Genetic association between the HLA-G 14-bp insertion/deletion polymorphism and the recurrent spontaneous abortions in Saudi Arabian women.

The non-classical class I human leukocyte antigen (HLA)-G molecule was found to be predominately expressed in the extravillous cytotrophoblasts at the fetal-maternal interface during pregnancy. This molecule is critically important for successful implantation during human pregnancy. The polymorphic insertion-deletion (indel) 14-base pair (bp) site localized at the 3' untranslated region was associated with HLA-G mRNA stability and isoform alternative splicing patterns, and thus may influence HLA-G function during pregnancy. We studied the association between the 14-bp indel polymorphism (rs16375) at the 3' untranslated region with recurrent spontaneous abortions in a Saudi population living in Riyadh. A group of 64 women with 2-11 successive abortions were included in this study. The control group included 62 women without reported abortions and at least 2 pregnancies, all visiting the King Khaled Hospital in Riyadh. The 14-bp indel was genotyped in the case and control groups. The frequency of the genotype +14/+14 was slightly higher in women with recurrent spontaneous abortions, but no significant differences were observed in the distribution of alleles and genotypes.

Sex differences in regional specialisation across the placental surface.

There may be regional specialisation in structure and function across the placental surface. In Riyadh, Saudi Arabia, the length and the breadth of the placental surface at birth were highly correlated, but the breadth was more closely associated with the size of the baby. To replicate this we studied 321 pregnant Saudi women in the town of Baish. We measured the size of the newborn babies and their placentas. The association of the length and breadth of the placental surface on the baby's body size differed in boys and girls. Among boys the breadth had a stronger association with all birth measurements except crown-heel length. This was similar to the findings in Riyadh. Placental surface length was related to crown-heel length. For each centimetre in surface length, crown-heel length increased by 0.27 cm (95% CI 0.09-0.44, p = 0.004). Among girls placental surface breadth was related to crown-heel length, whereas surface length was related to birth weight, head and thigh circumferences. For each centimetre in surface breadth, crown-heel length increased by 0.33 cm (0.13-0.53, p = 0.001). We conclude that, within Saudi Arabia, there are both geographical and sex differences in regional specialisation across the placental surface. In the adverse circumstances of Baish, linked to the mothers' short stature, boys were smaller at birth than girls. Boys may have compensated for under-nutrition by increasing the depth of spiral artery invasion rather than by recruiting additional spiral arteries. Girls may have had more effective regional specialisation across the placental surface.

The velocity of fetal growth is associated with the breadth of the placental surface, but not with the length.

OBJECTIVES: Studies of the placenta in pregnancies complicated by pre-eclampsia have led to the suggestion that tissue along the length and breadth of its surface has different functions. A recent study in Saudi Arabia showed that the body size of newborn babies was related to the breadth of the surface at birth but not to its length. We have now examined whether the association between placental breadth and body size reflects large size of the baby from an early stage of gestation or rapid growth between early and late gestation. METHODS: We studied 230 women who gave birth to singleton babies in King Khalid Hospital, Riyadh, Saudi Arabia. In total, 176 had ultrasound measurements both before 28 weeks and at 28 weeks or later, which we define as early and late gestation. We used these to calculate growth velocities between early and late gestation, which we expressed as the change in standard deviation scores over a 10-week period. RESULTS: The breadth of the placental surface was correlated with fetal growth velocity. The correlation coefficients were 0.24 (P = 0.002) for the head circumference, 0.24 (P = 0.001) for the biparietal diameter and 0.34 (P < 0.001) for the abdominal circumference. The length of the surface was not related to fetal growth velocity. CONCLUSIONS: Tissue along the breadth of the placental surface may be more important than tissue along the length in the transfer of nutrients from mother to baby. This may be part of a wider phenomenon of regional differences in function across the placental surface.

Intergenerational effects of in utero exposure to Ramadan in Tunisia.

UNLABELLED: We have reported that changes in the lifestyle of pregnant women during Ramadan affect more than one generation. In a series of newborn babies in Saudi Arabia, those whose mothers had been in utero during Ramadan differed from those whose mothers had not been in utero during Ramadan. These were unexpected findings and require replication. METHODS: We examined body size at birth in 1,321 babies (682 boys and 639 girls) born in Gafsa, a small city in Tunisia. RESULTS: Babies whose mothers had been in utero during Ramadan were smaller and thinner, and had smaller placentas, than those whose mothers had not been in utero during Ramadan. After adjustment for sex, the babies were 93 g lighter (95% confidence interval, 32-153, P=0.003) than those whose mother had not been in utero during Ramadan, their mean ponderal index was 0.52 kg/m(3) lower (0.24-0.79, P<0.001) and their placental weight was 21 g lower (5-37, P=0.01). The findings did not differ by trimester of maternal exposure to Ramadan. They were similar in boys and girls and in primiparous and multiparous mothers CONCLUSION: This study provides further evidence that changes in lifestyle during Ramadan have intergenerational effects.

The breadth of the placental surface but not the length is associated with body size at birth.

Studies of pregnancies complicated by preeclampsia led to the suggestion that the surface of the placenta is aligned along two axes, measured by its breadth and length. It was hypothesised that tissue along the breadth serves as a nutrient sensor, responding to the mother's nutritional state and fetal nutritional demands, while tissue along the length has different functions. To develop this hypothesis we measured the breadth and length of the placental surface in 401 neonates born in the King Khalid Hospital, Riyadh, Saudi Arabia, and related these measurements to the baby's body size. The breadth and length of the placental surface were highly correlated (coefficient = 0.7). Nevertheless, in a simultaneous regression with both measurements, only the breadth was associated with neonatal body size. There were strong trends of increasing birth weight, ponderal index, and the circumferences of the head, chest, abdomen and thigh with increasing placental breadth. In contrast no measurement of baby's body size was related to placental length. Birth weight increased by 125 g per cm increase in placental breadth (95% confidence interval 88 to 162, p < 0.001) but only by 20 g per cm increase in placental length (-13 to 53, p = 0.2). The corresponding figures for head circumference were 0.28 cm (0.17-0.39, p < 0.001) and 0.03 (-0.07 to 0.14, p = 0.5). The associations between placental breadth and neonatal body size were strongest if the mother's height was below the median (157 cm). The associations between a larger breadth of the placental surface and a larger baby are consistent with the hypothesis that tissue along the breadth plays a key role in nutrient transfer from mother to baby. Mothers who are short in stature are known to have lower rates of protein turnover in pregnancy. In these circumstances the ability of the placenta to transfer amino acids to the fetus may be critical.