Evaluation of Cesarean section scar using saline contrast sonohysterography in women with previous Cesarean scar pregnancy.

OBJECTIVE: To evaluate Cesarean scar defects using saline contrast sonohysterography (SCSH) in women with a history of Cesarean scar pregnancy (CSP). METHODS: A cohort of 38 non-pregnant women with a history of CSP treated with combined local and systemic methotrexate was investigated prospectively by SCSH. For the purpose of analysis, they were classified, according to the modified Delphi consensus criteria for CSP in early gestation, into three subgroups based on the depth of the gestational sac herniation in the midsagittal plane. Subgroup A included eight (21.1%) cases, in which the largest part of the gestational sac protruded towards the uterine cavity; Subgroup B included 20 (52.6%) cases, in which the largest part of the gestational sac was embedded in the myometrium; and Subgroup C included 10 (26.3%) cases, in which the gestational sac was located partially outside the outer contour of the cervix or uterus. RESULTS: SCSH revealed that all women in Subgroup C had a uterine niche. The median niche length (P = 0.006) and depth (P = 0.015) were significantly greater in Subgroup C than in Subgroups A or B. The median residual myometrial thickness (RMT) was significantly lower in Subgroup C than in Subgroups A or B (P = 0.006). CONCLUSIONS: Women with prior CSP who had a gestational sac protruding beyond the serosal line had a significantly greater niche length and depth, and lower RMT. This knowledge may guide individualized risk counseling. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

Change in prevalence of preterm birth in Israel following publication of national guidelines recommending routine sonographic cervical-length measurement at 19-25 weeks' gestation.

OBJECTIVE: To compare the prevalence of preterm birth (PTB) (delivery before 37 weeks) in Israel before and after publication of national guidelines recommending second-trimester sonographic cervical-length (CL) measurement. METHODS: The Israeli Society of Obstetrics and Gynecology (ISOG) guidelines, issued on 1 January 2012, specified that CL should be measured transabdominally or, if this is not possible, transvaginally, at the 19-25-week ultrasound anomaly scan and that CL < 25 mm should indicate further work-up and treatment, although the type of treatment was unspecified. In 2000, the Israel Ministry of Health issued a legal requirement for the submission of delivery records to a national registry. These data were used to compare PTB prevalence in the period before (2000-2011) and that after (2012-2020) publication of the guidelines, as well as trends within each time period. Information was available on singleton and multiple pregnancy and maternal age and parity, as well as low birth weight (< 2500 g). RESULTS: During the period 2000-2020, there were 3 403 976 infants liveborn in Israel: 1 797 657 before and 1 606 319 after publication of the ISOG guidelines. There were 247 187 PTBs overall, with a prevalence of 7.64% (95% CI, 7.52-7.77%) before publication of the guidelines and 6.84% (95% CI, 6.43-7.24%) afterwards (P < 0.0002, two-tailed). The annual PTB prevalence was static in the first time period but declined by 0.18% per annum during the second period, after publication of the guidelines. The proportionate reduction in PTB prevalence after compared with before publication of the guidelines was 10% overall, 9% for PTB at 33-36 weeks, 18% for PTB at 28-32 weeks and 24% for PTB at < 28 weeks. After publication of the guidelines, reduced prevalence of PTB was observed among singletons (5.49% before vs 4.83% after, P < 0.0001), but not among infants in twin or higher-order multiple pregnancy. There was a statistically significant reduction in the rate of PTB following publication of the guidelines in both nulliparous and parous women and in the 19-39-year-old maternal-age group. Although reductions in PTB prevalence were also noted in high-risk age groups (maternal age < 19 years and ≥ 40 years), these did not reach statistical significance. Following publication of the guidelines, there was a statistically significant reduction in the prevalence of birth weight under 2500 g, of a magnitude similar to that for PTB prevalence. CONCLUSIONS: The publication of national guidelines recommending routine CL measurement at the time of the second-trimester anomaly scan was associated with a fall in PTB prevalence in singleton pregnancies. Whilst direct evidence linking screening with this fall in prevalence is lacking, it is likely that implementation of routine CL screening played an important role in the reduction of PTB rate. Our experience indicates that screening can be incorporated into the second-trimester anomaly scan. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Obstetric outcomes of twin pregnancies presenting with a complete hydatidiform mole and coexistent normal fetus: a systematic review and meta-analysis.

