Pronóstico perinatal y materno de las gestaciones gemelares concebidas mediante fecundación in vitro,en relación con las obtenidas espontáneamente

Objective

To determine the outcomes of twin pregnancies resulting from in vitro fertilization (IVF) compared with those resulting from spontaneous conception.

Material and methods

We performed a historical cohort study comparing neonatal outcomes of twin pregnancies resulting from IVF (n = 44) with those resulting from spontaneous conception (n = 109) in the Complejo Hospitalario Universitario de Albacete (Spain) in 2001, 2001 and 2003. The primary variable was perinatal mortality. Secondary variables were fetal morbidity (neonatal abnormalities, Apgar < 7, acidotic arterial pH, admission to the neonatal unit), preterm delivery, maternal complications, and type of delivery.

Results

No differences in perinatal mortality and morbidity were found between spontaneous twin pregnancies and twins resulting from assisted reproductive techniques. The rate of preterm labor was significantly higher in spontaneous twin pregnancies (75.2 versus 52%; p = 0.006). The incidence of gestational diabetes was significantly higher in twin pregnancies resulting from IVF than in spontaneous twin pregnancies (25.5 versus 9.7%;p = 0.01).

Conclusions

Perinatal and maternal outcomes in twin pregnancies resulting from IVF are similar to those of spontaneous twin pregnancies.     

Maternal midtrimester serum AFP and free beta-hCG levels in in vitro fertilization twin pregnancies

We aimed to compare the levels of alpha-fetoprotein (AFP) and free beta-human chorionic gonadotrophin (beta-hCG) levels as multiples of the median (MoM) values between spontaneous and in vitro fertilized (IVF) twin pregnancies. The control group of spontaneous singleton pregnancies was used for calculating the gestational age specific median levels of the values. Within a cohort of 19 310 pregnancies, 145 twin pregnancies were identified. The data were collected from Down syndrome (DS) screening programmes in four University catchment areas in Finland between 1994-98. Maternal midtrimester serum marker levels were measured across gestational weeks 14-18. There were no fetal chromosome anomalies in either of the twin groups or the singleton group. Serum AFP of 145 and beta-hCG values of 39 spontaneous twin pregnancies were compared to the values of 6548 singleton pregnancies. In IVF twins 30 AFP and 29 beta-hCG values were compared to the levels of the control group. Both AFP and beta-hCG values were twice as high in the spontaneous twin pregnancies (medians 2.18 and 1.83 MoM respectively) as in the singleton group (medians 1.00 and 1.00 MoM respectively). In IVF twin pregnancies beta-hCG levels were higher (median 2.20 MoM) than in spontaneous twins (p=0.08), whereas no significant difference was found in AFP levels (2.30 MoM). In conclusion, the higher levels of beta-hCG levels in IVF twin pregnancies should be considered in DS screening to avoid high false positive rates.     

A comparison of maternal and perinatal outcome between in vitro fertilization and spontaneous dichorionic-diamniotic twin pregnancies

Objective: To compare the maternal and neonatal outcome of dichorionic diamniotic in vitro fertilization (IVF) twin and spontaneous twin pregnancies.

Material and methods: Maternal and fetal data of all consecutive dichorionic-diamniotic twin pregnancies delivered in our institution between January 2009 and May 2015 were abstracted from medical records and pregnancy outcome of IVF twin was compared to spontaneous twin.

Results: Overall 708 twin pregnancies (449 IVF and 259 spontaneous) were included. Women in the IVF group were 2 years older and more frequently nulliparous. The rate of pregnancy induced hypertension and preeclampsia (PIH/PET) was three times higher in the IVF group than in the spontaneous group. The rate of preterm births, before 37 weeks of gestation and the rate of cesarean section were higher in the IVF group. These results were confirmed by multivariate analysis. The neonatal outcome was similar in both the groups except for a lower mean newborn birthweight in the IVF group.

Conclusion: Women with IVF twins are at a significantly higher risk of having preterm births, PIH/PET and cesarean section but there was no significant adverse effect on neonatal outcome except for a lower mean newborn birth weight.     

Preeclampsia acts differently in in vitro fertilization versus spontaneous twins

Objective

To investigate risk factors and pregnancy outcome of spontaneous vs in-vitro fertilization (IVF) twins complicated with preeclampsia.

