Perinatal outcomes of in vitro fertilization twins: a systematic review and meta-analyses

Maternal and perinatal outcomes in twin pregnancies following assisted reproduction: a systematic review and meta-analysis involving 802 462 pregnancies

BACKGROUND

ART is associated with higher rates of twin pregnancies than singleton pregnancies. Whether twin pregnancies conceived following ART have additional maternal and neonatal complications compared with non-ART twin pregnancies is not known.

OBJECTIVE AND RATIONALE

The objective was to quantify the risk of adverse maternal and perinatal outcomes among twin pregnancies conceived following ART compared with non-ART and natural conception. Existing reviews vary in the reported outcomes, with many studies including triplet pregnancies in the study population. Therefore, we aimed to perform an up-to-date review with an in-depth analysis of maternal and perinatal outcomes limited to twin pregnancies.

SEARCH METHODS

We searched electronic databases MEDLINE and EMBASE from January 1990 to May 2023 without language restrictions. All cohort studies reporting maternal and perinatal outcomes following ART compared with non-ART twin pregnancies and natural conception were included. Case-control studies, case reports, case series, animal studies, and in vitro studies were excluded. The Newcastle-Ottawa Scale was used to assess the methodological quality of the studies. Using random-effects meta-analysis, the estimates were pooled and the findings were reported as odds ratios (OR) with 95% CI.

OUTCOMES

We included 111 studies (802 462 pregnancies). Twin pregnancies conceived following ART were at higher risk of preterm birth at <34 weeks (OR 1.33, 95% CI 1.14-1.56, 29 studies, I2 = 73%), <37 weeks (OR 1.26, 95% CI 1.19-1.33, 70 studies, I2 = 76%), hypertensive disorders in pregnancy (OR 1.29, 95% CI 1.14-1.46, 59 studies, I2 = 87%), gestational diabetes mellitus (OR 1.61, 95% CI 1.48-1.75, 51 studies, I2 = 65%), and caesarean delivery (OR 1.80, 95% CI 1.65-1.97, 70 studies, I2 = 89%) compared with non-ART twins. The risks for the above maternal outcomes were also increased in the ART group compared with natural conception. Of the perinatal outcomes, ART twins were at significantly increased risk of congenital malformations (OR 1.17, 95% CI 1.05-1.30, 39 studies, I2 = 59%), birthweight discordance (>25% (OR 1.31, 95% CI 1.05-1.63, 7 studies, I2 = 0%)), respiratory distress syndrome (OR 1.32, 95% CI 1.09-1.60, 16 studies, I2 = 61%), and neonatal intensive care unit admission (OR 1.24, 95% CI 1.14-1.35, 32 studies, I2 = 87%) compared with non-ART twins. When comparing ART with natural conception, the risk of respiratory distress syndrome, intensive care admissions, and birthweight discordance >25% was higher among the ART group. Perinatal complications, such as stillbirth (OR 0.83, 95% CI 0.70-0.99, 33 studies, I2 = 49%), small for gestational age <10th centile (OR 0.90, 95% CI 0.85-0.95, 26 studies, I2 = 36%), and twin-twin transfusion syndrome (OR 0.45, 95% CI 0.25-0.82, 9 studies, I2 = 25%), were reduced in twin pregnancies conceived with ART versus those without ART. The above perinatal complications were also fewer amongst the ART group than natural conception.

WIDER IMPLICATIONS

ART twin pregnancies are associated with higher maternal complications than non-ART pregnancies and natural conception, with varied perinatal outcomes. Women seeking ART should be counselled about the increased risks of ART twin pregnancies and should be closely monitored in pregnancy for complications. We recommend exercising caution when interpreting the study findings owing to the study's limitations.

Maternal and perinatal outcomes in primiparous singleton pregnancies conceived with assisted reproductive technology in British Columbia

OBJECTIVE

To evaluate the odds of developing adverse maternal and perinatal outcomes in primiparous singleton pregnancies conceived with assisted reproductive technology (ART) compared with pregnancies conceived without ART.

STUDY DESIGN

A retrospective population-based cohort study using data from the British Columbia Perinatal Data Registry. The population included primiparous women with singleton live or stillbirths delivering at or after 20 weeks' gestation between April 1st 2008-March 31st, 2021. Women who conceived with ART were compared with those who conceived without ART. The main outcome measures were gestational diabetes, hypertensive disorders of pregnancy, preterm birth, low birth weight, neonatal intensive care unit admission, stillbirth, and 5-minute Apgar score. Adjusted odds ratios were calculated.

RESULTS

The study population included 191,059 primiparous women: 183,819 conceived without ART, 7,240 conceived using ART. After controlling for age, body mass index, pre-gestational diabetes, and smoking status, singleton pregnancies conceived by ART had significantly higher odds of gestational diabetes (OR 1.18, 95 % confidence interval [CI] 1.10-1.26) and hypertensive disorders of pregnancy (OR 1.39, 95 % CI 1.29-1.51). There were also significantly increased odds of preterm birth (OR 1.35, 95 % CI 1.25-1.46), low birth weight (OR 1.35, 95 % CI 1.23-1.49), and neonatal intensive care unit admission (OR 1.21, 95 % CI 1.11-1.32). There was not a statistically significant difference in the odds of stillbirth (OR 1.06, 95 % CI 0.72-1.57) or 5-minute Apgar score < 7 (OR 1.10, 95 % CI 0.97-1.26).

CONCLUSION

There is an increased odds of developing several adverse maternal or neonatal outcomes in primiparous singleton pregnancies conceived by ART including gestational diabetes, hypertensive disorders of pregnancy, preterm birth, low birth weight, and increased incidence of neonatal intensive care unit admissions.

Validation of Ultrasound Dating Protocols Using Data From Twins Conceived Through In Vitro Fertilization in Nova Scotia: A Retrospective Cohort Study

OBJECTIVES

Clinical practice guidelines recommend determining gestational age (GA) for twin pregnancies using the fetal crown rump length (CRL) of the larger fetus. This study investigated whether the CRL of the larger or smaller fetus at 11-14 weeks best predicted in vitro fertilization (IVF) assigned GA.

METHODS

A retrospective cohort study of twin pregnancies conceived by IVF ± intracytoplasmic sperm injection, 2004-2022, generated GA estimations for each co-twin CRL at the 11-14 week ultrasound, to determine which fetus (smaller or larger) more consistently predicted IVF-assigned GA. Monoamniotic twins and twins with known structural or vascular abnormalities were excluded. Paired t tests evaluated the ability of CRL to predict GA, and logistic regression evaluated the predictive ability of each of the co-twin groups with increasing size differences. Statistical significance was set at P < 0.05.

RESULTS

Viewpoint 6 identified 359 eligible twin pairs. CRL was closest with the smaller fetus (0.38 days); CRL for both the smaller (95% CI 0.16-0.61) and the larger (2.25 days, 95% CI 2.04-2.46) fetus showed deviation from IVF-assigned GA. As the absolute difference between the small and large fetus increased, the ultrasound-estimated GA of the smaller fetus was still consistently closer to IVF-assigned GA.

CONCLUSIONS

In this selected population of twins with known GA, the CRL of the smaller fetus more accurately predicted IVF-assigned GA even with increasing differences in fetal size. These findings provide important information for appropriately dating pregnancies to facilitate adherence to national guidelines to monitor for pregnancy complications, and plan frequency and type of fetal surveillance, as well as timing of delivery.

Retrospective comparison of monochorionic diamniotic twin pregnancies stratified by spontaneous or artificial conception

OBJECTIVES

To compare outcomes of monochorionic diamniotic (MCDA) twin pregnancies by in vitro fertilization (IVF) vs. spontaneously conceived counterparts.

METHODS

Retrospective comparison. Data about MCDA twin pregnancies, conceived spontaneously or by IVF, attending the Twin Pregnancy Care Unit of Sant'Anna Hospital in Turin (Italy) between January 1st 2010 and March 31st 2022, were collected retrospectively. Obstetric, fetal, and neonatal outcomes of MCDA twin pregnancies by IVF were compared to those of spontaneously conceived counterparts. Data were described by univariate and multivariate analysis.

