Gestational carrier pregnancy

INTRODUCTION — Medical science allows motherhood to be divided into three categories: the genetic, the gestational, and the social mother. These "mothers" may be represented by as many as three different individuals. A gestational carrier is one who becomes pregnant with use of assisted reproductive technology and delivers a genetically unrelated child on behalf of someone else (ie, the intended parent[s]). This topic will review the indications, process, and outcomes for gestational carriers.

Related topics on the evaluation and treatment of infertility are presented separately.

●(See "Overview of infertility".)

●(See "Female infertility: Evaluation".)

●(See "Female infertility: Treatments".)

●(See "Approach to the male with infertility".)

●(See "Treatments for male infertility".)

In this topic, when discussing study results, we will use the terms "woman/en" or "patient(s)" as they are used in the studies presented. We encourage the reader to consider the specific counseling and treatment needs of transgender and gender-expansive individuals.

TERMINOLOGY — Gestational carrier pregnancy involves many reproductive roles, which may be carried out by the same or multiples individuals. Relevant terms include:

●Gestational carrier – Gestational carrier refers to a woman who becomes pregnant and carries a genetically unrelated child on behalf of another individual or couple (intended parent[s]) [1-3]. Gestational carriers do not provide their gametes for the child(ren) they gestate, and thus there is no genetic connection [2]. In vitro fertilization (IVF) is used to create an embryo, using either gametes of the intended parent(s) or donor gametes, which are transferred into the uterus of the gestational carrier [4,5]. In this review, the term "gestational carrier" will be used to refer to this group of women.

●Traditional surrogate – In comparison with a gestational carrier above, a traditional surrogate has a genetic connection to the embryo [1,2]. The surrogate's own egg is fertilized by intrauterine insemination of sperm from the intended father (or a sperm donor) [6]. Therefore, the surrogate has a genetic, as well as a gestational, connection to the embryo. While traditional surrogacy is acceptable in some situations, the genetic links make it more legally and ethically complex, and it is therefore less commonly offered [2,7,8].

●Intended parent(s) – Intended parent(s) are the individual(s) who "contract with the gestational carrier to achieve their reproductive goals and plan to be the social and legal parents of the child" [2].

●Gamete providers – Gamete providers are the sources of the sperm and oocyte used to create an embryo through IVF. They may or may not be the intended parent(s) [2].

The role of the gestational carrier is usually limited to carrying the pregnancy and delivering the child; it does not extend to raising the child (social mother). However, both gestational carriers and traditional surrogates may be family members and thus may maintain familial contact with the child [7].

EPIDEMIOLOGY — Use of gestational carriers has increased in frequency. In the United States, assisted-reproduction cycles involving a gestational carrier increased from 1 percent in 1999 to 2.5 percent in 2013, which represents an estimated 18,400 live born infants [2]. However, using a gestational carrier is not universally legal or available. For example, France bans all forms of gestational carrier pregnancy while the Ukraine permits use of all gestational carriers, including commercial carriers [9].

INDICATIONS — In countries that allow gestational carrier pregnancy, acceptable indications vary but generally include absent or nonfunctioning uterus, medical conditions that preclude safe pregnancy, and established inability to either conceive and/or carry a pregnancy [10]. The indication should be clearly documented in the patient's medical record.

Absent or nonfunctioning uterus — The absence of a functional uterus may result from congenital or acquired abnormalities (eg, Mayer-Rokitansky-Kuster-Hauser syndrome, hysterectomy for benign or malignant disease, Asherman syndrome) [11-15]. Some of these women may also have ovarian abnormalities or decreased ovarian reserve. For these women, an egg donor and/or gestational carrier can be used. (See "Congenital uterine anomalies: Clinical manifestations and diagnosis" and "Intrauterine adhesions: Clinical manifestation and diagnosis".)

For women with absolute uterine factor infertility, an alternative to using a gestational carrier is uterus transplantation [16]. Potential candidates for uterus transplantation include women who want to experience pregnancy or who do not have access (legal or financial) to a gestational carrier. However, this technique is only performed as part of an investigational protocol, entails significant medical, emotional, and financial concerns, and is not universally available.