BACKGROUND: Epidemiological data on obstetric and oncologic complications in twin pregnancies combining a complete hydatidiform mole (CHM) coexisting with a normal fetus and placenta are limited. OBJECTIVES: To evaluate perinatal and obstetric outcomes for mother and fetus and risk of gestational trophoblastic neoplasia (GTN) in twin pregnancies including a CHM. SEARCH STRATEGY: PubMed, MEDLINE and EMBASE and the grey literature were searched for articles published between May 1980 and May 2019 using a protocol designed a priori and registered on PROSPERO (CRD42018112524). SELECTION CRITERIA: Observational cohort studies of four or more cases confirmed by histopathology and providing data on pregnancy outcomes and GTN. DATA COLLECTION AND ANALYSIS: Two reviewers independently reviewed abstracts and full-text articles. The quality of the studies was assessed with the Newcastle-Ottawa scale and a meta-analysis was performed. MAIN RESULTS: Of the 344 abstracts identified, 14 studies (244 cases) met the eligibility criteria. The incidence of maternal complication in ongoing pregnancies was 80.8% and included vaginal bleeding, hyperthyroidism and pre-eclampsia. There were overall 91 (50%) live births in ongoing pregnancies and 83 (34%) of the total cases were subsequently diagnosed with GTN. Substantial and significant (P < 0.001) heterogeneity was found for the incidence of preeclampsia indicating variability in reporting the incidence of some obstetric complications between studies. CONCLUSIONS: Patients diagnosed with a twin pregnancy combining a CHM and an apparently normal fetus have a high risk of perinatal complications, low live-birth rates and around a third of them will develop a GTN and should be managed by specialised multidisciplinary teams. TWEETABLE ABSTRACT: Our study indicates a high rate of obstetric and oncologic complications in patients presenting with a complete hydatidiform mole and coexistent normal fetus.

Termination of pregnancy due to fetal central nervous system abnormalities performed after 24 weeks' gestation: survey of 57 fetuses from a single medical center.

PURPOSE: To assess fetal central nervous system (CNS) abnormalities presenting as major findings leading to late termination of pregnancy (late TOP) performed ≥ 24 weeks' gestation. METHOD: The study population included 2789 pregnant women that underwent late TOP in our institute between the years 1998 and 2015. RESULTS: Fifty-seven cases (2.0%) underwent late TOP because of fetal CNS indications and are the subjects of the current study. Those cases were subdivided into four categories (1) no routine prenatal screening with an incidental finding discovered ≥ 24 weeks' gestation (25 patients, 43.8%); (2) developmental or acquired findings detected during late second and third trimester (22 patients, 38.6%); (3) apparently normal routine screening with abnormal findings that could have been detected earlier (six patients, 10.6%); (4) routine prenatal care raised suspicion of abnormalities, and the final diagnosis was established only following additional tests (four patients, 7.0%). CONCLUSIONS: Combining the two categories of CNS abnormalities, i.e., pregnant women who did not undergo any fetal evaluation (group 1) and those that could have been detected earlier (group 3) consists 54% from our cohort in which late TOP could have been avoided. On contrary, 39% fetuses from our study population had CNS developmental findings which could be detected only at advanced stage of gestation.

Bedside risk estimation of morbidly adherent placenta using simple calculator.

