Maternal use of fertility drugs and risk of cancer in children--a nationwide population-based cohort study in Denmark

Risk factors for tumors or leukemia development in the first two years of life

OBJECTIVES

The objective of this study was to determine the incidence of neoplastic diseases and associated risk factors in the early stages of life.

METHODS

Data were retrospectively assessed in 730,000 live births between 2000 and 2019. The occurrence of tumors was monitored in the neonatal, infant (1-12 months), and toddler (13-24 months) periods. Risk factors were divided into demographic, internal, and environmental factors. The control group consisted of subjects in the same age category without oncological diseases.

RESULTS

A total of 452 neoplastic diseases were diagnosed in the study sample. In total, 24% (110/452) manifested during the neonatal period, 45% (203/452) in infants, and 31% (139/452) at the age of 13-24 months. Any genetic disease (OR 26.68; 95% CI 7.64-93.12) and medications used by the mother (OR 3.07; 95% CI 1.32-7.15) were identified as risk factors. Without adjustment for all factors, asphyxia in the first minute, a younger age of the mother, lower pregnancy, and the presence of a congenital defect manifested themselves as risk factors.

CONCLUSIONS

The highest risk factors for the development of early childhood tumors were identified as with medications used by the mother before or during pregnancy and genetic diseases.

Assisted reproductive technology and childhood morbidity: a longitudinal cohort study

OBJECTIVE

To evaluate the association between assisted reproductive technology (ART) and offspring morbidity in the first decade of life.

DESIGN

Longitudinal cohort study.

SETTING

Provincial health registry in Quebec, Canada.

PATIENT(S)

A total of 797,654 singleton children born between 2008 and 2019, followed up to 2020.

INTERVENTION(S)

Retrospective, noninterventional study of any ART procedure vs. no ART.

MAIN OUTCOME MEASURE(S)

Childhood morbidity, including hospitalization for infectious, allergic, malignant, and other diseases, assessed using adjusted Cox proportional hazards regression to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for the association with ART. We controlled for unmeasured family-level confounders that were shared among siblings through stratified Cox regression. To do so, we restricted the analysis to 10,097 siblings with discordant exposure to ART and compared the risk of outcomes in exposed vs. unexposed siblings.

RESULT(S)

Compared with no ART, ART was associated with 1.23 times the risk of any hospitalization (95% CI 1.19-1.27), 1.25 times the risk of infectious disease hospitalization (95% CI 1.21-1.29), and 1.25 times the risk of allergy hospitalization (95% CI 1.14-1.38). When we used a sibling design to control for shared genetic and environmental confounders, ART was not associated with a greater risk of childhood hospitalization (HR 0.92, 95% CI 0.78-1.08).

CONCLUSION(S)

ART is associated with an elevated risk of hospitalization up to 11 years of age, but discordant sibling analysis suggests that the association may be due to genetic, environmental, or other shared familial confounders.

Maternal Medication Use and Childhood Cancer in Offspring-Systematic Review and Considerations for Researchers

Cancer is an important cause of childhood mortality, yet the etiology is largely unknown. A combination of pre- and postnatal factors is thought to be implicated, including maternal medication use. We aimed to provide: 1) a systematic review of peer-reviewed publications on associations between maternal medication use and childhood cancer, with a focus on study design and methodology; and 2) suggestions for how to increase transparency, limit potential biases, and improve comparability in studies on maternal medication use and childhood cancer. We conducted a systematic search in the PubMed, Embase, Scopus, Cochrane, and Web of Science databases to June 8, 2020. Altogether, 112 studies were identified. The reviewed studies were heterogeneous in study design, exposure, and outcome classification. In 21 studies (19%), the outcome was any childhood cancer. Of the 91 papers that reported on specific types of cancer, 62% did not report the cancer classification system. The most frequently investigated medication groups were sex hormones (46 studies, excluding fertility medications), and antiinfectives (37 studies). Suggestions for strengthening future pharmacoepidemiologic studies on maternal medication use and childhood cancer relate to choice of cancer classification system, exposure windows, and methods for identification of, and control for, potential confounders.

Early-Pregnancy Dydrogesterone Supplementation Mimicking Luteal-Phase Support in ART Patients Did Not Provoke Major Reproductive Disorders in Pregnant Mice and Their Progeny

Progestogens are frequently administered during early pregnancy to patients undergoing assisted reproductive techniques (ART) to overcome progesterone deficits following ART procedures. Orally administered dydrogesterone (DG) shows equal efficacy to other progestogens with a higher level of patient compliance. However, potential harmful effects of DG on critical pregnancy processes and on the health of the progeny are not yet completely ruled out. We treated pregnant mice with DG in the mode, duration, and doses comparable to ART patients. Subsequently, we studied DG effects on embryo implantation, placental and fetal growth, fetal-maternal circulation, fetal survival, and the uterine immune status. After birth of in utero DG-exposed progeny, we assessed their sex ratios, weight gain, and reproductive performance. Early-pregnancy DG administration did not interfere with placental and fetal development, fetal-maternal circulation, or fetal survival, and provoked only minor changes in the uterine immune compartment. DG-exposed offspring grew normally, were fertile, and showed no reproductive abnormalities with the exception of an altered spermiogram in male progeny. Notably, DG shifted the sex ratio in favor of female progeny. Even though our data may be reassuring for the use of DG in ART patients, the detrimental effects on spermatogenesis in mice warrants further investigations and may be a reason for caution for routine DG supplementation in early pregnancy.