●(See "Uterus transplantation for absolute uterine factor infertility: Ethics, patient selection, and consent".)

●(See "Uterus transplantation for absolute uterine factor infertility: Surgery, immunosuppression, and obstetric management".)

Maternal medical disease — Gestational carriers may be used when the intended mother has an absolute medical contraindication to pregnancy or a medical condition that could threaten the health and life of the mother and/or fetus [10]. For example:

●Women with poor cardiac or renal function may experience irreversible deterioration during pregnancy. Pregnancy in women with Eisenmenger syndrome is associated with maternal mortality of 30 to 50 percent. (See "Pregnancy in women with congenital heart disease: Specific lesions" and "Pregnancy and contraception in patients with nondialysis chronic kidney disease".)

●Women with medical conditions such as cancer or organ transplants may need treatment with drugs that cross the placenta or other interventions, such as radiation therapy, that can adversely affect the fetus. Cancers that express estrogen receptors may be stimulated during ovulation induction or pregnancy; thus, it may be desirable to avoid these processes in affected women.

•(See "Overview of infertility and pregnancy outcome in cancer survivors".)

•(See "Liver transplantation in adults: Long-term management of transplant recipients", section on 'Pregnancy'.)

•(See "Heart transplantation in adults: Pregnancy after transplantation".)

•(See "Overview of care of the adult kidney transplant recipient", section on 'Pregnancy'.)

●Women with hypertension are at risk of developing superimposed preeclampsia, which may necessitate premature delivery of the fetus for maternal indications. Consequently, the fetus is at risk of developing long-term severe sequelae of prematurity. Severe preeclampsia is also associated with increased maternal morbidity and, rarely, mortality. (See "Preeclampsia: Clinical features and diagnosis".)

Biologic inability to conceive or bear a child — Women with recurrent pregnancy losses (RPL) or in vitro fertilization (IVF) implantation failures may consider use of a gestational carrier [3,10]. Women who decide to pursue this route should undergo a thorough evaluation as to the etiology of the RPL or failed IVF. If RPL or recurrent IVF failure is a result of aneuploidy, then one might consider a donor egg IVF cycle with or without a donor sperm prior to embarking on a gestational carrier approach to pregnancy.

Poor pregnancy outcome is another potential indication for using a gestational carrier. As an example, one report described a 29-year-old woman with three consecutive pregnancies complicated by early onset severe preeclampsia causing fetal demise at 22 and 24 weeks of gestation; a neonatal death at 25 weeks of gestation; and life-threatening maternal hemolysis, elevated liver enzymes, and low platelets [17]. To avoid these complications, two of the patient's embryos, created through IVF, were transferred to a gestational carrier; the pregnancy progressed without complications, and a healthy 3.2 kg infant was delivered at 39 weeks of gestation.

Gestational carrier pregnancies are also approved for and used by unpartnered individuals and same-sex couples [2,10,18]. Additionally, women of advanced maternal age who desire pregnancy have been reported to use gestational carriers.

ETHICAL CONSIDERATIONS AND RESULTANT AVAILABILITY — Both ethical and practical considerations impact the decision to use a gestational carrier and the selection of the individual carrier. In response to the high expense associated with gestational carriers in some areas and restricted access in others, cross-border reproductive care, also referred to as medical tourism, and use of gestational carriers from other countries has become more popular [19]. In response, concerns have been raised about potential social, economic, and racial exploitation of gestational carriers [20]. As an example, women in India were commonly employed for gestational carrier pregnancies, but the Indian government has since restricted this practice because of concerns about exploitation of vulnerable women [21,22]. Opponents of gestational carrier pregnancy contend that these individuals are either coerced secondary to their financial need or are not sufficiently educated to clearly appreciate the implications of the consent they are providing. As such, this would not constitute informed consent. By contrast, proponents of medical tourism argue that the benefit received by both the intended parents (child) and the gestational carriers (financial compensation) adequately justify the process [20].