PURPOSE: To construct a calculator for 'bedside' estimation of morbidly adherent placenta (MAP) risk based on ultrasound (US) findings. MATERIALS AND METHODS: This retrospective study included all pregnant women with at least one previous cesarean delivery attending in our US unit between December 2013 and January 2017. The examination was based on a scoring system which determines the probability for MAP. RESULTS: The study population included 471 pregnant women, and 41 of whom (8.7%) were diagnosed with MAP. Based on ROC curve, the most effective US criteria for detection of MAP were the presence of the placental lacunae, obliteration of the utero-placental demarcation, and placenta previa. On the multivariate logistic regression analysis, US findings of placental lacunae (OR = 3.5; 95% CI, 1.2-9.5; P = 0.01), obliteration of the utero-placental demarcation (OR = 12.4; 95% CI, 3.7-41.6; P < 0.0001), and placenta previa (OR = 10.5; 95% CI, 3.5-31.3; P < 0.0001) were associated with MAP. By combining these three parameters, the receiver operating characteristic curve was calculated, yielding an area under the curve of 0.93 (95% CI, 0.87-0.97). Accordingly, we have constructed a simple calculator for 'bedside' estimation of MAP risk. The calculator is mounted on the hospital's internet website ( http://www.assafh.org/Pages/PPCalc/index.html ). The risk estimation of MAP varies between 1.5 and 87%. CONCLUSIONS: The present calculator enables a simple 'bedside' MAP estimation, facilitating accurate and adequate antenatal risk assessment.

Prediction of morbidly adherent placenta using a scoring system.

OBJECTIVE: To evaluate the accuracy of an ultrasound-based scoring system for diagnosing morbidly adherent placenta (MAP). METHODS: This study included pregnant women referred to our ultrasound unit during 2013-2015 because of suspected MAP on a previous ultrasound examination or because they had at least one previous Cesarean delivery. All women were assessed using a scoring system based on the following: number and size of placental lacunae; obliteration of the demarcation between the uterus and placenta; placental location; color Doppler signals within placental lacunae; hypervascularity of the placenta-bladder and/or uteroplacental interface zone; and number of previous Cesarean deliveries. Each criterion was assigned 0, 1 or 2 points and the sum of points yielded the final score. Patients were classified into low, moderate or high probability for MAP based on the final score. The presence of MAP was determined by the surgeon at delivery and clinical descriptions were documented in the electronic patient file. Pathological diagnoses were available only in cases that underwent hysterectomy. RESULTS: In total, 258 pregnant women were included in the study, of whom 23 (8.9%) were diagnosed with MAP. There was a statistically significant difference in the prevalence of MAP when women were grouped according to the scoring system, with 0.9%, 29.4% and 84.2% in the low, moderate and high probability groups, respectively (P < 0.0001). All sonographic criteria of the scoring system were significantly associated with MAP (P < 0.0001). Receiver-operating characteristics (ROC) curves for prediction of MAP using the number of placental lacunae and obliteration of the uteroplacental demarcation yielded an area under the ROC curve of 0.94 (95% CI, 0.86-1.00). CONCLUSIONS: Our proposed scoring system is highly predictive of MAP in patients at risk. This allows an adequate multidisciplinary team approach for the planning and timing of delivery in such cases. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

First- and second-trimester maternal serum markers of pre-eclampsia in twin pregnancy.

