proportions of extremely low birth weight, very low birth weight, and low birth weight did not significantly differ.

CONCLUSION

There were no significant differences in reproductive outcomes on the basis of the time interval from cesarean delivery to FET, including LB. The proportion of preterm deliveries decreased with a longer time between cesarean delivery and FET. Differences in mean neonatal birth weight were not clinically significant because the proportion of low birth weight neonates was not significantly different over time. Although large, this sample cannot address all outcomes associated with short interpregnancy intervals, particularly rarer outcomes such as uterine rupture. When counseling patients, the timing of FET after cesarean delivery must be balanced against the risks of increasing maternal age on reproductive and neonatal outcomes.

Multifetal Pregnancy After Implementation of a Publicly Funded Fertility Program

Importance

A publicly funded fertility program was introduced in Ontario, Canada, in 2015 to increase access to fertility treatment. For in vitro fertilization (IVF), the program mandated an elective single-embryo transfer (eSET) policy. However, ovulation induction and intrauterine insemination (OI/IUI)-2 other common forms of fertility treatment-were more difficult to regulate in this manner. Furthermore, prior epidemiologic studies only assessed fetuses at birth and did not account for potential fetal reductions that may have been performed earlier in pregnancy.

Objective

To examine the association between fertility treatment and the risk of multifetal pregnancy in a publicly funded fertility program, accounting for both fetal reductions and all live births and stillbirths.

Design, Setting, and Participants

This population-based, retrospective cohort study used linked administrative health databases at ICES to examine all births and fetal reductions in Ontario, Canada, from April 1, 2006, to March 31, 2021.

Exposure

Mode of conception: (1) unassisted conception, (2) OI/IUI, or (3) IVF.

Main Outcomes and Measures

The main outcome was multifetal pregnancy (ie, a twin or higher-order pregnancy). Modified Poisson regression generated adjusted relative risks (ARRs) and derived population attributable fractions (PAFs) for multifetal pregnancies attributable to fertility treatment. Absolute rate differences (ARDs) were used to compare the era before eSET was promoted (2006-2011) with the era after the introduction of the eSET mandate (2016-2021).

Results

Of all 1 724 899 pregnancies, 1 670 825 (96.9%) were by unassisted conception (mean [SD] maternal age, 30.6 [5.2] years), 24 395 (1.4%) by OI/IUI (mean [SD] maternal age, 33.1 [4.4] years), and 29 679 (1.7%) by IVF (mean [SD] maternal age, 35.8 [4.7] years). In contrast to unassisted conception, individuals who received OI/IUI or IVF tended to be older, reside in a high-income quintile neighborhood, or have preexisting health conditions. Multifetal pregnancy rates were 1.4% (95% CI, 1.4%-1.4%) for unassisted conception, 10.5% (95% CI, 10.2%-10.9%) after OI/IUI, and 15.5% (95% CI, 15.1%-15.9%) after IVF. Compared with unassisted conception, the ARR of any multifetal pregnancy was 7.0 (95% CI, 6.7-7.3) after OI/IUI and 9.9 (95% CI, 9.6-10.3) after IVF, with corresponding PAFs of 7.1% (95% CI, 7.1%-7.2%) and 13.4% (95% CI, 13.3%-13.4%). Between the eras of 2006 to 2011 and 2016 to 2021, multifetal pregnancy rates decreased from 12.9% to 9.1% with OI/IUI (ARD, -3.8%; 95% CI, -4.2% to -3.4%) and from 29.4% to 7.1% with IVF (ARD, -22.3%; 95% CI, -23.2% to -21.6%).

Conclusions and Relevance

In this cohort study of more than 1.7 million pregnancies in Ontario, Canada, a publicly funded IVF program mandating an eSET policy was associated with a reduction in multifetal pregnancy rates. Nevertheless, ongoing strategies are needed to decrease multifetal pregnancy, especially in those undergoing OI/IUI.

The risk of perinatal and cardiometabolic complications in pregnancies conceived by medically assisted reproduction

PURPOSE

To examine the impact of medically assisted fertility treatments on the risk of developing perinatal and cardiometabolic complications during pregnancy and in-hospital deliveries.