Study design

A retrospective population-based cohort study comparing maternal and neonatal outcome in IVF vs spontaneously conceived twins was conducted. Deliveries occurred in a tertiary medical center between the years 1988 and 2010. Women who conceived after ovulation induction and those with chronic hypertension were excluded from the study. Multiple logistic regression models were used to control for confounders.

Results

The study population included 4428 twin pregnancies, of these 314 (7.1%) had preeclampsia; 64 (20.3%) were IVF twins and 250 (79.7%) were spontaneous twins. Preeclampsia was more common in IVF compare to spontaneous twins (13.8 vs 7.6%, OR = 1.81, CI = 1.50–2.17, P < 0.001). The mothers of IVF twins were significantly older, and were more likely to be nulliparous. The rate of cesarean delivery was higher among IVF twins. The mean gestational age at delivery and the mean birth weight were significantly lower in IVF twins. While controlling for confounders using a multivariate analysis, IVF was found as an independent risk factor for preterm delivery in twin pregnancies with preeclampsia. However, there was no difference in the perinatal mortality or 5 min Apgar scores < 7 between the two groups.

Conclusion

Preeclampsia is more common in IVF twins compared to spontaneous twin pregnancies. IVF twins with preeclampsia are at an increased risk for cesarean delivery, preterm delivery and low birth weight.

     

IVF twins have similar obstetric and neonatal outcome as spontaneously conceived twins: a prospective follow-up study

Studies comparing the outcome of spontaneous versus IVF twin pregnancies report heterogeneous results. This may depend on differences in the studied populations and/or in the management approach to twin pregnancy. The aim of the present study was to compare both maternal and perinatal outcomes in dichorionic diamniotic twin pregnancies who where spontaneously conceived or originated by successful homologous IVF. In order to get homogeneous observations, monochorionic twin pregnancies and triplet pregnancies were excluded. Moreover, to avoid any possible bias deriving from differences in the obstetric management, all pregnancies were managed by the same team applying fixed obstetric protocols. The study included 223 twin pregnancies, 84 conceived by IVF and 139 spontaneously conceived. Overall, maternal and perinatal outcomes were similar in the two groups: no significant differences were observed as far as gestational age at delivery, birthweight, perinatal morbidity and mortality, and rate of malformations were concerned. The rate of Caesarean section was slightly, but not significantly, higher in IVF pregnancies. In conclusion, the outcome of IVF twin pregnancies is comparable to that of spontaneously conceived twin pregnancies, provided that the same management criteria are applied.     

Obstetric and neonatal outcomes of IVF versus spontaneously conceived dichorionic twins

ObjectiveTo evaluate the obstetric and neonatal outcomes of dichorionic twin (DD) pregnancies after IVF in comparison to spontaneous conception (SC).DesignRetrospective cohort study.SettingWomen Hospital – Hamad Medical Corporation, Doha, Qatar.Material and methodsAll cases of DD twin pregnancies during the period from January 2002 to December 2011 were included. Demographic and clinical data, obstetric and neonatal outcomes of DD twin pregnancies after IVF and SC were compared.Main outcome measuresMaternal and neonatal outcome.Results145 (80%) and 175 (79.6%) DD twins after IVF and SC were included respectively. IVF was not associated with more obstetric complications than SC group. Six neonatal deaths occurred in both groups. The rate of CS was slightly but not significantly higher in IVF pregnancies (78% versus 68%). In IVF and SC there were 15 malformed fetuses in each group.ConclusionsThe present study reported comparable obstetric and neonatal outcomes of DD twin pregnancies after IVF in comparison to SC provided that the same management criteria are applied to both types of twin pregnancy.     

Pregnancy complications,obstetric risks,and neonatal outcome in singleton and twin pregnancies after GIFT and IVF

Purpose In vitro fertilization (IVF) and to a lower extent gamete intra-fallopian transfer (GIFT) have become routine infertility treatments in industrialized countries. Our purpose is to compare the obstetric and neonatal characteristics of singleton and twin pregnancies after GIFT and IVF with those conceived spontaneously.Methods This case-control study was conducted in a tertiary care medical center. The 322 singleton and 78 twin pregnancies after GIFT or IVF from 1991 through 1996 were evaluated and compared with each other, and with a control group that conceived spontaneously and matched for parity, maternal and gestational age. Statistical significance of differences was assessed by ² test or two-tailed Fisher exact test. Continuous variables were compared by the paired t-test.Results Pregnancy-induced hypertension (PIH) and vaginal bleeding were significantly more frequent maternal complications in the GIFT/IVF singleton groups compared to controls. In twin pregnancies the rate of cesarean sections, vaginal bleeding and preterm labor were more common after GIFT/IVF but did not reach statistical significance. Assisted reproduction was associated with low birth weight only in twin pregnancies when controlled for confounding variables, however perinatal outcome was comparable. There was no significant difference in the outcome measures between GIFT and IVF pregnancies.Conclusion After controlling for parity, maternal and gestational age, singleton pregnancies conceived by GIFT/IVF are at increased obstetrical risk, however the perinatal outcome is comparable despite a lower average birth weight.     

