A recent study published in the Annals of Internal Medicine, “Severe Maternal and Neonatal Morbidity Among Gestational Carriers: A Cohort Study” by Velez et al., has brought attention to maternal health outcomes in surrogacy. As leaders in the field of surrogacy and advocates for both surrogates and intended parents, we want to provide a thorough analysis of this research.
Our commitment to transparency and education drives us to examine such studies closely. We aim to offer a comprehensive understanding of the data, its implications and its limitations. As experts in surrogacy, we have a responsibility to interpret and share accurate information, ensuring that both surrogates and intended parents can make informed decisions.
In this analysis, we’ll break down the study’s findings, explore its methodology and discuss what these results might mean for the surrogacy community. We’ll also address the study’s limitations and contextualize the data, drawing on our extensive experience in surrogacy.
The Impact of Sample Sizes on Study Findings
The study reported severe maternal morbidity (SMM) rates of 2.3% for unassisted conceptions, 4.3% for in vitro fertilization (IVF) conceptions and 7.8% for gestational carrier surrogacies. However, in evaluating medical research, the sample population’s size and distribution significantly influence the results’ reliability and interpretation. In this case, the study examined three groups with significantly different sample sizes:
- Unassisted conceptions: 846,124 cases
- In vitro fertilization (IVF) conceptions: 16,087 cases
- Gestational carrier surrogacies: 806 cases
This substantial disparity in sample sizes requires careful interpretation of the study’s results. Smaller sample groups, such as the gestational carrier cohort, are more susceptible to percentage fluctuations due to individual cases having a proportionally larger impact. For example, while the 7.8% SMM rate reported for gestational carriers seems concerning, it represents only 62 cases out of 806. In contrast, unassisted conceptions, with a lower percentage of 2.3%, account for over 19,000 cases of SMM.
For accurate comparisons between groups, it’s important to have similar-sized samples. When group sizes differ as greatly as in this study, relying only on percentage-based differences can lead to potentially misleading conclusions. It’s like comparing the population of a small town to a big city; percentages alone don’t tell the whole story. Larger sample sizes typically provide more reliable trends, while smaller samples, such as the gestational carrier group, may overemphasize outcomes that aren’t representative of the broader population.
Analyzing Severe Maternal Morbidity Rates
The study reports that 19,460 women who conceived without assistance experienced SMM, accounting for 2.3% of cases. IVF conceptions resulted in 691 cases of SMM, or 4.3%. While showing the highest percentage at 7.8%, gestational carriers account for only 62 cases.
This data underscores the importance of considering raw numbers alongside percentages. Although the percentage of gestational carriers experiencing SMM is higher, the actual number of cases is significantly lower than unassisted conceptions. Unassisted conceptions account for over 31,000% more SMM cases than gestational carriers. This sharp contrast suggests that the issue may not be isolated to surrogacy but could reflect broader systemic issues in maternal care across the general population.
Another study found that severe obstetric morbidity among gestational carriers was significantly less common compared to non-surrogate IVF pregnancies (1.7% vs. 5.5%), further supporting the idea that gestational carriers may experience better outcomes compared to others who conceive through IVF. This reinforces the need to consider the unique health profiles of gestational carriers and evaluate their outcomes with care.
The takeaway from this data is that focusing solely on percentages in small sample sizes can obscure the bigger picture. Gestational carriers comprise a tiny fraction of the population studied, and higher percentages in small groups can be misleading. Instead, we should concentrate on improving maternal care for all women, regardless of conception method.
Evaluating Severe Neonatal Morbidity Rates
The study also examined severe neonatal morbidity (SNM) rates across the three groups, providing additional insight into the health outcomes associated with different conception methods:
- Unassisted conception: 49,921 cases of SNM (5.9% of 846,124)
- IVF conception: 1,431 cases of SNM (8.9% of 16,087)
- Gestational carriers: 53 cases of SNM (6.6% of 806)
These findings reveal that IVF conceptions show a higher rate of SNM compared to unassisted conceptions, which aligns with existing medical knowledge. IVF pregnancies are known to have an increased risk of complications such as preterm birth and low birth weight — factors that can contribute to higher neonatal morbidity.
However, an interesting observation emerges in the gestational carrier group. Despite undergoing IVF as part of the surrogacy process, children born to gestational carriers exhibit a lower SNM rate (6.6%) compared to the overall IVF group (8.9%). This difference, while not dramatic, suggests that gestational surrogacy may not necessarily increase the risk of severe neonatal morbidity compared to other IVF pregnancies.
This unexpected outcome could be attributed to the rigorous screening and selection process of gestational carriers. Surrogacy agencies typically ensure that potential surrogates are in good health and have a history of uncomplicated pregnancies, factors that may contribute to better neonatal outcomes.
While these findings don’t eliminate the risks associated with IVF, they highlight the need for further research into the specific factors that might lead to better outcomes in gestational surrogacy.
The Missing Genetic and Identity Data in IVF
One of the study’s major limitations is the lack of genetic and identity information for the sperm and eggs used in the IVF procedures. This missing information raises significant concerns, as genetic factors can substantially influence maternal and neonatal health outcomes. An individual’s genetic makeup can affect various aspects of pregnancy, including the progression of the pregnancy, the risk of complications such as hypertensive disorders and the likelihood of preterm birth.
Without access to the genetic profiles of the gametes used in IVF, researchers face challenges in accurately assessing the risks for gestational carriers and making valid comparisons between surrogates and those who conceive naturally. This missing data creates a significant gap in understanding the risks associated with different conception methods.
Incorporating genetic data into future studies could help provide a more complete picture of the risks associated with IVF, particularly in surrogacy cases. By including genetic information, researchers could better understand the factors contributing to maternal and neonatal morbidity.
