Neonatal outcome of spontaneous and assisted twin pregnancies

Concordance of the risk of neonatal respiratory morbidity assessed by quantitative ultrasound lung texture analysis in fetuses of twin pregnancies

To evaluate the concordance of the risk of neonatal respiratory morbidity (NRM) assessed by quantitative ultrasound lung texture analysis (QuantusFLM) between twin fetuses of the same pregnancy. Prospective study conducted in twin pregnancies. Fetal ultrasound lung images were obtained at 26.0–38.6 weeks of gestation. Categorical (high or low) and continuous results of the risk of NRM were compared between twins. Fetal ultrasound lung images from 131 pairs (262 images) of twins were included. The images were classified into three gestational age ranges: Group 1 (26.0–29.6 weeks, 78 images, 39 pairs [29.8%]); Group 2 (30.0–33.6 weeks, 98 images, 49 pairs [37.4%]) and Group 3 (34.0–38.6 weeks, 86 images, 43 pairs [32.8%]). Concordance was good in Groups 1 and 3 and moderate in Group 2. In Groups 2 and 3 at least one fetus presented high-risk results in 26.5% and 11.6% of twin pairs, respectively. Only gestational age < 32 weeks, gestational diabetes mellitus, and spontaneous conception were associated with a high risk of NRM in Group 2. There was good concordance of the risk of NRM between twins < 30.0 weeks and > 34.0 weeks. From 30.0 to 33.6 weeks 26.5% of the twin pairs had discordant results, with moderate concordance of the risk of NRM.

Exploring co-occurrence of sensory, motor and neurodevelopmental problems and epilepsy in children with severe-profound intellectual disability

BACKGROUND

Severe to profound intellectual disability (SPID) is associated with multiple neurodevelopmental disorders and problems. In the most severe cases, the term profound intellectual and multiple disabilities (PIMD) is used. This study aimed to explore the co-occurring disorders and neurodevelopmental problems in a sample of twins where the proband had SPID.

METHOD

Within a population-based sample of (30 312) twins, 20 individuals with a national patient register SPID diagnosis were identified. Parent telephone interview data (screening of neurodevelopmental disorders) and register data (APGAR, birth weight, intellectual disabilities, epilepsy, motor and sensory disorders) were gathered for probands and co-twins.

RESULTS

The 20 individuals with SPID all had between one and five additional disorders or problems, with autistic traits, motor problems and epilepsy being the most common. Clear discordance was found for ID and all additional disorders and problems between probands with SPID and their non-SPID co-twins.

CONCLUSION

Children with SPID almost never present without neurodevelopmental and/or sensory and/or motor comorbidities. This heterogeneity should be reflected in clinical routine and in research targeting individuals with SPID. The results support a previously suggested conceptualization of a S/PIMD "spectrum". Autism may be considered for inclusion in future elaborations of such a S/PIMD spectrum.

The co-occurrence of neurodevelopmental problems in dyslexia

The primary aim of this study was to explore the overlaps between dyslexia and a range of neurodevelopmental disorders and problems (NDPs), specifically symptoms of attention-deficit/hyperactivity disorder, autism spectrum disorder, atypical sensory perception and developmental coordination disorder. Capitalizing on a population-based sample of twins, secondary aims included estimating the heritability of dyslexia and reporting on the measurement characteristics of the scale used to assess dyslexia. A telephone interview regarding symptoms of dyslexia and other NDPs was conducted with parents of 1,688 nine-year-old twins. The prevalence and the heritability of dyslexia were estimated at 8 and 52%, respectively. The boy: girl ratio was 1.5:1. Results revealed that there was more than an eight-fold increase in (diagnostic proxy) NDPs prevalence in the dyslexia group as compared to typical readers. Quantitatively measured symptoms of inattention, oral language problems and atypical sensory perception significantly predicted dyslexia status in a multivariate analysis. By contrast, ASD-related inflexibility was inversely associated with dyslexia in the multivariate model. In sum, dyslexia often overlaps with other NDPs. The current study provides new knowledge supporting the position to move beyond isolated diagnostic categories into behavioural profiles of co-occurring problems when trying to understand the pattern of strengths and needs in individuals with dyslexia.

The impact of fertility treatment on the neonatal respiratory outcomes and amniotic lamellar body counts in twin pregnancies

BACKGROUND

To elucidate the impact of fertility treatment on neonatal respiratory outcomes and amniotic lamellar body counts (LBCs) in twin pregnancies.