Maternal risks and perinatal outcome in a Danish national cohort of 1005 twin pregnancies: the role of in vitro fertilization

BACKGROUND: Twin pregnancies constitute 25% of all in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) pregnancies. There is a lack of knowledge on maternal risks and perinatal outcome of IVF/ICSI twin pregnancies. METHODS: National survey by questionnaire (n = 1769). The study population consisted of all IVF/ICSI twin mothers (n = 266) and the two control groups of all IVF/ICSI singleton mothers (n = 764) and non-IVF/ICSI twin mothers (n = 739) who delivered in Denmark in 1997. The response rate was 89% among IVF twin mothers and overall 81%. RESULTS: In terms of maternal risks and perinatal outcome no significant differences were observed between IVF/ICSI twin and non-IVF/ICSI twin pregnancies after stratification for maternal age and parity. Nevertheless, IVF/ICSI twin mothers were more frequently on sick leave (OR 2.5, 95% CI 1.5-4.0) and hospitalized (OR 1.9, 95% CI 1.3-2.8) during pregnancy. Compared with IVF/ICSI singleton pregnancies, IVF/ICSI twin pregnancies were characterized by a higher incidence of preeclampsia (OR 2.4, 95% CI 1.5-4.2) and a higher frequency of sick leave (OR 6.8, 95% CI 4.4-10.5) and hospitalizations during pregnancy (OR 3.5, (95% CI 2.5-4.9); moreover, mean birthweight (p < 0.001) and gestational age (p < 0.001) were lower. No differences were observed in the incidence of pregnancy-induced hypertension and gestational diabetes between IVF/ICSI twin and singleton pregnancies. CONCLUSION: Although this population study indicates that maternal risks in IVF/ICSI twin pregnancies are comparable with non-IVF/ICSI twin pregnancies, the IVF/ICSI twin mothers were more likely to be on sick leave or hospitalized during pregnancy. Furthermore, maternal risks were higher and obstetric outcome poorer in IVF/ICSI twin vs. IVF/ICSI singleton pregnancies.     

IVF versus spontaneous twin pregnancies – which are at higher risk of complications?

Objective: To analyze the course of twin pregnancies, deliveries and neonatal outcome after in vitro fertilization (IVF) and compare them with spontaneous twins (ST). Methods: The studied material consisted of 131 women in twin pregnancies: 43 patients with IVF and 83 with ST, who delivered at the 1st Department of Obstetrics and Gynecology, Medical University of Warsaw in years 2005–2009. Results: Complications of pregnancy, especially imminent abortion and imminent preterm delivery, were significantly more often diagnosed in IVF versus ST. The rate of preterm delivery was similar in both groups. The vast majority of all analyzed twin pregnancies were delivered by cesarean section. The dominant indication was other than cephalic presentation of either one of the twins. Regardless of the group, all cases of neonatal mortality were a result of sepsis and extreme prematurity. The length of hospitalization and treatment period depended mostly on prematurity. It was also dependent on the method of conception – IVF was in favor of shorter treatment time. Conclusions: The method of conception seems not to have a negative impact on the course of pregnancy, risk of preterm delivery and obstetric outcome. Neonatal complications of IVF and spontaneous twins are mostly a result of prematurity.     

Neonatal outcome of spontaneous and assisted twin pregnancies

OBJECTIVES: Over the last 10 years, diffusion of assisted reproduction techniques (ovarian stimulation, IVF, GIFT) has led to an increased incidence of multiple pregnancies and consequently, of the related obstetric-neonatal problems. In this study, multiple births have been studied, with particular reference to the twin births occurring in the Gemelli hospital, Rome. The hospital is also a reference centre for obstetric pathologies and infertility treatment. In particular, attention has been focused on neonatal outcome, comparing twins born from spontaneous and assisted pregnancies. STUDY DESIGN: 228 neonates from spontaneous twin pregnancies and 32 from assisted twin pregnancies were taken into consideration with regard to: premature birth, low birth-weight, intrauterine growth retardation, weight discordance, Apgar score, major neonatal diseases, and mortality. RESULTS: Results showed a significant higher incidence of prematurity and low birth-weight, as well as a significant lower gestational age, occurring more frequently in twins resulting from assisted pregnancies than in twins from spontaneous pregnancies. Furthermore, the incidence of severe depression at birth and respiratory disease was significantly higher in twins from assisted pregnancies than in those from spontaneous pregnancies, despite similar gestational age and birth-weight.     