Possible association between in vitro fertilization technologies and offspring neoplasm

OBJECTIVE

To study the association among fertility treatments, treatment protocol, and offspring neoplasm risk up to the age of 18 years.

DESIGN

A population-based retrospective cohort.

SETTING

Soroka University Medical Center (SUMC), the single tertiary medical center and in vitro fertilization (IVF) unit in southern Israel.

PATIENT(S)

All offspring born at the SUMC between the years 1995 and 2018 after IVF treatment (the exposed group) and offspring conceived spontaneously (the unexposed group).

INTERVENTION(S)

The study was performed at the SUMC, the single tertiary medical center and IVF unit in southern Israel. The exposed and unexposed were matched with a ratio of 1:4, based on maternal age and calendar month of delivery. Data collection included a summary of the couple's medical records, delivery data, and offspring neoplasm diagnoses.

MAIN OUTCOME MEASURE(S)

Offspring neoplasm of any kind and time to diagnosis in each of the groups.

RESULT(S)

A total of 1,583 exposed and 5,874 offspring were included in the study. The incidences of offspring benign neoplasm were 14 (0.9%) versus 21 (0.4%), and the incidences of malignancies were 17 (1.1%) versus 29 (0.5%) among offspring of the IVF and spontaneous groups, respectively. The association between mode of conception and offspring neoplasm risk remained significant after adjusting for confounders, including mode of delivery and pregnancy complications such as hypertensive disorder, gestational diabetes mellitus, and preterm delivery compared with spontaneously conceived offspring. Among the IVF group, the increased risk for neoplasm was found among offspring who were transferred as fresh embryos, at an earlier stage of development (cleavage stage), or after three or more aspirated oocytes.

CONCLUSION(S)

IVF treatment is associated with offspring neoplasm risk; specifically, the risk was greater among offspring who were returned as fresh embryos, at an earlier embryotic stage (cleavage stage), or after three or more aspirated oocytes.

The Principle of "Damage Exclusion" as a Benchmark in Catholic Discussions of Homologous Artificial Insemination

The Catholic perspective rejects assisted human reproduction techniques, but the morality of artificial insemination (AI) is open for discussion. This article aims to analyze the morality of AI from a new angle, namely whether these interventions exclude all possibility of damaging the human embryo and the offspring's health. The scientific evidence about the children's health who are born through AI allows us to affirm that the procedures do not comply with the principle of damage exclusion: AI does not exclude all possibility of damaging the embryo and impacting the health and exposure to disease of the offspring born through these techniques.

The association between fertility treatments and the incidence of paediatric cancer: A systematic review and meta-analysis

BACKGROUND

It is important to explore the association between different fertility treatments and the incidence of paediatric cancer, as this will provide crucial guidance for clinical decision-making. Previous studies have explored the relationship between fertility treatments and different types of cancer in offspring, but the results are controversial.

METHOD

Two authors searched PubMed, Embase, Web of Science and Cochrane databases independently to acquire qualified studies. Then, the same authors extracted data from these studies and analysed these data using RevMan 5.3.

MAIN RESULTS

Eleven case-control studies and 16 cohort studies were included in this review and meta-analysis. The relative risk of association between in vitro fertilisation (IVF) and paediatric cancer incidence was 1.01 (95% confidence interval [CI]: 0.80-1.28) in cohort studies and 1.09 (95% CI: 0.74-1.58) in case-control studies. The relative risk of association between intracytoplasmic sperm injection (ICSI) and paediatric cancer incidence was 0.97 (95% CI: 0.80-1.17) in cohort studies. The relative risk of association between fertility drugs and paediatric cancer incidence was 1.07 (95% CI: 0.68-1.69) in cohort studies and 1.12 (95% CI: 0.90-1.41) in case-control studies. The relative risk of association between frozen embryo transfer and paediatric cancer incidence was 1.37 (95% CI: 1.04-1.81) in natural pregnancy controls and 1.28 (95% CI: 0.96-1.69) in fresh embryo transfer controls.

CONCLUSION

There is no evidence that IVF, ICSI and fertility drugs are associated with an increase in paediatric cancer incidence in offspring; however, frozen embryo transfer is associated with an increase in paediatric cancer incidence in the offspring, but this finding needs further research and attention.

Understanding the correlation between artificial insemination and offspring health outcomes

Although numerous articles have shown intracytoplasmic sperm injection and in vitro fertilization to be correlated with increased risk of disease, a few works have been published on the risks associated with artificial insemination. Meanwhile, questions about the possible causes underlying these correlations have remained in the background. The main objective of this work is not to review the risks associated with artificial insemination, but rather to describe how developmental processes may be affected by these techniques. Thus, we offer a theoretical framework for understanding the possible causes that underlie the correlation between low-complexity or milder techniques and offspring health outcomes.

Association Between Fertility Treatment and Cancer Risk in Children

IMPORTANCE

An increasing number of children worldwide are born after the use of fertility treatment, although it remains unclear whether the treatment affects the risk of childhood cancer and whether any associations observed are due to the use of specific drugs, the use of specific procedures, or the underlying infertility.

OBJECTIVE

To examine the association between different types of fertility treatments and cancer risk in children.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study based on Danish population-based registry data and the Danish Infertility Cohort (individual record linkage) that included 1 085 172 children born in Denmark between January 1, 1996, and December 31, 2012, linked with parental information. There were a total of 2217 children diagnosed with cancer (follow-up occurred during 1996-2015).

