Prenori searches for the healthiest 0.005% of surrogates to build your child's starting foundation for life.
Blood pressure in US women aged 20 to 39
Blood sugar (HbA1c) in US women aged 20 to 39
BMI in US women aged 20 to 39
Height in US women aged 20 to 39
Resting heart rate in US women aged 20 to 39
A child’s health isn’t decided by genes alone. The womb is the first place a child lives, and conditions there affect how genes are switched on and off. This is called epigenetics, and its effects last a lifetime. Adults exposed to the Dutch famine in the womb had more obesity and heart disease.1 Children exposed to untreated gestational diabetes had more body fat at 10 to 14.2 Adults born early have more high blood pressure and diabetes.3
With surrogacy, you choose the genes. The surrogate provides everything else, so her health is part of your child’s starting point. These are differences in risk across large groups, not guarantees.
Agencies check for a minimum, and about 27% of US women aged 20 to 39 pass.4 But risk keeps falling well inside the normal range. Blood pressure of 125 passes, yet carries about 29% higher odds of preeclampsia than under 120.5 We set each threshold where the research shows risk is lowest.
What we screen for
We screen on seven things: blood pressure, blood sugar, BMI, height, resting heart rate, age and pregnancy history. Each limit sits where the research shows risk is lowest.
Blood pressure
Typical agencyAccepts under 130 mmHg98% of US women 20–39 meet this
Our targetUnder 110 mmHg50% of US women 20–39 meet this
Compared with women under 120, preeclampsia odds are 1.29 times higher at 120–129 and 2.35 times higher at 130–139.5
Blood sugar (HbA1c)
Typical agencyAccepts under 5.7% (not prediabetic)93% of US women 20–39 meet this
Our target5.0% or lower20% of US women 20–39 meet this
In a study of 23,316 pregnancies, rates of large babies, C-sections and preeclampsia rose steadily with blood sugar, with no safe cutoff.6 That study used a glucose tolerance test. Our HbA1c limit of 5.0% is based on that trend.
BMI before pregnancy
Typical agencyAccepts 18 to 3267% of US women 20–39 meet this
Our target20 to 2314% of US women 20–39 meet this
Preeclampsia, gestational diabetes and stillbirth all rise with BMI, even inside the normal range. Preterm birth rises again below 20, so the target range is narrow.
Height
Typical agencyDoesn’t screen for height—
Our target170 cm or taller14% of US women 20–39 meet this
Each extra centimetre of height lowers preterm risk by about 3%.7 A surrogate’s height does not affect how tall the child grows. Agencies don’t screen for it.
Resting heart rate
Typical agencyDoesn’t screen for it—
Our target65 bpm or lower16% of US women 20–39 meet this
We use resting heart rate as a check on fitness. No study has tested resting heart rate itself against pregnancy outcomes, but regular exercise (150 minutes a week or more) is linked to lower rates of gestational diabetes and preeclampsia.
Age
Typical agencyAccepts 21 to 4295% of US women 20–39 meet this
Our target25 to 3030% of US women 20–39 meet this
US women are spread about evenly across these ages, so the curve is flat. A study comparing sisters puts the lowest risk of preterm birth and small babies at about 24 to 30.
Past pregnancies
Preterm birth, after a past preterm birth~30%
Preterm birth, after a past full-term birth~5%
Preeclampsia, after past preeclampsia14%
Gestational diabetes, after past gestational diabetes48%
Typical agencyAt least one uncomplicated birth47% of US women 20–39 meet this
Our targetNo past complications19% of US women 20–39 meet this
How often a complication comes back in the next pregnancy.8 We require no preterm birth, preeclampsia or gestational diabetes in any past pregnancy, all vaginal deliveries, and 18 to 23 months since the last birth.
How rare this makes her
Each criterion on its own rules out a lot of women. Put together, only about 1 in 19,000 to 1 in 56,000 US women aged 20 to 39 meet all of them.4 That’s roughly 800 to 2,300 women in the whole country.
20,000 US women aged 20 to 39
Orange5,400 meet a typical agency’s requirements
Blue, circledAt most 1 meets ours
This uses our highest estimate. With the lower estimate, it’s about 1 in 56,000.
Share of US women 20–39 left after each criterion (log scale)
All US women 20–39100%
+ Blood pressure under 11050%
+ HbA1c 5.0% or lower10%
+ BMI 20 to 231.4%
+ Height 170 cm or taller0.20%
+ Resting heart rate 65 or lower0.031%
+ Age 25 to 300.009%
+ No past complications0.002%
For comparison: a typical agency’s requirements27%
This assumes the criteria are independent. Blood pressure, blood sugar and weight are linked, so the real share could be up to 3 times higher, about 0.005%.
27%of US women 20–39 meet a typical agency’s requirements
0.002–0.005%meet ours
0–1of the ~6,000 women who become surrogates each year would qualify
Because so few existing surrogates qualify, we recruit candidates directly instead of picking from agency lists. We expect to screen 5,400 to 17,000 candidates who already meet agency standards for each match.
Optimized before transfer
Some markers can be brought into their best range within weeks, with a supplement, a medication or a vaccine. We test every one, and each match comes with her results and an evidence-based plan to optimize them before transfer.