The effect of ICSI, maternal age, and embryonic stage on early clinical loss rate of twin versus singleton pregnancies

OBJECTIVES: To compare early loss rates between twin and singleton pregnancies following ART. STUDY DESIGN: First-trimester sonography counted the number of embryos with positive heartbeat in women undergoing IVF/ICSI and transfer of one to three embryos. The number of lost pregnancies was calculated from a second-trimester sonogram. Loss rates of the entire pregnancy were related to maternal age <38 or > or = 38 years, IVF or ICSI, and cleavage or blastocyst stage embryo transfers (in ICSI cases). RESULTS: Patients underwent IVF with (n = 672) and without (n = 189) ICSI. The overall odds of miscarrying the entire singleton pregnancy were 2.6 times that of a twin gestation (95% CI 1.5, 4.5). The disadvantage for singletons compared to twins seems more apparent in pregnancy after ICSI in the subgroup of patients <38 years (OR 2.9, 95% CI 1.5, 5.8). In this subgroup, the disadvantage conferred to singletons appeared only among days 2-3 embryo transfers (OR 3.0, 95% CI 1.3, 7.2). CONCLUSION: A significantly lower early spontaneous loss rate of twin pregnancies seems related to ICSI followed by cleavage stage embryo transfer in patients <38 years.     

Perinatal outcome of twin pregnancies after in vitro fertilization

BACKGROUND: There are conflicting data concerning perinatal outcome of twin, in vitro fertilization (IVF) pregnancies. The aim of this study was to evaluate and compare perinatal and neonatal outcomes in twin IVF pregnancies to those of spontaneously conceived twin gestations. METHODS: The medical files of 73 IVF and 148 naturally conceived twin pregnancies were studied retrospectively. Data concerning maternal characteristics, obstetric complications, and neonatal outcome were recorded and compared by chi2 test. The one-way analysis of variance (anova) was used to compare the means of groups. RESULTS: Mean maternal age, the proportion of nulliparous women, and the incidence of premature rupture of membranes, cesarean section, and premature delivery were significantly higher in the study group. The mean birthweight was significantly lower, the frequency of admission to the intensive care unit and the duration of hospitalization were significantly higher in the study group. The incidence of intraventricular hemorrhage was significantly higher in the IVF group. The number of perinatal deaths was similar. CONCLUSION: IVF twin pregnancies are at greater risk for obstetric complications and adverse neonatal outcome in comparison with naturally conceived twin gestations.     

The costs to the NHS of multiple births after IVF treatment in the UK

OBJECTIVES: To determine the cost to the NHS resulting from multiple pregnancies arising from IVF treatment in the UK, and to compare those costs with the cost to the NHS due to singleton pregnancies resulting from IVF treatment. DESIGN: A modelling study using data from published literature and cost data from national sources in the public domain, calculating direct costs from the diagnosis of a clinical pregnancy until the end of the first year after birth. SETTING: Academic Unit of Reproductive and Developmental Medicine. POPULATION: Theoretic core modelling study using data from published literature. METHODS: The analysis was based on the total annual number of births resulting from an IVF treatment in the UK. Main outcome measures total direct costs to the NHS per IVF singleton, twin or triplet family. MAIN OUTCOME MEASURES: Cost of singleton, twin and triplet IVF pregnancies in the UK. RESULTS: Total direct costs to the NHS per IVF twin or triplet family (maternal + infant costs) are substantially higher than per IVF singleton family (singleton: pounds 3313; twin: pounds 9122; and triplet: pounds 32,354). Multiple pregnancies after IVF are associated with 56% of the direct cost of IVF pregnancies, although they represent less than 1/3 of the total annual number of maternities in the UK. CONCLUSIONS: Multiple pregnancies after IVF are associated with high direct costs to the NHS. Redirection of money saved by implementation of a mandatory 'two embryo transfer' policy into increased provision of IVF treatment could double the number of NHS-funded IVF treatment cycles at no extra cost. Further savings could be made if a selective 'single embryo transfer' policy were to be adopted.     