There are many other ethical and religious viewpoints regarding the practice of gestational carrier and traditional surrogate pregnancy. Some find use of gestational carriers or surrogates reasonable "if it is an altruistic act by a woman to help a couple for which it is impossible or medically contraindicated to carry a pregnancy" [1]. Others object on moral or religious grounds [23]. Additional controversies include use of family members as gestational carriers, financial compensation, potential financial or emotional coercion, the obligations of clinicians, provision of consent for the newborn, and cross-border reproductive care [1,2,24,25]. The role of financial compensation is discussed further below. (See 'Financial compensation' below.)

The multitude of ethical and moral viewpoints has resulted in uneven regional and global access to the procedure. As an example, within the United States, the majority of states do not have clear laws relating to the parenthood of intended parents, and thus a formal adoption process is required postpartum. Some countries allow both altruistic and financially compensated gestational carriers (Russia, India, Iran, South Africa), some allow altruistic procedures only (Denmark), and some ban all forms of the procedure (France, Italy, China). In some countries, procedure legality varies by state (United States, Australia, Canada) [20].

NONMEDICAL ISSUES — Prior to the medical evaluation and procedure, a gestational carrier must first be identified, selected, and legally contracted.

Finding a gestational carrier — Gestational carriers are recruited through advertisements by the couple's attorney, independent recruiters, in vitro fertilization (IVF) programs, surrogacy agencies (which prescreen potential surrogates), or the couple themselves using personal contacts and the media, including internet sites. This can take several months or more. In the United States, at least one state requires that the gestational carrier be related to one of the intended parents [20]. Individuals who cannot act as gestational carriers include owners, operators, laboratory directors, or employees of the fertility practice itself [10].

In one study in which gestational carriers were evaluated by psychodiagnostic interview and by the Minnesota Multiphasic Personality Interview-2, gestational carriers were motivated by a wish to help an infertile couple, enjoyed being pregnant, showed narcissistic needs, and expressed a wish for secondary financial gain [26]. The majority considered becoming a traditional surrogate but felt they could not surrender a child that was genetically theirs.

Selection of a gestational carrier — There are no universal guidelines regarding criteria for choosing a gestational carrier, but multiple factors need to be considered in selecting a carrier [1,2,27].

Medical and emotional history — The potential gestational carrier's obstetric and general medical history is reviewed, as it is important to select women with low risk of pregnancy complications. A successful obstetric history is predictive of favorable gestational outcomes for the intended parents. As an example, a history of preterm birth is the strongest risk factor for recurrent preterm birth, although most women who have had a preterm birth will have subsequent pregnancies of a normal duration. We use gestational carriers who have a history of at least one uncomplicated pregnancy (eg, no preeclampsia, gestational diabetes, preterm birth) and no chronic medical conditions, with the exception of adequately treated hypothyroidism. Some programs restrict selection of gestational carriers to women who have only had vaginal births; others allow women with one prior cesarean delivery to become a gestational carrier. The American Society for Reproductive Medicine (ASRM) advises that a gestational carrier "should not have had more than a total of five previous deliveries or three deliveries via cesarean section" [10].

Maternal age between 21 and 45 years is desirable since advancing age may have deleterious effects on the uterus, which render it a less favorable environment for pregnancy [10,28]. As an example, older women are more likely to have uterine leiomyoma or endometrial scarring from previous surgical procedures. They may also have reduced uterine artery blood flow or endometrial receptivity [29-32]; however, these factors appear to play no more than a minor role compared with ovarian aging [33,34]. Perhaps more importantly, advanced maternal age, particularly over 44, increases maternal and obstetric risk [35]. (See "Effects of advanced maternal age on pregnancy".)

