Biologic fundamentals of motherhood in the absence of genetic bonding. Learnings from oocyte donation (OD)

      OBJECTIVE: Several studies demonstrate the capacity of reproductive systems to function without a sense of genetic belonging. A primed uterus accepts any healthy embryo; post partum breasts provide nourishing milk to any suckling baby, and challenging family paradigms, women are gifted with an immense capacity to love babies and build families beyond a genetic identity within family members. Our objective is to provide data to sustain that motherhood (capacity of a woman to implant an embryo, carry it through pregnancy and delivery, and nurture the newborn through successful breastfeeding) can be established in the absence of genetic dependence.
      DESIGN: Retrospective cohort study of pregnancies and deliveries from in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) in OD and oocyte recipients (OR).
      MATERIALS AND METHODS: Cohort 1: Follow up of 140 pregnant women, 70 of which conceived with their own oocytes and simultaneously donated spare oocytes to other 70 pregnant recipients. Implantation rates (IR), gestational age at delivery, weight of newborns and duration of lactation was compared between OD and OR sharing the same cohort of oocytes. Cohort 2: Outcome of pregnancies from embryo implantation to birth in 6024 pregnancies in OR and 31550 pregnancies in regular IVF and ICSI, reported to the Latin American Registry of Assisted Reproduction from 1995 to 2005.
      RESULTS: Cohort 1. Median age in OR, 40 years (27-50), was significantly higher than their donors 30.5 (23-36); nevertheless, there were no differences in IR (47.4 and 52.2%), nor in the duration of gestation. In addition, the weight of newborns was also similar in OR: 2980g in singletons, 2390 in twins and 1650 in triplets and their donors: 3170, 2057 and 1365g respectively. Furthermore, the mean duration of lactation reached 6.8 months in both groups. Cohort 2. In every age category, IR was higher in OR than in regular IVF/ICSI. Out of 1965 singletons from OR, 79% weighed ≥2500g compared with 79.3% in 8194 IVF. In 1328 twins from OR, 46.8% weighted ≥2500g compared with 50.2% in 6362 IVF twins (NS).
      CONCLUSIONS: Embryos can implant and cohabit equally well in the uterus of donors and recipients. The proportion of term deliveries and healthy newborns is also similar in recipients and their donors. Furthermore, the prolonged lactation in both OD and OR, contributes to the hypothesis that “motherhood” does not require genetic bonding, and that the biologic and emotional substance of women act in perfect harmony when nurturing a new life.