In recent years，with the development of assisted reproductive technology and the increase in women of advanced maternal age，the incidence of twin pregnancy is increasing. Compared with singleton pregnancy，the incidence of maternal and fetal comorbidities in twin pregnancy is greatly increased. It is a great challenge for clinical medical staff to manage twin pregenancy during gestational period. Determining chorionic nature is the key factor that affecting the outcome of twin pregnancy and in making pregnancy monitoring and management plan. The probability of fetal chromosomal and structural abnormalities in twin pregnancy is increases，so prenatal screening and prenatal diagnosis are necessary. The complications of twin pregnancy can be reduced by cluster management of nutrition and lifestyle during pregnancy. The timing and mode of delivery of twin pregnancy need to be comprehensively evaluated according to chorionic nature，gestational age，maternal and fetal comorbidities and complications. Twin pregnancy itself is not an indication for cesarean section. Vaginal delivery of twins needs to be carried out in a tertiary hospital with the ability to rescue pregnant women and newborns. Obstetricians need to have rich experience in vaginal delivery of twins.Strengthening the management of twin pregnancy during gestational period and delivery is helpful to reduce the incidence of pregnancy comorbidities and improve the prognosis of mothers and fetuses.

The management of monochorionic diamniotic（MCDA）twins is a challenge in perinatal medicine. Since the two fetuses share a single placenta，clinical consultation faces numerous challenges when one of the MCDA twins has discordant structural malformations. For such complex twins，referral to a fetal medical center with intrauterine treatment capabilities is necessary for consultation，follow-up and management. Individualized clinical counseling and management should be provided. The management plan should be formulated based on the type and severity of the malformations，as well as the impact on the other fetus. The principle of minimizing the impact on the healthy fetus and the mother should be followed;meanwhile the parents also be fully respected in making decisions. A personalized plan should be made to implement a sequential and integrated management model from the prenatal stage to through delivery and even to the neonatal period.

Complicated twin pregnancies refer to a set of severe complications occurring in monochorionic twin pregnancies，whose clinical phenotypes mainly include twin-to-twin transfusion syndrome，selective fetal growth restriction，twin reversed arterial perfusion sequence，and monochorionic monoamniotic twin pregnancies. Current clinical treatment methods include fetoscopic laser occlusion of chorioangiopagous vessels，radiofrequency ablation and microwave ablation，and novel treatment approaches are gradually emerging, such as artificial intelligence-assisted intrauterine therapy and robot-assisted surgery. The neurodevelopmental prognosis of surviving fetuses after intrauterine intervention for complicated twin pregnancies requires urgent attention，and it is recommended to establish a systematic long-term follow-up system. In the future，through the deepening of multidisciplinary collaboration models and the integration of innovative diagnostic and therapeutic technologies，it is anticipated that the management of complicated twin pregnancies will advance towards precision and intelligence.

Monochorionic twins，accounting for about 30% of twin pregnancies，are prone to complicated complications such as TTTS and sFGR，which can lead to adverse outcomes，including birth defects，preterm birth and so on. The pathogenesis of these complications involves abnormal placental structures，hemodynamic disorders，molecular biological and genetic factors. In recent years，some advancements have been made in this field at home and abroad. For example，studies on placental vascular anastomosis have been deepened，and genetic studies have revealed the relationship between specific gene mutations and complications，laying a foundation for early diagnosis and treatment of complicated twin complications. This review summarizes the current research progress in the pathogenesis of complicated twin complications and explores intervention strategies，aiming to provide references for further clinical research and treatment.

The risk of maternal complications and comorbidities in twin pregnancy is high. Severe maternal complications and comorbidities increase maternal mortality rate. By analyzing the relevant studies in China and overseas，we systematically expound the latest progress in the prediction and management of severe maternal complications and comorbidities in twin pregnancy，which offers a theoretical basis for the clinical prevention and treatment of severe maternal complication and comorbidities in twin pregnancy.

Preterm birth is the most common complication in twin pregnancies. Monochorionic twins，history of previous preterm birth，history of cervical surgery and advanced maternal age have been shown to be correlated with a higher risk of preterm birth in twin pregnancies. Transvaginal cervical length measurement during the second trimester is the best predictor for spontaneous preterm birth in twin pregnancies. For asymptomatic twin pregnancies with short cervix，fetal fibronectin（FFN）and amniotic fluid sludge screening may have additional predictive value. Clinical management of the risk of preterm birth in twins requires a detailed assessment of medical history and personalized management，including regular prenatal check-ups and ultrasound monitoring of cervical length and fetal conditions. Monochorionic diamniotic twins should be closely monitored for complications such as twin-to-twin transfusion syndrome（TTTS）and selective intrauterine growth restriction（sIUGR）. Vaginal progesterone may be beneficial in preventing preterm birth in twin pregnancies with cervical length ≤25mm，but its efficacy needs further validation by high-quality randomized controlled trials. Routine use of cervical cerclage is not recommended for twin pregnancies，although emergency cerclage may be beneficial when the cervix is extremely short and accompanied by dilation. Clinical decisions should take specific conditions of patients and the latest research developments into account.

Monochorionic diamniotic（MCDA）twin pregnancy is considered as high-risk pregnancy，which can progress during gestation to specific MCDA complications such as selective fetal growth restriction，and it has high incidence of adverse pregnancy outcomes. Here，we summarize the existing predictive indicators for specific complications associated with MCDA twin pregnancies，and investigate the direction for future development.

In recent years，with the continuous development of assisted reproductive technology and the adjustment of China's fertility policy，pregnant women are facing the trend of "advanced age"，and the proportion of twin pregnancies assisted by assisted reproductive technology is also increasing. Twin pregnancies are high-risk pregnancies and are more likely to cause various obstetric comorbidities and complications than singleton pregnancies. Assisted reproductive technology（ART）-assisted twin pregnancy may be at a higher risk of adverse pregnancy outcomes due to its specificity. In order to improve the quality of perinatal care and reduce the incidence of related complications in assisted reproductive technology-assisted twin pregnancies，this article provides some key management strategies.