OBJECTIVE: To evaluate the distribution of first- and second-trimester maternal serum markers in twin pregnancy with and without pre-eclampsia. METHODS: One-hundred and forty-four twin and 109 unaffected singleton pregnancies were recruited from the same institution. First- and second-trimester maternal blood samples were stored and measured retrospectively for serum placental growth factor (PlGF), pregnancy-associated plasma protein-A (PAPP-A), free ß-human chorionic gonadotropin (ß-hCG) and α-fetoprotein (AFP). All had measurement of first-trimester serum markers, and 167 (66%) had second-trimester tests. Values were expressed in multiples of the gestation-specific median (MoMs) in singletons, adjusted for maternal weight, as appropriate. RESULTS: Pre-eclampsia was diagnosed in 12 (9.0%) twin pregnancies of 133 continuing beyond 22 weeks. In unaffected twin pregnancies, all serum markers were statistically significantly increased (P < 0.0001), consistent with a doubling of concentration. Among twin pregnancies, those with pre-eclampsia had a significantly reduced median PlGF compared with surviving unaffected twin pregnancies (0.96 MoM vs 1.46 MoM; P < 0.0002, two-tailed), whilst median PAPP-A, which is known to be reduced in affected singleton pregnancies, was increased (3.91 MoM vs 2.43 MoM; P < 0.0005, two-tailed). The levels of free ß-hCG (P < 0.02) and AFP (P < 0.05) were also significantly raised, but to a lesser extent than was the level of PAPP-A. Using a logistic regression algorithm based on first- and second-trimester PlGF and PAPP-A, together with previously published uterine artery Doppler and mean arterial pressure measurements in the same series, the predicted pre-eclampsia detection rate was 65% for a 10% false-positive rate. CONCLUSIONS: In twin pregnancy, the predicted detection rate of pre-eclampsia using first- and second-trimester maternal serum and biophysical markers is good. In contrast to singleton pregnancy, PAPP-A levels are raised in the first trimester of twin pregnancies destined to develop pre-eclampsia and therefore a different prediction algorithm is needed. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Evaluation of Fetal Weight Estimation Formulas in Assessing Small-for-Gestational-Age Fetuses.

PURPOSE: The aim of this study was to compare the accuracy of multiple sonographic fetal weight estimation models in assessing small-for-gestational-age (SGA) fetuses. MATERIALS AND METHODS: The cohort included all singleton pregnancies recorded at a single medical center from January 2004 to September 2011, with a minimum of 24 weeks of gestation. SGA was defined as a fetal weight of less than the 10th percentile. We used birth weight (BW) distribution curves for our population, matched according to fetal gender and gestational age. Predicted birth weights were calculated using 26 sonographic fetal weight estimation models, including targeted formulas for SGA fetuses. RESULTS: 1218 cases of SGA fetuses that underwent sonographic fetal weight estimation within one week prior to delivery were found. Prediction of fetal weight was significantly less accurate in SGA fetuses than in the general population. The random error for SGA fetuses ranged from 7.2 % to 13.9 % in different models, while the systematic error ranged from -12.8 % to 26 %. Most non-targeted formulas showed a specificity of over 90 % but a sensitivity of only 20 - 35 % in the detection of SGA fetuses, while most targeted formulas had a low specificity but a high sensitivity. The model by Scott et al. was found to be the most accurate in assessing SGA fetuses in our population. CONCLUSION: Estimation of fetal weight in SGA fetuses is less accurate than in the general population. Some formulas which are designed for SGA are more accurate than others and their use might increase the sensitivity in identifying SGA fetuses, with only a small decline in specificity.

Fetal diagnosis of testicular torsion: what shall we tell the parents?

OBJECTIVES: The objectives of this study are to present our collective experience with the prenatal diagnosis of testicular torsion and to propose a possible prenatal management scheme. METHODS: We retrospectively collected and reviewed all medical records of cases that were diagnosed with perinatal testicular torsion in our medical center between the years 2002 and 2013. Prenatal torsion was categorized as torsion diagnosed in utero or on immediate newborn examination. RESULTS: A total of five unilateral prenatal torsions were diagnosed. Two fetuses were diagnosed in the third trimester of pregnancy. In both cases, cesarean section was performed immediately upon diagnosis. One newborn underwent immediate orchiectomy with contralateral orchiopexy. Torsion was confirmed by pathological examination. The other was managed conservatively, just as the three newborns who were diagnosed immediately after birth. On follow-up scan, the affected testicle was found atrophied with lack of blood flow on color Doppler examination. The unaffected contralateral testicle remained within the normal size with good blood flow. CONCLUSIONS: Prenatal diagnosis of unilateral testicular torsion is a coincidental rare finding. Because the twisted testicle cannot be salvaged, induced delivery and prompt surgery are not recommended.

[Prenatal diagnosis of trisomy 13 and trisomy 18: the experience of Assaf-Harofe Medical Center].