EXPOSURES

Maternal fertility treatment during the index pregnancy, including the use of fertility drugs (clomiphene [n = 33 835], gonadotropins [n = 57 136], gonadotropin-releasing hormone analogs [n = 38 653], human chorionic gonadotropin [n = 68 181], progesterone [n = 41 628], and estrogen [n = 16 948]) and assisted reproductive technology (in vitro fertilization [n = 19 448], intracytoplasmic sperm injection [n = 13 417], and frozen embryo transfer [n = 3356]). Each exposure was examined separately and compared with children born to fertile women.

MAIN OUTCOMES AND MEASURES

Hazard ratios and incidence rate differences for childhood cancer.

RESULTS

After 12.2 million person-years of follow-up (mean, 11.3 years), the incidence rate of childhood cancer was 17.5 per 100 000 for children born to fertile women (n = 910 291) and 44.4 per 100 000 for children born after the use of frozen embryo transfer (n = 3356). Compared with children born to fertile women, the use of frozen embryo transfer was associated with an elevated risk of childhood cancer (14 cancer cases; hazard ratio, 2.43 [95% CI, 1.44 to 4.11]; incidence rate difference, 26.9 [95% CI, 2.8 to 51.0] per 100 000), mainly due to an increased risk of leukemia (5 cancer cases; incidence rate, 14.4 per 100 000; hazard ratio, 2.87 [95% CI, 1.19 to 6.93]; incidence rate difference, 10.1 [95% CI, -4.0 to 24.2] per 100 000) and sympathetic nervous system tumors (<5 cancer cases; hazard ratio, 7.82 [95% CI, 2.47 to 24.70]). There were no statistically significant associations with the use of the other types of fertility treatment examined.

CONCLUSIONS AND RELEVANCE

Among children born in Denmark, the use of frozen embryo transfer, compared with children born to fertile women, was associated with a small but statistically significant increased risk of childhood cancer; this association was not found for the use of other types of fertility treatment examined.

Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy

BACKGROUND

Multiple pregnancy is a strong risk factor for preterm birth, and more than 50% of women with a twin pregnancy will give birth prior to 37 weeks' gestation. Infants born preterm are recognised to be at increased risk of many adverse health outcomes, contributing to more than half of overall perinatal mortality. Progesterone is produced naturally in the body and has a role in maintaining pregnancy, although it is not clear whether administering progestogens to women with multiple pregnancy at high risk of early birth is effective and safe. Since publication of this new review in Issue 10, 2017, we have now moved one study (El-Refaie 2016) from included to studies awaiting classification, pending clarification about the study data.

OBJECTIVES

To assess the benefits and harms of progesterone administration for the prevention of preterm birth in women with a multiple pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the administration of a progestogen by any route for the prevention of preterm birth in women with multiple pregnancy. We did not include quasi-randomised or cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed reports identified by the search for eligibility, extracted data, assessed risk of bias and graded the quality of the evidence.

MAIN RESULTS

We included 16 trials, which all compared either vaginal or intramuscular (IM) progesterone with a placebo or no treatment, and involved a total of 4548 women. The risk of bias for the majority of included studies was low, with the exception of three studies that had inadequate blinding, or significant loss to follow-up or both, or were not reported well enough for us to make a judgement. We graded the evidence low to high quality, with downgrading for statistical heterogeneity, design limitations in some of the studies contributing data, and imprecision of the effect estimate. 1 IM progesterone versus no treatment or placebo More women delivered at less than 34 weeks' gestation in the IM progesterone group compared with placebo (risk ratio (RR) 1.54, 95% confidence interval (CI) 1.06 to 2.26; women = 399; studies = 2; low-quality evidence). Although the incidence of perinatal death in the progesterone group was higher, there was considerable uncertainty around the effect estimate and high heterogeneity between studies (average RR 1.45, 95% CI 0.60 to 3.51; infants = 3089; studies = 6; I2 = 71%; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up. There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (RR 1.05, 95% CI 0.98 to 1.13; women = 2010; studies = 5; high-quality evidence); preterm birth less than 28 weeks (RR 1.08, 95% CI 0.75 to 1.55; women = 1920; studies = 5; moderate-quality evidence); infant birthweight less than 2500 g (RR 0.99, 95% CI 0.90 to 1.08; infants = 4071; studies = 5; I2 = 76%, moderate-quality evidence)). No childhood outcomes were reported in the trials. 2 Vaginal progesterone versus no treatment or placebo by dose There were no clear group differences in incidence of preterm birth before 34 weeks (average RR 0.90, 95% CI 0.66 to 1.23; women = 1503; studies = 5; I2 = 36%; low-quality evidence). Although fewer births before 34 weeks appeared to occur in the progesterone group, the CIs crossed the line of no effect. Incidence of perinatal death was higher in the progesterone group, although there was considerable uncertainty in the effect estimate and the quality of the evidence was low for this outcome (RR 1.23, 95% CI 0.74 to 2.06; infants = 2287; studies = 3; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up. There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (average RR 0.97, 95% CI 0.89 to 1.06; women = 1597; studies = 6; moderate-quality evidence); preterm birth less than 28 weeks (RR 1.53, 95% CI 0.79 to 2.97; women = 1345; studies = 3; low-quality evidence); infant birthweight less than 2500 g (average RR 0.95, 95% CI 0.84 to 1.07; infants = 2640; studies = 3; I2 = 66%, moderate-quality evidence)). No childhood outcomes were reported in the trials. For secondary outcomes, there were no clear group differences found in any of the other maternal outcomes except for caesarean section, where women who received vaginal progesterone did not have as many caesarean sections as those in the placebo group, although the difference between groups was not large (8%) (RR 0.92, 95% CI 0.86 to 0.98; women = 1919; studies = 5; I2 = 0%). There were no clear group differences found in any of the infant outcomes except for mechanical ventilation, which was required by fewer infants whose mothers had received the vaginal progesterone (RR 0.70, 95% CI 0.52 to 0.94; infants = 2695; studies = 4).

