Case Report: Successful delivery in a 44-year-old woman using vitrified human oocytes taken from the woman at 41 years of age

Introduction

Given the advancement in technology for human egg freezing, the use of social egg freezing is increasing in developed countries^1,2. The increase in social egg freezing is associated with a number of different personal, professional, economical and psychological reasons^1,2.

However, successful pregnancies and deliveries are rare in women over 40 years of age^1,2. Furthermore, no case report about a successful delivery from a woman over 40 years of age using vitrified oocytes obtained through social egg freezing from a woman over 40 years of age has been published to date (as assessed through a PubMed database search).

Case

The patient visited our in vitro fertilization (IVF) clinic in April 2012. The patient was a 41-year-old woman who wanted to freeze her eggs for social reasons. She provided written informed consent. From April 2012 to June 2013, 8 oocytes were vitrified through ultra-rapid cooling using a high concentration of cryoprotectants (15% ethylene glycol + 15% DMSO + 0.5 mol/l sucrose) in a cryo device (Vitrification Media Kit, KITAZATO CORPORATION, Tokyo, Japan) by plunging the oocytes into liquid nitrogen (-196°C). The 8 oocytes were cryopreserved within liquid nitrogen (-196°C). The vitrified oocytes were thawed at the time of use. In June 2014, two embryos (day 2; a vitrified oocyte-derived embryo and a standard-derived embryo) were transferred to the uterus. The embryo transfers were carried under ultrasound guidance when endometrium thickness reached 7.0 mm. However, the patient’s pregnancy was not confirmed by the presence of a gestational sac (GS) at this time.

In August 2014, an embryo (day 5) from a vitrified oocyte was transferred to the uterus (the endometrium thickness: 7.5 mm), and the patient’s pregnancy was confirmed by the presence of a GS at 5 weeks (Figure 1). Repeated ultrasonography during the pregnancy revealed normal fetal growth and development. The 44-year-old patient delivered a 2534 g female infant by Caesarean section in the 37th week of pregnancy in May 2015. The female infant’s Apgar scores were 9 at 1 min and 9 at 5 min. The female infant exhibited no anomalies and is developing normally under the close surveillance of pediatricians.

Figure 1. The patient’s pregnancy was confirmed by the presence of a gestational sac (GS) at 5 weeks.

Discussion

Human oocyte vitrification holds great promise for women who need to preserve their fertility due to cancers that require chemotherapy or radiation^1,2. This technique is also referred to as “social egg freezing,” and many women who wish to delay pregnancy and/or delivery to pursue educational or professional goals want to have this option available to them^1,2. However, the guidelines of the American Society for Reproductive Medicine (ASRM) caution against the use of oocyte vitrification to circumvent the effects of age on the reproductive potential of healthy women given that there are insufficient data to support the safety, efficacy, ethics, emotional risks and cost-effectiveness of oocyte cryopreservation³. In 2013, the Japan Society for Reproductive Medicine (JSRM) issued a guideline allowing egg freezing for women under 40⁴. In addition, in 2015, an expert panel from the Japan Society of Obstetrics and Gynecology (JSOG) said it is not recommended that young and healthy women preserve their frozen eggs for future pregnancies and deliveries^4,5.

Furthermore, after performing a PubMed database search, no case reports have been published demonstrating the safety and efficacy of oocyte cryopreservation in women over 40 years of age who used the technique for social reasons. Therefore, we report a case of a successful live birth from a 44-year-old woman using vitrified oocytes obtained through social egg freezing from the woman at 41 years of age. Although the oocyte-to-baby rate was 1.8% and the number of oocytes typically needed to achieve a baby in women over 40 years of age is 55.5⁶, we were fortunately able to obtain a successful example. However, the concept of social egg freezing has medical, ethical and social problems. In general, a woman’s ovarian reserve declines as she ages, resulting in fewer oocytes and an increased risk of embryonic aneuploidy¹. Although we do not necessarily recommend having a child in the later stages of life, many patients who visit our IVF clinic are older than 40 years of age. Therefore, careful counseling is required because the patients must understand the uncertainties regarding the safety and efficacy of social egg freezing.

In addition, the rates of live births differ among clinics and/or hospitals due to variations in the vitrification and warming techniques used¹. Therefore, information from individual clinics and/or hospitals about the risks, the rates of successful live births and the cost of social egg freezing should be provided to patients to aid in the patient’s decision-making process.

Conclusion

We report a successful live birth from a 44-year-old woman using vitrified oocytes obtained through social egg freezing from the woman when she was 41 years old. However, the concept of social egg freezing is controversial. Therefore, information concerning this process should be disclosed to aid in the patient’s decision-making process.

Consent

Written informed consent for publication of the clinical details and clinical images was obtained from the patient.