INTRODUCTION: Trisomy 18 and 13 are the most common autosomal trisomies, after trisomy 21, and their frequency is rising due to the increased maternal age of pregnant women. The fetuses suffer from multi-organ damage that may lead to many gestational complications as well as short life expectancy. OBJECTIVE: To assess the indications for prenatal karyotyping of trisomy 13 (T-13, Patau syndrome) and trisomy 18 (T-18, Edwards syndrome) during pregnancy in our medical center. METHODS: This retrospective cohort study involved all singleton pregnancies locally diagnosed or referred to our Institute because of T-13 and T-18, during the years 1998-2011. RESULTS: There were 1879 cases of termination of pregnancies (TOPs) because of fetal indications, of them 53 cases of T-18 and 10 cases of T-13. The main indications for prenatal karyotyping in our study group were abnormal sonographic findings during anomaLy scans. In addition, 7 newborns with T-18 and 3 infants with T-13 were born in our hospital during the same period of time. We examined all cases that led to the Live birth of newborns with chromosomal anomalies, stemming from the Lack of extraction of the tests mentioned above and/or ignoring findings that raise suspicion that requires performing prenatal karyotyping during pregnancy. DISCUSSION: Our findings corresponded with other studies and showed that prenatal diagnosis of T-13/T-18 due to abnormal sonographic finding is rising. CONCLUSIONS: Our study shows that it was possible to identify the vast majority of T-13/T-18 among the pregnant women who had an increased risk based on a combination of the routine screening tests applied in Israel.

A search for the most accurate formula for sonographic weight estimation by fetal sex - a retrospective cohort study.

OBJECTIVE: The aim of this study was to assess the effect of fetal sex on the accuracy of multiple formulas for sonographic estimation fetal weight (SEFW). METHODS: The cohort included all singleton live births recorded at a single medical center from January 2004 to September 2011. The accuracy of SEFW was compared between male and female fetuses using 6575 SEFW performed within 3 days prior to delivery. Fetal weight was estimated using 27 models. RESULTS: The accuracy of different formulas in predicting birth weight of male and female fetuses was found to be significantly different in almost every accuracy index that was compared (P < 0.05). The model by Sabbagha et al. was found to be the most accurate in assessing female fetuses. The most accurate model for male fetuses was a sex-specific formula by Melamed et al. We also found that a combination of the most accurate formula for each sex to one combined sex-specific model increased SEFW accuracy significantly. CONCLUSION: The accuracy of SEFW is significantly related to fetal sex. The combination of the formulas by Melamed et al. and Sabbagha et al. for male and female fetuses accordingly allowed more accurate SEFW in our research population.

First trimester markers of preeclampsia in twins: maternal mean arterial pressure and uterine artery Doppler pulsatility index.

OBJECTIVE: This study aims to evaluate the distribution of mean arterial pressure (MAP) and uterine artery Doppler pulsatility index (PI) in first trimester twins with and without preeclampsia. METHOD: A total of 147 twins were recruited from a specialist clinic and 110 unaffected singleton pregnancies attending the same institution served as controls. MAP and Doppler PI values were expressed in multiples of the gestation-specific median using published equations. RESULTS: Among the twins, 12 had preeclampsia and two had pregnancy-induced hypertension. Among unaffected pregnancies, there was no significant difference in MAP levels between twins and singletons (P = 0.17, Wilcoxon rank sum test, two-tail). However, the Doppler PI levels were highly statistically significantly lower than in singletons (P < 0.0005). MAP was unrelated to chorionicity (P = 0.46), but there was a statistically significant increase in Doppler PI among monochorionic compared with dichorionic twins (P < 0.01). In twins with preeclampsia, MAP was significantly higher than in unaffected twins (P < 0.02, one-tail), whereas Doppler PI levels were significantly reduced (P < 0.01, two-tail). CONCLUSION: If first trimester screening for preeclampsia is extended to twins, a different normal median Doppler PI equation will be needed. Contrary to expectations, Doppler PI levels may not be raised in affected twins, although this needs confirmation in a larger study.