METHODS

We conducted a retrospective cohort study using medical health records of deliveries occurring in 2016-2022 at a women's specialty hospital in a southern state of the Unites States (US). Pregnancies achieved using medically assisted reproductive (MAR) techniques were compared with unassisted pregnancies using propensity score matching (PSM), based on demographic, preexisting health, and reproductive factors. Study outcomes included cesarean delivery, gestational diabetes mellitus (GDM), hypertensive disorders of pregnancy (HDP), delivery complications, and postpartum readmission. We used Poisson regression with robust standard errors to generate risk ratios (RRs) and 95% confidence intervals (CIs) for all study outcomes.

RESULTS

Among 57,354 deliveries, 586 (1.02%) pregnancies were achieved using MAR and 56,768 (98.98%) were unassisted ("non-MAR"). Compared to the non-MAR group, MAR pregnancies had significantly higher prevalence of all study outcomes, including GDM (15.9% vs. 11.2%, p < 0.001), HDP (28.2% vs. 21.1%, p < 0.001), cesarean delivery (56.1% vs. 34.6%, p < 0.001), delivery complications (10.9% vs. 6.8%, p = 0.03), and postpartum readmission (4.3% vs. 2.7%, p = 0.02). In a PSM sample of 584 MAR and 1,727 unassisted pregnancies, MAR was associated with an increased risk of cesarean delivery (RR = 1.11, 95% CI = 1.01-1.22); whereas IVF was associated with an increased risk of cesarean delivery (RR = 1.15, 95% CI = 1.03-1.28) and delivery complications (RR = 1.44, 95% CI = 1.04-2.01).

CONCLUSIONS

Women who conceived with MAR were at increased risk of cesarean deliveries, and those who conceived with IVF were additionally at risk of delivery complications.

Impact of Caesarean section on pregnancy outcomes in ART after transfer of one or more frozen blastocysts

INTRODUCTION

The prevalence of Caesarean delivery is rising steadily worldwide, and it is important to identify its future impact on fertility. A number of articles have been published on this subject, but the impact of Caesarean section on reproductive outcomes is still under debate, and none of these articles focus exclusively on frozen blastocysts.

OBJECTIVE

The aim of this study was to evaluate the impact of a previous Caesarean delivery compared with a previous vaginal delivery on the chances of a live birth following the transfer of one or more frozen embryos at the blastocyst stage.

METHODS

This was a retrospective, bicentric study at the University Hospitals of Nîmes and Montpellier, conducted between January 1st, 2016 and February 1st, 2021. Three hundred and ninety women with a history of childbirth and a transfer of one or more frozen embryos at blastocyst stage were included in the analysis. The primary outcome was the number of live births. Secondary outcomes were: the rate of positive HCG, miscarriage, ectopic pregnancy and clinical pregnancy, as well as the live birth rate according to the presence or absence of an isthmocele.

RESULTS

Of the 390 patients included, 118 had a previous Caesarean delivery and 272 a vaginal delivery. No statistically significant differences were found for the primary (p = 0.9) or secondary outcomes. A trend towards lower live birth rates was observed in patients with isthmoceles, but this did not reach significance (p>0.9). On the other hand, transfers were more often described as difficult in the Caesarean delivery group (p = 0.011).

CONCLUSION

Our study found no effect of previous Caesarean delivery on the chances of live birth after transferring one or more frozen blastocysts. However, further prospective studies are needed to confirm these results.

Infertility and Risk of Autism Spectrum Disorder in Children

Importance

Previous studies on the risk of childhood autism spectrum disorder (ASD) following fertility treatment did not account for the infertility itself or the mediating effect of obstetrical and neonatal factors.

Objective

To assess the association between infertility and its treatments on the risk of ASD and the mediating effect of selected adverse pregnancy outcomes on that association.

Design, Setting, and Participants

This was a population-based cohort study in Ontario, Canada. Participants were all singleton and multifetal live births at 24 or more weeks' gestation from 2006 to 2018. Data were analyzed from October 2022 to October 2023.

Exposures

The exposure was mode of conception, namely, (1) unassisted conception, (2) infertility without fertility treatment (ie, subfertility), (3) ovulation induction (OI) or intrauterine insemination (IUI), or (4) in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI).

Main Outcome and Measures

The study outcome was a diagnosis of ASD at age 18 months or older. Cox regression models generated hazard ratios (HR) adjusted for maternal and infant characteristics. Mediation analysis further accounted for the separate effect of (1) preeclampsia, (2) cesarean birth, (3) multifetal pregnancy, (4) preterm birth at less than 37 weeks, and (5) severe neonatal morbidity.