RESULTS

541 MCDA twin pregnancies were included in the study, among which 45 conceived by IVF and 496 spontaneously conceived. Women with IVF twins were older than those who conceived spontaneously (36.7 ± 5.7 vs. 32.1 ± 5.2 years; p<0.001). No significant difference in the prevalence of pregnancy complications between the two groups was found, except for an increased incidence of hypertensive disorders among IVF pregnancies (17.8 vs. 8.5 %; p=0.039), which resulted nonsignificant after adjusting for maternal age and parity (aOR 1.9, 95 % CI 0.8-4.6). Data about 1,046 live born babies (90 conceived by IVF and 956 spontaneously) were also collected: perinatal outcomes did not differ between the two groups.

CONCLUSIONS

Our results suggest that MCDA twin pregnancies following IVF are not at increased risk of adverse outcomes compared to spontaneous MCDA twin pregnancies.

Neonatal condition at birth of twins conceived by medically assisted reproductive technology compared to those conceived spontaneously: A retrospective study

OBJECTIVE

To examine neonatal outcomes at birth among twins conceived spontaneously or by medically assisted reproduction (MAR).

METHODS

A retrospective study was conducted at a single university teaching hospital on data collected between January 1995 and September 2019. Live twin deliveries at more than 24 weeks of pregnancy were included. The study group consisted of women who conceived by MAR and the controls were spontaneously conceived twins. The study group was further divided into two groups: in vitro fertilization (IVF) and ovulation induction (OI) groups. The primary outcomes were umbilical artery pH less than 7.1 and/or Apgar score less than 7 of any twin 5 min after birth.

RESULTS

Overall, 2235 eligible twin gestations were included, corresponding to a total of 4470 live neonates; 1009 (45.1%) conceived by MAR (762 [75.5%] IVF and 247 [24.5%] OI) and 1226 (54.9%) conceived spontaneously. Incidence of the primary outcome was 5.3% and 5.1% in the study and control groups, respectively (P = 0.71). The primary outcome was comparable among the IVF (5%), OI (6.2%), and control (5.1%) groups. The results did not change even after adjusting for demographic and obstetric variables, including mode of delivery, which differed between the groups.

CONCLUSION

Neonatal condition of twin pregnancies at birth among MAR subgroups is similar to spontaneously conceived twins.

Pregnancy and neonatal outcomes of monozygotic twins resulting from assisted reproductive technology: a 10-year retrospective study

BACKGROUND

Monozygotic twins (MZTs) are associated with high risks of maternal and fetal complications. Even with the widely used elective single embryo transfer (SET), the risk of MZTs following assisted reproductive technology (ART) treatments remains. However, most studies of MZTs focused on the relevant etiology, with few studies describing pregnancy and neonatal outcomes.

METHODS

This retrospective cohort study included 19,081 SET cycles resulting from in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), preimplantation genetic testing (PGT) and testicular sperm aspiration (TESA) performed between January 2010 and July 2020 in a single university-based center. A total of 187 MZTs were included in this investigation. The main outcome measures were the incidence, pregnancy and neonatal outcomes of MZTs. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy loss.

RESULTS

The overall rate of MZTs from ART treatment in SET cycles was 0.98%. No significant difference was found in the incidence of MZTs among the four groups (p = 0.259). The live birth rate of MZTs in the ICSI group (88.5%) was significantly more favorable than in the IVF, PGT and TESA groups (60.5%, 77.2% and 80%, respectively). IVF resulted in a significantly increased risk of pregnancy loss (39.4%) and early miscarriage (29.5%) in MZT pregnancies compared to ICSI (11.4%, 8.5%), PGT (22.7%, 16.6%) and TESA (20%, 13.3%). The total rate of twin-to-twin transfusion syndrome (TTTS) in MZTs was 2.7% (5/187); however, the TESA group had the highest rate at 20% and was significantly higher than the PGT group (p = 0.005). The four ART groups had no significant effect on the occurrence of congenital abnormalities or other neonatal outcomes in newborns from MZT pregnancies. Multivariate logistic regression analysis revealed that infertility duration, cause of infertility, the total dose of Gn used, history of miscarriages, and the number of miscarriages were not related to the risk of pregnancy loss (p > 0.05).

CONCLUSIONS

The rate of MZTs was similar among the four ART groups. The pregnancy loss and the early miscarriage rate of MZTs was increased in IVF patients. Neither the cause of infertility nor the history of miscarriage was correlated with the risk of pregnancy loss. MZTs in the TESA group had a higher risk of TTTS, placental effects influenced by sperm and paternally expressed genes may play a role. However, due to the small total number, studies with larger sample sizes are still needed to validate these result. Pregnancy and neonatal outcomes of MZTs after PGT treatment seem to be reassuring but the duration of the study was short, and long-term follow-up of the children is needed.

Ovarian hyperstimulation syndrome and adverse pregnancy outcome

INTRODUCTION

The aim of this study was to investigate the association between ovarian hyperstimulation syndrome (OHSS) and adverse pregnancy outcome.

EVIDENCE ACQUISITION

Medline, Embase and Cochrane databases were searched. The primary outcome was a composite score of adverse maternal outcome including either preterm birth (PTB), gestational diabetes mellitus (GDM), pre-eclampsia (PE) or pregnancy induced hypertension, intrahepatic cholestasis of pregnancy, thromboembolic events or need for caesarean section (CS). Secondary outcomes were a composite score of adverse fetal outcome including either miscarriage, low birthweight, fetal anomalies or intrauterine fetal death (IUD) and the individual components of both primary and secondary outcomes.

EVIDENCE SYNTHESIS

Thirteen studies (3303 ART pregnancies with and 89,720 without OHSS) were included. The risk of composite adverse maternal outcome (RR: 8.8, 95% CI: 8.1-9.5) was higher in women with compared to those without OHSS. The association between OHSS and adverse pregnancy outcome was mainly due to the higher risk of PTB (RR: 11.4, 95% CI: 10.5-12.4), while there was no difference in the risk of others primary outcome. Likewise, the risk of composite fetal outcome was higher in pregnancies with a prior OHSS (RR: 1.5, 95% CI: 1.1-2.0). The strength of association between OHSS and composite adverse maternal outcome persisted when considering singleton pregnancies or those with severe disease.

CONCLUSIONS

Pregnancies complicated by OHSS are at high risk of adverse pregnancy outcome, especially PTB.

Medically Assisted Reproduction Treatment Types and Birth Outcomes

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments themselves.

OBJECTIVE:

To compare risks of adverse birth outcomes among pregnancies conceived with and without medically assisted reproduction treatments.

METHODS:

Birth certificates were used to study birth outcomes of all neonates born in Utah from 2009 through 2017. Of the 469,919 deliveries, 52.8% (N=248,013) were included in the sample, with 5.2% of the neonates conceived through medically assisted reproduction. The outcome measures included birth weight, gestational age, low birth weight (LBW, less than 2,500 g), preterm birth (less than 37 weeks of gestation), and small for gestational age (SGA, birth weight less than the 10th percentile). Linear models were estimated for the continuous outcomes (birth weight, gestational age), and linear probability models were used for the binary outcomes (LBW, preterm birth, SGA). First, we compared the birth outcomes of neonates born after medically assisted reproduction and natural conception in the overall sample (between-family analyses), before and after adjustment for parental background and neonatal characteristics. Second, we employed family fixed effect models to investigate whether the birth outcomes of neonates conceived through medically assisted reproduction differed from those of their naturally conceived siblings (within-family comparisons).

RESULTS:

Neonates conceived through medically assisted reproduction weighed less, were born earlier, and were more likely to be LBW, preterm, and SGA than neonates conceived naturally. More invasive treatments (assisted reproductive technology [ART] and artificial insemination [AI] or intrauterine insemination) were associated with worse birth outcomes; for example, the proportion of LBW and preterm birth was 6.1% and 7.9% among neonates conceived naturally and 25.5% and 29.8% among neonates conceived through ART, respectively. After adjustments for various neonatal and parental characteristics, the differences in birth outcomes between neonates conceived through medically assisted reproduction and naturally were attenuated yet remained statistically significant; for example, neonates conceived through ART were at 3.2 percentage points higher risk for LBW (95% CI 2.4–4.1) and 4.8 percentage points higher risk for preterm birth (95% CI 3.9–5.7). Among siblings, the differences in the frequency of adverse outcomes between neonates conceived through medically assisted reproduction and neonates conceived naturally were small and statistically insignificant for all types of treatments.