The emotional well-being of gestational carriers is important since they must be emotionally prepared to give a newborn child to the intended parents upon delivery. The range of emotions associated with the delivery and transfer of the infant to the intended parents is unpredictable. Both biological and nonbiological factors play a role in defining the relationship between a parent and a child [36-40]. A thorough review of the potential gestational carrier's religious, moral, and ethical views with regard to this process increases the likelihood that transfer of the newborn to the intended parents will proceed smoothly [41]. It is important for the carrier to have a psychological screening prior to the start of the process and throughout the pregnancy and thereafter [10].

Family member as gestational carrier — The use of family members as gestational carriers raises unique concerns about future family dynamics and interactions. The inherent long-term relationship between a family member who becomes a gestational carrier and the intended parent means the association will continue beyond the delivery of the child. This raises social and psychological concerns that need to be properly discussed prior to embarking on use of a family member as a carrier [7]. The ASRM provides detailed discussions of the issues specific regarding use of family members as gestational carriers .

Before embarking on pregnancy, the following relationships should be discussed and clarified for all parties:

●Potential carrier and the intended parent – All parties should agree on the interactions of the intended parent with the carrier. As these individuals are also family members, these interactions may be significantly different since lifestyle patterns of the carrier are much more familiar to the intended parent, who might attempt to regulate or control activity beyond the level of traditional intended parent-carrier agreements.

●Potential carrier and the future child – The relationship between the future child and their biological relative be altered in any manner due to the unique involvement as a carrier.

●Potential carrier and the rest of the family – Given varying family dynamics, one might anticipate and evaluate for undue familial pressure on the potential carrier to consent to surrogacy.

Criteria for rejection — While criteria for rejection of a potential gestational carrier vary, the ASRM views the following as absolute contraindications for being a gestational carrier [10]:

●Cognitive or emotional inability to comply or consent

●Evidence of financial or emotional coercion

●Abnormal psychological evaluation/testing as determined by a qualified mental health professional

●Unresolved or untreated addiction; child abuse; sexual abuse; physical abuse; depression; eating disorders; or traumatic pregnancy, labor, and/or delivery

●History of major depression, bipolar disorder, psychosis, or a significant anxiety disorder

●Current marital or relationship instability

●Chaotic lifestyle; current major life stressor(s)

●Inability to maintain respectful and caring relationship with intended parent(s)

●Evidence of emotional inability to separate from/surrender the child at birth

Relative contraindications to being a gestational carrier include failure to exhibit altruistic commitment, problematic personality disorder, insufficient emotional support, excessively stressful family demands, history of conflict with authority, inability to perceive and understand the perspective of others, motivation to use the financial compensation to resolve one's own infertility, and unresolved issues with a negative reproductive event [10].

Contractual concerns — An expert team of health care providers, counselors, and attorneys should be involved in drafting the agreement between the gestational carrier and the intended parents [36-46]. We advise that couples considering use of a gestational carrier consult with an attorney with expertise in third party reproduction. The laws of the state and country in which the gestational carrier delivers determine whether the contracting couple or the gestational carrier will be the legal parent at the time of delivery. In some states, prebirth adoption is possible, while in others, legal documents created prior to birth can result in the intended parents' names being legally placed on the birth certificate [47]. It is vital that these policies be clear to the intended parents and gestational carrier prior to embarking on pregnancy. Both the gestational carrier and the intended parents should be represented by independent legal counsel, even if the gestational carrier is a family member [2]. Gestational carriers should be free to choose their own counsel, although the cost is typically not their responsibility (ie, cost covered by the intended parents).

While it is impossible to anticipate every possible scenario, it is prudent to have extensive discussion and clear statements of intent prior to embarking on this route. The expectations of both parties during the gestational process and immediately following delivery should be determined before any assisted reproductive technology is applied. Individual state law governs to what extent, if any, the intended parents may influence actions and behaviors of the gestational carrier that might impact the pregnancy. As an example, the intended parents may not want the gestational carrier to smoke during the course of the pregnancy. They may facilitate this intervention by paying for treatment for smoking cessation. However, the intended parents may not be able to require that the gestational carrier engage in a smoking cessation program.