Results

A total of 1 370 152 children (703 407 male [51.3%]) were included: 1 185 024 (86.5%) with unassisted conception, 141 180 (10.3%) with parental subfertility, 20 429 (1.5%) following OI or IUI, and 23 519 (1.7%) following IVF or ICSI. Individuals with subfertility or fertility treatment were older and resided in higher-income areas; the mean (SD) age of each group was as follows: 30.1 (5.2) years in the unassisted conception group, 33.3 (4.7) years in the subfertility group, 33.1 (4.4) years in the OI or IUI group, and 35.8 (4.9) years in the IVF or ICSI group. The incidence rate of ASD was 1.93 per 1000 person-years among children in the unassisted conception group. Relative to the latter, the adjusted HR for ASD was 1.20 (95% CI, 1.15-1.25) in the subfertility group, 1.21 (95% CI, 1.09-1.34) following OI or IUI, and 1.16 (95% CI, 1.04-1.28) after IVF or ICSI. Obstetrical and neonatal factors appeared to mediate a sizeable proportion of the aforementioned association between mode of conception and ASD risk. For example, following IVF or ICSI, the proportion mediated by cesarean birth was 29%, multifetal pregnancy was 78%, preterm birth was 50%, and severe neonatal morbidity was 25%.

Conclusions and Relevance

In this cohort study, a slightly higher risk of ASD was observed in children born to individuals with infertility, which appears partly mediated by certain obstetrical and neonatal factors. To optimize child neurodevelopment, strategies should further explore these other factors in individuals with infertility, even among those not receiving fertility treatment.

Fetal Growth Velocity according to the Mode of Assisted Conception

INTRODUCTION

Pregnancies conceived through assisted reproductive techniques (ARTs) are on the rise worldwide and have been associated with a higher risk of placental-related disease in the third trimester.

METHODS

A cohort was created of singleton pregnancies after assisted reproduction, admitted at our institution for delivery, between January 2020 and August 2022. Fetal growth velocity from the second trimester to delivery was compared against a gestational-age-matched group of pregnancies spontaneously conceived according to the origin of the selected oocyte (i.e., autologous vs. donated).

RESULTS

125 singleton pregnancies conceived through ART were compared to 315 singleton spontaneous conceptions. Overall, after adjusting for possible confounders, multivariate analysis demonstrated that ART pregnancies had a significantly lower estimated fetal weight (EFW) z-velocity from the second trimester to delivery (adjusted mean difference = -0.002; p = 0.035) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 2.32 [95% CI, 1.15-4.68]). Also, when ART pregnancies were compared according to the type of oocyte, those conceived with donated oocytes showed a significantly lower EFW z-velocity from the second trimester to delivery (adjusted mean difference = -0.008; p = 0.001) and a higher frequency of EFW z-velocity in the lowest decile (adjusted OR = 5.33 [95% CI, 1.34-21.5]).

CONCLUSIONS

Pregnancies achieved through ART exhibit a pattern of lower growth velocity across the third trimester, especially those conceived with donated oocytes. The former represents a sub-group at the highest risk of placental dysfunction that may warrant closer follow-up.

IVF outcomes following ICSI cycles using testicular sperm in obstructive (OA) vs. non-obstructive azoospermia (NOA) and the impact of maternal and paternal age: a SART CORS data registry

PURPOSE

To assess the differences in IVF outcomes between couples with obstructive azoospermia (OA), non-obstructive azoospermia (NOA), and male factor (MF).

METHODS

Using the SART CORS data from 2016 to 2017, we included all initial autologous cycles with a diagnosis of male factor with ejaculated and surgically obtained sperm. We analyzed 71,121 cycles, including 3467 with a diagnosis of azoospermia and 67,654 with other non-azoospermic MF. Using a multivariate binomial regression, we estimated adjusted risk ratios comparing outcomes for ICSI cycles using surgically acquired (OA and NOA) versus ejaculated sperm (MF). Outcomes reported per initial cycle included clinical pregnancy, live birth, biochemical pregnancy, and miscarriage. Outcomes reported per singleton pregnancy included full-term delivery (≥ 37 weeks), normal birth weight (≥ 2500 g), and delivery method.