CONCLUSION:

Medically assisted reproduction treatments are associated with adverse birth outcomes; however, those risks are unlikely to be associated with the infertility treatments itself.

The Association between Assisted Reproductive Technology and Preterm delivery in Twin pregnancies

OBJECTIVE

To determine whether ART is associated with a higher risk of preterm deliveries in twin gestations compared with non-exposure to ART.

STUDY DESIGN

This is a secondary analysis of a randomized, double-blinded, placebo-controlled trial of weekly progesterone to prevent preterm delivery in twin gestations. For our analysis, all subjects with twin gestations and known gestational age at delivery were included. Women were excluded if they had intrauterine insemination or congenital fetal anomalies. Our primary exposure was ART, defined as IVF and ICSI. Subjects non-exposed to ART either had spontaneous conceptions or were conceived with ovarian stimulation. Our primary outcome was preterm delivery, defined as delivery prior to 35 weeks gestation. Secondary outcomes included spontaneous or indicated preterm delivery less than 35 weeks.

RESULTS

Of the 1261 subjects, 309 (24.5%) had ART, and 952 (75.5%) were not exposed to ART. Women exposed to ART were more likely to be white, older, and have dichorionic twins, and they were less likely to be smokers. The groups had similar rates of prior preterm births. The rates of overall PTB (40.8% v. 39.3%, p=0.642) and spontaneous PTB (20.8% v. 24.1%, p=0.221) were similar. After adjusting for confounders, ART exposure was not related to any preterm birth category, and the strongest predictors for spontaneous preterm birth was a prior preterm birth (aOR: 3.38, 95% CI: 2.04-5.59, p=<0.0001) and Black race (aOR 1.61, 95% CI: 1.06-2.45, p=0.026).

CONCLUSION

In our cohort of twin pregnancies, ART was not an independent risk factor for preterm birth.

The Risk of Congenital Anomalies by Fertility Treatment Modality

Importance

Up to 4% of all births in developed nations involve assisted reproductive technology (ART), along with other fertility treatment modalities. Thus, ART pregnancies constitute an important epidemiologic population with a known increased risk of congenital anomalies. In this review, we summarize current fertility treatment modalities and their associated risk of congenital anomalies.

Objective

To review the risk of birth defects among pregnancies conceived with ART and other fertility treatments.

Evidence Acquisition

Articles were obtained from PubMed and the American College of Obstetricians and Gynecologists and American Society of Reproductive Medicine committee opinions.

Results

In vitro fertilization has been associated with a 25% to 50% increased risk of birth defects, including abnormalities of these organ systems: cardiovascular (25%-40% of anomalies), genitourinary (10%-60%), gastrointestinal (10%-20%), and musculoskeletal (10%-35%). Although the data are mixed, intracytoplasmic sperm injection has also been found to be associated with an increased risk of defects, particularly hypospadias, when compared with conventional in vitro fertilization. The risk among fresh versus frozen cycles and cleavage stage versus blastocyst transfers remains uncertain. There appears to be no significant added risk with preimplantation genetic testing, although more studies are needed. Ovulation induction with oral agents appears safe and not associated with an increased risk of anomalies. Oocyte cryopreservation also appears safe, but the data are still limited, requiring future investigation.

Conclusions and Relevance

While the relative risk of birth defects among ART pregnancies is increased when compared with spontaneous conceptions, the absolute risk remains low. There are no standard screening recommendations for ART pregnancies. Per the American College of Obstetricians and Gynecologists, patients who have undergone ART should be counseled regarding the risk of birth defects and available antenatal evaluation, including fetal echocardiogram and detailed ultrasound evaluation.

Women with multiple gestations have an increased risk of development of hypertension in the future

Background

Multiple gestations are associated with an increased incidence of preeclampsia. However, there exists no evidence for an association between multiple gestations and development of hypertension(HTN) later in life. This study aimed to determine whether multiple gestations are associated with HTN beyond the peripartum period.

Methods

In this retrospective nationwide population-based study, women who delivered a baby between January 1, 2007, and December 31, 2008, and underwent a national health screening examination within one year prior to their pregnancy were included. Subsequently, we tracked the occurrence of HTN during follow-up until December 31, 2015, using International Classification of Diseases-10th Revision codes.

Results

Among 362,821 women who gave birth during the study period, 4,944 (1.36%) women had multiple gestations. The cumulative incidence of HTN was higher in multiple gestations group compared with singleton group (5.95% vs. 3.78%, p < 0.01, respectively). On the Cox proportional hazards models, the risk of HTN was increased in women with multiple gestations (HR 1.35, 95% CI 1.19, 1.54) compared with those with singleton after adjustment for age, primiparity, preeclampsia, atrial fibrillation, body mass index, blood pressure, diabetes mellitus, high total cholesterol, abnormal liver function test, regular exercise, and smoking status.

Conclusions

Multiple gestations are associated with an increased risk of HTN later in life. Therefore, guidelines for the management of high-risk patients after delivery should be established.

Assisted reproductive technologies and the risk of stillbirth in singleton pregnancies: a systematic review and meta-analysis

OBJECTIVE

To identify the risk of stillbirth from in vitro types of assisted reproductive technologies compared with spontaneous conception (SC), limited to singleton births.

DESIGN

Systematic literature search and search chaining on online databases: PubMed, Embase, and Scopus.

SETTING

Not applicable.

PATIENT(S)

Singleton pregnancies from in vitro fertilization (IVF) or fertilization by IVF and intracytoplasmic sperm injection (IVF-ICSI).

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Adjusted odds ratio for stillbirth or prevalence of stillbirth in case-control groups of IVF/IVF-ICSI singletons and SCs, respectively, in matched studies.

RESULT(S)

A total of 19 studies were included, and study quality was mixed. Ten studies qualified for inclusion to the meta-analysis, which revealed a significantly increased risk of stillbirth in IVF/IVF-ICSI compared with that in SC (odds ratio [95% confidence interval]: 1.82 [1.37-2.42]), and there was no evidence of publication bias.

CONCLUSION(S)

In vitro fertilization and IVF-ICSI treatment increases the risk of stillbirth compared with natural conception.

CLINICAL TRIAL REGISTRATION NUMBER

PROSPERO 216768.

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

Background

Caesarean section rates are higher among pregnancies conceived by assisted reproductive technology (ART) compared to spontaneous conceptions (SC), implying an increase in neonatal and maternal morbidity. We aimed to compare caesarean section rates in ART pregnancies versus SC, overall, by indication (elective versus emergent), and by type of ART treatment (in-vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), fresh embryo transfer, frozen embryo transfer) in a systematic review and meta-analysis.

Methods

We searched Medline, EMBASE and CINAHL databases using the OVID Platform from 1993 to 2019, and the search was completed in January 2020. The eligibility criteria were cohort studies with singleton conceptions after in-vitro fertilization and/or intracytoplasmic sperm injection using autologous oocytes versus spontaneous conceptions. The study quality was assessed using the Newcastle Ottawa Scale and GRADE approach. Meta-analyses were performed using odds ratios (OR) with a 95% confidence interval (CI) using random effect models in RevMan 5.3, and I-squared (I²) test > 75% was considered as high heterogeneity.

Results

One thousand seven hundred fifty studies were identified from the search of which 34 met the inclusion criteria. Compared to spontaneous conceptions, IVF/ICSI pregnancies were associated with a 1.90-fold increase of odds of caesarean section (95% CI 1.76, 2.06). When stratified by indication, IVF/ICSI pregnancies were associated with a 1.91-fold increase of odds of elective caesarean section (95% CI 1.37, 2.67) and 1.38-fold increase of odds of emergent caesarean section (95% CI 1.09, 1.75). The heterogeneity of the studies was high and the GRADE assessment moderate to low, which can be explained by the observational design of the included studies.