AUTHORS' CONCLUSIONS

Overall, for women with a multiple pregnancy, the administration of progesterone (either IM or vaginal) does not appear to be associated with a reduction in risk of preterm birth or improved neonatal outcomes. Future research could focus on a comprehensive individual participant data meta-analysis including all of the available data relating to both IM and vaginal progesterone administration in women with a multiple pregnancy, before considering the need to conduct trials in subgroups of high-risk women (for example, women with a multiple pregnancy and a short cervical length identified on ultrasound).

Cancer Risk in Children and Young Adults (Offspring) Born after Medically Assisted Reproduction: A Systematic Review and Meta-Analysis

Many studies have investigated the relationship between medically assisted reproduction (MAR) and health outcomes, particularly cancer, in the offspring. This meta-analysis investigated the association between MAR and childhood cancer. Data sources were PubMed, Scopus, and Web of Science up until June 2018. From the selected studies, we extracted the cancer risk estimates of the exposure of interest (MAR, assisted reproductive technology—ART, and in fitro fertilization—IVF). We conducted the meta-analysis using a random effects model. The outcomes of interest were childhood cancers, classified according to the international classification of childhood cancer (ICCC-3). In our meta-analysis (18 cohort and 15 case-control studies) the overall cancer risk was significantly increased in children conceived by MAR, ART, or IVF. MAR and ART significantly increased the risk for hematological tumors, hepatic tumors, and sarcomas (odds ratio (OR) 1.54; 95% CI 1.18–2.02 and OR 1.92; 95% CI 1.34–2.74, respectively). MAR increased acute myeloid leukemia risk (OR 1.41; 95% CI 1.02–1.95) and ART increased neural cancer risk (OR 1.21; 95% CI 1.01–1.46). Our results suggest an increased risk of cancer in children conceived by MAR. Further studies are needed to investigate the impact of fertility treatments, parental subfertility status, and their association on health outcomes in the offspring.

Parental age and the risk of childhood acute myeloid leukemia: results from the Childhood Leukemia International Consortium

BACKGROUND

Parental age has been associated with several childhood cancers, albeit the evidence is still inconsistent.

AIM

To examine the associations of parental age at birth with acute myeloid leukemia (AML) among children aged 0-14 years using individual-level data from the Childhood Leukemia International Consortium (CLIC) and non-CLIC studies.

MATERIAL/METHODS

We analyzed data of 3182 incident AML cases and 8377 controls from 17 studies [seven registry-based case-control (RCC) studies and ten questionnaire-based case-control (QCC) studies]. AML risk in association with parental age was calculated using multiple logistic regression, meta-analyses, and pooled-effect estimates. Models were stratified by age at diagnosis (infants <1 year-old vs. children 1-14 years-old) and by study design, using five-year parental age increments and controlling for sex, ethnicity, birthweight, prematurity, multiple gestation, birth order, maternal smoking and education, age at diagnosis (cases aged 1-14 years), and recruitment time period.

RESULTS

Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) derived from RCC, but not from the QCC, studies showed a higher AML risk for infants of mothers ≥40-year-old (OR = 6.87; 95% CI: 2.12-22.25). There were no associations observed between any other maternal or paternal age group and AML risk for children older than one year.

CONCLUSIONS

An increased risk of infant AML with advanced maternal age was found using data from RCC, but not from QCC studies; no parental age-AML associations were observed for older children.

Risk of cancer in children and young adults conceived by assisted reproductive technology

STUDY QUESTION

Do children conceived by ART have an increased risk of cancer?

SUMMARY ANSWER

Overall, ART-conceived children do not appear to have an increased risk of cancer.

WHAT IS KNOWN ALREADY

Despite the increasing use of ART, i.e. IVF or ICSI worldwide, information about possible long-term health risks for children conceived by these techniques is scarce.

STUDY DESIGN, SIZE, DURATION

A nationwide historical cohort study with prospective follow-up (median 21 years), including all live-born offspring from women treated with subfertility treatments between 1980 and 2001.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All offspring of a nationwide cohort of subfertile women (OMEGA study) treated in one of the 12 Dutch IVF clinics or two fertility clinics. Of 47 690 live-born children, 24 269 were ART-conceived, 13 761 naturally conceived and 9660 were conceived naturally or through fertility drugs, but not by ART. Information on the conception method of each child and potential confounders were collected through the mothers' questionnaires and medical records. Cancer incidence was ascertained through linkage with The Netherlands Cancer Registry from 1 January 1989 until 1 November 2016. Cancer risk in ART-conceived children was compared with risks in naturally conceived children from subfertile women (hazard ratios [HRs]) and with the general population (standardized incidence ratios [SIRs]).

