What does ASRM recommend, and why?
ASRM, the American Society for Reproductive Medicine, recommends single embryo transfer for gestational carriers. Its committee opinion on the number of embryos to transfer sets limits by the egg source's age and the embryo's stage and testing, and it treats gestational carriers as a group for whom one embryo is the standard.
ASRM also recommends single embryo transfer for euploid blastocysts in any patient under 38. Verify the age cutoffs against the most recent edition of the ASRM committee opinion.
The reasoning is simple. A second embryo raises the chance of twins much more than it raises the chance of having a baby. Twins carry higher risks for the surrogate and for the babies. A surrogate takes on those risks in her own body, for your family. ASRM's guidance asks clinics not to add risk to her pregnancy for a small gain in the chance of success.
At Private Label Surrogacy (PLS), usually one embryo is transferred. The number is agreed at matching and written into the gestational carrier agreement, not decided on transfer day.
How much does a second embryo change the chance of a baby?
Less than most people expect.
Transferring two embryos modestly raises the chance of at least one pregnancy. It sharply raises the chance of twins. It does not double the chance of a baby, because the main thing limiting success is the quality of each embryo, not the number placed in the uterus. If one embryo is chromosomally abnormal, adding a second does not fix it.
Studies of IVF patients show that two single embryo transfers in sequence give a cumulative chance of a live birth close to that of one double transfer, with far fewer twins.
| Single embryo transfer | Double embryo transfer | |
|---|---|---|
| Chance of at least one live birth (qualitative, per ASRM) | Good with a good-quality embryo; best with a euploid embryo | Modestly higher per transfer, not double |
| Twin rate | Low; identical twins from a split embryo are uncommon | Sharply higher |
| Preterm birth risk | Singleton baseline | Substantially higher if twins result |
| Surrogate compensation add-on at PLS | None | $5,000 if twins result ($10,000 for triplets) |
| Insurance and NICU exposure | Standard pregnancy and newborn care | Higher: high-risk pregnancy, likely cesarean, more NICU care |
| Clinic acceptance for a gestational carrier | Standard | Many clinics decline |
| Surrogate acceptance | Standard | Many surrogates decline in their criteria |
With a euploid embryo, the gain from adding a second is smaller still. A tested embryo already has the best chance per transfer. See PGT-A testing and embryo quality.
What are the risks of twins for the surrogate and the babies?
A twin pregnancy is treated as high risk. Compared with a singleton pregnancy, twins carry higher rates of:
- Preterm birth. Most twins are born before 37 weeks, per CDC birth data.
- Low birth weight.
- NICU admission for one or both babies.
- Cesarean delivery for the surrogate.
- Preeclampsia, a pregnancy blood pressure disorder that can become serious.
- Gestational diabetes and other pregnancy complications.
- Bed rest and time off work in later pregnancy.
For the surrogate, a twin pregnancy usually means more appointments, more physical strain, a higher chance of surgery, and a longer recovery. For the babies, prematurity is the main concern, and its effects can extend beyond the newborn period. For the full picture, see twins and multiples in surrogacy.
What does a double transfer cost in surrogacy?
The cost of a double transfer is not on transfer day. It arrives if both embryos implant.
In a PLS journey, twins add:
- Surrogate compensation: $5,000 for twins ($10,000 for triplets). Figures confirm with Nancy.
- Maternity clothing: $1,000 for multiples, instead of $750. Figures confirm with Nancy.
- Lost wages: more likely to apply, and for longer, because bed rest and early leave are more common with twins.
- Insurance exposure: a high-risk pregnancy and a likely cesarean increase claims on her health coverage, and higher deductibles and co-pays you have agreed to cover.
- NICU costs: newborn care, including NICU stays, falls on your own health plan as the babies' insurance from birth. Confirm your plan's newborn enrollment rules.
A single transfer that fails costs another cycle. A double transfer that leads to a preterm twin birth can cost far more, in money and in health.
Who decides: parents, surrogate, clinic?
All three must agree.
- The clinic decides what it will do. Many clinics will not perform a double transfer into a gestational carrier.
- The surrogate decides what she will consent to. Most surrogates, including PLS surrogates, state in their matching criteria whether they would ever accept a double transfer. Many decline.
- You decide what you will ask for, and that decision shapes which surrogates you are matched with.
At PLS, transfer number is a matching criterion, alongside termination, selective reduction and vaccination. Parents who want the option of a double transfer are matched only with surrogates who would consent. The agreed number is then written into the gestational carrier agreement.
If the three do not line up, the most conservative answer usually wins: a clinic that will not transfer two does not, and a surrogate who has not consented to two is not asked to on the day. Raise the question early. If a double transfer matters to you, say so in your Intended Parent Questionnaire, ask your clinic for its policy before you sign with an agency, and expect that it will narrow your pool of surrogates and may lengthen matching, which already averages about 6 months at PLS.
A transfer-day change of mind does not override the agreement. If you, your surrogate or the clinic wants to revisit the number, it happens before the cycle, with both attorneys involved.
When do clinics consider two embryos?
Some clinics consider two embryos in limited situations, such as:
- Embryos that are untested and lower graded.
- An older egg source, where each embryo's chance is lower.
- Previous failed transfers with good-quality embryos.
Even in these situations, many clinics will not transfer two embryos into a gestational carrier, and ASRM's recommendation for carriers remains one. If your clinic raises a double transfer, ask what it expects the chance of twins to be for your embryos, whether testing would change its advice, and whether your surrogate would consent.
How to plan for a second child instead
If you hope for two children, plan two journeys rather than one twin pregnancy.
A sibling journey with a single embryo transfer each time gives your surrogate, or a new surrogate, a singleton pregnancy with lower risk, and your children a safer start. Many surrogates are open to carrying again for the same family.
PLS charges 50% of the program fee for a sibling journey. Program fee: confirm current schedule. If you have frozen embryos left after your first child is born, they can be used for that second journey. Keep them stored at your clinic, keep the storage fees current, and ask your clinic how long it recommends between a birth and the next transfer if the same surrogate will carry again. Her OB decides when she has recovered enough for another pregnancy.
Spacing your children by a journey, rather than carrying them together, also gives you time with your first baby before the second arrives, and gives your surrogate a recovery between pregnancies. If speed is the reason you are considering twins, weigh the time a second journey takes against the added NICU, insurance and lost-wage exposure of a twin pregnancy, and against the health of your surrogate and your babies. For how it works, see the sibling journey.
Sources
- ASRM (American Society for Reproductive Medicine), Practice Committee opinion on guidance on the limits to the number of embryos to transfer (most recent edition), and guidance on gestational carriers. https://www.asrm.org
- SART (Society for Assisted Reproductive Technology). https://www.sart.org
- CDC (Centers for Disease Control and Prevention), Assisted Reproductive Technology reporting.