Uterus didelphys (double womb) in pregnancy and labour: what to expect

The womb normally forms before birth as two tubes fuse into one chamber. In uterus didelphys the two halves do not fuse, so there are two separate uterine cavities. The guideline from NHS Greater Glasgow and Clyde lists it, in everyday terms as a double womb, alongside other congenital uterine anomalies such as the bicornuate (heart-shaped) womb, the unicornuate womb, the septate or subseptate womb and the arcuate womb.

Many women do not know they have one until they have a scan or a problem in pregnancy. The guideline notes that many women have no symptoms, although some may experience heavy periods. Because the same developmental period shapes the kidneys and urinary tract, it also recommends considering ultrasound of the renal tract where indicated.

This page concentrates on pregnancy and birth rather than on the diagnosis and treatment of the anomaly itself.

The Greater Glasgow and Clyde guideline says the implications of congenital uterine anomalies depend on type and severity and can include a higher risk of first and second trimester miscarriage, restricted growth of the baby, fetal malpresentation, pre-eclampsia and preterm birth.

For uterus didelphys specifically, it cites studies showing an increased risk of preterm labour (an odds ratio of 3.58) and of fetal malpresentation (an odds ratio of 3.7), and states that variations in the size and shape of the womb are associated with a two to five-fold increase in the risk of spontaneous preterm birth compared with a normally shaped womb. Odds ratios are a research measure of how much more likely an outcome is; they are not a prediction for an individual woman.

A related Patient.info professional article lists abnormalities of the uterus, including a partial septate uterus, among the predisposing factors to malpresentation.

The guideline refers to UK Preterm Birth Clinical Network advice that women with a congenital uterine anomaly are referred to a consultant antenatal clinic to form a plan for the rest of the pregnancy. In that health board the suggestion is for a named-consultant appointment at 16 weeks, so that findings from the early scan can be discussed.

Suggested management also includes growth scans in the third trimester to monitor for poor growth and to confirm the position of the baby by 36 weeks. Women are advised to contact the maternity assessment unit at any hour if they have signs and symptoms of preterm labour.

• Tell your midwife and doctors about the double womb early, including at any booking appointment.

• Ask which scans and appointments are planned and when.

• Know the signs of preterm labour and who to ring at any hour.

• Attend all growth scans, as they are used to check position and growth.

Whether labour is likely to be vaginal depends mainly on the position of the baby and the usual obstetric factors rather than the double womb alone. The guideline reviewed here does not give a rule about mode of birth, but it does stress confirming the position of the baby by 36 weeks, because a baby in a non-head-down position such as breech or transverse may need a different plan for birth. The NHS lists a breech baby that has not turned as one of the reasons a caesarean may be recommended.

NICE's guideline on intrapartum care lists malpresentation (breech or transverse lie) and preterm labour among the factors in the current pregnancy that indicate increased risk and suggest planned birth at an obstetric unit. If either applies, the usual advice is therefore to plan to give birth in an obstetric-led unit, where staff can respond if labour is premature or the baby is not head-down.

If a caesarean section is planned or needed, the NHS describes planned caesareans as usually done from the 39th week of pregnancy and says the operation normally takes about 40 to 50 minutes. Preterm labour is managed according to gestation, and the guideline mentions medicines such as corticosteroids, magnesium sulphate and antibiotic cover where preterm birth is confirmed before 30 weeks.

There is no special aftercare required purely because of a double womb. Postnatal care follows the usual pathway, with extra attention if the baby was born early and needs neonatal care. If you are planning another pregnancy, ask for the findings and the account of the birth to be recorded so that your next team has them.

Antenatal scans, consultant clinics and obstetric-led births for women with a uterine anomaly are available through NHS maternity services, and the guideline reviewed here is itself an NHS document. If you are considering private obstetric care, ask how it would manage preterm labour, a baby that is not head-down, or an emergency, and what happens if your baby needs neonatal intensive care.