MAIN RESULTS AND THE ROLE OF CHANCE

The median follow-up was 21 years (interquartile range (IQR): 17-25) and was shorter in ART-conceived children (20 years, IQR: 17-23) compared with naturally conceived children (24 years, IQR: 20-30). In total, 231 cancers were observed. Overall cancer risk was not increased in ART-conceived children, neither compared with naturally conceived children from subfertile women (HR: 1.00, 95% CI 0.72-1.38) nor compared with the general population (SIR = 1.11, 95% CI: 0.90-1.36). From 18 years of age onwards, the HR of cancer in ART-conceived versus naturally conceived individuals was 1.25 (95% CI: 0.73-2.13). Slightly but non-significantly increased risks were observed in children conceived by ICSI or cryopreservation (HR = 1.52, 95% CI: 0.81-2.85; 1.80, 95% CI: 0.65-4.95, respectively). Risks of lymphoblastic leukemia (HR = 2.44, 95% CI: 0.81-7.37) and melanoma (HR = 1.86, 95% CI: 0.66-5.27) were non-significantly increased for ART-conceived compared with naturally conceived children.

LIMITATIONS, REASONS FOR CAUTION

Despite the large size and long follow-up of the cohort, the number of cancers was rather small for subgroup analyses as cancer in children and young adults is rare.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, ART-conceived children do not appear to have an increased cancer risk after a median follow-up of 21 years. This large study provides important results, enabling physicians to better inform couples considering ART about the long-term safety of ART for their children. However, larger studies with prolonged follow-up are needed to investigate cancer risk in adults and in children conceived by ICSI and/or from cryopreserved embryos.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by The Dutch Cancer Society (NKI 2006-3631) which funded the OMEGA-women's cohort and Children Cancer Free (KIKA;147) which funded the OMEGA-offspring cohort. We declare no competing interests.

Cancer risk among children conceived by fertility treatment

Prior studies on the association between fertility treatment and childhood cancer risk have generated inconsistent results. We performed a systematic review and meta-analysis of observation studies to summarize the evidence regarding the relation of fertility treatment with childhood cancer risk. A systematic literature search of several databases was conducted through April 2018 to identify relevant studies. The outcomes of interest included overall cancer, haematological malignancies, neural tumours, other solid tumours, and eight specific cancers. The overall risk estimates and corresponding 95% confidence intervals (CIs) were pooled using random-effects meta-analysis. Sixteen cohort and thirteen case-control studies were included. Results showed that children conceived by fertility treatment had significantly higher risk for developing overall cancer (relative risk [RR]: 1.16, 95% CI: 1.01, 1.32), haematological malignancies (RR: 1.39, 95% CI: 1.21, 1.60) and other solid tumours (RR: 1.57, 95% CI: 1.14, 2.16). For specific cancers, fertility treatment was associated with a significantly increased risk of leukaemia (RR: 1.31, 95% CI: 1.09, 1.57) and hepatic tumours (RR: 2.26, 95% CI: 1.32, 3.85). Sensitivity analysis validated evidence of the robustness of the findings. The results may demonstrate a possible association between fertility treatment and an increased risk of cancer among the offspring. However, the findings cannot say whether this increased risk is due to the subfertility itself or to the fertility treatment. Further research is needed to address the underlying mechanisms.

Rescue Adjuvant Vaginal Progesterone May Improve Outcomes in Cervical Cerclage Failure

Introduction Aim of the study was to evaluate the effect of rescue adjuvant vaginal progesterone in women with ongoing, transvaginal ultrasound (TVUS)-confirmed cervical shortening despite cervical cerclage.

Materials and Methods A retrospective case control study was performed of women undergoing cervical surveillance following either history- or ultrasound-indicated cervical cerclage. We compared women managed with cervical cerclage and vaginal progesterone to women managed with cervical cerclage alone. Women with a singleton pregnancy who underwent cervical cerclage were identified from a database. Data on the concurrent use of vaginal progesterone, cervical length measurements, interventions and birth outcomes were collected from patient notes and clinical pathology notes. Patients from each intervention group were matched, based on exact shortest cervical length measurements obtained during surveillance and age of gestation when the measurement was obtained.

Results 66 women were matched and included in the study, based on exact shortest cervical length measurements. Each group had an identical mean shortest cervical length of 12.09 mm. The outcomes of 33 women who received both cervical cerclage and vaginal progesterone were compared to the outcomes of 33 women who were treated with cervical cerclage alone. The administration of vaginal progesterone to women with ongoing cervical shortening despite cervical cerclage was found to significantly prolong the pregnancy (36.36 weeks vs. 32.63 weeks; p = 0.0036) compared to women treated with cerclage alone. This use of rescue adjuvant vaginal progesterone was also associated with higher birth weights (2829 g vs. 2134 g; p = 0.0065) compared to women who had cervical cerclage alone; however, there was no difference in Apgar scores, composite neonatal morbidity or neonatal intensive care admission.

Conclusion Women with cervical shortening despite the presence of cervical cerclage may benefit from further TVUS cervical length surveillance and the administration of vaginal progesterone if further cervical shortening occurs. Despite both groups having clinically significant shortened cervical lengths and cervical cerclage in situ, adjunct vaginal progesterone treatment resulted in older gestational age at birth and higher birth weight. Further investigation and confirmation of this finding in a larger prospective trial is warranted to explore this potential benefit for the management of preterm birth in future.

