BACKGROUNDThe prevalence of congenital uterine anomalies in high-risk women is unclear, as several different diagnostic approaches have been applied to different groups of patients. This review aims to evaluate the prevalence of such anomalies in unselected populations and in women with infertility, including those undergoing IVF treatment, women with a history of miscarriage, women with infertility and recurrent miscarriage combined, and women with a history of preterm delivery.METHODSSearches of MEDLINE, EMBASE, Web of Science and the Cochrane register were performed. Study selection and data extraction were conducted independently by two reviewers. Studies were grouped into those that used ‘optimal’ and ‘suboptimal’ tests for uterine anomalies. Meta-analyses were performed to establish the prevalence of uterine anomalies and their subtypes within the various populations.RESULTSWe identified 94 observational studies comprising 89 861 women. The prevalence of uterine anomalies diagnosed by optimal tests was 5.5% [95% confidence interval (CI), 3.5–8.5] in the unselected population, 8.0% (95% CI, 5.3–12) in infertile women, 13.3% (95% CI, 8.9–20.0) in those with a history of miscarriage and 24.5% (95% CI, 18.3–32.8) in those with miscarriage and infertility. Arcuate uterus is most common in the unselected population (3.9%; 95% CI, 2.1–7.1), and its prevalence is not increased in high-risk groups. In contrast, septate uterus is the most common anomaly in high-risk populations.CONCLUSIONSWomen with a history of miscarriage or miscarriage and infertility have higher prevalence of congenital uterine anomalies compared with the unselected population.

(RR, 2.39; 95% CI, P = 0.003) and fetal malpresentation at delivery (RR, 2.53; 95% CI,; P < 0.001). Canalization defects were associated with reduced clinical pregnancy rates (RR, 0.86; 95% CI, P = 0.009) and increased rates of first-trimester miscarriage (RR, 2.89; 95% CI; P < 0.001), preterm birth (RR, 2.14; 95% CI,; P < 0.001) and fetal malpresentation (RR, 6.24; 95% CI,; P < 0.001). Unification defects were associated with increased rates of preterm birth (RR, 2.97; 95% CI, P < 0.001) and fetal malpresentation (RR, 3.87; 95% CI, P < 0.001

Objective To estimate the prevalence of congenital uterine anomalies in subfertile women and to evaluate their influence on early pregnancy following assisted reproduction treatment (ART). Methods (n = 164 (11.8%)) followed by septate (n = 7 (0.5%)), unicornuate (n = 6 (0.4%)), subseptate (n = 5 (0.4%)), bicornuate (n = 1 (0.1%)) and T-shaped uteri (n = 1 (0.1%)). A total of 440 subjects who underwent ART were followed up. The pregnancy rates in women with arcuate uteri (36/66 (54.5%)) and major uterine anomalies (7/10 (70.0%)) were statistically similar (P = 0.09 and P = 0.11, respectively) to that of the matched controls with normal uteri (158/364 (43.4%)

Plain language summary Congenital uterine anomalies (CUAs) are malformations of the womb that develop during fetal life. When a baby girl is in her mother’s womb, her womb develops as two separate halves from two tubular structures called ‘müllerian ducts’, which fuse together before she is born. Abnormalities that occur during the baby’s development can be variable from complete absence of a womb through to more subtle anomalies, which are classified into specific categories. While conventional ultrasound is good in screening for CUAs, 3D ultrasound is used to confirm a diagnosis. If a complex womb abnormality is suspected, MRI scanning may also be used, with a combination of laparoscopy in which a camera is inserted into the cavity of the abdomen, and hysteroscopy, when the camera is placed in the womb cavity. As there can be a link between CUAs and abnormalities of the kidney and bladder, scans of these organs are also usually requested. Although CUAs are present at birth, adult women typically do not have any symptoms, although some may experience painful periods. Most cases of CUA do not cause a woman to have difficulty in becoming pregnant and the outcome of pregnancy is good. However, these womb anomalies are often discovered during investigations for infertility or miscarriage. Moreover, depending upon the type and severity of CUA, there may be increased risk of first and second trimester miscarriages, preterm birth, poor growth of the baby in the mother’s womb (fetal growth restriction), pre‐eclampsia and difficult positioning of the baby for birth (fetal malpresentation). Surgical treatment is only recommended to a woman who has had recurrent miscarriages and has a septate uterus, i.e., the womb cavity is divided by a partition. In this case, surgery may improve her chances for a successful pregnancy, although the risks of surgery, especially scarring of the womb should be considered. However, further evidence from randomised controlled trials are required to provide conclusive evidence‐based recommendations for surgical treatment for septate uterus. Surgical treatment for other types of CUAs is not usually recommended as the risks outweigh potential benefits, and evidence for any benefits is lacking. Women with CUAs may be at an increased risk of preterm birth even after surgical treatment for a septate uterus. These women, if suspected to be at an increased risk of preterm birth based on the severity of CUA, should be followed up using an appropriate protocol for preterm birth as outlined in UK Preterm Birth Clinical Network Guidance.1>

ObjectiveTo compare success rates, associated risks and cost-effectiveness between intrauterine insemination (IUI) and in vitro fertilisation (IVF).DesignRetrospective observational study.SettingThe UK from 2012 to 2016.ParticipantsData from Human Fertilisation and Embryology Authority’s freedom of information request for 2012–2016 for IVF/ICSI (intracytoplasmic sperm injection)and IUI as practiced in 319 105 IVF/ICSI and 30 669 IUI cycles. Direct-cost calculations for maternal and neonatal expenditure per live birth (LB) was constructed using the cost of multiple birth model, with inflation-adjusted Bank of England index-linked data. A second direct-cost analysis evaluating the incremental cost-effective ratio (ICER) was modelled using the 2016 national mean (baseline) IVF and IUI success rates.Outcome measuresLB, risks from IVF and IUI, and costs to gain 1 LB.ResultsThis largest comprehensive analysis integrating success, risks and costs at a national level shows IUI is safer and more cost-effective than IVF treatment.IVF LB/cycle success was significantly better than IUI at 26.96% versus 11.49% (p<0.001) but the IUI success is much closer to IVF at 2.35:1, than previously considered. IVF remains a significant source of multiple gestation pregnancy (MGP) compared with IUI (RR (Relative Risk): 1.45 (1.31 to 1.60), p<0.001) as was the rate of twins (RR: 1.58, p<0.001).In 2016, IVF maternal and neonatal cost was £115 082 017 compared with £2 940 196 for IUI and this MGP-related perinatal cost is absorbed by the National Health Services. At baseline tariffs and success rates IUI was £42 558 cheaper than IVF to deliver 1LB with enhanced benefits with small improvements in IUI. Reliable levels of IVF-related MGP, OHSS (ovarian hyperstimulation syndrome), fetal reductions and terminations are revealed.ConclusionIUI success rates are much closer to IVF than previously reported, more cost-effective in delivering 1 LB, and associated with lower risk of complications for maternal and neonatal complications. It is prudent to offer IUI before IVF nationally.