The Importance of Surrogate Selection Criteria
While the Velez study provides valuable insights into severe maternal and neonatal morbidity rates among gestational carriers, the selection criteria for surrogates in these studies warrant closer examination. According to Dr. Kate Swanson, a perinatologist and clinical geneticist, many gestational carriers in the Velez dataset may not have met the criteria set forth by the American Society of Reproductive Medicine (ASRM). She said, “Really, it shows me that a lot of the people participating as gestational carriers were maybe not ideal candidates.”
Swanson noted that some surrogates had never experienced pregnancy before or had reported using substances such as tobacco or other drugs. This raises concerns about the pool of candidates selected for surrogacy, especially in countries like Canada, where surrogates are not compensated beyond pregnancy-related costs. Swanson explained that this may lead to a smaller and potentially less selective pool of candidates, which could affect the health outcomes of both the surrogate and the child.
The selection process for gestational carriers is one of the most important aspects of the surrogacy journey. Reputable surrogacy agencies like Joy of Life implement rigorous health and experience standards to ensure the well-being of both the surrogate and the child. These criteria are designed to minimize complications and improve outcomes, reinforcing the importance of clear and consistent selection guidelines in surrogacy practices.
Exclusion of Multiple Births From the Study
Another notable limitation of the study is its exclusion of multiple births, which are more common in IVF pregnancies. By focusing exclusively on singleton births (pregnancies resulting in only one child), the study overlooks a significant category of pregnancies that often carry higher risks for both mother and child.
Multiple pregnancies, such as twins or triplets, are associated with increased risks of complications. These include a higher likelihood of preterm birth, low birth weight and severe maternal morbidity. For gestational carriers who undergo IVF, the chance of carrying multiples is elevated. By not including these cases, the study may not fully capture the range of risks associated with gestational surrogacy and IVF.
Another study reported that multifetal gestations in gestational carriers were associated with increased odds of neonatal morbidity and preterm births. This omission could potentially misrepresent the true health risks associated with surrogacy, as multifetal gestations often carry inherently higher risks than singleton pregnancies.
This highlights the need for more comprehensive research that includes these higher-risk pregnancies. Future studies that incorporate multiple births could provide a more complete picture of how surrogacy and IVF affect maternal and neonatal health across all types of pregnancies.
Socioeconomic Factors Influencing Maternal Mortality
The study reveals another critical factor influencing maternal health outcomes: socioeconomic status. The data shows that gestational carriers in the study were more likely to come from lower-income regions, a group that faces significantly higher risks during childbirth. Women from these areas experience maternal mortality rates that are up to 40 times higher than those from higher-income regions.
Socioeconomic status is a well-established determinant of health outcomes, and this data underscores the disparities that exist in maternal healthcare. Access to quality prenatal and postnatal care, nutrition and overall healthcare resources are often limited in lower-income communities, contributing to these alarming statistics.
To improve maternal mortality rates, particularly for gestational carriers and other vulnerable populations, addressing these healthcare disparities is essential. Efforts should be focused on providing equitable access to high-quality care, regardless of income level, to ensure that all mothers, whether gestational surrogates or not, receive the support they need for healthy pregnancies and deliveries.
Interpreting the Data: A Call for Nuanced Understanding
As we reflect on the data presented in this study, it’s clear that context is key. While the percentages associated with gestational carriers may initially appear concerning, it’s important to approach them with careful consideration.
- The study’s small sample size can skew results, leading to misleadingly high percentages, such as the 7.8% SMM rate for surrogates.
- The exclusion of important factors, like genetic and identity data for IVF pregnancies, limits the ability to assess the true risks for gestational carriers.
- By excluding multiple births, the study may underestimate the risks associated with surrogacy and IVF.
- Broader systemic issues — such as socioeconomic disparities, access to healthcare and underlying health conditions — are not adequately addressed, which affects maternal outcomes across all populations.
- The study’s focus on surrogacy as a high-risk process ignores the need to improve maternal healthcare for all mothers, especially those facing systemic inequalities.
In this light, interpreting the data requires a more nuanced approach. Rather than jumping to conclusions based on surface-level percentages, we must critically analyze the underlying causes and contributing factors. This includes acknowledging the study’s limitations and understanding how broader systemic inequities shape maternal and neonatal health outcomes. Encouraging deeper analysis will lead to more informed discussions and better healthcare solutions for all women.
Navigating Maternal Health in Surrogacy With Care and Insight
At Joy of Life, we’re committed to creating a supportive community where surrogates feel informed, cared for and empowered. We ensure that every candidate is thoroughly vetted before selection, prioritizing the health of the surrogate and the child. We strive to provide the highest quality care, frequent contact and follow-ups and personalized support throughout your journey.
We encourage anyone considering surrogacy to seek expert guidance and ask questions. We’re committed to transparency, and our team is always available to discuss these important issues in depth. If you have any questions or concerns, please don’t hesitate to contact us.
Sources:
Swanson, K., Debbink, M., Letourneau, J.M. et al. Association of multifetal gestation with obstetric and neonatal outcomes in gestational carrier pregnancies. J Assist Reprod Genet 38, 661–667 (2021). https://doi.org/10.1007/s10815-020-02034-8
Swanson, K., Letourneau, J.M., Kuppermann, M. et al. Obstetric morbidity in gestational carrier pregnancies: a population-based study. J Assist Reprod Genet 38, 177–183 (2021). https://doi.org/10.1007/s10815-020-02000-4
Velez, Maria P., et al. “Severe Maternal and Neonatal Morbidity Among Gestational Carriers: A Cohort Study.” Annals of Internal Medicine, American College of Physicians, 24 Sept. 2024, https://doi.org/10.7326/M24-0417
