Preventing Preterm Birth in Twin Pregnancies

Carrying twins brings extra appointments, more detailed scans and a greater focus on the timing of birth. Spontaneous preterm labour occurs more often in twin pregnancies than in singleton pregnancies, so clinicians may monitor the cervix alongside fetal growth, placental position and maternal wellbeing. Cervical length screening can help identify some women who may benefit from closer review or preventive treatment.

The cervix is the lower, tunnel-shaped part of the uterus. During pregnancy it usually remains long and closed until labour approaches. A shorter cervix, particularly in the middle months of pregnancy, is associated with a higher chance of early birth. The measurement is generally taken with a transvaginal ultrasound because this method gives a more reliable view than an abdominal scan.

Screening does not predict the exact day a baby will arrive. It is one part of a wider risk assessment that includes previous preterm birth, vaginal bleeding, uterine abnormalities, infection, fetal growth and the type of twin pregnancy. The most appropriate plan depends on whether the twins share a placenta, the gestational age, symptoms and local specialist advice.

For Australian families, care may involve a GP, an obstetrician, a maternal-fetal medicine specialist and a sonographer. Public hospitals such as the Royal Women’s Hospital in Melbourne, King Edward Memorial Hospital in Perth and Westmead Hospital in Sydney manage complex pregnancies, while private obstetric care is also common. The FAOPS 2020 archive reflects the international research setting in which perinatal and neonatal questions are discussed.

Why Twin Pregnancies Need Tailored Surveillance

Twins place greater physical demands on the uterus and are more likely to be born early. The risk is particularly relevant for monochorionic twins, who share a placenta and require additional monitoring for complications such as twin-to-twin transfusion syndrome. Dichorionic twins have two placentas, although they still carry a higher preterm birth risk than a singleton pregnancy.

Cervical shortening may be associated with spontaneous preterm birth, but a screening result should be interpreted carefully. A woman with a short cervix may remain pregnant for many weeks, while someone with a cervix in the expected range can still develop contractions, membrane rupture or other complications. The measurement is therefore a risk marker rather than a guarantee.

Australian maternity services often organise twin care through a high-risk or multiple pregnancy clinic. Families living outside Sydney, Melbourne, Brisbane or Perth may need to travel to a regional centre or tertiary hospital for serial scans. Travel planning matters, especially when work, childcare and accommodation near a hospital become part of the practical workload.

How Cervical Length Screening Is Performed

A transvaginal cervical length scan usually takes only a few minutes. The woman is positioned comfortably, and a covered ultrasound probe is inserted gently into the vagina. The bladder is generally empty, and the sonographer may take several measurements while the cervix is at rest. Pressure from the probe, a full bladder or contractions can affect the result, so standard technique is important.

Screening is commonly considered during the mid-trimester, often around the anatomy scan period. Exact timing and repeat scans vary between services. Some clinicians measure cervical length as part of a routine fetal assessment, while others recommend a targeted examination when there is a previous history of spontaneous preterm birth, cervical surgery or other risk factors.

The measurement is recorded in millimetres. A cervix below a particular threshold, often 25 mm in singleton research, may prompt further discussion, but the ideal threshold and treatment pathway in twins are less straightforward. Twin-specific evidence has developed over time, and recommendations can differ between professional organisations and hospitals.

A scan should never delay assessment of symptoms. Pelvic pressure, regular tightening, period-like pain, bleeding, fluid leakage or a sudden increase in discharge warrants prompt contact with the maternity unit. In Australia, the local birth suite or maternity assessment service is usually the right first contact, rather than waiting for the next booked appointment.

What a Short Cervix May Mean

When a short cervix is found, the clinician will consider the gestational age, the degree of shortening, whether the cervix is opening, and whether there are contractions or ruptured membranes. A repeat transvaginal scan may be arranged to confirm the result. The care team may also review infection symptoms, fetal wellbeing and the overall twin pregnancy plan.

Vaginal progesterone is sometimes discussed for cervical shortening, although the evidence in twin pregnancies is more limited and nuanced than in singleton pregnancies. Cervical cerclage, which places a stitch around the cervix, is not automatically recommended for every twin pregnancy with a short measurement. It may be considered in selected circumstances, such as cervical dilation or a very high-risk history, under specialist guidance.

A cervical pessary is another intervention that has been studied, but trial results have been inconsistent. This is why families may hear different views about the same treatment. A sensible decision weighs potential benefit, possible discomfort or complications, the quality of available evidence and the expertise of the treating service.

Care should include more than physical surveillance. Anxiety can rise quickly after a concerning scan, particularly when parents are already preparing for two babies. Resources on perinatal mental health are relevant because emotional screening, clear explanations and timely support can improve the experience of high-risk maternity care.

A Practical Care Checklist

A useful plan combines clinical monitoring with clear arrangements for daily life. Ask which service will review the scan, who should be called after hours and whether a repeat measurement is needed. If the family lives in regional New South Wales, northern Queensland or rural Western Australia, it is worth discussing when travel to a tertiary hospital may become advisable.

Medicare-funded public care can reduce direct costs, although appointments, parking, transport and time away from work still create pressure. Private patients may have more continuity with one obstetrician but should confirm which hospital has neonatal intensive care facilities if an early birth becomes likely. Twin parents may also need to organise leave, school pickups and support for other children earlier than expected.

Helpful questions for an appointment include:

• What was the cervical length and how was it measured?
• Does the twin type change the recommended follow-up?
• When should the scan be repeated?
• Which symptoms require an immediate call or hospital visit?

Practical preparations can reduce stress if the pregnancy becomes more complex:

• Keep the maternity unit’s phone number in the mobile.
• Plan transport for daytime and overnight hospital visits.
• Ask about neonatal care, steroids and magnesium sulphate if early birth is a concern.
• Arrange flexible help with meals, work and other children.

These steps are not a substitute for medical advice, but they make it easier to act promptly. Australian hospitals may use terms such as “birth suite”, “maternity assessment” or “early pregnancy and antenatal clinic”, so families should learn the wording used by their own service.

Comparing Screening and Prevention Options

No single intervention prevents every preterm birth in twins. Screening helps identify a possible risk, while treatment decisions depend on the clinical picture and the evidence available for multiple pregnancies. The following summary can support a conversation with an obstetrician or maternal-fetal medicine specialist.

The strongest plan is individualised. A previous spontaneous preterm birth may alter management, while a normal scan in an otherwise low-risk twin pregnancy may lead to routine follow-up. Treatment should also account for membrane status, bleeding, infection and the wellbeing of both babies.

Perinatal medicine works best when research is translated into understandable choices. The broader conference context represented by FAOPS included neonatal outcomes and regional health priorities, including HIV progress. That wider perspective is valuable: preventing early birth involves obstetric care, neonatal readiness, mental health support and communication across services.

Cervical length screening is therefore best viewed as a structured opportunity to identify risk, not as a pass-or-fail test. Families should receive the result, its uncertainty and the proposed follow-up in plain language. If the advice from different clinicians differs, asking them to explain the evidence and the reason for their recommendation can make the plan clearer.

Speak with your GP, obstetrician or maternity unit about whether cervical length assessment is appropriate for your twin pregnancy and how results would change care. Seek urgent maternity advice for contractions, bleeding, fluid leakage or significant pelvic pressure, and keep the hospital’s after-hours contact details accessible throughout pregnancy.