METHODS

One hundred ninety twin pairs, including 99 dichorionic twin (DCT) and 91 monochorionic twin (MCT) pairs were registered at our institutions. All amniotic fluid samples were obtained from each sac at cesarean section. Samples were analyzed immediately after arrival at the laboratory without centrifugation. We divided the patients into 3 groups: the no therapy group (natural conception), the induced ovulation group (with or without intrauterine insemination), and the assisted reproductive technology (ART) group (in vitro fertilization or intracytoplasmic sperm injection).

RESULTS

No statistically significant associations between the fertility treatment and the rates of neonatal RDS/TTN were observed in the whole study population (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.45-2.00), DCT (OR, 0.86; 95%CI, 0.30-2.47), and MCT (OR, 1.45; 95%CI, 0.41-5.11). In addition, there was no association between the fertility treatment and neonatal RDS/TTN in the propensity score analysis of the whole study population (OR, 1.25; 95%CI, 0.57-2.74).

CONCLUSIONS

None of the individual types of fertility treatment had a direct impact on respiratory disorders such as RDS and TTN in twin infants.

Dizygotic twin pregnancies after medically assisted reproduction and after natural conception: maternal and perinatal outcomes

OBJECTIVE

To compare maternal and perinatal outcomes in dizygotic twin pregnancies conceived after medically assisted reproduction (MAR) with outcomes after natural conception (NC).

DESIGN

Nationwide registry based study.

SETTING

Academic medical center.

PATIENT(S)

Primiparous women who delivered opposite sex twins between January 2000 and December 2012 in the Netherlands, comprising dizygotic twin pregnancies: 6,694 women, 470 after ovulation induction (OI), 511 after intrauterine insemination with controlled ovarian hyperstimulation (IUI-COH), 2,437 after in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI), and 3,276 after NC.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Multivariable logistic regression and generalized linear mixed models to evaluate differences in outcomes: maternal outcomes of hypertension, preeclampsia, preterm delivery, hemorrhage, and delivery mode, perinatal outcomes including small for gestational age (SGA) with birth weight <10th percentile, birth weight <1,500 g, 5-minute Apgar score <7, admission to neonatal intensive care unit, congenital anomalies, and perinatal mortality.

RESULT(S)

We found no statistically significant differences in maternal or perinatal outcomes after OI compared with NC. Women pregnant after IVF-ICSI had a lower risk for hypertension (adjusted odds ratio [aOR] 0.74; 95% confidence interval [CI], 0.66-0.83) compared with women pregnant after NC. After IUI-COH more children had Apgar scores <7 (adjusted odds ratio (aOR) 1.38; 95% confidence interval (CI) 1.05-1.81) and perinatal mortality rates were higher (aOR 1.56; 95% CI, 1.04-2.33) compared with NC. We found no differences in perinatal outcomes after IVF-ICSI compared with NC.

CONCLUSION(S)

Overall, maternal and perinatal risks other than those due to multiplicity are similar for twin pregnancies conceived after MAR and after NC.

Differential effect of mode of conception and infertility treatment on fetal growth and prematurity

Objectives To examine perinatal outcomes in pregnancies conceived by different methods: fertile women with spontaneous pregnancies, infertile women who achieved pregnancy without treatment, pregnancies achieved by ovulation induction (OI) and in vitro fertilization or intra-cytoplasmic sperm injection (IVF/ICSI). Methods Retrospective single-center cohort study including 200 fertile and 748 infertile women stratified according to infertility treatment. The outcome measurements were preterm delivery (PTD), small-for-gestational-age (SGA), gestational diabetes, placenta previa or preeclampsia. Results The overall rate of pregnancy complications was significantly increased in all infertility groups regardless of the infertility treatment (adjusted odds ratio (OR): infertile without treatment 2.3 versus OI 2.2 versus IVF/ICSI 3.4). While PTD was mainly associated to IVF/ICSI (adjusted OR: infertile without treatment 1.3 versus OI 1.6 versus IVF/ICSI 3.3), SGA was significantly associated to both OI and IVF/ICSI (adjusted OR: infertile without treatment 1.9 versus OI 2.7 versus IVF/ICSI 2.6). All these associations remained statistically significant after adjusting by maternal age and twin pregnancy. Conclusions This study confirms the higher prevalence of pregnancy complications in infertile women irrespectively of receiving infertility treatment or not, and further describes a preferential association of prematurity with IVF/ICSI, and SGA with treated infertility (OI and IVF/ICSI).

