Single embryo transfer: Discussing Success and Multiple Pregnancy Risk

Single embryo transfer means placing one embryo into the uterus during a transfer procedure. When several suitable embryos are available and one is deliberately selected, this is often called elective single embryo transfer. The aim is to pursue a pregnancy while reducing the risks associated with carrying more than one baby.

Understand why embryo number matters

Transferring more than one embryo increases the possibility of twins or a higher multiple pregnancy. Multiple pregnancy carries greater risks, including premature birth, low birthweight, preeclampsia and gestational diabetes. These are part of the treatment decision, not simply details to consider after a positive test.

One transferred embryo can occasionally split, so single embryo transfer does not make twins impossible. It does substantially reduce the main avoidable source of multiple pregnancy in IVF: transferring several embryos together. Ask the clinic to discuss both the chance of a baby and the chance of a multiple pregnancy for the proposed plan.

Ask how the recommendation fits your circumstances

The decision should take account of the embryo, previous treatment and your medical history. For frozen embryos, the age when the eggs were obtained is relevant to the assessment. A medical condition that makes multiple pregnancy especially risky also matters when deciding how many embryos to transfer.

A lower embryo grade or an unsuccessful previous attempt should prompt an individual discussion, not an automatic assumption that another embryo must be added. The embryo development and grading guide explains why appearance helps selection but cannot predict a particular outcome with certainty.

Compare outcomes across the proposed course of treatment

Ask the clinician to explain results for one transfer and for the wider plan involving any embryos kept for later use. These are different measures. If suitable embryos can be frozen, a later transfer may be an option without repeating egg collection, although embryo survival and success are not guaranteed.

Request estimates that match your situation and clearly state what they count. Do not assume that transferring two embryos doubles the chance of a baby, or that one transfer and several later opportunities are the same comparison. The IVF statistics guide helps you read pregnancy, live birth and cumulative outcome figures.

Make space for practical concerns before consent

Time, cost and the emotional demands of treatment can influence how you feel about another transfer. Tell the team which of these concerns is driving your preference. Ask for the costs and practical steps of storing and using remaining embryos so the discussion includes a realistic alternative plan.

If more than one embryo is proposed, ask why the team believes that choice is appropriate and how the additional pregnancy risks have been considered. Confirm the agreed number before treatment and request an explanation if the recommendation changes. You should have enough information to understand the decision, rather than feeling responsible for choosing a number without clinical guidance.