Another important issue is how the parties will resolve issues relating to prenatal diagnosis. Who has the authority to make decisions about terminating the pregnancy if a fetal abnormality is diagnosed? What are the legal rights of a gestational carrier who wants to continue the pregnancy when the intended parents choose to terminate and vice versa [43]?

When is the gestational carrier's obligation to the intended parents fulfilled? Following delivery, the intended parents may want the gestational carrier to provide breast milk or breastfeed the newborn. These postpartum issues should be addressed contractually and preconceptually.

Finally, what role, if any, will the gestational carrier assume in the event of the untimely demise of an intended parent [44]? This is more than a theoretical issue for gestational carriers for women with serious medical disorders. When the gestational carrier does not have any biological relationship to the child, counseling and legal consultation should review the legal implications and obligations of the intended parent and carrier toward the child based on the specific state's laws.

The Committee on Ethics of the American College of Obstetricians and Gynecologists has published a Committee Opinion on Carrier Motherhood that reviews these issues [8].

Financial compensation — Financial remuneration also needs to be determined prior to conception and in accordance with local laws. Issues include appropriate compensation for the gestational carrier and which expected and unexpected expenses will be covered by the intended parents. Expenses may involve medical, housing, transportation, legal, or health insurance bills. Generally, relatives are not financially compensated by those for whom they carry a pregnancy. For gestational carriers that are not relatives or friends, the amount of remuneration varies depending on the chosen carrier, legal fees, geographic region, and agency involvement. When the gestational carrier has been recruited by the couple's attorney, by independent recruiters, or by IVF programs themselves, these entities have vested financial interests in pairing a gestational carrier with the intended parent.

There is no consensus as to whether or not direct compensation of a gestational carrier (as opposed to compensation for expenses only) is ethical, and legality of compensation varies by geographic location [1,2]. ASRM concludes that compensation for gestational carrier arrangements is ethical, but the amount of compensation should not "create undue inducement or risks of exploitation" [2]. By contrast, the ESHRE guideline specifies that "altruistic surrogacy is the only acceptable form" to minimize potential risk of exploitation or coercion [1].

●Supporting arguments – Arguments supporting financial compensation include reproductive autonomy and studies reporting a positive experience for both gestational carriers and intended parents [41,48,49].

●Counter arguments – Arguments against direct financial compensation include commodification of the body and potential for reproductive abuse and human trafficking, particularly for economically disadvantaged women [50-52].

MEDICAL PROCESS

Protection of gestational carrier — Guidelines are in place to protect the health and ensure the safety of the gestational carrier [10,53,54]. Testing for infectious disease is required for the genetic parents, as well as the gestational carrier, in order to protect the gestational carrier from possible infection that could be transmitted via an embryo (table 1) [10]. As an example, HIV-infected couples have requested use of a gestational carrier. Although there are no definitive data that gametes can transmit HIV to the embryo and, in turn, to the gestational carrier, the theoretical risk of transmitting infection to the gestational carrier has been ascertained as an unacceptable infectious health risk, and such requests have been denied [55]. Transfer of embryos derived from gamete donors who would otherwise be ineligible due to other infectious diseases may be available for transfer, with full disclosure to the gestational carrier and signing of a waiver [10].

In the United States, the Ethics Committee of the American Society for Reproductive Medicine (ASRM) defined the rights of the gestational carrier as follows [2]:

●Gestational carriers have a right to be fully informed of the risks of the gestational carrier process and of pregnancy, including physical, psychological, and social risks.

●Gestational carriers are the sole source of consent for their medical needs from embryo transfer through delivery and aftercare.

●Gestational carriers should receive psychological evaluation and counseling.

●Gestational carriers should have independent legal counsel.

●Provision of reasonable economic compensation to the gestational carrier is ethical (in the United States).

●The intended parents should be the legal parents of any children born from a gestational carrier arrangement.