Conclusions

The odds of delivering by caesarean section are greater for ART singleton pregnancies compared to spontaneous conceptions. Preconception and pregnancy care plans should focus on minimizing the risks that may lead to emergency caesarean sections and finding strategies to understand and decrease the rate of elective caesarean sections.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03711-x.

Which is better for mothers and babies: fresh or frozen-thawed blastocyst transfer?

BACKGROUND

In recent years, there have been many reports on the pregnancy outcomes of fresh blastocyst transfer (BT) and frozen-thawed BT, but the conclusions are controversial and incomplete. To compare the pregnancy outcomes, maternal complications and neonatal outcomes of fresh and frozen-thawed BT in the context of in vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) cycles, we conducted a meta-analysis.

METHODS

A meta-analysis was conducted by searching the PubMed, Embase, and Cochrane Library databases through May 2020. Data were extracted independently by two authors.

RESULTS

Fifty-four studies, including 12 randomized controlled trials (RCTs), met the inclusion criteria. Fresh BT was associated with a lower implantation rate, pregnancy rate, ongoing pregnancy rate, and clinical pregnancy rate and higher ectopic pregnancy rate than frozen-thawed BT according to the results of the RCTs. The risks of moderate or severe ovarian hyperstimulation syndrome, placental abruption, placenta previa and preterm delivery were higher for fresh BT than for frozen-thawed BT. The risk of pregnancy-induced hypertension and pre-eclampsia was lower for fresh BT; however, no significant differences in risks for gestational diabetes mellitus and preterm rupture of membrane were found between the two groups. Compared with frozen-thawed BT, fresh BT appears to be associated with small for gestational age and low birth weight. No differences in the incidences of neonatal mortality or neonatal malformation were observed between fresh and frozen-thawed BT.

CONCLUSIONS

At present there is an overall slight preponderance of risks in fresh cycles against frozen, however individualization is required and current knowledge does not permit to address a defintive response.

Gestational age at delivery of twins and perinatal outcomes: a cohort study in Aberdeen, Scotland

Background: Twin pregnancy is associated with a threefold increase in perinatal death compared to singletons.  The objective of this study was to determine the risk of perinatal death in twins by week of gestation and to quantify the effect of known risk factors. Methods: A cohort analysis was performed using data from the Aberdeen Maternity and Neonatal Databank (AMND).  The exposure was gestational age at delivery and the primary outcome was perinatal death.  Adjusted hazard ratios (aHRs) for perinatal death according to gestational age at delivery were determined by multivariate Cox proportional hazards regression modelling with robust standard errors to account for clustering in the twin infants.  Confounders and risk factors quantified and adjusted for in the model included maternal age, smoking, parity, marital status and year of birth.  Kaplan-Meier time to event analysis was used to determine the differences in survival according to chorionicity and assisted reproduction technologies (ART) conception status. Results: The population comprised of 7,420 twin babies born between 1950 and 2013 in the Grampian area of Northern Scotland.  There were 272 stillbirths in the cohort (3.67%) and 273 neonatal deaths (3.68%). Compared to delivery at 37-38 weeks, delivery before 37 weeks was associated with a 2-fold increase in perinatal death. Monochorionic twins had a 2-fold increase in perinatal death compared to dichorionic twins (aHR 2.15, 95% CI 1.60-2.90). Twins conceived by ART did not have a greater risk of perinatal death compared to those naturally conceived (aHR 1.21, 95% CI 0.87-1.68) Conclusion:  This study suggests that delivery of twins at 37-38 weeks is associated with the lowest risk of perinatal death.

Pregnancy complications following fertility treatment-disentangling the role of multiple gestation

Background

To assess the extent to which multiple gestations mediate risk of pregnancy complications from fertility treatment and to address possible confounding by the underlying infertility.

Methods

From the nearly 1.8 million pregnancies recorded in the Swedish Medical Birth Register between 1996 and 2013, we selected the 9.9% (N = 174 067) that occurred to couples with known trouble conceiving (clinical infertility). Fertility treatment was identified from self-reports, medical records and procedural information from fertility clinics. We used logistic regression to estimate odds ratios (ORs) and their 95% confidence intervals (CIs), and decomposed the total effect into direct and mediated effects to estimate the proportion mediated by multiple gestations.

Results

Compared with pregnancies achieved without any assistance, those having received some treatment had higher odds of all studied complications except gestational diabetes. Associations with placenta previa (OR 2.17, 95% CI 1.95-2.40) and placental abruption (OR 1.77, 95% CI 1.54-2.03) were almost entirely independent of multiple gestations. In contrast, the majority of the associations with preterm birth (OR 1.69, 95% CI 1.62-1.77), caesarean delivery (RR 1.15, 95% CI 1.13-1.17) and pre-eclampsia (OR 1.17, 95% CI 1.11-1.22) were mediated by multiple gestations (87%, 62% and 91% of the effect mediated, respectively). Both direct and mediated pathways contributed to the remaining positive associations with chorioamnionitis, labour induction and postpartum haemorrhage. Results were similar when considering primi- and multi-parous women separately, and after restriction to assisted reproductive technologies only.

Conclusion

Multiple gestations are responsible for a large proportion of pregnancy complications associated with fertility treatment, suggesting that interventions to restrict the occurrence of multiples could reduce excess risk of pre-eclampsia, preterm birth and caesarean delivery after fertility treatment. However, the elevated risk of serious placental complications after fertility treatment appears to be largely independent of multiple gestations.

Impact of the recommendation for embryo transfer limitation on multiple pregnancy: A population-based study in Japan

OBJECTIVE

Limitations on the number of embryos transferred have been recommended worldwide to reduce the number of medically assisted multiple births. Our aim was to evaluate the impact of this recommendation for embryo transfer limitation on perinatal outcomes of multiple births.

STUDY DESIGN

A retrospective and population-based study compared all multiple births in Shiga prefecture of Japan in 2014-2015 (2015 group) with those in 2007-2008 (2008 group). The perinatal background and neonatal outcomes of multiple births were compared.

RESULTS

The number of multiple pregnancies in the 2015 group (n = 251) was almost the same as in the 2008 group (n = 245). The proportion of multiple pregnancies conceived through assisted reproductive technology significantly decreased to 23% in the 2015 group compared to 31% in the 2008 group. In contrast, the rate of ovulation induction significantly increased to 24% in the 2015 group from 15% in the 2008 group. There was no significant difference in the outcome of multiple-birth infants between the two groups.

CONCLUSION

The method of conception in multiple pregnancies markedly shifted from in vitro fertilization to non-in vitro fertilization after the issuance of a recommendation for limits on embryo transfer. It should be necessary for the assessment of the impact of this recommendation to monitor closely multiple pregnancies via non-in vitro fertilization as well as via in vitro fertilization.

Gestational age at delivery of twins and perinatal outcomes: a cohort study in Aberdeen, Scotland

Background: Twin pregnancy is associated with a threefold increase in perinatal death compared to singletons.  The objective of this study was to determine the risk of perinatal death in twins by week of gestation and to quantify the effect of known risk factors. Methods: A cohort analysis was performed using data from the Aberdeen Maternity and Neonatal Databank (AMND).  The exposure was gestational age at delivery and the primary outcome was perinatal death.  Adjusted hazard ratios (aHRs) for perinatal death according to gestational age at delivery were determined by multivariate Cox proportional hazards regression modelling with robust standard errors to account for clustering in the twin infants.  Confounders and risk factors quantified and adjusted for in the model included maternal age, smoking, parity, marital status and year of birth.  Kaplan-Meier time to event analysis was used to determine the differences in survival according to chorionicity and assisted reproduction technologies (ART) conception status. Results: The population comprised of 7,420 twin babies born between 1950 and 2013 in the Grampian area of Northern Scotland.  There were 272 stillbirths in the cohort (3.67%) and 273 neonatal deaths (3.68%). Compared to delivery at 37-38 weeks, delivery at or beyond 39 weeks was associated with a significant increase in perinatal death (aHR 2.00 [95% CI 1.45-2.78]).  Monochorionic twins had a 2-fold increase in perinatal death compared to dichorionic twins (aHR 2.15, 95% CI 1.60-2.90). Twins conceived by ART did not have a greater risk of perinatal death compared to those naturally conceived (aHR 1.21, 95% CI 0.87-1.68) Conclusion:  This study suggests that delivery of twins at 37-38 weeks is associated with the lowest risk of perinatal death.