RESULTS

After frozen embryo transfers (FET), patients with NOA had 7% higher odds of live birth compared to MF (aOR 1.23 (0.94-1.74)), and those with OA had 2.6% lower chance of live birth compared to MF (aOR 0.73 (95%CI 0.5-1.05)). After fresh ET, patients with NOA had 5% higher chance of live birth (aOR 1.11 (0.9-1.36)), and those with OA had a 2.5% higher chance of live birth (aOR 1.10 (95%CI 0.89-1.34)) compared to MF. All three subgroups had lower fresh live birth rates (LBR) compared to FETs.

CONCLUSION

Couples with either NOA or OA have overall comparable ART and perinatal outcomes to couples with MF, and their success is primarily dependent on both patient's and partner's age.

The cost of preterm birth and cesarean section as a result of infertility and its treatment: A review

Infertility, irrespective of receipt of fertility treatment, is associated with an increased risk of adverse pregnancy outcomes, including cesarean section (CS) and preterm birth (PTB). These complications are associated with significant physical, mental, emotional, social, and financial costs to individuals, healthcare systems, and society at large. Although multiple pregnancy is one of the most significant contributors to the elevated CS and PTB rates in women receiving fertility treatment, singleton pregnancy is also at an increased risk of these outcomes. Single embryo transfer policies through publicly funded in vitro fertilization programs have demonstrated beneficial health outcomes and cost savings. Low-dose aspirin prophylaxis may be considered for PTB reduction in patients with infertility. Finally, upstream prevention strategies such as lifestyle modification and social policies to address the underlying needs for fertility treatment may also beneficially impact both CS and PTB rates.

Reproductive outcomes in women and men conceived by assisted reproductive technologies in Norway: prospective registry based study

Objectives

To determine whether the perinatal outcomes of women or men who were conceived by assisted reproductive technologies are different compared with their peers who were naturally conceived.

Design

Prospective registry based study.

Setting

Medical Birth Registry of Norway.

Participants

People born in Norway between 1984 and 2002 with a registered pregnancy by the end of 2021.

Exposure

People who were conceived by assisted reproductive technologies and have had a registered pregnancy.

Main outcome measures

Comparing pregnancies and births of people who were conceived by assisted reproductive technologies and people who were naturally conceived, we assessed mean birth weight, gestational age, and placental weight by linear regression, additionally, the odds of congenital malformations, a low 5 min Apgar score (<7), transfer to a neonatal intensive care unit, delivery by caesarean section, use of assisted reproductive technologies, hypertensive disorders of pregnancy and pre-eclampsia, preterm birth, and offspring sex, by logistic regression. The occurrence of any registered pregnancy from people aged 14 years until age at the end of follow-up was assessed using Cox proportional regression for both groups.

Results

Among 1 092 151 people born in Norway from 1984 to 2002, 180 652 were registered at least once as mothers, and 137 530 as fathers. Of these, 399 men and 553 women were conceived by assisted reproductive technologies. People who were conceived by assisted reproductive technologies had little evidence of increased risk of adverse outcomes in their own pregnancies, increased use of assisted reproductive technologies, or any difference in mean birth weight, placental weight, or gestational age. The only exception was for an increased risk of the neonate having a low Apgar score at 5 min (adjusted odds ratio 1.86 (95% confidence interval 1.20 to 2.89)) among women who were conceived by assisted reproductive technologies. Odds were slightly decreased of having a boy among mothers conceived by assisted reproductive technologies (odds ratio 0.79 (95% confidence interval 0.67 to 0.93)). People conceived by assisted reproductive technologies were slightly less likely to have a registered pregnancy within the follow-up period (women, adjusted hazard ratio 0.88 (95% CI 0.81 to 0.96); men, 0.91 (0.83 to 1.01)).

Conclusions

People conceived by assisted reproductive technologies were not at increased risk of obstetric or perinatal complications when becoming parents. The proportion of people conceived by assisted reproductive technologies with a registered pregnancy was lower than among people who were naturally conceived, but a longer follow-up is required to fully assess their fertility and reproductive history.

Does advanced maternal age explain the longer hospitalisation of mothers after childbirth?

BACKGROUND

Fertility postponement, which has comprised the most significant reproductive trend in developed countries over the last few decades, involves a number of social, personal and health consequences. The length of stay (LOS) in hospital following childbirth varies considerably between countries. Czechia, where the fertility postponement process has been particularly dynamic, has one of the longest mean LOS of the OECD member countries.

OBJECTIVE

We analyse the influence of the age of mothers on the LOS in hospital associated with childbirth.