Controversies about the Secondary Prevention of Spontaneous Preterm Birth

Preterm birth is one of the major global health problems and part of the Millennium Development goals because of the associated high number of perinatal or neonatal mortality and long-term risks of neurodevelopmental and metabolic diseases. Transvaginal sonography has meanwhile been established as a screening tool for spontaneous preterm birth despite its relatively low sensitivity when considering only the cervical length. Vaginal progesterone has been shown to reduce prematurity rates below 34 weeks in a screening population of singleton pregnancies. Up to now, no positive long-term effect could be demonstrated after 2 years. It seems to have no benefit to prolong pregnancies after a period of preterm contractions and in risk patients without cervical shortening. Meta-analyses still demonstrate conflicting results dependent on quality criteria used for selection. A cerclage is only indicated in singleton pregnancies with previous spontaneous preterm birth and a combined cervical shortening in the current pregnancy. Nevertheless, the short- and long-term outcome has never been evaluated, whereas maternal complications may be increased. There is no evidence for a prophylactic cervical cerclage in twin pregnancies even in cases with cervical shortening. Emergency cerclage remains an indication after individual counseling. The effect of a cervical pessary in singleton pregnancy seems to be more pronounced in studies where a few investigators with increasing experience have treated and followed the patients at risk for preterm birth. Mainly in twin pregnancies, pessary treatment seems to be promising compared to other treatment options of secondary prevention when the therapy is started at early stages of precocious cervical ripening. At present, several international trials with the goal to reduce global rates of prematurity are in progress which will hopefully allow to specify the indications and methods of intervention for certain subgroups. When trials are summarized, prospective meta-analyses carry a lower risk of bias than the meanwhile uncontrolled magnitude of retrospective meta-analyses with conflicting results.

Prenatal and perinatal risk factors for solid childhood malignancies: A questionnaire-based study

IMPORTANCE

Childhood solid tumors account for the highest proportion of childhood cancers and are one of the leading causes of death in childhood. However, their pathogenesis is unclear.

OBJECTIVE

To explore prenatal and perinatal risk factors for solid malignancies in children.

METHODS

We enrolled 71 consecutive pediatric patients (44 boys and 27 girls; median age, 30 months) with solid tumors who were diagnosed and treated at our center from January 2013 to December 2016 as the case group. We also enrolled 211 age- and residence-matched healthy children (ratio of approximately 3:1 with the case group) as the control group. We conducted a questionnaire-based survey with the parents of these 282 children. Univariate and multivariate conditional logistic regression analyses of the collected data were performed.

RESULTS

Confirmed solid malignancies included neuroblastoma (n = 32), rhabdomyosarcoma (n = 18), retinoblastoma (n = 7), renal tumors (n = 3), and other tumors (n = 11). Risk factors for solid childhood tumors in the univariate analysis were the parents' age, gravidity, parity, abortion history, vaginal bleeding, family history of malignancy, and prenatal use of folic acid or hematinics/iron supplements (P < 0.05), and those in the multivariate analysis were higher parity (odds ratio [OR], 2.482; 95% confidence interval [CI], 1.521-4.048), family history of malignancy (OR, 3.667; 95% CI, 1.679-8.009), and prenatal use of hematinics/iron supplements (OR, 2.882; 95% CI, 1.440-5.767). In contrast, use of prenatal folic acid was protective (OR, 0.334; 95% CI, 0.160-0.694).

INTERPRETATION

A family history of malignancy, use of prenatal hematinics/iron supplements, and higher parity are risk factors for solid childhood tumors, whereas use of prenatal folic acid is a protective factor.

Prenatal administration of progestogens for preventing spontaneous preterm birth in women with a multiple pregnancy

BACKGROUND

Multiple pregnancy is a strong risk factor for preterm birth, and more than 50% of women with a twin pregnancy will give birth prior to 37 weeks' gestation. Infants born preterm are recognised to be at increased risk of many adverse health outcomes, contributing to more than half of overall perinatal mortality. Progesterone is produced naturally in the body and has a role in maintaining pregnancy, although it is not clear whether administering progestogens to women with multiple pregnancy at high risk of early birth is effective and safe.

OBJECTIVES

To assess the benefits and harms of progesterone administration for the prevention of preterm birth in women with a multiple pregnancy.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (1 November 2016) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the administration of a progestogen by any route for the prevention of preterm birth in women with multiple pregnancy. We did not include quasi-randomised or cross-over studies.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed reports identified by the search for eligibility, extracted data, assessed risk of bias and graded the quality of the evidence.