Obstetric and perinatal outcomes of dizygotic twin pregnancies resulting from in vitro fertilization versus spontaneous conception: a retrospective study

This study was designed to to assess perinatal and neonatal outcomes of dizygotic twin pregnancies conceived naturally or by in vitro fertilization (IVF). After strict selection, the study included 470 dizygotic twin pregnancies. There were 249 resulting from IVF treatments and 221 conceiving spontaneously. After adjusting maternal age and primiparity, the results showed that there were no significant differences between the two groups (P > 0.05) in terms of maternal antenatal complications and neonatal outcomes. In conclusion, our study does not reveal increased risks for pregnancy-related complications and adverse neonatal outcomes in dizygotic twin pregnancies following IVF treatments. With these fundamental data, this study could provide a reference for perinatal care and clinical assisted reproductive technology (ART) treatment and help to inform infertile parents about the potential risks of IVF treatments.

Medically assisted reproduction and birth outcomes: a within-family analysis using Finnish population registers

BACKGROUND

Children born after medically assisted reproduction are at higher risk of adverse birth outcomes than are children conceived naturally. We aimed to establish the extent to which this excess risk should be attributed to harmful effects of treatment or to pre-existing parental characteristics that confound the association.

METHODS

We used data from Finnish administrative registers covering a 20% random sample of households with at least one child aged 0-14 years at the end of 2000 (n=65 723). We analysed birthweight, gestational age, risk of low birthweight, and risk of preterm birth among children conceived both by medically assisted reproduction and naturally. First, we estimated differences in birth outcomes by mode of conception in the general population, using standard multivariate methods that controlled for observed factors (eg, multiple birth, birth order, and parental sociodemographic characteristics). Second, we used a sibling-comparison approach that has not been used before in medically assisted reproduction research. We compared children conceived by medically assisted reproduction with siblings conceived naturally and, thus, controlled for all observed and unobserved factors shared by siblings.

FINDINGS

Between 1995 and 2000, 2776 (4%) children in our sample were conceived by medically assisted reproduction; 1245 children were included in the sibling comparison. Children conceived by medically assisted reproduction had worse outcomes than did those conceived naturally, for all outcomes, even after adjustments for observed child and parental characteristics-eg, difference in birthweight of -60 g (95% CI -86 to -34) and 2·15 percentage point (95% CI 1·07 to 3·24) increased risk of preterm delivery. In the sibling comparison, the gap in birth outcomes was attenuated, such that the relation between medically assisted reproduction and adverse birth outcomes was statistically and substantively weak for all outcomes-eg, difference in birthweight of -31 g (95% CI -85 to 22) and 1·56 percentage point (95% CI -1·26 to 4·38) increased risk of preterm delivery.

INTERPRETATION

Children conceived by medically assisted reproduction face an elevated risk of adverse birth outcomes. However, our results indicate that this increased risk is largely attributable to factors other than the medically assisted reproduction treatment itself.

FUNDING

European Research Council, the Academy of Finland, and the Signe and Ane Gyllenberg Foundation.

Uses of dietary supplements and herbal medicines during pregnancy in women undergoing assisted reproductive technologies- A study of taiwan birth cohort

OBJECTIVE

This study aimed to assess the efficacy of dietary supplements and herbal medicines for the care of pregnant women undergoing assisted reproductive technologies (ART).

MATERIALS AND METHODS

A total of 366 women undergoing ART and their children from the dataset of Taiwan Birth Cohort Study (TBCS, 2005) were enrolled in this study. Structured questionnaires were applied to collect the health information at 6-month follow-up after their delivery. The related use patterns were analyzed to investigate the final birth outcomes.

RESULTS

Comparing with those of non-ART group, the women undergoing ART consumed more supplements of multivitamin, fish oil, and calcium than herbal medicines during pregnancy. This study revealed that the consumptions of multivitamin, calcium pills, Genseng, and Suz-Wu-Tang were associated with low birth weight, whereas the intake of Huanglian was associated with birth weight. Besides, the uses of multivitamin and Suz-Wu-Tang were related to lower gestational age of infants.

CONCLUSIONS

Physicians and nurses must educate themselves in dietary supplements and herbal/alternative medicines for offering accurate advices for pregnant women to optimize their care. The results could be of reference for further investigation on longitudinal effects of dietary supplements and herbal medicines during pregnancy in women undergoing ART continuously followed with TBCS.

Perinatal outcome of monochorionic and dichorionic twins after spontaneous and assisted conception: a retrospective cohort study

Introduction

The aim of this study was to compare pregnancy outcomes in twin pregnancies after assisted conception and spontaneous conception, according to chorionicity.

Material and methods

Retrospective cohort study of 1305 twin pregnancies between 1995 and 2015. All spontaneous (n = 731) and assisted conception conceived (n = 574) twin pregnancies with antenatal care and delivery in University Medical Center Utrecht, the Netherlands, a tertiary obstetric care center were studied according to chorionicity.

Results

Maternal age and incidence of nulliparity were higher among the assisted conception twins. Hypertensive disorders also appeared to be more frequent in assisted conception pregnancies, which could largely be explained by the higher proportion of elderly nulliparous women in this group. Spontaneously conceived twins were born earlier than twins after assisted conception, with subsequent lower birthweights and more admissions to a neonatal intensive care unit with increased neonatal morbidity. Monochorionic twins had worse pregnancy outcomes compared with dichorionic twins, irrespective of mode of conception; monochorionic twins conceived by assisted reproduction had more neonatal morbidity (mainly respiratory distress syndrome and necrotizing enterocolitis) and late neonatal deaths compared with spontaneously conceived monochorionic twins.

Conclusions

Spontaneously conceived twins have worse pregnancy outcome compared with twins after assisted conception, probably due to a lower incidence of monochorionicity in the assisted conception group. The already increased perinatal risks in monochorionic twins are even higher in monochorionic twins conceived after infertility treatments compared with spontaneously conceived monochorionic twins, which warrants extra attention to these high‐risk pregnancies.

Parental health status and infant outcomes: Upstate KIDS Study

OBJECTIVE

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

DESIGN

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

SETTING

Not applicable.

PATIENT(S)

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

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

Comparison of conventional 2D ultrasound to magnetic resonance imaging for prenatal estimation of birthweight in twin pregnancy

BACKGROUND

During prenatal follow-up of twin pregnancies, accurate identification of birthweight and birthweight discordance is important to identify the high-risk group and plan perinatal care. Unfortunately, prenatal evaluation of birthweight discordance by 2-dimensional ultrasound has been far from optimal.

OBJECTIVE

The objective of the study was to prospectively compare estimates of fetal weight based on 2-dimensional ultrasound (ultrasound-estimated fetal weight) and magnetic resonance imaging (magnetic resonance-estimated fetal weight) with actual birthweight in women carrying twin pregnancies.