Twin-to-twin delivery time: neonatal outcome of the second twin

OBJECTIVE

To examine the effect of twin-to-twin delivery time (TTDT) on neonatal outcome.

METHODS

We evaluated twin deliveries >34 weeks of gestation. Twin pregnancies with both twins delivered by cesarean section and pregnancies with antenatal complications were excluded. We analyzed TTDT and neonatal outcomes of the second twin (umbilical arterial pH value (pH(art)), Apgar scores at 1, 5 and 10 minutes, need for intensive care). The study population was divided into two homogenous groups based on the mode of delivery: (A) vertex presentation and vaginal delivery of both twins, (B) vertex presentation and vaginal or vaginal operative delivery of twin I, breech or transverse presentation and vaginal breech delivery or cesarean section (CS) of twin II.

RESULTS

A total of 207 twin pairs were included in our study. In Group A (n = 151) there were no significant correlations between TTDT and pH(art) or Apgar scores at 1,5 and 10 minutes of twin II (p = .156; 0.861; 0.151 and 0.384, respectively). In Group B (n = 56), the mean pH(art) of twin II was inversely correlated to TTDT, but not significantly (p = .417). TTDT was inversely related to 1-min and 5-min Apgar scores, but not significantly (p = .330; p = .138, respectively). The 10-min Apgar score showed no correlation with TTDT (p = .638).

CONCLUSION

Increasing TTDT was not associated with adverse fetal outcome. Expectant management of the second twin appears possible and elapsed time alone does not appear to be an indication for intervention.

[Twin delivery with the first twin in breech position. A study of 137 continuous cases]

AIM

The first twin (T1) in breech position is at risk of complications during vaginal delivery, making the choice of the appropriate delivery route highly important. Although British and American practice guidelines recommend the cesarean section, the French National College of Obstetricians and Gynecologists concluded that there was not enough data to choose one delivery route or the other. In this context, we set out to describe practices in our centre.

MATERIAL AND METHODS

Our retrospective study was conducted at a level III labor ward between January 1st, 1995 and December 31st, 2006. One hundred and thirty-seven twin pregnancies at more than 26 gestational weeks (GW), with T1 in breech and T2 in any position, were included.

RESULTS

A cesarean section was performed before labor in 60.6 % cases. Among the 54 (39.4 %) cases where a trial of labor was accepted, 29 patients (53.7 % success rate) delivered vaginally and 25 (46.3 %) had a cesarean section during labor. No statistical difference was observed between the neonatal outcomes after cesarean section as compared to vaginal birth. However, a significant relationship was found between delivery route and parity. Less than one-third of nulliparas versus two-third of patients with a history of at least one delivery, having trials of labor, ultimately gave birth vaginally. Thus, we observed a high rate of cesarean section during labor in nulliparas (68 % of the initially accepted trials of labor).

CONCLUSION

Our study is the first one that clearly shows that the success rate of the trial of labor is closely related to a history of vaginal birth. Following these results and because of more than two-third of cesarean section during labor in nulliparas, we subsequently plan an elective cesarean section at the 38th GW for nulliparas with twin pregnancies and T1 in breech position. Nevertheless, if any of these patients go in labor before the cesearean section, a careful trial of labor is offered.

Toward a bioethical issue: induced multiple pregnancies and neonatal outcomes

Assisted reproductive technology has made great progress during the last three decades. After the initial enthusiasm, many ethical, legal and social issues related to the application of these procedures began to evolve. Multifetal pregnancy and fetal reduction, embryo cryopreservation, preimplantation genetic diagnosis, risks of birth defects and other adverse outcome associated with assisted reproductive technology are issues that have to be addressed building future collaborative studies and continuing the debate on related ethical issues.

Twins born following assisted reproductive technology: perinatal outcome and admission to hospital

BACKGROUND

Compared with spontaneously conceived (SC) singletons, adverse perinatal outcome, neonatal intensive care unit (NICU) admission and hospital admission in infancy are more common in those born following Assisted Reproductive Technology (ART). Similar comparisons for twins have shown conflicting results.

METHODS

We investigated perinatal outcome and hospital admission during the first 3 years of life for all twin children born in Western Australia between 1994 and 2000 [700 ART, 4097 SC].

RESULTS

ART twins had a greater risk of adverse perinatal outcome including preterm birth, low birthweight and death compared with SC twins of unlike-sex. In their first year of life, ART twins had a longer birth admission; were 60% more likely to be admitted to a NICU; and had a higher risk of hospital admission. The increased risk of hospital admission continued in the second and third year but was not statistically significant in the third year.