Cost analysis of singleton versus twin pregnancies after in vitro fertilization

OBJECTIVE: To determine the difference in costs between singleton and twin pregnancies after IVF treatment from pregnancy to 6 weeks after delivery from a health care perspective. DESIGN: Retrospective cost analysis. SETTING: IVF department at the University Medical Center Nijmegen, The Netherlands. PATIENT(S): A representative sample of singleton and twin pregnancies after IVF treatment between 1995 and 2001 at the University Medical Center Nijmegen. INTERVENTION(S): IVF with or without intracytoplasmic sperm injection and with or without cryopreservation. MAIN OUTCOME MEASURE(S): Medical costs per singleton and twin pregnancy after IVF. RESULT(S): In patients pregnant with twins, the incidence of hospital antenatal care, complicated vaginal deliveries, and cesarean sections was higher and was associated with more frequent and longer maternal and neonatal hospital admissions. Maternal and neonatal hospital admissions were the major cost drivers. The medical cost per twin pregnancy was found to be more than five times higher than per singleton pregnancy, 13,469 and 2,550, respectively. CONCLUSION(S): The medical cost per twin pregnancy was more than 10,000 higher than per singleton pregnancy. A reduction in the number of twin pregnancies by elective single ET will save substantial amounts of money. This money might be used for the additional IVF cycles that will probably be needed to achieve similar success rates between single ET and two-embryo transfer.     

First trimester screening with free beta-hCG,PAPP-A and nuchal translucency in pregnancies conceived with assisted reproduction

OBJECTIVE: To evaluate the effect of in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) on free beta-human chorionic gonadotrophin (beta-hCG), pregnancy-associated plasma protein A (PAPP-A) and nuchal translucency (NT). METHODS: First trimester maternal dried whole blood specimens from 74 singleton pregnancies (32 by IVF and 42 by ICSI) and 30 twin pregnancies (16 by IVF and 14 by ICSI) in which conception was achieved with assisted reproduction techniques were matched with five controls resulting in 370 singleton controls and 150 twin controls. NT was measured using the Fetal Medicine Foundation protocol. Free beta-hCG, PAPP-A and NT levels were compared between the IVF and control groups and between the ICSI and control groups using the Mann-Whitney U test. RESULTS: In singleton pregnancies, the only significant difference was a 21% (95% CI: -35%--7%) reduction in PAPP-A in IVF cases. In twin pregnancies, the only significant difference was a 12% (95% CI: -34%--3%) reduction in NT in IVF cases. In singleton pregnancies, the false-positive rate for Down syndrome screening was 1.4% and 1.9% greater for the IVF and ICSI groups, respectively, compared to controls for a general screening population. CONCLUSIONS: Patients undergoing assisted reproduction techniques should be counseled about the possibility of increased false-positive rates. Larger studies are needed to confirm this observation and to develop appropriate adjustment factors to reduce false-positive rates.     

A comparative study of obstetric outcomes in electively or spontaneously reduced triplet pregnancies

Purpose

This study aimed at evaluating the pregnancy outcomes of IVF triplets which are spontaneously or electively reduced to twins and to compare them with non-reduced triplets and twins.

Methods

Retrospective analysis of trichorionic triplets and dichorionic twins of IVF pregnancies.

Results

Preeclampsia rate was significantly higher in triplet group (p = 0.014). Premature contractions requiring tocolysis were seen more often in spontaneous reduction and triplet groups compared to elective reduction and twin groups (p < 0.001). Elective reduction and twin groups had significantly lower rate of infants weighing less than 1,500 g than those of triplets (p < 0.001). Highest rate for infants weighing over 2,500 g was found in primary twin group. Preterm delivery rates were significantly lower in both twin and elective reduction groups compared to triplet and spontaneous reduction groups (p < 0.001). Proportion of women giving birth at term was not different in elective reduction and twin groups, and they were significantly higher compared to spontaneous reduction group (p = 0.024). Perinatal mortality rates of both elective reduction and twin groups were significantly less than those in the triplet group (p = 0.045 and p < 0.001, respectively).

Conclusions

Obstetric outcomes of triplets from IVF or ovulation induction cycles undergoing elective reduction are better than ongoing triplet and spontaneous reduction groups and are similar to that of dichorionic twins.     