DATA AND METHODS

We employed anonymised individual data provided by the General Health Insurance Company of the Czech Republic on women who gave birth in 2014. Kaplan-Meier survival plots and binary logistic regression were employed to identify factors associated with long stays (> = 7 days for vaginal births, > = 9 days for CS births).

RESULTS

The impact of the maternal age on the LOS is U-shaped. A higher risk of a longer hospitalisation period for young mothers was identified for both types of birth (OR = 1.58, 95% CI 1.33-1.87, p˂0.001 for age less than 20, OR = 1.31, 95% CI 1.20-1.44, p˂0.001 for age 20-24 compared to 30-34). The risk of a longer stay in hospital increases with the increasing age of the mother (OR = 1.23, 95% CI 1.13-1.35, p˂0.001 for age 35-39, OR = 2.05, 95% CI 1.73-2.44, p˂0.001 for age 40+ compared to 30-34), especially with concern to vaginal births.

CONCLUSION

The probability of a long LOS increases significantly after the age of 35, especially in the case of vaginal births. Thus, the fertility postponement process with the significant change in the age structure of mothers contributes to the increase in health care costs associated with post-birth hospitalisation.

Assisted reproductive technology and neonatal intensive care unit: A retrospective observational study from a single center

BACKGROUND

An increasing number of infants are being conceived using assisted reproductive technology (ART). The effects of infertility treatments (IFTs) on infant outcomes have been extensively debated; however, a consensus has not yet been reached. In the present study, we investigated the impact of IFTs on neonatal intensive care unit (NICU) managements using data collected at a single large NICU center.

METHODS

We retrospectively investigated patients admitted to the University of Tokyo Hospital NICU during three different time periods (2010, 2015, and 2020). We included 131, 201, and 323 infants, respectively, and compared a number of factors among groups classified by the mode of conception: spontaneous pregnancy (SP), non-ART (conceived with assisted ovulation or artificial insemination), and ART. We also compared the mode of conception among inborn singletons.

RESULTS

The rate of admission of ART infants significantly increased from 2010 (9.1%) to 2015 (22.9%) and 2020 (25.7%) (p values of <0.05 and <0.01, respectively). When compared among inborn singletons, ART infants were more often admitted to NICU (p < 0.01). Congenital anomalies and surgical interventions were significantly more frequent in the SP group than in the ART group (p < 0.01). No significant differences were observed in neonatal outcomes among ART infants from 2010 to 2015/2020.

CONCLUSIONS

The rate of ART infants admitted to the NICU has significantly increased, with ART pregnancies now accounting for 25% of admissions to the perinatal medical center. ART procedure may be a risk factor for NICU admission. Neonatal intensive care is becoming increasingly indispensable for ART pregnancies.

Mode of conception in patients with endometriosis and adverse pregnancy outcomes: a population-based cohort study

OBJECTIVE

To evaluate the association between endometriosis and adverse pregnancy outcomes.

DESIGN

Population-based retrospective cohort study using linked universal health databases through ICES Ontario.

PATIENT(S)

All singleton pregnancies with an estimated date of confinement between October 2006 and February 2014.

INTERVENTION(S)

Endometriosis was determined based on a surgical and/or medical diagnosis (defined as an in-hospital admission or surgery with a diagnosis code of International Classification of Diseases [ICD]9-617 or ICD10-N80 and/or 2 medical consults billed as ICD9-617).

MAIN OUTCOME MEASURE(S)

The association between endometriosis and pregnancy outcomes was quantified by relative risks, derived using modified Poisson regression, and adjusted for maternal age, income quintiles, and history of fibroids (aRR). Mediation analysis was conducted to estimate direct effects of endometriosis diagnosis and indirect effects through mode of conception, namely: infertility without fertility treatment (known infertility but conceived without assistance), ovulation induction or intrauterine insemination, and in vitro fertilization or intracytoplasmic sperm injection, relative to unassisted conception.