Tests before transfer
Test
Why it matters
How to optimize
Omega-3 index
Supplements cut early preterm birth by 42% across 26 trials, mostly in women who started with low levels.9 About 11% of US adults are at 6% or higher.
Fish oil for about 12 weeks, to 6% or higher
Vitamin D
Low levels are linked to higher rates of preeclampsia and gestational diabetes.
Supplement if low
Iron (ferritin)
Iron deficiency is linked to preterm birth and low birth weight.
Supplement if low
Thyroid (TSH)
The baby relies on the mother’s thyroid hormone early on. An untreated underactive thyroid is linked to miscarriage and preterm birth.
Treat if out of range
Folate and B12
Both lower the risk of neural tube defects such as spina bifida.
Folic acid from at least a month before transfer; B12 if low
Iodine
Needed for the baby’s brain development. Mild deficiency is common in US women.
Prenatal vitamin with 150 µg iodine
Calcium intake
In women who get little calcium from food, supplements lower the risk of preeclampsia.
Supplement if intake is low
Rubella and chickenpox immunity
Either infection during pregnancy can cause birth defects.
Vaccinate at least a month before transfer
Your surrogate and her doctors decide which of these to act on.
A care plan to match
Finding her is our job. Your surrogate and her doctors run the pregnancy. To hold it to the same standard, every match comes with a care plan that covers standard care, then goes further. Each step is rated by the strength of its evidence.
Strong
Strong: randomized trials or major guidelines
Moderate
Moderate: consistent studies, smaller trials
Emerging
Emerging: promising, not yet proven
01Before transfer
Standard care
Prenatal vitamin with folic acid, infection screening, vaccines up to date, medical and psychological evaluation.
StrongSingle-embryo transfer, so she carries one baby at a time.
ModerateEvery pre-transfer marker brought into its optimal range: omega-3, vitamin D, iron, thyroid, B12 and iodine.
EmergingScreening for sleep apnea, which is linked to preeclampsia and gestational diabetes.
EmergingDental exam, with treatment of any gum disease.
02First trimester
Standard care
Dating ultrasound, prenatal blood work, cell-free DNA screening.
StrongPreeclampsia risk screening (blood pressure, uterine artery Doppler and a placental growth factor test), with 150 mg of aspirin nightly from 11–14 weeks if risk is high. In the ASPRE trial, this cut preterm preeclampsia by 62%.10
ModerateGlucose testing early in pregnancy, not only at 24–28 weeks.
ModerateA maternal-fetal medicine specialist from the first visit.
03Throughout pregnancy
Standard care
Regular prenatal visits, flu, Tdap and RSV vaccines, anatomy scan at 20 weeks, glucose test at 24–28 weeks.
Strong150 minutes a week of moderate exercise, with a prenatal trainer.
StrongScreening for depression and anxiety each trimester, with counseling available.
ModerateA nutrition plan from a registered dietitian, covering choline, DHA, iodine, and calcium if her intake is low.
ModerateAn sFlt-1/PlGF blood test if preeclampsia is suspected. A normal result rules it out for the following week with over 99% accuracy.11
EmergingHome blood pressure monitoring with a connected cuff, reviewed by her care team.
EmergingA continuous glucose monitor and a sleep and heart-rate wearable, shared with her care team.
EmergingClean air at home, with a HEPA purifier and less exposure to smoke and traffic pollution.
04Delivery and recovery
Standard care
Hospital delivery, newborn screening, a postpartum checkup.
StrongDelayed cord clamping, waiting at least 30–60 seconds.
StrongColostrum and expressed breast milk for your baby, if she chooses to provide it.
ModerateDelivery at a hospital with a Level III or IV NICU.
ModerateBlood pressure checks in the first 10 days after birth, plus pelvic floor physical therapy and mental health support.
Your surrogate and her doctors make every medical decision. Every step beyond standard care is offered to her, and she can accept or decline it.
Our commitments
We tell you exactly what we screen for and why, with sources and a rating of how strong the evidence is.
When a threshold goes beyond what a study measured, we say so.
The surrogate makes her own medical decisions and chooses which family she works with.
Get started
Start by building your search. It takes about three minutes: tell us what matters to you in a surrogate and a little about your family, and see how many women meet our standard and your preferences. Your search lead will be in touch within one business day.
Interested in becoming a surrogate? See our page for surrogates about pay, care and choosing a family. [Link]
Sources
Heijmans et al. Persistent epigenetic differences associated with prenatal exposure to famine in humans. PNAS, 2008. Roseboom et al. The Dutch famine and its long-term consequences for adult health. Early Human Development, 2006. ↩
Lowe et al. (HAPO Follow-up Study). Association of gestational diabetes with maternal disorders of glucose metabolism and childhood adiposity. JAMA, 2018. ↩
Our estimates, from fits to NHANES data for US women aged 20–39, with each marker treated as independent. The upper end of the range allows for blood pressure, blood sugar and weight being linked. ↩
Sutton et al. Early-pregnancy blood pressure categories and preeclampsia. Obstetrics & Gynecology, 2020. Adjusted odds ratios. ↩
HAPO Study Cooperative Research Group. Hyperglycemia and adverse pregnancy outcomes. NEJM, 2008. ↩
Zhang et al. Maternal height and gestational duration. PLoS Medicine, 2015. Height distribution from NCHS. ↩