MAIN RESULTS

We included 17 trials, which all compared either vaginal or intramuscular (IM) progesterone with a placebo or no treatment, and involved a total of 4773 women. The risk of bias for the majority of included studies was low, with the exception of four studies that had inadequate blinding, or significant loss to follow-up or both, or were not reported well enough for us to make a judgement. We graded the evidence low to high quality, with downgrading for statistical heterogeneity, design limitations in some of the studies contributing data, and imprecision of the effect estimate. 1 IM progesterone versus no treatment or placeboMore women delivered at less than 34 weeks' gestation in the IM progesterone group compared with placebo (risk ratio (RR) 1.54, 95% confidence interval (CI) 1.06 to 2.26; women = 399; studies = 2; low-quality evidence). Although the incidence of perinatal death in the progesterone group was higher, there was considerable uncertainty around the effect estimate and high heterogeneity between studies (average RR 1.45, 95% CI 0.60 to 3.51; infants = 3089; studies = 6; I2 = 71%; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up.There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (RR 1.05, 95% CI 0.98 to 1.13; women = 2010; studies = 5; high-quality evidence); preterm birth less than 28 weeks (RR 1.08, 95% CI 0.75 to 1.55; women = 1920; studies = 5; moderate-quality evidence); infant birthweight less than 2500 g (RR 0.99, 95% CI 0.90 to 1.08; infants = 4071; studies = 5; I2 = 76%, moderate-quality evidence)). No childhood outcomes were reported in the trials. 2 Vaginal progesterone versus no treatment or placebo by doseThere were no clear group differences in incidence of preterm birth before 34 weeks (average RR 0.83, 95% CI 0.63 to 1.09; women = 1727; studies = 6; I2 = 46%; low-quality evidence). Although fewer births before 34 weeks appeared to occur in the progesterone group, the CIs crossed the line of no effect. Incidence of perinatal death was higher in the progesterone group, although there was considerable uncertainty in the effect estimate and the quality of the evidence was low for this outcome (RR 1.23, 95% CI 0.74 to 2.06; infants = 2287; studies = 3; low-quality evidence). No studies reported maternal mortality or major neurodevelopmental disability at childhood follow-up.There were no clear group differences found in any of the other maternal or infant outcomes (preterm birth less than 37 weeks (average RR 0.97, 95% CI 0.89 to 1.06; women = 1597; studies = 6; moderate-quality evidence); preterm birth less than 28 weeks (RR 1.22, 95% CI 0.68 to 2.21; women = 1569; studies = 4; low-quality evidence); infant birthweight less than 2500 g (RR 0.95, 95% CI 0.88 to 1.03; infants = 3079; studies = 4; I2 = 49%, moderate-quality evidence)). No childhood outcomes were reported in the trials.For secondary outcomes, there were no clear group differences found in any of the other maternal outcomes except for caesarean section, where women who received vaginal progesterone did not have as many caesarean sections as those in the placebo group, although the difference between groups was not large (7%) (RR 0.93, 95% CI 0.88 to 0.98; women = 2143; studies = 6; I2 = 0%). There were no clear group differences found in any of the infant outcomes except for mechanical ventilation, which was required by fewer infants whose mothers had received the vaginal progesterone (RR 0.61, 95% CI 0.48 to 0.77; infants = 3134; studies = 5).

AUTHORS' CONCLUSIONS

Overall, for women with a multiple pregnancy, the administration of progesterone (either IM or vaginal) does not appear to be associated with a reduction in risk of preterm birth or improved neonatal outcomes.Future research could focus on a comprehensive individual participant data meta-analysis including all of the available data relating to both IM and vaginal progesterone administration in women with a multiple pregnancy, before considering the need to conduct trials in subgroups of high-risk women (for example, women with a multiple pregnancy and a short cervical length identified on ultrasound).

Literature review on cancer risk in children born after fertility treatment suggests increased risk of haematological cancers

Medically assisted fertility treatment, including assisted reproductive technology (ART), is increasingly being used and the subsequent child health outcomes are of interest. Some studies have suggested an elevated risk of somatic morbidity, while others have reported an elevated cancer risk. This review summarises the literature on fertility treatments and childhood cancer, based on 23 cohort and case-control studies.

CONCLUSION

The findings varied, but reassuring results on overall childhood cancer and fertility treatment were observed. However, some studies suggested an elevated risk of haematological cancers. More large population-based studies are needed, and the growing population of ART children should be monitored.

Fertility treatments and pediatric neoplasms of the offspring: results of a population-based cohort with a median follow-up of 10 years

OBJECTIVE

Studies have questioned the long-term health effects of offspring conceived after fertility treatments.

METHODS

We aimed to evaluate whether an association exists between mode of conception (in vitro fertilization, ovulation induction, or spontaneous pregnancy) and neoplasm risk (both benign and malignant tumors) among the offspring; we observed the offspring for up to 18 years.

STUDY DESIGN

A population-based cohort analysis was performed that compared the risk for neoplasms among children (up to the age of 18 years) based on mode of conception. Neoplasm diagnoses were based on hospital records of the same single tertiary center in the region. All singletons born during from 1991-2013 and discharged alive were included in the study. Offspring with congenital malformations were excluded from the analysis. Kaplan-Meier survival curves were constructed to compare cumulative neoplasms incidence; multivariable survival analyses were used to control for confounders that included gestational age, pregnancy complications, and maternal factors.

RESULTS

During the study period, 242,187 newborn infants met the inclusion criteria: 2603 (1.1%) were conceived after in vitro fertilization; 1721 (0.7%) were conceived after ovulation induction treatments, and 237,863 (98.3%) were conceived spontaneously. During the follow-up period (median, 10.55 years), 1498 neoplasms(0.6%) were diagnosed. Incidence density rate for neoplasms was higher among children conceived either after in vitro fertilization (1.5/1000 person years) or ovulation induction treatments (1.0/1000 person years), as compared with naturally conceived children (0.59/1000 person years; Kaplan-Meier log rank, P<.001). The association between in vitro fertilization and total pediatric neoplasms and the association between any fertility treatments and malignancies remained significant; we controlled for confounders such as gestational diabetes mellitus, hypertensive disorders, preterm birth, and maternal age (adjusted hazard ratio, 2.48; 95% confidence interval, 1.71-3.50; and adjusted hazard ratio, 1.96; 95% confidence interval, 1.14-3.36, for all neoplasms and all malignancies, respectively).

CONCLUSION

Children conceived after fertility treatments are at an increased risk for pediatric neoplasms.

Childhood Cancer Risk in the Siblings and Cousins of Men with Poor Semen Quality

PURPOSE

Poor semen quality is associated with reduced somatic health and increased cancer risk. Infertility and cancer are increasingly being linked by epidemiologists and basic scientists. We sought to identify semen parameters associated with an increased childhood cancer risk in the family members of subfertile men.