RESULT(S)

A total of 19,099 pregnancies had an antecedent diagnosis of endometriosis, while 768,350 did not. Mean time (standard deviation) from endometriosis diagnosis to the index pregnancy was 5.6 (4.3) years. Endometriosis was associated with an increased risk of hypertensive disorders of pregnancy (aRR, 1.09; 95% confidence interval [CI], 1.02-1.16), preterm birth <37 weeks (aRR, 1.26; 95% CI, 1.20-1.33), early preterm birth <34 weeks (aRR, 1.33; 95% CI, 1.17-1.50), placenta previa (aRR, 2.07; 95% CI, 1.84-2.33), placenta abruption (aRR, 1.55; 95% CI, 1.31-1.83), other placental disorders (aRR, 1.77; 95% CI, 1.36-2.30), cesarean delivery (aRR, 1.18; 95% CI, 1.16-1.21), and stillbirth (aRR, 1.32; 95% CI, 1.09-1.59). Mediation analysis suggests that endometriosis directly affects most adverse pregnancy outcomes studied, except for stillbirth where infertility diagnosis or fertility treatment indirectly accounted for part of the increased risk.

CONCLUSION(S)

Endometriosis was associated with adverse pregnancy, independent of infertility diagnosis, or fertility treatment. Future studies should investigate the mechanisms of action and potential interventions.

Mode of conception and risk of spontaneous vs. provider-initiated preterm birth: population-based cohort study

OBJECTIVE

To study the association between mode of conception and risk of preterm birth, including, spontaneous and provider-initiated subtypes.

DESIGN

Population-based retrospective cohort study.

SETTING

Not applicable.

PATIENTS

All singleton livebirths and stillbirth in Ontario, Canada, 2006-2014.

INTERVENTION

The main exposure was mode of conception, namely unassisted conception, infertility without fertility treatment (i.e., known infertility but conceived without assistance), ovulation induction (OI) or intrauterine insemination (IUI), and in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Modified Poisson regression generated risk ratios (RRs) and 95% confidence intervals for the association between exposure categories and preterm birth adjusted for clinically relevant covariates using a propensity score.

MAIN OUTCOME MEASURE(S)

The primary outcome was preterm birth <37 weeks, further categorized as spontaneous or provider-initiated subtypes. The secondary outcome was preterm birth <34 weeks.

RESULTS

We included 732,810 singleton births born to 649,918 mothers, of which 646,926 (88.3%) were from an unassisted conception, 68,822 (9.4%) with infertility but no fertility treatment, 9,024 (1.2%) following OI/IUI, and 8,038 (1.1%) following IVF/ICSI. Preterm birth <37 weeks occurred among 6.0% of births by unassisted conception, 7.7% with infertility without fertility treatment, 8.0% with OI/IUI, and 10.8% following IVF/ICSI. Relative to unassisted conception, the unadjusted RR of provider-initiated preterm birth was 1.30 (1.26-1.33) in women with infertility without fertility treatment, 1.36 (1.26-1.45) after OI/IUI, and 1.82 (1.70-1.93) after IVF/ICSI. The corresponding adjusted RRs (aRR) were 1.23 (1.16-1.31), 1.48 (1.29-1.69), and 2.35 (2.09-2.64). The unadjusted RR of spontaneous preterm birth was 1.22 (1.18-1.27) in women with infertility without fertility treatment, 1.22 (1.12-1.34) after OI/IUI, and 1.47 (1.35-1.60) after IVF/ICSI. The corresponding aRR were 1.15 (1.10-1.19), 1.19 (1.09-1.31), and 1.40 (1.27-1.53). For preterm birth <34 weeks, the RRs followed a similar pattern as for preterm birth <37 weeks, with the exception of women with infertility without fertility treatment (aRR 1.08; confidence interval, 0.95-1.23).

CONCLUSIONS

Infertility and receipt of fertility treatment are each associated with a higher risk of preterm birth, spontaneous and provider-initiated subtypes, even in singleton pregnancies. Strategies are needed to reduce the risk for preterm birth in these women.

Attention-deficit hyperactivity disorder in children born to mothers with infertility: a population-based cohort study

STUDY QUESTION

Is the risk of attention-deficit hyperactivity disorder (ADHD) increased in children born to mothers with infertility, or after receipt of fertility treatment, compared to mothers with unassisted conception?

SUMMARY ANSWER

Infertility itself may be associated with ADHD in the offspring, which is not amplified by the use of fertility treatment.

WHAT IS KNOWN ALREADY

Infertility, and use of fertility treatment, is common. The long-term neurodevelopmental outcome of a child born to a mother with infertility, including the risk of ADHD, remains unclear.

