Dana Prince on August 18th, 2011
Red Dragon Roll

Is Sushi Safe During Pregnancy?

Is baby craving sushi? Pregnancy food cravings can be powerful. And sometimes knowing that you can’t have something is enough to bring on a ravenous craving.  If you’re wondering if sushi is safe to eat during pregnancy, you’ll find it on just about every No-No list near the top. But there are some that say sushi can be totally fine to eat, if it’s prepared properly and you choose the right rolls and dishes.

Maki Rolls During Pregnancy

Many maki rolls don’t contain raw fish and could be fine to eat. There are options that contain cooked fish, for example. Vegetable sushi, if prepared in a restaurant with good hygiene, is more than likely going to be safe for pregnant women. And many people enjoy Wasabi and ginger with their japanese food / maki rolls, which can have antimicrobial properties.

Sushi and Sashimi During Pregnancy

Sushi and sashimi are more likely to be dangerous to eat while pregnant due to food poisioning and listeria. But most of today’s sushi bars and restaurants use very safe food prep practices. Fish needs to be frozen before use in most places and the freezing process not only keeps it fresh but can kill bacteria. In many cases, the food prep is more dangerous than the fish itself. And, in terms of sashimi and sushi safety during pregnancy, it’s wise for women of childbearing age to minimise how much high-mercury fish they eat. Be careful about eating anything when pregnant…use your ultra sensitive pregnancy nose as it will often alert you to potential dangers. If sushi smells fishy, it’s probably not fresh and therefore unsafe to eat for anyone, pregnant or not.

Author’s Opinion: I love to go for sushi but my favourites tend to be vegetarian maki or sushi (I love avocado sushi and avocado maki as well as yam / sweet potato rolls) with cooked chicken and beef in it instead of raw fish. In terms of pregnancy, I wouldn’t risk taking anything that could be dangerous. You can give up anything for nine months, right? That said, I think there are blanket statements that aren’t always correct. Going for sushi can be fun and healthy and many Japanese women eat this way throughout pregnancy. Common sense, research, and special care can help you enjoy Japanese food without putting your baby at risk. And there are a lot of other foods at sushi restaurants as well, such as teriyaki, edamame, miso soup, tempura vegetables, and more. Don’t always believe every wive’s tale.Always read and research to find out your options and talk to your doctor if you have specific questions.

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Vanishing twin’ explains increased risk of birth defects in surviving baby after infertility treatment

Stockholm, Sweden: Australian researchers have made the significant discovery that loss of a twin during very early pregnancy explains the increased risk of birth defects seen in multiple pregnancies after infertility treatment.

Professor Michael Davies will tell the annual meeting of the European Society of Human Reproduction and Embryology today (Wednesday) that the “vanishing twin” phenomenon, in which only one child is born from a pregnancy that originally starts as a multiple pregnancy, is linked to a nearly two-fold increased risk in any congenital malformation and to a nearly three-fold risk of multiple malformations.

Prof Davies, who is an Associate Professor and co-director of the Research Centre for the Early Origins of Health and Disease at the University of Adelaide, Australia, will say: “Our findings show that a ‘vanishing twin’ is a significant risk factor for congenital malformations in the surviving baby. This discovery means that we can now investigate what factors are occurring earlier in the process that could be influencing embryo development and loss. This has significant potential for advancing our understanding of the origins of congenital malformation, not just after infertility treatment, but also in spontaneously conceived pregnancies.”

It is difficult to study what factors in early pregnancy might be causing congenital malformations such as heart and skeletal defects and cerebral palsy. This is because, in the general population, the majority of pregnancy losses, including vanishing twins, occur in the early days and weeks of pregnancy, often before the woman even knows that she is pregnant. The first ultrasound scans are usually carried out at around six to eight weeks. However, in women undergoing fertility treatment, early pregnancy is much easier to study because doctors know exactly when eggs were fertilised and transferred to the woman’s womb, and this is followed by close monitoring with pregnancy tests and ultrasounds from the very beginning.

Prof Davies and his team studied data from all assisted reproductive technology (ART) cycles that took place in South Australia between January 1986 and December 2002, and linked them to registry data on birth defects and cerebral palsy. They identified cases in which a foetus had been lost by comparing routine six-week ultrasound data, which would show the presence of an empty foetal sac, and the number of babies actually delivered. These results were compared with pregnancies that had started off as single pregnancies and which had continued without loss of the foetus.

During this period 7,462 babies were delivered. In pregnancies where ultrasound had detected an empty foetal sac at six weeks, 14.6% of babies born had subsequent congenital malformations. The presence of an empty sac nearly doubled the risk of any malformation, and nearly trebled the risk of multiple malformations. Multiple pregnancies without any foetal loss were not associated with an increase in malformations when compared with single pregnancies without loss in the infertility group.

Prof Davies also looked at pregnancy loss after the first six weeks and he found that this was associated with birth defects in the surviving twin as well.

He will tell the conference: “To our knowledge, this appears to be the first report of the association of very early loss of a co-twin and a range of congenital malformations. This result is important for several reasons. Firstly, it appears that the developmental competency, or ‘quality’ of embryos in twins is related. Where one fails to develop, it appears to be an important indicator of the health of the survivor. This is certainly a sensible interpretation within ART, where the embryos result from the same stimulation cycle and embryo culture conditions, and are returned together.

“However, it may be possible to generalise these results to birth defects seen in fraternal twins – twins created from two separate eggs – from spontaneous pregnancies in the general population. This is important from the point of reproductive biology. One interpretation is that twinning reflects a failure in the regulation of egg recruitment and early embryo selection to ensure that only a single best egg and embryo implant. From a clinical perspective, it also emphasises the importance of embryo quality – not just for pregnancy rates but also for the competency of the foetus to develop normally.” Now he and his team will be trying to discover what mechanism is involved and whether it could be used to predict and improve embryo quality.