Risk of spontaneous preterm birth in IVF-conceived twin pregnancies

Objective: To compare the mean transvaginal ultrasound (TVU) cervical length (CL) at midtrimester in screening for preterm birth in in vitro (IVF)-conceived twin pregnancies versus spontaneously-conceived twin pregnancies.

Methods: This was a retrospective cohort study. Potential study subjects were identified at the time of a routine second trimester fetal ultrasound exam at 18 0/7 to 23 6/7-week gestation. All women with twin diamniotic pregnancies screened with a single TVU CL for this trial were included. Mean TVU CLs were compared between IVF-conceived twin pregnancies and spontaneously-conceived twin pregnancies. The relationship of TVU CL with gestational age at delivery was assessed. Incidence of short TVU CL, defined as TVU CL ≤30?mm, was also calculated in the two groups. The primary outcome was the mean of TVU CL. Distribution of CL was determined and normality was examined in both groups

Results: A total of 668 women with diamniotic twin pregnancies who underwent TVU CL screening between 18 0/6 and 23 6/7 weeks were included. 158 (23.7%) were IVF-conceived pregnancies, and 510 (76.3%) were spontaneously-conceived pregnancies. No women received progesterone, pessary, or cerclage for preterm birth prevention during pregnancy. The mean TVU CL was significantly lower in the IVF-conceived group (32.2?±?10.5?mm) compared to the spontaneously-conceived group (34.1?±?9.1?mm) (mean difference (MD)???1.90?mm, 95%CI ?3.72 to ?0.08). The incidence of TVU CL ≤30?mm was 30.4% in the IVF-conceived group and 21.6% in the spontaneously-conceived group (adjusted odds ratio (aOR) 1.59, 95%CI 1.06–2.37). IVF-conceived twins had a significantly higher risk of spontaneous preterm birth <34 weeks (32.9 versus 21.2%; aOR 1.83, 95% confidence interval (CI) 1.23–2.71) and higher rate of delivery due to spontaneous onset of labor (64.5 versus 54.9%; aOR 1.50, 95%CI 1.03–2.17). For any given TVU CL measured between 18 0–7 and 23 6/7 weeks, gestational age at delivery for IVF-conceived twins was earlier by about 1 week on average compared with spontaneously-conceived twins.

Conclusions: The higher rate of spontaneous preterm birth in IVF-conceived twin pregnancies is predicted by lower midtrimester TVU CL, as well as by the lower gestational age at birth per any given CL in the IVF-conceived compared to the spontaneously-conceived twin pregnancies.     

Gestation sac size in in-vitro fertilization pregnancies

The gestation sac size in pregnancies resulting from in-vitro fertilization (IVF) and embryo transfer have been compared with those in spontaneous pregnancies. Small-for-dates gestational sac sizes were found in 36% of the IVF pregnancies. This proportion held for both singleton and multiple pregnancies. With increasing gestation beyond 8 weeks the gestation sac volume increasingly approached normal. In contrast to spontaneous conceptions, IVF pregnancies had a low rate of pregnancy loss once fetal heart movements were demonstrated, when the gestation sac size was small-for-dates. Small sac size in an IVF pregnancy may lead to the misdiagnosis of a failed pregnancy.     

Obstetric and perinatal outcome of 1655 ICSI and 3974 IVF singleton and 1102 ICSI and 2901 IVF twin births: a comparative analysis

A total of 3974 IVF and 1655 ICSI singleton births and 2901 IVF and 1102 ICSI twin births were evaluated. Pregnancies after both fresh and frozen transfers were included. IVF and ICSI singleton pregnancies were very similar for most obstetric and perinatal variables. The only significant difference was a higher risk for prematurity (< 37 weeks of amenorrhoea) in IVF pregnancies compared with ICSI pregnancies (12.4 versus 9.2%, OR = 1.39, 95% CI = 1.15-1.70). For twin pregnancies, differences were not statistically different except for a higher incidence of stillbirths in the ICSI group (2.08 versus 1.03%, OR = 2.04, 95% CI = 1.14-3.64). Intrauterine growth retardation with or without pregnancy-induced hypertension was observed more often in the ICSI group. Regression analysis of the data with correction for parity and female age showed similar results for twins. For singletons, this analysis showed similar results with the exception of low birth weight babies (< 2500 g), which were also observed more often in IVF pregnancies (9.6 versus 7.9%, OR = 0.79, CI = 0.65-0.98, P = 0.03). This large case-comparative retrospective analysis showed that the obstetric outcome and perinatal health of IVF and ICSI pregnancies is comparable.