STUDY DESIGN, SIZE, DURATION

This population-based cohort study comprised all singleton and multiple hospital births in Ontario, Canada, 2006–2014. Outcomes were assessed up to June 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Linked administrative datasets were used to capture all hospital births in Ontario, maternal health and pregnancy measures, fertility treatment and child outcomes. Included were all children born at ≥24 weeks gestation between 2006 and 2014, and who were alive at age 4 years. The main exposure was mode of conception, namely (i) unassisted conception (reference group), (ii) infertility without fertility treatment (history of an infertility consultation with a physician within 2 years prior to conception but no fertility treatment), (iii) ovulation induction (OI) or intrauterine insemination (IUI) and (iv) IVF or intracytoplasmic sperm injection (ICSI). The main outcome was a diagnosis of ADHD after age 4 years and assessed up to June 2020. Hazard ratios (HRs) were adjusted for maternal age, income quintile, rurality, immigration status, smoking, obesity, parity, any drug or alcohol use, maternal history of mental illness including ADHD, pre-pregnancy diabetes mellitus or chronic hypertension and infant sex. In addition, we performed pre-planned stratified analyses by mode of delivery (vaginal or caesarean delivery), infant sex, multiplicity (singleton or multiple), timing of birth (term or preterm <37 weeks) and neonatal adverse morbidity (absent or present).

MAIN RESULTS AND THE ROLE OF CHANCE

The study included 925 488 children born to 663 144 mothers, of whom 805 748 (87%) were from an unassisted conception, 94 206 (10.2%) followed infertility but no fertility treatment, 11 777 (1.3%) followed OI/IUI and 13 757 (1.5%) followed IVF/ICSI. Starting at age 4 years, children were followed for a median (interquartile range) of 6 (4–8) years. ADHD occurred among 7.0% of offspring in the unassisted conception group, 7.5% in the infertility without fertility treatment group, 6.8% in the OI/IUI group and 6.3% in the IVF/ICSI group. The incidence rate (per 1000 person-years) of ADHD was 12.0 among children in the unassisted conception group, 12.8 in the infertility without fertility treatment group, 12.9 in the OI/IUI group and 12.2 in the IVF/ICSI group. Relative to the unassisted conception group, the adjusted HR for ADHD was 1.19 (95% CI 1.16–1.22) in the infertility without fertility treatment group, 1.09 (95% CI 1.01–1.17) in the OI/IUI group and 1.12 (95% CI 1.04–1.20) in the IVF/ICSI group. In the stratified analyses, these patterns of risk for ADHD were largely preserved. An exception was seen in the sex-stratified analyses, wherein females had lower absolute rates of ADHD but relatively higher HRs compared with that seen among males.

LIMITATIONS, REASONS FOR CAUTION

Some mothers in the isolated infertility group may have received undocumented OI oral therapy, thereby leading to possible misclassification of their exposure status. Parenting behaviour, schooling and paternal mental health measures were not known, leading to potential residual confounding.

WIDER IMPLICATIONS OF THE FINDINGS

Infertility, even without treatment, is a modest risk factor for the development of ADHD in childhood. The reason underlying this finding warrants further study.

STUDY FUNDING/COMPETING INTEREST(s)

This study was made possible with funding from the Canadian Institutes of Health Research, Grant number PJT 165840. The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Has the cesarean epidemic in Czechia been reversed despite fertility postponement?

Background

Although the percentage of cesarean sections (CS) in Czechia is below the average of that of other developed countries (23.6%), it still exceeds WHO recommendations (15%). The first aim of the study is to examine the association between a CS birth and the main health factors and sociodemographic characteristics involved, while the second aim is to examine recent trends in the CS rate in Czechia. 

Methods

Anonymized data on all mothers in Czechia for 2018 taken from the National Register of Expectant Mothers was employed. The risk of cesarean delivery for the observed factors was tested via the construction of a binary logistic regression model that allowed for adjustments for all the other covariates in the model.

Results

Despite all the covariates being found to be statistically significant, it was determined that health factors represented a higher risk of a CS than sociodemographic characteristics. A previous CS was found to increase the risk of its recurrence by 33 times (OR = 32.96, 95% CI 30.95–35.11, p<0.001). The breech position increased the risk of CS by 31 times (OR = 31.03, 95% CI 28.14–34.29, p<0.001). A multiple pregnancy increased the odds of CS six-fold and the use of ART 1.8-fold. Mothers who suffered from diabetes before pregnancy were found to be twice as likely to give birth via CS (OR = 2.14, 95% CI 1.76–2.60, p<0.001), while mothers with gestational diabetes had just 23% higher odds of a CS birth (OR = 1.23, 95% CI 1.16–1.31, p<0.001). Mothers who suffered from hypertension gave birth via CS twice as often as did mothers without such complications (OR = 2.01, 95% CI 1.86–2.21, p<0.001).

