Multiple pregnancies come with a higher risk of preterm birth. Certain conditions, such as diabetes, high blood pressure, and obesity, can increase the chances of preterm labor. It is important to work with your healthcare provider to keep any chronic conditions under control. Statistics show that more than 60 percent of twins and nearly all multiple pregnancies are premature (born before 37 weeks).The greater the number of fetuses during pregnancy, the greater the risk of preterm birth.
Premature babies are born before their bodies and organ systems have fully matured. These babies are usually small, with low birth weight (less than 2500 grams or 5.5 pounds) and may need help breathing, eating, fighting infections and staying warm. Very preterm babies, those born before 28 weeks, are especially vulnerable.Many of their organs may not be prepared for life outside the mother's womb and may be too immature to work well. Many babies with multiple births will need care in a neonatal intensive care unit (NICU).
The reasons for this may include uncertain gestational weeks, single or multiple pregnancies, and whether the previous
preterm birthwas spontaneous or iatrogenic.A study of 3,288 patients with twin pregnancies and 6,576 newborns found that intrahepatic cholestasis during pregnancy (OR 0.533, 95% CI: 0.295—0.964, P %3D 0.03) was associated with a decrease in the risk of preterm delivery before 32 weeks. Other pre-pregnancy complications related to a history of premature birth or late abortion or other comorbidities such as thyroid disorders, diabetes mellitus, hypertension, liver disease, iron deficiency anemia, autoimmune diseases, and heart disease were also taken into consideration.Monochorionicity significantly increased the risk of preterm birth for ≤ 28 (OR 2.14), 95% CI: 1.52—3.0; ≤ 32 (OR 1.55), 95% CI: 1.27—1.8; ≤ 34 (OR 1.47), 95% CI: 1.27—1.6; and so on.The analysis of possible risk factors for preterm birth before 32 weeks of gestation revealed that ICP seemed to be an independent protective factor while PE had no significant effect on preterm delivery. This can be partly explained by the fact that the pre-pregnancy BMI in 66.1% of patients was normal and only 3.7% could be defined as obese according to Chinese categories.Methods for predicting preterm birth and risk factors for preterm birth in twin pregnancy have been studied for a long time. Women with multiple fetuses are more than twice as likely to develop high blood pressure during pregnancy.The recommendations on GWG during pregnancy for Chinese women still lack consensus and the IOM recommendations for normal, overweight and obese women overlap.
The twin pregnancy rate was 3.3%, while the PTB rate before 37, 34 and 32 weeks in this population was 62.1%, 18.8%, and 10.4%, respectively.