Medical and psychological evaluation — A detailed description of the extensive medical and psychological evaluations of gestational carriers and intended parents can be found at the ASRM website and directly online [10]. These guidelines are specific to the United States and include information from the Centers for Disease Control and Prevention (CDC), the US Food and Drug Administration (FDA), and the American Association of Tissue Banks (AATB). As the prevalence of sexually transmitted infections and genetic diseases varies by geographic region, so too may practice recommendations differ.

In general, ASRM recommends screening and testing both the intended parents and the gestational carrier for a broad panel of infectious diseases. The oocyte source should be screened within 30 days of the egg retrieval and sperm source within 7 days of collection. The carrier should be screened within 30 days prior to transfer of embryos [10]. Any abnormal test results must be fully disclosed to the gestational carrier prior to embryo transfer. These tests are performed before initiation of each fertility treatment cycle. The gestational carrier may refuse the embryo transfer if parental tests for infection reveal positive results.

Per the ASRM guidelines, the potential carrier should complete a medical and sexual history, undergo physical examination, and be in excellent physical health. The potential carrier should not use tobacco, alcohol, or other drugs. The gestational carrier's partner, if there is one, must also consent to infectious disease (gonorrhea, chlamydia, HTLV-1 and HTLV-2, CMV) and psychological screening [10]. Typical testing includes [10]:

●Testing for infectious diseases – Additional testing of the gestational carrier includes evaluation for HIV-1, HIV-2, hepatitis B, hepatitis C, syphilis, gonorrhea, chlamydia, and cytomegalovirus (CMV) to minimize the chance of transmitting disease to the fetus.

•(See "Screening for sexually transmitted infections".)

●Additional serum tests – Serum tests are performed for blood type, Rh factor, presence of existing antibodies, and titers for varicella and rubella. One testing goal is to avoid hemolytic disease of the fetus and newborn.

•(See "Red blood cell antigens and antibodies".)

•(See "RhD alloimmunization in pregnancy: Overview".)

●Routine screening – Individuals should be screened for cervical, breast, and colon cancers as indicated.

•(See "Screening for cervical cancer in resource-rich settings".)

•(See "Screening for breast cancer: Strategies and recommendations".)

•(See "Screening for colorectal cancer: Strategies in patients at average risk".)

●Screening for substance use – A urine drug screen is typically performed.

•(See "Testing for drugs of abuse (DOAs)".)

The psychosocial education and psychological evaluation of the intended gestational carrier and intended parents are extensive [10]. If a family member is also the gestational carrier, the psychological evaluation is even more involved [7].

Procedure — Once the clinical decision has been made to use a gestational carrier and appropriate counseling has been performed, the two components of the procedure are (1) generating the embryo(s) to be transferred and (2) preparing the gestational carrier endometrium for embryo transfer. These steps can be done in either a staged or continuous approach.

●Staged – In staged procedures, the embryo(s) are frozen in the interim between creation and transfer. The staged approach is more commonly used as it avoids the need for menstrual synchronization and allows for genetic screening of the embryos for either known pathogenic mutations (preimplantation genetic testing for monogenic disorders [PGT-M]) or aneuploidy screening (preimplantation genetic testing for aneuploidy [PGT-A]), collectively called preimplantation genetic testing (PGT). (See "Preimplantation genetic testing".)

●Continuous – In the continuous approach, the gestational carrier must be identified in advance as there is no gap between embryo generation and transfer. The menstrual cycles of both the egg donor and gestational carrier are synchronized with medication.

●Role of preimplantation genetic testing for aneuploidy (PGT-A) – PGT-A of embryos prior to gestational carrier transfer has largely become the standard of care. Due to the significant costs and emotional and legal investment in this process, intended parents are inclined to transfer a single euploid embryo. While a retrospective analysis of outcomes did not report increased live birth rates by using PGT-A-screened euploid embryos [56], this analysis was limited by small sample sizes [57]. The ASRM Practice Committee, recognizing the complexity of interpreting these data and age-dependent implications, advise considering PGT-A screening in patients >38 years of age [58]. Regardless of the status of PGT-A-tested or -untested embryos, single-embryo transfer is advised because of reductions in adverse birth outcomes compared with double embryo transfers [56,58].