Conclusions

The increasing age of mothers, a significant risk factor for a CS, was found to be independent of other health factors. Accordingly, delayed childbearing is thought to be associated with the increase in the CS rate in Czechia. However, since other factors come into play, further research is needed to assess whether the recent slight decline in the CS rate is not merely a temporal trend.

Caesarean birth in women with infertility: population-based cohort study

Objective

Caesarean section (CS) is more common following infertility treatment (IT) but the reasons why remain unclear and confounded. The Robson 10‐Group Classification System (TGCS) may further explain variation in CS rates. We assessed the association between mode of conception and CS across Robson groups.

Design

Population‐based cohort study.

Setting

Ontario, Canada, in a public healthcare system.

Population

921 023 births, 2006–2014.

Methods

Modified Poisson regression produced relative risks (RR) and 95% confidence intervals, comparing the risk of CS among women with (1) subfertility without IT, (2) non‐invasive IT (OI, IUI) or (3) invasive IT (IVF)—each relative to (4) spontaneous conception (SC).

Main outcome measures

CS rate according to one of four modes of conception, overall and stratified by each of the TGCS groups.

Results

Relative to SC (26.9%), the risk of CS increased in those with subfertility without IT (RR 1.17, 95% CI 1.16–1.18), non‐invasive IT (RR 1.21, 95% CI 1.18–1.24) and invasive IT (RR 1.39, 95% CI 1.36–1.42). Within each Robson group, similar patterns of RRs were seen, but with markedly differing rates. For example, in Group 1 (nulliparous, singleton, cephalic at ≥37 weeks, with spontaneous labour), the respective rates were 15.0, 19.4, 18.7 and 21.9%; in Group 2 (nulliparous, singleton, cephalic at ≥37 weeks, without spontaneous labour), the rates were 35.9, 44.4, 43.2 and 54.1%; and in Group 8 (multiple pregnancy), they were 55.9, 67.5, 65.0 and 69.3%, respectively.

Conclusions

CS is relatively more common in women with subfertility and those receiving IT, an effect that persists across Robson groups.

Tweetable abstract

Caesarean delivery is more common in women with infertility independent of demographics and prenatal conditions.

Caesarean delivery is more common in women with infertility independent of demographics and prenatal conditions.

Changes in maternal risk factors and their association with changes in cesarean sections in Norway between 1999 and 2016: A descriptive population-based registry study

BACKGROUND

Increases in the proportion of the population with increased likelihood of cesarean section (CS) have been postulated as a driving force behind the rise in CS rates worldwide. The aim of the study was to assess if changes in selected maternal risk factors for CS are associated with changes in CS births from 1999 to 2016 in Norway.

METHODS AND FINDINGS

This national population-based registry study utilizes data from 1,055,006 births registered in the Norwegian Medical Birth Registry from 1999 to 2016. The following maternal risk factors for CS were included: nulliparous/≥35 years, multiparous/≥35 years, pregestational diabetes, gestational diabetes, hypertensive disorders, previous CS, assisted reproductive technology, and multiple births. The proportion of CS births in 1999 was used to predict the number of CS births in 2016. The observed and predicted numbers of CS births were compared to determine the number of excess CS births, before and after considering the selected risk factors, for all births, and for births stratified by 0, 1, or >1 of the selected risk factors. The proportion of CS births increased from 12.9% to 16.1% (+24.8%) during the study period. The proportion of births with 1 selected risk factor increased from 21.3% to 26.3% (+23.5%), while the proportion with >1 risk factor increased from 4.5% to 8.8% (+95.6%). Stratification by the presence of selected risk factors reduced the number of excess CS births observed in 2016 compared to 1999 by 67.9%. Study limitations include lack of access to other important maternal risk factors and only comparing the first and the last year of the study period.

CONCLUSIONS

In this study, we observed that after an initial increase, proportions of CS births remained stable from 2005 to 2016. Instead, both the size of the risk population and the mean number of risk factors per birth continued to increase. We observed a possible association between the increase in size of risk population and the additional CS births observed in 2016 compared to 1999. The increase in size of risk population and the stable CS rate from 2005 and onward may indicate consistent adherence to obstetric evidence-based practice in Norway.