CONCLUSIONS

Couples undertaking ART should be aware that in addition to the known increased perinatal risks associated with a twin birth, ART twins are more likely than SC twins to be admitted to a NICU and hospitalized in the first 3 years of life.

Advanced maternal age and risk of antepartum and intrapartum stillbirth

AIM

We sought to assess the risk of antepartum and intrapartum stillbirth subtypes among women of advanced age.

METHODS

This is a retrospective cohort study using the Missouri maternally linked data containing births from 1978 to 1997. We examined the impact of maternal age on total, antepartum and intrapartum stillbirth across five maternal age group quintiles (20-24, 25-29, 30-34, 35-39 and >or=40) using mothers aged 20-24 years as the referent category. By means of the Cox proportional hazards regression models we obtained adjusted hazards ratios that quantified the magnitude of association between maternal age and the stillbirth subtypes.

RESULTS

The rates of antepartum and intrapartum stillbirth were greatest for older mothers (9.3/1000 and 1.2/1000 respectively) and lowest for gravidas aged 25-29 years (3.6/1000 and 0.8/1000 respectively). After adjusting for potentially confounding characteristics, older mothers still remained at greatest risk for antepartum and intrapartum stillbirth (adjusted hazards ratio = 3.6, 95% confidence interval = 2.9-4.4; and adjusted hazards ratio = 2.7, 95% confidence interval = 2.0-3.6 for antepartum and intrapartum stillbirth respectively). The risks for the two subtypes of stillbirth also increased with ascending maternal age in a dose-dependent pattern.

CONCLUSIONS

As the demographic distribution of pregnant women persistently shifts to the right, care-providers will be increasingly confronted with elevated risks for adverse fetal outcomes among older mothers. Our results confirm this phenomenon and add new findings in relation to the elevated risk for intrapartum stillbirth among mothers advanced for age.

Neonatal outcomes in triplet pregnancies: assisted reproduction versus spontaneous conception

AIMS

The purpose of this study is to compare neonatal outcomes of spontaneously conceived triplets with triplets conceived by assisted reproduction.

METHODS

This was a retrospective cohort study of all cases from assisted triplet pregnancies and controls from spontaneous triplet pregnancies. A total of 24 triplet pregnancies were studied: six spontaneous and 18 assisted. The following variables were evaluated in all newborns: prematurity, birth-weight, small for gestational age, birth-weight discordance, Apgar scores, major neonatal morbidity and perinatal mortality.

RESULTS

Gestational age (33+/-1 vs. 33+/-2 weeks) and birth-weight (1760+/-256 vs. 1907+/-452 g) were similar in spontaneous and assisted triplet pregnancies. There were no significant differences in the rates of small for gestational age, discordance, and major neonatal morbidity. In the assisted reproduction group only the following cases were recorded: 1 surgically treated patent ductus arteriosus, 1 feto-fetal transfusion syndrome, 2 grade II intraventricular hemorrhage, 1 Cri du Chat syndrome and 1 stillbirth with malformations.

CONCLUSIONS

This study is unable to assess the influence of assisted reproduction on the neonatal outcomes of triplet pregnancies. However, the results suggest that the incidence of major neonatal morbidity, especially malformations, might increase due to assisted reproduction. This finding requires further confirmation.

Twin pregnancy outcome among cases of spontaneous conception, intrauterine insemination, and in vitro fertilization/intracytoplasmic sperm injection

In a retrospective university hospital-based study of spontaneously conceived (SC), intrauterine insemination (IUI), and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) groups, this study finds maternal complications or the neonatal outcomes of twins to be similar between the groups.

Twin gestation in older women: antepartum, intrapartum complications, and perinatal outcomes

OBJECTIVE

The aim of this study is to present pregnancy and perinatal outcomes of twin gestations in older women and compare them with that for younger women.

STUDY DESIGN

We conducted a retrospective cohort study of twin pregnancies in our department between 1988 and 2003. The women were classified into two groups by maternal age: women of age 35 years and older (study group) and women less than 35 years (control group). Population characteristics, complications during pregnancy and delivery, and neonatal outcomes were assessed. The Student's t-test, chi2 test, Fisher exact test, and binary logistic regression analysis were used to examine the relationship between maternal age and the different variables.