STUDY DESIGN

Written informed consent was obtained for this ethics committee-approved study. Between September 2011 and December 2015 and within 48 hours before delivery, ultrasound-estimated fetal weight and magnetic resonance-estimated fetal weight were conducted in 66 fetuses deriving from twin pregnancies at 34.3-39.0 weeks; gestation. Magnetic resonance-estimated fetal weight derived from manual measurement of fetal body volume. Comparison of magnetic resonance-estimated fetal weight and ultrasound-estimated fetal weight measurements vs birthweight was performed by calculating parameters as described by Bland and Altman. Receiver-operating characteristic curves were constructed for the prediction of small-for-gestational-age neonates using magnetic resonance-estimated fetal weight and ultrasound-estimated fetal weight. For twins 1 and 2 separately, the relative error or percentage error was calculated as follows: (birthweight - ultrasound-estimated fetal weight (or magnetic resonance-estimated fetal weight)/birthweight) × 100 (percentage). Furthermore, ultrasound-estimated fetal weight, magnetic resonance-estimated fetal weight, and birthweight discordance were calculated as 100 × (larger estimated fetal weight-smaller estimated fetal weight)/larger estimated fetal weight. The ultrasound-estimated fetal weight discordance and the birthweight discordance were correlated using linear regression analysis and Pearson's correlation coefficient. The same was done between the magnetic resonance-estimated fetal weight and birthweight discordance. To compare data, the χ², McNemar test, Student t test, and Wilcoxon signed rank test were used as appropriate. We used the Fisher r-to-z transformation to compare correlation coefficients.

RESULTS

The bias and the 95% limits of agreement of ultrasound-estimated fetal weight are 2.99 (-19.17% to 25.15%) and magnetic resonance-estimated fetal weight 0.63 (-9.41% to 10.67%). Limits of agreement were better between magnetic resonance-estimated fetal weight and actual birthweight as compared with the ultrasound-estimated fetal weight. Of the 66 newborns, 27 (40.9%) were of weight of the 10th centile or less and 21 (31.8%) of the fifth centile or less. The area under the receiver-operating characteristic curve for prediction of birthweight the 10th centile or less by prenatal ultrasound was 0.895 (P < .001; SE, 0.049), and by magnetic resonance imaging it was 0.946 (P < .001; SE, 0.024). Pairwise comparison of receiver-operating characteristic curves showed a significant difference between the areas under the receiver-operating characteristic curves (difference, 0.087, P = .049; SE, 0.044). The relative error for ultrasound-estimated fetal weight was 6.8% and by magnetic resonance-estimated fetal weight, 3.2% (P < .001). When using ultrasound-estimated fetal weight, 37.9% of fetuses (25 of 66) were estimated outside the range of ±10% of the actual birthweight, whereas this dropped to 6.1% (4 of 66) with magnetic resonance-estimated fetal weight (P < .001). The ultrasound-estimated fetal weight discordance and the birthweight discordance correlated significantly following the linear equation: ultrasound-estimated fetal weight discordance = 0.03 + 0.91 × birthweight (r = 0.75; P < .001); however, the correlation was better with magnetic resonance imaging: magnetic resonance-estimated fetal weight discordance = 0.02 + 0.81 × birthweight (r = 0.87; P < .001).

CONCLUSION

In twin pregnancies, magnetic resonance-estimated fetal weight performed immediately prior to delivery is more accurate and predicts small-for-gestational-age neonates significantly better than ultrasound-estimated fetal weight. Prediction of birthweight discordance is better with magnetic resonance imaging as compared with ultrasound.

Maternal and neonatal outcomes in triplet gestations by trial of labor versus planned cesarean delivery. J Matern Fetal Neonatal Med 2017;32:1874-1879. [PMID: 29278965 DOI: 10.1080/14767058.2017.1421931]

OBJECTIVE

To determine the rate of vaginal delivery after vaginal trial of labor (TOL) among women with triplet gestations.

STUDY DESIGN

This is a retrospective cohort study of all women delivering a viable triplet gestation between 2005 and 2016. The primary outcome was rate of vaginal delivery among all women attempting vaginal delivery. Secondary outcomes included factors associated with undergoing triplet TOL, and maternal and neonatal complications by planned delivery approach.

RESULTS

Of the 83 eligible women, 21 (25.3%) underwent TOL. A majority of these (57.1, 95% confidence interval 36.5-75.5%) achieved a vaginal delivery of all three triplets. Women who underwent TOL were more likely to be multiparous or to have spontaneous preterm labor. There were no differences in adverse maternal or neonatal outcomes by planned delivery approach.

CONCLUSIONS

The rate of vaginal delivery among women with triplet gestations is higher in this institution than in reported literature, without increased morbidity.

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

BACKGROUND

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

OBJECTIVE

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

STUDY DESIGN

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

RESULTS

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

CONCLUSION

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

Perinatal health services organization for preterm births: a multinational comparison

OBJECTIVE

To explore population characteristics, organization of health services and comparability of available information for very low birth weight or very preterm neonates born before 32 weeks' gestation in 11 high-income countries contributing data to the International Network for Evaluating Outcomes of Neonates (iNeo).

STUDY DESIGN

We obtained population characteristics from public domain sources, conducted a survey of organization of maternal and neonatal health services and evaluated the comparability of data contributed to the iNeo collaboration from Australia, Canada, Finland, Israel, Italy, Japan, New Zealand, Spain, Sweden, Switzerland and UK.

RESULTS

All countries have nationally funded maternal/neonatal health care with >90% of women receiving prenatal care. Preterm birth rate, maternal age, and neonatal and infant mortality rates were relatively similar across countries. Most (50 to >95%) between-hospital transports of neonates born at non-tertiary units were conducted by designated transport teams; 72% (8/11 countries) had designated transfer and 63% (7/11 countries) mandate the presence of a physician. The capacity of 'step-down' units varied between countries, with capacity for respiratory care available in <10% to >75% of units. Heterogeneity in data collection processes for benchmarking and quality improvement activities were identified.

CONCLUSIONS

Comparability of healthcare outcomes for very preterm low birth weight neonates between countries requires an evaluation of differences in population coverage, healthcare services and meta-data.

Optimizing the number of embryos to transfer on day 5: two should be the limit

Objective

To define the appropriate number of embryos to be transferred at day 5.

Methods

Retrospective analysis of 784 consecutive fresh day-5 embryo transfers performed between 2007 and 2015, divided in three groups: Group A (N = 219): received the only 2 embryos that reached a transferable stage; Group B (N = 357): received 2 selected embryos among several that reached a transferable stage; Group C (N = 208): received the only 3 developing embryos. Clinical pregnancy, implantation, multiple pregnancy and delivery rates were registered. Kruskal-Wallis and Fisher Exact tests were applied as appropriate.

Results

Age and previous attempts were comparable in the 3 groups. Compared with Group A, Groups B and C had a higher oocyte recovery (10.7 ± 5.6 vs. 14.7 ± 8.0 vs. 13.8 ± 6.6), fertilization rate (75.97% vs. 81.60% vs. 83.29%) and percentage of embryos reaching a transferable stage on day 5 (39.98% vs. 63.99% vs. 60.97%), as well as a significantly higher clinical pregnancy (42.92% vs. 61.06% vs. 58.17%) and implantation rates (21.09% vs. 40.98% vs. 36.97%). The multiple pregnancy rate was higher in Groups B and C than in Group A (11.70% vs. 31.19% vs. 37.19%). The high order multiple pregnancy rate (> 2) was significantly increased in group C (1.06% vs. 0.92% vs. 14.05%).

Conclusions

In patients with 3 or more day 5 developing embryos, delivery rates are similar if 2 or 3 embryos are transferred. The transfer of 3 embryos carries an unacceptable increase in the risk of high order multiple pregnancy, with its known consequences. According to our data, we should not exceed the number of 2 day-5 fresh embryos transferred.

Twin pregnancies complicated by gestational diabetes mellitus: a single centre cohort study

AIMS

In women with a twin pregnancy, to determine the incidence of, risk factors for and outcomes of women with gestational diabetes mellitus, and assess how these have changed with a change in gestational diabetes screening.

METHODS

Retrospective cohort study of women with a twin pregnancy attending an Australian tertiary hospital, 2002-2013. Information on gestational diabetes status, gestational diabetes risk factors and pregnancy outcomes was ascertained. Pregnancy outcomes included hypertensive disorders, twin birthweight centile and a composite adverse pregnancy outcome. Analysis was stratified pre/post screening protocol change (epoch 1: 2002-2009, epoch 2: 2010-2013) and by gestational diabetes status.

