Primipaternities and human birthweights

The necessity to specify paternities in all obstetrical files in multigravidae

OBJECTIVE

To compare in singleton multiparous pregnancies the effect of having a new father for an index pregnancy as compared with multiparas with the same male partner and primiparas.

MATERIAL AND METHODS

21 year data, 2001-2021, Reunion island. We compared 2233 multiparas who had a new partner NewPMP (cases) with 50,364 same partner multiparas samePMP (controls) and 30,741 primiparas. Paired t-test in for parametric, Mann-Whitney U test for non-parametric continuous variables. P-values < 0.05.

RESULTS

As compared with primiparas, New paternity multiparas had similar neonatal outcomes: average birthweights 3044 g and 3017 g (vs 3125 g grams SamePMP, p < 0.0001), rates of low birthweights, very low birthweights (< 1500 g), rate of prematurity < 37 weeks, rate of early prematurity < 33 weeks and also "placental " intrauterine growth retardation, IUGR. Both primiparas and NewPMP had significant worse neonatal outcomes as compared with same partner multiparas for all these same items (all p < 0.05)). NewPMP had a much higher risk of preeclampsia than primiparas and samePMP (respectively, OR 1.74 and 2.9, p < 0.001), fetal deaths and perinatal mortality respectively, OR 1.4 and 1.8, p < 0.001. In 4 logistical models (primiparity, primipaternity, preeclampsia and "placental IUGR") new paternity multiparas had similar results compared with primiparas but very different results when compared with same partner multiparas.

CONCLUSIONS

New paternity multiparas share with primiparas a significantly higher risk of perinatal and maternal morbidities than same partner multiparas. Paternity needs to be specified in all obstetrical files, perinatal databases- Health Registries.

Progress in the understanding of the pathophysiology of immunologic maladaptation related to early-onset preeclampsia and metabolic syndrome related to late-onset preeclampsia

Among mammalian species, human reproduction has 2 outstanding features. The human hemochorial placentation is characterized by a very deep endovascular trophoblast invasion in the spiral arteries, reaching deep into the myometrium. This requires an agonistic direct cell-cell interaction between the maternal immune system and semiallogeneic trophoblast. The second feature is preeclampsia, a heterogeneous syndrome, a uniquely human condition. The human female is one of the few mammals exposed to her partner's semen on multiple occasions before conception. Regulatory T cells, especially paternal antigen-specific regulatory T cells, play an important role in the maintenance of pregnancy. Sexual intercourse increases the number of dendritic cells in the uterus that play an important role in the induction of paternal antigen-specific regulatory T cells. Paternal antigen-specific regulatory T cells maintain pregnancy by inducing tolerance. In the decidua basalis of preeclamptic cases, clonal regulatory T cells are reduced; these would normally monoclonally expand to recognize fetal or paternal antigens. Programmed cell death-1 expressed on T cells regulate cytotoxic T-cell activity and protect the fetus against maternal rejection. Programmed cell death-1 expression on clonal cytotoxic T cells is reduced in preeclampsia especially in early-onset preeclampsia, making the fetus and placenta vulnerable to attack by cytotoxic T cells. These phenomena can explain the epidemiologic phenomenon that preeclampsia is more common in couples using condom contraception, with shorter cohabitation periods, first pregnancies, first pregnancies in multiparous women when they change partner, and pregnancies after assisted reproduction using donated gametes. In contrast to its importance in early-onset preeclampsia, shallow trophoblast invasion does not play a role in the development of preeclampsia, that is, immune maladaptation does not seem to be involved. Late-onset preeclampsia (>34 weeks' gestation), representing 80% to 90% of preeclampsia in most developed countries with a "Western lifestyle," is strongly associated with maternal cardiometabolic variables (metabolic syndrome). Although the underlying pathophysiology might be quite different, syncytiotrophoblast stress is the final common pathway leading to the maternal syndrome among the subtypes of preeclampsia by causing an imbalance between proangiogenic factors (placental growth factor and vascular endothelial growth factor) and antiangiogenic factors (soluble fms-like tyrosine kinase-1 and soluble endoglin). Low-dose aspirin, started before 16 week's gestation, will prevent up to 60% of early-onset preeclampsia but will not prevent late-onset preeclampsia. Optimizing prepregnancy weight and controlling gestational weight gain may be the most effective ways to prevent preeclampsia.