RESULTS

A total of 238 twin pregnancies were enrolled (study group, 57 women; control group, 181 women). Spontaneous conceptions were significantly higher in the control group (P < 0.001), while conceptions after in vitro fertilization (IVF) were significantly higher in study group (P < 0.001). Mean figures of gestational age at delivery and birth weight for the older group did not differ significantly from the younger group. Although the antepartum and intrapartum complications were more common in the study group, they were not statistically significant compared to the control group. This was also true for the perinatal outcomes. Only the very low birth weight (VLBW < 1,500 g) rate was significantly higher in the study group. The number of perinatal deaths was similar on comparison by maternal age.

CONCLUSIONS

Based on our study, advanced maternal age at twin gestation does not seem to affect significantly pregnancy complications and perinatal outcomes. VLBW was the only unfavorable perinatal outcome related to advanced maternal age.

IVF/ICSI twin pregnancies: risks and prevention

Since the 1970s, the national twin birth rates have been increasing worldwide. Apart from the increasing childbearing age, the main cause is the use of assisted reproductive technologies (ART). To explore the overall consequences of dual embryo transfer (DET), the literature has been reviewed systematically regarding short- and long-term outcomes of IVF/ICSI twin pregnancies i.e. pregnancy complications, maternal risks, obstetric outcome and long-term morbidity including neurological sequelae, cognitive development and family implications. Another consequence of DET is vanishing twins, which seems to be a possible cause of adverse outcome in IVF singletons. The sparse literature on vanishing twins in IVF pregnancies and the influence on the surviving co-twin were also addressed. Finally, to determine the effects of implementing elective single embryo transfer (eSET), trials concerning eSET versus DET were analysed. In the light of the steadily increasing twin birth rates and the findings in this overview, where IVF/ICSI twins carry adverse outcome, it should be emphasized that the major obstacle in IVF remains the high twin birth rate. Furthermore vanishing twins account for another hazard of DET. These problems can be resolved by implementing eSET, diminishing the twin birth rate without affecting the overall goal of achieving a healthy infant.

Obstetric outcome in women with subfertility

BACKGROUND

It has been suggested that a history of subfertility is associated with increased obstetric and perinatal risks. It is unclear if the cause is inherent characteristics in the women or the fertility treatment.

OBJECTIVES

To compare the obstetric and perinatal risks of singleton pregnancies in women with a history of subfertility in comparison with the general population.

DESIGN

Population cohort.

SETTING

Aberdeen, Scotland.

POPULATION

Cases were women attending the Fertility Clinic between 1989 and 1999 who subsequently went on to have singleton pregnancies. Controls included the general population of women who delivered singletons over the same period.

METHODS

We performed a retrospective cohort study to investigate the obstetric outcome of singleton pregnancies in women with subfertility. The general population of women who delivered singletons over the same period served as controls.

MAIN OUTCOME MEASURES

Obstetric and perinatal complications in singleton pregnancies.

RESULTS

Maternity records were available for a total of 1437 subfertile women and 21,688 controls. Subfertile women were older [mean (SD) age: 31 (4.7) years vs 27 (5.4) years, P < 0.01] and more likely to be primiparous (70% vs 65%, P < 0.001). After adjusting for age and parity, subfertile women were at increased risk of pre-eclampsia (OR 1.9, 95% CI 1.5-2.5), placenta praevia (OR 3.9, 95% CI 2.2-7.0) and placental abruption (OR 1.8, 95% CI 1.1-3.0), and more likely to undergo induction of labour (OR 1.5, 95% CI 1.3-1.6), caesarean section (OR 2.1, 95% CI 1.8-2.4) and instrumental delivery (OR 2.2, 95% CI 1.8-2.6), and deliver low birthweight (OR 1.4, 95% CI 1.3-1.7) and preterm (OR 1.7, 95% CI 1.2-2.2) infants. There were no differences between treatment-related and treatment-independent pregnancies.

CONCLUSION

Subfertile women are at higher risk of obstetric complications, which persist after adjusting for age and parity.

Assisted reproductive technologies and the risk of birth defects—a systematic review

BACKGROUND

The risk of birth defects in infants born following assisted reproductive technology (ART) treatment is a controversial question. Most publications examining the prevalence of birth defects in ICSI and IVF infants compared to spontaneously conceived infants have serious methodological limitations; despite this, most researchers have concluded that there is no increased risk.

METHODS

We carried out a systematic review to identify all papers published by March 2003 with data relating to the prevalence of birth defects in infants conceived following IVF and/or ICSI compared with spontaneously conceived infants. Independent expert reviewers used criteria defined a priori to determine whether studies were suitable for inclusion in a meta-analysis. Fixed effects meta-analysis was performed for all studies and reviewer-selected studies.