Prof Davies believes that the same mechanism may also be operating when babies with birth defects are born after spontaneously conceived single pregnancies, and that this could explain why a family history of miscarriage or a previous miscarriage is a risk factor for birth defects in a singleton pregnancy. “This interpretation may help us understand why both twinning and birth defects increase with maternal age, as there may be a common mechanism.”

The results of the research to be presented today may have important implications for fertility treatment, for instance when implementing a policy of single embryo transfer. “It may reinforce the importance of maximising embryo quality and factors that contribute to it,” he will say. “Furthermore, creating and using multiple embryos of lower quality may increase the risk of a developmentally compromised embryo both being selected for transfer and surviving to birth. However, it also appears that there may be predictable circumstances under which twin pregnancies do not carry a significant additional overall risk for birth defects, although twinning would continue to be a high-risk pregnancy for mother and baby for numerous other reasons.”

He will conclude: “It is particularly exciting to consider that in the near future we should be able to understand and influence the factors related to embryo quality in such a way as to drastically reduce the risk of congenital malformations in ART babies. Further, it appears plausible that these same factors will operate in the general population, and may, in principle, be modifiable.”

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Stockholm, Sweden: Two studies from France and Denmark have shown that children born after frozen embryo transfer are larger and heavier. The risk for a baby to be too heavy for its gestational age at birth is increased 1.6 fold compared to IVF children from fresh embryo transfer and 1.5 fold compared to naturally conceived children, the 27th Annual Meeting of the European Society of Human Reproduction and Embryology will hear (Wednesday).

In the first study, French scientists looked at neonatal outcome in terms of mode of delivery, gestational age, preterm birth rate (less than 37 weeks of gestation), mean child measurements, low birth weight (less than 2,500g) and perinatal mortality. When comparing the cryo singletons to the fresh cohort, the scientists showed that mean birth weight, mean height and head circumference were lower in the fresh population. The mean birth weight of the cryo babies was 102g higher compared to the fresh cohort. Low birth weight for children born to term (more than 37 weeks) was also significantly lower in fresh babies. Low birth weight to normal birth weight ratio was twice as high in the fresh population (3.6% compared to 1.8%).

“Frozen embryo transfer did not seem to adversely affect neonatal outcome,” says Dr. Sylvie Epelboin, from Bichat-Claude Bernard Hospital, Paris. “We are not sure why the cryo babies are heavier and larger, but we think it may have something to do with the hormonal hyperstimulation during the fresh cycles.”

The researchers found no significant difference between the two cohorts in terms of preterm birth rate and mode of delivery. However, the boys to girls ratio was 1.05 times higher in the cryo group as was the IVF/ICSI ratio (84% compared to 65%). The ratio of women who had given birth once to multiparous women was 1.6 times higher in the fresh cohort. The group analysed 16,002 singletons, 2,140 of these children were in the cryo group and 13,682 were from fresh embryo transfers.

In a second study from Denmark Dr. Anja Pinborg and her group from the Rigshospital at Copenhagen University compared intrauterine parameters of 910 singletons born after frozen embryo transfer (FET) with 9,603 babies from fresh embryo transfer and 4,656 naturally conceived (NC) children. The rate of large-for-gestational age (LGA) babies was significantly different between the three groups with 16.9% for FET, 10.3% for fresh transfer and 11.4% for NC babies. The same applied to the rate of babies with birth weight of 4,500g or more (5.6%, 2.8% and 3.4% respectively).

“Cryopreservation of embryos can result in ‘Large Offspring Syndrome’, which may be explained by epigenetic changes in the very early embryonic stages caused by freezing and thawing procedures,” says Dr. Pinborg. “Future studies must look into the precise epigenetic changes causing LGA offspring in humans. In animal studies, there is evidence that abnormal gene expression of certain developmentally important genes may be responsible for the observed large offspring syndrome.”

The risk for a baby to be too heavy for the gestational age at birth is increased 1.6 fold compared to children from fresh embryo transfer and 1.5 fold compared to naturally conceived children. The group found a similar significant pattern for small-for-gestational age (SGA) children. Only 9.2% of FET singletons were SGA compared to 14.8% in fresh IVF and ICSI and 11.3% in NC children.

“We think that because in FET cycles hormone supplementation mimics the natural cycle, compared to the superphysiologically high hormonal stimulation of women in fresh cycles, this ‘similar-to-natural-cycle concept’ may influence endometrial receptivity, early implantation and placental development in a positive way, leading to higher foetal growth and higher mean weight,” Dr. Pinborg will say.

Placenta previa (PP)* was seen in 0.9% of FET pregnancies compared to 1.5% of fresh IVF/ICSI and 0.3% of NC children. However, these figures were not significantly different and there was no association between PP and the risk of being SGA in any of the cohorts. “This lower risk in placenta previa in FET compared to the other groups may be explained with alterations in the endometrial contractility,” says Dr. Pinborg. “Ovarian stimulation and/or oocyte retrieval may induce alterations in the endometrial contractility leading to fewer implantation sites than in the unstimulated frozen cycles. The transcervical embryo replacement may also have some impact and hence lead to a higher placenta previa rate in FET compared to natural cycles.”

Babies with a high birth weight may face an increased rate of delivery by Caesarean section and obstetric intervention causing complications for both mother and baby.
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* Placenta previa is an obstetric complication in which the placenta is attached to the uterine wall close to or covering the cervix

Abstract no: Dr. Epelboin O-229 Wednesday 6 July 2011, 10.00 hrs CEST (Hall A2)
Dr. Pinborg O -230 Wednesday 6 July 2011, 10.15 hrs CEST (Hall A2)

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