RESULTS

Gestational diabetes was diagnosed in 86/982 (8.8%) women, increasing from 4.4% to 14.7% between epochs (P = 0.0001). The proportion of women with hypertensive disorders increased (11.7% vs. 13.4%, P = 0.009), but the proportion of infant's birthweight > 90th centile decreased (11.0% vs. 7.6%, P = 0.02) between epochs. Overall, 33.6% of women had ≥ 1 risk factors for gestational diabetes. Three-quarters (73.7%) of women overall had an adverse pregnancy outcome, with a slightly higher proportion in women with gestational diabetes compared with those with no gestational diabetes (79.7% vs. 73.1%, P = 0.06). The rate of the adverse pregnancy outcome did not change by epoch, after adjusting for maternal and pregnancy risk factors (adjusted odds ratio = 0.96, 95% confidence interval 0.73-1.26).

CONCLUSIONS

Almost 1 in 10 women with a twin pregnancy were diagnosed with gestational diabetes, with the incidence of gestational diabetes increasing threefold with a new screening protocol. The pregnancy outcomes of women with a twin pregnancy did not change with increased detection and treatment for gestational diabetes.

Risk of adverse pregnancy and perinatal outcomes after high technology infertility treatment: a comprehensive systematic review

In the literature, there is growing evidence that subfertile patients who conceived after infertility treatments have an increased risk of pregnancy and perinatal complications and this is particularly true for patients who conceived through use of high technology infertility treatments. Moreover, high technology infertility treatments include many concomitant clinical and biological risk factors. This review aims to summarize in a systematic fashion the current evidence regarding the relative effect of the different procedures for high technology infertility treatments on the risk of adverse pregnancy and perinatal outcome. A literature search up to August 2016 was performed in IBSS, SocINDEX, Institute for Scientific Information, PubMed, Web of Science and Google Scholar and an evidence-based hierarchy was used to determine which articles to include and analyze. Data on prepregnancy maternal factors, low technology interventions, specific procedures for male factor, ovarian tissue/ovary and uterus transplantation, and chromosomal abnormalities and malformations of the offspring were excluded. The available evidences were analyzed assessing the level and the quality of evidence according to the Oxford Centre for Evidence-Based Medicine guidelines and the Grading of Recommendations Assessment, Development, and Evaluation system, respectively. Current review highlights that every single procedure of high technology infertility treatments can play a crucial role in increasing the risk of pregnancy and perinatal complications. Due to the suboptimal level and quality of the current evidence, further well-designed studies are needed.

Antenatal Hospitalizations Among Pregnancies Conceived With and Without Assisted Reproductive Technology

OBJECTIVE

To describe the prevalence of antenatal hospitalizations, compare characteristics of women with and without antenatal hospitalizations, and compare timing, length of stay, and reason for hospitalization among pregnancies conceived with and without assisted reproductive technology (ART).

METHODS

We performed a retrospective cohort analysis using linked ART surveillance, vital records, and hospital discharge data from Michigan to calculate the hospitalization ratio as the number of antenatal admissions per 100 live birth deliveries for ART and non-ART deliveries during 2004-2012 and compare trends by ART status. We then restricted analysis to 2008-2012 and used logistic, multinomial, and Poisson regression analysis to model antenatal admissions, trimester of admission, and length of stay, respectively, for ART compared with non-ART deliveries. We examined reason for hospitalization by ART status.

RESULTS

Between 2004 and 2012, the hospitalization ratio for ART deliveries decreased from 14.6 to 12.3 per 100 deliveries (P<.001). Of 557,708 live deliveries during 2008-2012, 22,763 (4.1%) had an antenatal hospitalization. Assisted reproductive technology was a risk factor for having any antenatal admission (singletons adjusted risk ratio [RR] 1.63, 95% confidence interval [CI] 1.43-1.83; multiples adjusted RR 1.24, 95% CI 1.12-1.38) and two or more admissions (singletons adjusted RR 1.86, 95% CI 1.25-2.75; multiples adjusted RR 1.33, 95% CI 1.14-1.54). The percent of time (days) hospitalized during the antenatal period was greater for ART deliveries than non-ART deliveries (singleton adjusted RR 1.28, 95% CI 1.09-1.51; multiples adjusted RR 1.14, 95% CI 1.01-1.29). The most common reason for antenatal admission was preterm labor among all non-ART and multiple gestation deliveries and vaginal bleeding among ART singleton gestations.

CONCLUSION

Deliveries after ART were associated with increased risk of antenatal admissions and longer hospitalizations compared with non-ART deliveries.

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.

Use of assisted reproductive technology treatment as reported by mothers in comparison with registry data: the Upstate KIDS Study

OBJECTIVE

To assess the validity of maternally reported assisted reproductive technologies (ART) use and to identify predictors of reporting errors.

DESIGN

Linkage study.

SETTING

Not applicable.

PATIENT(S)

A total of 5,034 (27%) mothers enrolled, from whom 4,886 (97%) self-reported information about use of infertility treatment, including ART, for the index birth.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Four measures of validity (sensitivity, specificity, positive and negative predictive values) and use of net reclassification improvement (NRI) methods to identify predictors associated with concordant/discordant maternal reporting.

RESULT(S)

The Upstate New York Infant Development Screening Program (Update KIDS Study) was linked with the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) using a defined algorithm for 2008-2010. The sensitivity, specificity, positive and negative predictive values were high (0.93, 0.99, 0.80, and 1.00, respectively). The validity of maternal report was high, reflecting few differences by participant characteristics except for maternal age dichotomized at 29 years as identified with NRI methods.

CONCLUSION(S)

Maternally reported ART is valid, with little variation across various characteristics. No strong predictors of discordant reporting were found, supporting the utility of population-based research with SART CORS linkage.

Assisted reproductive technology and risk of congenital malformations: a meta-analysis based on cohort studies

PURPOSE

To assess the association between assisted reproductive technology (ART) and risk of congenital malformations (CM) by conducting a meta-analysis of cohort studies.

METHODS

PubMed, Google Scholar, Cochrane Libraries and Chinese database were searched through August 2014 to identify studies that met pre-stated inclusion criteria. Either a fixed- or a random-effects model was used to calculate the overall combined risk estimates. Subgroup analysis was performed to explore potential heterogeneity moderators.

RESULTS

Fifty-seven studies involving 119,874 infants conceived following ART and 1,212,320 infants conceived naturally were included in the analysis. The ART-conceived infants were associated with a higher risk of CM [relative risk (RR) = 1.33; 95 % confidence interval (CI) 1.24-1.43] when compared with those conceived naturally. When data were restricted to singleton births (RR = 1.38; 95 % CI 1.30-1.47), major CM (RR = 1.47; 95 % CI 1.29-1.68), matched/adjusted studies (RR = 1.37; 95 % CI 1.27-1.47) or high quality studies (RR = 1.40; 95 % CI 1.27-1.55), the increased risk of CM still existed in ART pregnancies. Additionally, an increased risk of CM was also found when the ART twin (RR = 1.18; 95 % CI 1.06-1.32) or multiple births (RR = 1.16; 95 % CI 1.05-1.27) were separately compared with spontaneously conceived twin or multiple births. Substantial heterogeneity was observed across studies (I (2) = 68, 44, 39, and 33 % for all infants, singletons, twins and multiples, respectively). Whether confounding factors were matched or adjusted, study quality and sample size as the first three of the most relevant heterogeneity moderators have been identified. No evidence of publication bias was observed (P > 0.10).

CONCLUSIONS

The ART-conceived infants have a higher risk of CM compared with those conceived naturally. However, these estimates have to be viewed with caution because of heterogeneity.

Systemic vasculitis and pregnancy: a multicenter study on maternal and neonatal outcome of 65 prospectively followed pregnancies

OBJECTIVE

Systemic vasculitis (SV) are uncommon diseases that rarely affect women during their reproductive age; little data, mainly retrospective, is available on this topic. The aim of our study was to evaluate maternal/neonatal outcome and disease course before, during and after pregnancy.

METHODS

Sixty-five pregnancies in 50 women with SV were followed by a multispecialistic team in 8 institutions between 1995 and 2014. Clinical data on pregnancy, 1year before and 1year after delivery was retrospectively collected. The rate of pregnancy complications was compared to that of a General Obstetric Population (GOP) of 3939 women.