Both staged and continuous treatment pathways start with the planned egg donors undergoing assisted reproductive treatment using controlled hormonal ovarian hyperstimulation to promote oocyte recruitment and development. Following egg retrieval, the eggs are fertilized in vitro to generate embryos. The resultant embryos may be grown for possible PGT, cryopreservation, and future transfer (staged cycle) or immediate transfer (continuous cycle). (See "In vitro fertilization: Procedure", section on 'IVF cycle'.)

The second step is to prepare the gestational carrier's endometrium for embryo transfer. As part of this process, the gestational carrier is typically treated with a GnRH agonist (eg, Lupron) to suppress their own ovulation.

●For continuous cycles, the gestational carrier's treatment is coordinated with the in vitro fertilization cycle, and the cultured embryos are transferred into the uterus of the gestational carrier within the same cycle.

●For staged cycles, the cryopreserved embryos are thawed at the appropriate time in the gestational carrier's treatment cycle (ie, when the endometrial lining of the uterus appears ready for an embryo transfer).

Discussion of the IVF procedures is available separately. (See "In vitro fertilization: Procedure", section on 'Embryo transfer'.)

OUTCOMES

Live birth rates — Gestational carriers have higher live birth rates compared with matched control patients undergoing routine in vitro fertilization (IVF) (live birth rates of 54 to 57 percent for gestational carrier IVF cycles versus 44 to 46 percent for IVF cycles without gestational carriers) [27,59-65].

Possible explanations include that gestational carriers are generally younger than intended parents (which may confer a more favorable uterine environment), often have proven fertility (which reduces infertility-associated adverse pregnancy outcomes), and typically undergo single embryo transfer (which is associated with lower rates of multiple gestation and related complications) [64,65].

Obstetric and perinatal

●Perinatal outcomes – Retrospective studies suggest that gestational carrier pregnancy is associated with a higher mean birth weight but a slightly shorter mean gestational age, while data on preterm birth conflict.

•A retrospective analysis of data from the Society for Assisted Reproductive Technologies (SART) compared obstetric outcome for gestational carrier pregnancies, pregnancies in couples undergoing IVF with their own gametes, and IVF pregnancies conceived using donor eggs [66]. Infants of gestational carrier pregnancies had higher mean birth weight than infants from the other two groups (3309 versus 3236 to 3265 grams) but slightly lower mean gestational age at birth (37.2 versus 37.4 weeks in donor egg pregnancies and 37.7 weeks in IVF pregnancies). The higher birth weight in gestational carrier pregnancies may have reflected the proven uterine environment and absence of infertility-related disorders in these women. The slightly lower gestational age at birth in gestational carriers and donor egg pregnancies was unexplained.

•A subsequent retrospective cohort study of 124 gestational carriers who achieved a total of 494 pregnancies (both surrogate and spontaneous) reported that gestational carrier pregnancies had a shorter gestational age compared with spontaneously conceived pregnancies in the same woman (38.8±2.1 versus 39.7±1.4, respectively) [67]. However, when compared with spontaneous pregnancies in the same woman, gestational carrier pregnancies had higher rates of preterm birth (3 percent for spontaneous versus 11 percent for gestational carrier).

●Obstetric outcomes – A systematic review of 55 studies reported hypertensive disorders of pregnancy ranged from 3 to 10 percent of gestational carrier pregnancies, and placenta previa/abruption occurred in 5 percent [68], which is similar to the general obstetric population. (See "Gestational hypertension" and "Preeclampsia: Clinical features and diagnosis".)

There is no clear evidence that women with poor obstetric histories transfer these obstetric risks to their gestational carrier [69]. The few cases of obstetric complications in gestational carriers reported in the literature do not appear to be above the baseline rate for the general obstetric population [70]. However, there is a paucity of studies examining this issue, and further investigation is necessary. In some cases, obstetric complications may have been related to preexisting conditions in the gestational carrier. Thus, it is important to thoroughly review the prior medical and obstetric history of gestational carrier candidates, as with any woman seeking preconception counseling. (See "The preconception office visit".)