Nuchal translucency in twins according to mode of assisted conception and chorionicity.

OBJECTIVES: The impact of nuchal translucency (NT) screening in twins conceived after use of assisted reproduction technology (ART) has not been addressed properly in the literature. The aim of the current study was to assess, in a large cohort from a single center, NT in twins following various modes of ART as compared with NT in spontaneously-conceived twins and to differentiate results with regard to chorionicity. METHODS: Retrospective data from 825 twin pregnancies were available for this study. All pregnant women underwent NT screening and chorionicity determination between 11 + 0 and 13 + 6 weeks' gestation in our center. Information about mode of conception and pregnancy outcome was obtained from hospital records and by telephone interviews. Twins were classified as having been conceived after in-vitro fertilization (IVF) with the woman's own or a donated embryo, after non-IVF ART or spontaneously. NT distribution in subgroups of fetuses was compared on the basis of the multiple of the normal median (MoM), SD of log10 MoM estimated by the 90(th) -10(th) centile range divided by 2.563 and the proportion of NT values exceeding the normal 95(th) centile which was 1.641 MoM in the singletons. RESULTS: NT values were statistically significantly higher in ART pregnancies as compared with spontaneously-conceived pregnancies (Wilcoxon rank-sum test, P < 0.05) with medians of 1.073 and 1.038 MoM, respectively, but the proportion with values above the normal 95(th) percentile did not differ (chi-square test, P = 0.89). Among the ART twins, NT values were significantly higher for those conceived using IVF methods (P < 0.005), with a median of 1.082 MoM, compared with a median of 1.022 MoM using other methods. However, although a greater proportion exceeded the 95(th) centile (7.3% compared with 4.8%) this difference did not reach statistical significance (P = 0.17). There were no differences in NT values according to chorionicity (Wilcoxon rank-sum test, P = 0.75). The standard deviation of log10 NT was similar for all subgroups of twins. The correlation coefficient between fetuses in ART pregnancies was statistically significantly lower than that in spontaneously-conceived pregnancies (P < 0.05) but no significant differences were found between types of ART or according to chorionicity. CONCLUSIONS: There was a small but significant increase in NT levels among ART pregnancies, which appeared to be confined to those conceived using IVF, and a small reduction in the correlation between fetuses. These effects probably have little impact on the estimated risk based on algorithms in use today.

Cesarean scar pregnancy and early placenta accreta share common histology.

OBJECTIVE: To determine, by evaluation of histological slides, images and descriptions of early (second-trimester) placenta accreta (EPA) and placental implantation in cases of Cesarean scar pregnancy (CSP), whether these are pathologically indistinguishable and whether they both represent different stages in the disease continuum leading to morbidly adherent placenta in the third trimester. METHODS: The database of a previously published review of CSP and EPA was used to identify articles with histopathological descriptions and electronic images for pathological review. When possible, microscopic slides and/or paraffin blocks were obtained from the original researchers. We also included from our own institutions cases of CSP and EPA for which pathology specimens were available. Two pathologists examined all the material independently and, blinded to each other's findings, provided a pathological diagnosis based on microscopic appearance. Interobserver agreement in diagnosis was determined. RESULTS: Forty articles were identified, which included 31 cases of CSP and 13 cases of EPA containing histopathological descriptions and/or images of the pathology. We additionally included six cases of CSP and eight cases of EPA from our own institutions, giving a total of 58 cases available for histological evaluation (37 CSP and 21 EPA) containing clear definitions of morbidly adherent placenta. In the 29 cases for which images/slides were available for histopathological evaluation, both pathologists attested to the various degrees of myometrial and/or scar tissue invasion by placental villi with scant or no intervening decidua, consistent with the classic definition of morbidly adherent placenta. Based on the reviewed material, cases with a diagnosis of EPA and those with a diagnosis of CSP showed identical histopathological features. Interobserver correlation was high (kappa = 0.93). CONCLUSIONS: EPA and placental implantation in CSP are histopathologically indistinguishable and may represent different stages in the disease continuum leading to morbidly adherent placenta in the third trimester.