MATERIALS AND METHODS

We performed a retrospective cohort study in men from the SHARE (Subfertility Heath and Assisted Reproduction) study who underwent semen analysis between 1994 and 2011. We used fertile population controls from the Utah Population Data Base. Our primary outcome was the risk of any childhood (18 years or younger) cancer in the siblings and cousins of men who underwent semen analysis compared to fertile, age matched controls. Cox proportional hazard regression models were used to test the association between semen quality and childhood cancer incidence.

RESULTS

We selected 10,511 men with complete semen analysis and an equal number of fertile controls. These men had a total of 63,891 siblings and 327,753 cousins. A total of 170 and 958 childhood cancers were identified in siblings and cousins, respectively. The 3 most common cancers diagnosed in siblings were acute lymphoblastic leukemia in 37, brain cancer in 35 and Hodgkin lymphoma in 15. Oligozoospermia was associated with a twofold increased risk of any childhood cancer and a threefold increased risk of acute lymphoblastic leukemia in the siblings of subfertile men compared to fertile controls (HR 2.09, 95% CI 1.18-3.69 vs HR 3.07, 95% CI 1.11-8.46).

CONCLUSIONS

Siblings of men with oligozoospermia are at increased risk for any-site cancer and acute lymphoblastic leukemia. This suggests a shared genetic/epigenetic insult or an environmental exposure that merits further investigation.

Vaginal progesterone combined with cervical pessary: A chance for pregnancies at risk for preterm birth?

BACKGROUND

Precocious cervical ripening, as defined by cervical shortening on transvaginal sonography, has prompted a broad evaluation of secondary strategies (such as cerclage, vaginal progesterone, or a cervical pessary) to prevent preterm delivery. However, there is still a lack of direct comparisons between individual treatments or their combinations.

OBJECTIVE

We sought to compare at-risk patients and screening patients who had been treated with cervical pessary alone with patients who had been treated with pessary plus vaginal progesterone.

STUDY DESIGN

This is a pre- and postintervention cohort study from a preterm labor clinic where placement of a cervical pessary has been the standard treatment since 2008 for at-risk women defined by (1) a history of spontaneous preterm birth at <37 weeks of gestation, (2) conization, or (3) a cerclage because of a previous short cervical length of <3rd percentile and, additionally, with a cervical length of <10th percentile in the ongoing pregnancy. Patients who did not meet the criteria for the "at risk" group, but who had a cervical length of <3rd percentile comprised the screening group. From July 2011 onward, vaginal progesterone (200 mg, suppositories) was prescribed in addition to the pessary. Both at-risk patients (n = 55) and screening patients (n = 51) were treated at the time of diagnosis. The primary outcome was the rate of preterm deliveries at <34 weeks of gestation. Secondary outcomes included deliveries at <28, <32, and <37 weeks of gestation, the days from start of therapy until delivery, a composite index of neonatal outcome, and the number of days in the neonatal intensive care unit. Primary and secondary outcomes were compared between groups with the use of multivariable models to adjust for possible confounders.

RESULTS

Delivery at <34 weeks of gestation occurred in 17 of 53 patients (32.1%) who were treated with pessary plus progesterone, compared with 13 of 53 patients (24.5%) who were treated with pessary alone (P = .57). Similarly, there was no difference in the rate of preterm delivery at <28, <32, or <37 weeks of gestation. The composite poor neonatal outcome was 15.1% in the pessary group vs 18.9% in the combined group (P = .96). The mean duration of stay in the neonatal intensive care unit was 46.5 days (range, 9-130 days) in the combined vs 52.0 days (range, 3-151 days) in the pessary group (P < .001).

CONCLUSION

In this cohort study, treatment of precocious cervical ripening with cervical pessary plus vaginal progesterone did not reduce the rates of preterm delivery at <28, <32, <34, or <37 weeks of gestation compared with pessary alone. The neonatal intensive care use was shorter in patients who received additional vaginal progesterone, although there was no difference in composite poor neonatal outcome. These preliminary results may serve as a pilot for future trials and provide a basis for treatment until larger trials are completed.

Risk of Cancer in Children Conceived by Assisted Reproductive Technology

BACKGROUND AND OBJECTIVE

An increasing number of children are born after assisted reproductive technology (ART), and monitoring their long-term health effects is of interest. This study compares cancer risk in children conceived by ART to that in children conceived without.

METHODS

The Medical Birth Registry of Norway contains individual information on all children born in Norway (including information of ART conceptions). All children born between 1984 and 2011 constituted the study cohort, and cancer data were obtained from the Cancer Registry of Norway. Follow-up started at date of birth and ended on the date of the first cancer diagnosis, death, emigration, or December 31, 2011. A Cox proportional hazards model was used to calculate hazard ratios (HR) and 95% confidence intervals (CI) of overall cancer risk between children conceived by ART and those not. Cancer risk was also assessed separately for all childhood cancer types.

RESULTS

The study cohort comprised 1 628 658 children, of which 25 782 were conceived by ART. Of the total 4554 cancers, 51 occurred in ART-conceived children. Risk of overall cancer was not significantly elevated (HR 1.21; 95% CI 0.90-1.63). However, increased risk of leukemia was observed for children conceived by ART compared with those who were not (HR 1.67; 95% CI 1.02-2.73). Elevated risk of Hodgkin's lymphoma was also found for ART-conceived children (HR 3.63; 95% CI 1.12-11.72), although this was based on small numbers.

CONCLUSIONS

This population-based cohort study found elevated risks of leukemia and Hodgkin's lymphoma in children conceived by ART.