Psychological — Although data are limited to observational studies, it appears that psychological well-being, parenting, and child development in families created through gestational carrier pregnancies are at least as good as natural conception families [38,68,71].

●Child – In a longitudinal study comparing the interview and questionnaire results of 65 assisted reproduction families with 52 unassisted conception families, the psychological adjustment of the young adult children, as assessed by the Strengths and Difficulties Questionnaire (SDQ), were similar across the groups (SDQ self-report scores were surrogacy: 11.5 ± 5.00 versus unassisted conception 11.72 ± 5.56) [71]. Additionally, similar outcomes were reported for maternal depression and anxiety and couple relationship quality. The study group included 22 gestational carrier families, 17 egg donation families, and 26 sperm donation families, and the interviews and questionnaires were conducted when the children were age 20 years (the seventh phase of this study).

●Gestational carrier – Gestational carriers have positive experiences of surrogacy and mostly do not appear to experience psychological problems as a result of carrying a child for someone else, although difficulties have been reported [68,72,73]. Family relationships within the gestational carrier's own family appear to be good, and the carrier's children do not appear to be negatively affected by their mother's decision to be a gestational carrier [73,74].

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Female infertility".)

SUMMARY AND RECOMMENDATIONS

●Terminology – A gestational carrier is a woman who agrees to carry a genetically unrelated child on behalf of another individual or couple (intended parent[s]). The intended mother provides the egg and the intended father provides the sperm; rarely, egg donors or sperm donors are involved. In vitro fertilization (IVF) is used to create an embryo, which is transferred into the uterus of the gestational carrier. (See 'Terminology' above.)

●Indications – In countries that allow gestational carrier pregnancy, acceptable indications vary but generally include absent or nonfunctioning uterus, medical conditions that preclude safe pregnancy, and established inability to either conceive and/or carry a pregnancy. The indication should be clearly documented in the patient's medical record. (See 'Indications' above.)

●Global variation in access – The multitude of ethical and moral viewpoints has resulted in uneven global access to gestational carrier pregnancy. The clinician should be aware of local laws and advise patients to seek appropriate legal representation. (See 'Ethical considerations and resultant availability' above.)

●Selection of gestational carrier – There are no universal guidelines regarding criteria for choosing a gestational carrier, but multiple factors need to be considered. The physical and emotional health of potential gestational carriers should be evaluated. Carriers who are also family members need to address the unique relationships that result from their role as carriers. Common criteria for rejection should be excluded. (See 'Selection of a gestational carrier' above.)

●Contractual concerns – We advise that an expert team of health care providers, counselors, and attorneys be involved in drafting an agreement between the gestational carrier and the intended parents for the protection of both parties. It is critical that both the intended parents and the gestational carrier have independent legal counsel. (See 'Contractual concerns' above.)

●Role of financial compensation – Financial remuneration needs to be determined prior to conception and in accordance with local laws. Issues include appropriate compensation for the gestational carrier and which expected and unexpected expenses will be covered by the intended parents. (See 'Financial compensation' above.)

●Medical evaluation guidelines – Guidelines are in place to protect the health and ensure the safety of the gestational carrier and the child. A detailed description of the extensive medical and psychological evaluations of gestational carriers and intended parent(s) can be found at the American Society for Reproductive Medicine web site and directly online. (See 'Medical process' above.)

●Live birth – The live birth rate of gestational carriers is as high or higher than that in age-matched controls undergoing routine IVF. Retrospective studies suggest that gestational carrier pregnancy is associated with a higher mean birth weight but a slightly shorter mean gestational age, while data on preterm birth conflict.

●Child and parent outcomes – Gestational carrier pregnancy does not appear to negatively impact parenting or child development. (See 'Obstetric and perinatal' above.)