Long-term outcomes of children with umbilical vein varix diagnosed prenatally.

OBJECTIVES: The current study aims were to assess the long-term outcomes of children who were diagnosed with umbilical vein varix (UVV) prenatally. METHODS: The study included fetuses with UVV diagnosed in the community between the years 2005 and 2011. They all have been refereed to our Ultrasound Unit for diagnosis' confirmation. This has been conducted locally by a single operator. After delivery, they were matched by gestational age at birth with a set of newborns from a random list. Developmental delay was assessed by telephone interview using a questionnaire based on Ages and Stages Questionnaire. If the child's score (both in the study and control group) was below the cut-off in one or more domain(s), the families were offered an examination by a child developmental health care team. RESULTS: There was no perinatal mortality in both groups. A low-development score was found in 41.7% (15/36) and 3.7% (4/108) in UVV and control group, respectively (P < 0.05). In 10 out of 15 (67%) children in the UVV group with low scores, formal developmental assessment was performed. Four (40%) were diagnosed having developmental delay. Among the four controls with low score, two families refused additional assessment and one child died. The remaining child was found to have normal development. CONCLUSIONS: A possible association between UVV diagnosed prenatally and child developmental delay was found. However, the clinical implications of these findings are still premature; thus, additional studies are needed.

Do assisted-reproduction twin pregnancies require additional antenatal care?

Iatrogenic twinning has become the main side-effect assisted reproduction treatment. We have evaluated the evidence for additional care that assisted-reproduction twins may require compared with spontaneous twins. Misacarriages are increased in women with tubal problems and after specific treatments. Assisted-reproduction twin pregnancies complicated by a vanishing twin after 8 weeks have an increased risk of preterm delivery and of low and very low birthweight compared with singleton assisted-reproduction pregnancies. Monozygotic twin pregnancies occur at a higher rate after assisted reproduction treatment and are associated with a higher risk of perinatal complications. The incidence of placenta praevia and vasa praevia is increased in assisted-reproduction twin pregnancies. Large cohort studies do not indicate a higher rate of fetal congenital malformations in assisted-reproduction twins. Overall, assisted-reproduction twins in healthy women <45 years of age are not associated with a notable increase in antenatal complication rates and thus do not require additional antenatal care compared with spontaneous twins. The risks of maternal and fetal morbidity and mortality associated with assisted-reproduction twins is only increased in women with a pre-existing medical condition such as hypertensive disorders and diabetes and most of these risks can be avoided with single-embryo transfer. Following the birth of the first IVF baby, rumours started to spread in both the medical literature and the media about the long-term health effects for children born following assisted reproduction treatment. However, after more than 30 years, the most common complications associated with IVF treatment remain indirect and technical such as the failure of treatment and ovarian hyperstimulation. Iatrogenic twinning has become the main side-effect of assisted reproduction treatment and the increasing number of twin pregnancies, in particular in older women, has generated numerous debates on the need for additional healthcare provision. In this review, we have evaluated the evidence for additional care that assisted-conception twin pregnancies may require compared with spontaneous twin pregnancies. Twin pregnancies are obviously at higher risk of perinatal complications than singletons due to a natural increase in the incidence of fetal anomalies, antenatal disorders and obstetric and neonatal complications associated with the development of two fetuses instead of one. Overall, our review indicates that some antenatal complications are more frequent in assisted-conception twin pregnancies than in spontaneous twin pregnancies but their prevalence is low and thus their impact on the morbidity and mortality of an individual assisted-conception twin pregnancy is limited. Assisted reproduction treatment has become available to older women with pre-existing maternal medical conditions such as chronic hypertension and diabetes. The increased obstetrical risks in this population must be considered prior to attempts at assisted conception, and the transfer of more than one embryo should be avoided in women with a pre-existing maternal medical condition.