RESULTS

Twenty-five studies were identified for review. Two-thirds of these showed a 25% or greater increased risk of birth defects in ART infants. The results of meta-analyses of the seven reviewer-selected studies and of all 25 studies suggest a statistically significant 30-40% increased risk of birth defects associated with ART.

CONCLUSIONS

Pooled results from all suitable published studies suggest that children born following ART are at increased risk of birth defects compared with spontaneous conceptions. This information should be made available to couples seeking ART treatment.

Quality of intrapartum cardiotocography in twin deliveries

OBJECTIVE

Intrapartum fetal heart rate (FHR) recordings in twins were compared for fetal signal loss during both stages of labor to assess the quality of these recordings by the method that had been used: external ultrasound or directly via a scalp electrode.

STUDY DESIGN

Analysis of recordings collected between January 1, 1994, and January 1, 2002, from consecutive twin deliveries at the Vrije Universiteit Medical Center in Amsterdam. One hundred seventy-two twins that delivered via the vaginal route were included in the study. FHR recordings had a duration of at least 1 hour before the birth of the second twin. Subdivision took place on the basis of the recording technique, ie, ultrasound or scalp electrode. FHR data was obtained with HP-M1350 cardiotocographs. The status (pen on, pen off, maternal signal) and the mode of the signals were acquired. The duration of pen lifts and maternal signals was divided by the total duration of the recording. Statistical analyses were performed with the Mann-Whitney U test and the Wilcoxon signed ranks test.

RESULTS

Recordings obtained via ultrasound demonstrated significantly more fetal signal loss than those obtained via the direct mode, particularly in the second stage. Approximately 26% to 33% of first stage and 41% to 63% of second stage ultrasound intrapartum FHR recordings in twins exceeded the International Federation of Gynecology and Obstetrics (FIGO) criteria for fetal signal loss.

CONCLUSION

Intrapartum FHR monitoring via ultrasound provides far poorer quality FHR signals than the direct mode. The direct mode deserves a more prominent position in fetal surveillance than it currently has.

Delivery of the term twin

The ever-increasing incidence of twin pregnancies world wide, together with the increasing trend to caesarean delivery, has resulted in intense scrutiny of the most appropriate method of twin delivery. The term twin has an increased risk of twin mortality compared to term singletons and this might be a result of the increase risk of labour and delivery compared to that of singletons. There are three ways to address this from the literature. The first is to compare outcome for the second twin versus the first twin, and to compare these outcomes in those twins delivered vaginally compared to those delivered by lower section caesarean section (LSCS). The second is to compare outcomes for twins delivered vaginally and for those delivered by caesarean section (CS). These data show higher rates of adverse perinatal outcome for the twin at or near term if delivery is vaginal versus CS. The third method is to compare outcomes for twins delivered by planned vaginal birth (VB; actual VB plus emergency CS) versus planned CS. This chapter will review this data thus outline an ongoing randomized controlled trial--the Twin Birth Study.

The risk of birth defects in children born after assisted reproductive technologies

PURPOSE OF REVIEW

This review addresses the question of whether there is evidence of an increased risk of birth defects in children born following assisted reproductive technologies compared with spontaneously conceived children.

RECENT FINDINGS

Three recent studies added relatively little new information given their modest size (56-472 assisted reproductive technology children). We therefore considered all published papers that compared birth defects in children born following assisted reproductive technologies with those in children born following spontaneous conception. Overall, only six of the 26 relevant papers concluded there was an increased risk of birth defects following assisted reproductive technologies. The interpretation of many studies was based on statistical significance testing alone. When results showed a greater proportion of defects in the assisted reproductive technology group compared with the spontaneous group, but the results were not statistically significant, this was often interpreted as showing no increase in risk, rather than an increase in risk that may have been due to chance. The vast majority of individual studies were too small to have sufficient power to detect, as statistically significant, clinically relevant results. We found that although only eight (30%) of the studies had statistically significant results, 24 (89%) had an odds ratio estimate comparing assisted reproductive technology with spontaneously conceived children of over 1.0; 19 (70%) had an estimate of 1.20 or greater; and 14 (52%) had an estimate of 1.5 or greater.

SUMMARY

Current evidence suggests there is an elevated risk of birth defects in children born following assisted reproductive technologies. Whilst others may disagree with our interpretation, one certainly cannot exclude this possibility on the basis of the current evidence.