RESULTS

In 2 patients the diagnosis of SV was done during pregnancy; 59 out of the remaining 63 started when maternal disease was quiescent. We recorded 56 deliveries with 59 live births, 8 miscarriages and 1 fetal death. In SV, preterm, particularly early preterm (<34weeks) deliveries and cesarean sections appeared significantly more frequent than in GOP (11.3% vs 5.0%, p=0.049 and 48.2% vs 31.0%, p=0.009). Vasculitis-related complications occurred in 23 pregnancies (35.4%), with 5 severe events (7.7%) including 3 cases of transient ischemic attack (TIA). Data about the post-partum period were available for 56 pregnancies: 12 flares (21.4%) occurred, with 1 severe event (1.8%).

CONCLUSION

SV patients can have successful pregnancies (especially during a disease remission phase) despite an increased rate of preterm delivery. Severe flares were limited, but the occurrence of 3 TIA suggests that particular attention should be given to possible thrombotic complications in SV patients during pregnancy and puerperium.

Features of multiple pregnancies obtained by in vitro fertilization or spontaneously

BACKGROUND

The aim of this study was to investigate the prognosis of infants born to multiple pregnancies obtained by in vitro fertilization (IVF) or spontaneously.

METHODS

The records of multiple pregnancies in Bakirkoy Maternity and Children's Hospital between February 2008 and January 2009 were investigated. Maternal, perinatal and postnatal data of multiple pregnancies were evaluated. The congenital anomalies determined by physical examination and/or imaging studies in the prenatal, natal and postnatal period and the difference between groups in terms of morbidity and mortality were investigated as well.

RESULTS

A total of 401 spontaneous multiple pregnancies and 128 IVF multiple pregnancies were included in the study. Rate of multiple pregnancies for live births and IVF rate were 3.8% and 0.79%, respectively. The mean maternal age was 30.1 years (21-43) in the IVF group and 27.9 years (13-43) in the spontaneous group (P < 0.05). The cesarean delivery rate was 100% in the IVF group and 78% in the spontaneous group (P = 0.002). Premature rupture of membranes rate was 9.8% in the IVF group and 3.6% in the spontaneous group (P < 0.05).

CONCLUSIONS

Multiple pregnancies constitute an important health problem due to high perinatal risks and increased health costs. We found maternal age, premature rupture of membranes and cesarean delivery rate significantly high in the IVF group. No significant differences were found between spontaneous and IVF multiple pregnancies in terms of demographic features, hospitalization stay and rate, admission to neonatal intensive care unit, mortality and congenital malformation.

The economic implications of multiple pregnancy following ART

The clinical risks to mothers and babies associated with assisted reproductive technology (ART) multiple birth pregnancies are well described and widely recognized. In contrast, the long-term economic consequences that follow are less appreciated. The few economic analyses that do exist consistently demonstrate the greater patient, healthcare and societal costs associated with twins and higher-order multiples when compared with singleton infants, and convincingly add to the argument that single embryo transfer should be standard practice in most patient groups. Several recent studies have shown that the relative price paid by patients for ART treatment not only has implications for who can afford to access treatment, but also plays an important role in incentivizing embryo transfer practices and thus ART multiple birth rates. This review summarizes the current literature on the costs and consequences of ART multiple births, the contribution of ART multiple births to the economic burden associated with preterm birth, the evidence for the cost-effectiveness of single embryo transfer, and the association between the cost of treatment and the downstream costs associated with multiple births.

Obstetric and perinatal outcomes of twin pregnancies conceived following IVF/ICSI treatment compared with spontaneously conceived twin pregnancies

OBJECTIVE

Twin pregnancy is associated with increased obstetric and perinatal risk. There are conflicting reports on whether assisted conception (ART) further increases these risks. The aim of this study is to assess the obstetric and perinatal outcomes of twin pregnancies according to mode of conception.

STUDY DESIGN

A retrospective study of all viable dichorionic-diamniotic (DCDA) twin pregnancies (n=539) delivered at Cork University Maternity Hospital, Ireland between 2009 and 2012, divided according to spontaneous conception (SC) and ART conception, specifically IVF or ICSI.

RESULTS

The ART conceived group were on average 4 years older (36.8±4.23 vs 32.3±4.93 years) and more frequently nulliparous (73.7%; n=126 vs 36.1%; n=133) than their SC counterparts (p<0.001). There was no significant difference in maternal antenatal complications. ART twins were twice as likely to be delivered by caesarean section (CS) (OR 2.35; 95% CI 1.76-3.14). There was no significant difference in the rates of preterm birth or NICU admission according to mode of conception. ART conceived twins were almost twice as likely to be delivered moderately preterm (32-33(+6)) (OR 1.98, 95% CI 1.21-3.23) and were more likely to have RDS and neonatal hypoglycaemia

CONCLUSIONS

Twin pregnancy, irrespective of mode of conception, carries an increased risk of morbidity and mortality for both mother and babies and therefore couples should be counselled regarding the increased risk of iatrogenic twinning associated with double embryo transfer. However, for those that do conceive twins, they can be advised that assisted conception conveys no significant disadvantage over naturally conceived twin pregnancies.

Multiple pregnancies following assisted reproductive technologies--a happy consequence or double trouble?

The association between assisted reproduction technologies (ART) and multiple pregnancy is well-established, with a multiple birth rate of 24% in ART pregnancies. Multiple pregnancy is associated with significantly increased maternal and perinatal morbidity and mortality, as well as increased costs to the National Health Service. Evidence relating to the obstetric outcomes of ART twins versus naturally conceived twins is discussed in this review. Methods to reduce the risk of multiple births including elective single embryo transfer and multifetal pregnancy reduction are also discussed.

Maternal pre-gravid body mass index and obstetric outcomes in twin gestations

OBJECTIVE

The aim of this study is to evaluate the impact of maternal pre-gravid and/or first trimester overweight and obesity, and the adverse obstetrics outcome in twin pregnancies.

STUDY DESIGN

This is a retrospective study of women who delivered viable twins after 23 weeks of gestation with available prepregnancy body mass index (BMI) and/or were at their earliest visit during the first trimester of pregnancy in the period 2007-2011. The patients were divided into four subgroups according to their BMI (underweight, normal weight, overweight and obese) according to the WHO classification and their outcomes were compared. Obstetrical outcomes of interest including gestational diabetes, gestational hypertension, preterm birth, antepartum hemorrhage, intrahepatic cholestasis of pregnancy, method of delivery and neonatal intensive care unit (NICU) admission were all studied and compared.

RESULT

Electronic records of 1228 pregnant subjects who delivered twins were abstracted. Five hundred and four patients with twin gestations with available BMI were identified (underweight BMI<18.5% (n=22), normal weight BMI 18.5-24.9% (n=260), overweight 25-29.9% (n=114) and obese ⩾30% (n=108)). Obstetric complications occurred more often in the overweight and obese groups as compared with the normal weight group. There was an increased risk of gestational diabetes in overweight and obese women (odds ratio (OR), 3.3; 95% confidence interval (CI) 1.52-7.3; P=0.001) and (OR, 3.2; 95% CI, 1.41-7.1; P=0.002), respectively. There was an increased risk of gestational hypertension in the obese group compared with the normal weight group (OR, 2.29; 95% CI, 1.1-4.7; P=0.02) but not in the overweight group (OR, 1.71; 95% CI, 0.8-3.6; P=0.1). In addition, an increased risk of very preterm delivery (<32 weeks) in the overweight group and obese groups was seen when compared with the normal weight group (OR, 2.2; 95% CI, 1.18-4.20; P=0.014 and OR, 2; 95% CI, 1.024-3.91; P=0.04, respectively). Increased rate of cesarean section in the obese group was seen when compared with the normal weight group (OR, 2; 95% CI, 1.2-3.4; P=0.006). Risks of antepartum hemorrhage, intrahepatic cholestasis and NICU admission were similar between the groups.

CONCLUSION

In addition to the known obstetrics complications associated with twin gestations, the pregnancy outcomes in twins are further adversely influenced by increased maternal prepregnancy BMI.