What does the 6-week ultrasound show?
The first ultrasound after a positive beta hCG usually happens at about 6 weeks of pregnancy, which is 3 to 4 weeks after the embryo transfer. It is done at the fertility clinic or a monitoring clinic near the surrogate's home, using a transvaginal probe, because the pregnancy is still too small to see well through the abdomen.
A word on how weeks are counted. Pregnancy weeks are measured as if from a last menstrual period, about two weeks before conception, even in IVF. On the day of a day 5 blastocyst transfer, the pregnancy is dated at 2 weeks and 5 days. So "6 weeks pregnant" arrives only a little more than 3 weeks after transfer.
At 6 weeks, the clinic looks for three things:
- A gestational sac inside the uterus. This confirms the pregnancy is in the right place and rules out an ectopic pregnancy.
- A yolk sac, a small ring inside the gestational sac that nourishes the embryo in the earliest weeks.
- A heartbeat, usually. It is a flicker on the screen, and the clinic measures its rate.
It also counts. With a single embryo transferred, the scan almost always shows one sac. Occasionally an embryo splits, and the 6-week scan is where identical twins are first seen.
If no heartbeat is seen at 6 weeks, it is not necessarily bad news. Dates can be off by a few days. The clinic repeats the scan in about a week.
What are the 7 to 8 week and 9 to 10 week scans for?
Each scan answers the next question.
The 7 to 8 week scan checks growth and heartbeat. The embryo should be visibly larger, and its measurement, the crown-rump length, should match the dates from transfer. The heartbeat should be faster than at 6 weeks. A missing heartbeat at 7 to 8 weeks usually means the pregnancy has stopped developing.
The 9 to 10 week scan confirms viability before the clinic tapers estrogen and progesterone. It is the last check before the surrogate leaves the fertility clinic's care.
Clinics vary. Some do two scans, some do three, and some release earlier. The clinic decides the schedule.
| Week of pregnancy | Days after transfer | Test or scan | What is confirmed | Who performs it |
|---|---|---|---|---|
| About 4 | 9 to 11 days | Beta hCG blood test | Pregnancy hormone present and rising | Lab near the surrogate's home; result to the fertility clinic |
| About 6 | About 3 to 4 weeks | First transvaginal ultrasound | Gestational sac in the uterus, yolk sac, usually a heartbeat; number of pregnancies | Fertility clinic or local monitoring clinic |
| 7 to 8 | About 4 to 5 weeks | Second ultrasound | Growth matches dates; heartbeat faster | Fertility clinic or local monitoring clinic |
| 9 to 10 | About 6 to 7 weeks | Third ultrasound, at many clinics | Ongoing viability before the medication taper | Fertility clinic or local monitoring clinic |
| 10 to 12 | About 7 to 9 weeks | Release to the obstetrician | Clinic sends records; OB takes over prenatal care | Fertility clinic, then the surrogate's OB |
What heartbeat and growth figures do clinics look for?
At about 6 weeks, a heart rate of around 100 to 120 beats per minute is typical. By 7 to 8 weeks, clinics usually look for a rate above 120 beats per minute. Heart rate figures are pending review by Dr. Silverberg.
The heart rate rises quickly over these weeks, so the number only means something in relation to the date. A rate that is low for 6 weeks may be normal a few days later. That is why clinics repeat scans rather than deciding on one.
For growth, the clinic compares the crown-rump length to the expected size for the dates. Because the transfer date is known precisely, IVF pregnancies are dated more accurately than most natural pregnancies. A measurement close to the expected size is reassuring.
When do estrogen and progesterone stop?
In a medicated frozen embryo transfer cycle, the surrogate's body has not been making its own progesterone. The clinic supplies it until the placenta takes over.
That handover happens in the first trimester. Clinics usually continue estrogen and progesterone until about 10 weeks of pregnancy and then taper them over days or a couple of weeks. The clinic sets the taper, often after the 9 to 10 week scan. The surrogate should never stop on her own. See the frozen embryo transfer protocol page for the medications themselves.
What does release to the OB mean, and what changes for the surrogate?
Release, sometimes called graduating from the fertility clinic, is the point where the fertility clinic hands care to the surrogate's own obstetrician. It usually happens at 10 to 12 weeks. Some clinics release at 8 to 10 weeks.
At release:
- The fertility clinic sends records to the OB: the transfer, the beta results, the ultrasounds and the medication taper.
- The OB takes over routine prenatal care, as for any pregnancy.
- PLS confirms the surrogate's health insurance covers the pregnancy. That check was first done before matching. At release it matters again, because the OB and hospital will now bill for care. If her own plan excludes surrogacy, a dedicated policy is arranged in advance. See surrogate health insurance.
The surrogate usually chooses her own OB, often the one who delivered her own children. That choice is subject to the insurance network and to the delivering hospital's experience with surrogacy.
For the surrogate, release often feels like a return to normal: no more injections, fewer early-morning blood draws, and visits with a doctor she knows.
How does the OB coordinate with PLS and the parents?
The OB's patient is the surrogate. Her medical care and her privacy belong to her, and the OB works with her directly.
The parents stay informed through the arrangements set at matching. Parents can attend ultrasounds, in person or by video, if the surrogate agrees. Most PLS matches set this at the match meeting, so expectations are clear before the first scan.
PLS keeps the threads together. Case managers Natalie Gaudio-Fricano and Jenni Symons carry the active matches and stay in touch with the surrogate through the pregnancy. Both have been surrogates themselves. Julie Bendix, MPH, RD, LD, CLC, a registered dietitian and lactation counselor, provides at least six nutrition consults per surrogate across the journey.
If a scan brings bad news, PLS supports both parties through it, and the next step is planned with your clinic.
What is the schedule of prenatal visits and scans after release?
After release, the surrogate follows the same prenatal schedule as any pregnancy, adjusted by her OB.
A typical schedule is a visit every 4 weeks until about 28 weeks, every 2 weeks until about 36 weeks, and then weekly until delivery. Common milestones include a detailed anatomy ultrasound at about 18 to 22 weeks, glucose screening for gestational diabetes at about 24 to 28 weeks, and a group B strep test at about 36 to 37 weeks. Her OB may add visits or scans based on her history.
Late-pregnancy blood work is covered on the third trimester labs page. From transfer to delivery, the pregnancy itself takes roughly nine months, within a journey that typically runs 18 to 24 months.
This page gives general information. It is not medical advice. The fertility clinic and the surrogate's OB decide her care.
Sources
- ACOG (American College of Obstetricians and Gynecologists), guidance on prenatal care, dating of pregnancy and early pregnancy loss. https://www.acog.org/
- ASRM (American Society for Reproductive Medicine), patient information on early pregnancy after IVF. https://www.asrm.org/
- SART (Society for Assisted Reproductive Technology), patient information on IVF. https://www.sart.org/