考虑为1800克左右，目前一定要注意休息，加强营养，不可以过于劳累，也不可以性生活的。

您的胎儿：双顶径80mm，股骨长55mm，羊水60妈妈，7个半月了可以通过以下公式计算胎儿B超正常参数值：孕周双顶径(平均值)cm腹围(平均值)cm股骨长(平均值)cm13周2.52士0.256.90士l.651.17士0.3114周2.83士0.577.77士1.821.38士0.4815周3.23士0.519.13士1.561.74士0.5816周3.62士0.5810.32士1.922.10士0.5117周3.97士0.4411.49士1.622.52士0.4418周4.25士0.5312.41士l.892.71士0.4619周4.52士0.5313.59士2.303.03士0.5020周4.88士0.5814.80士l.893.35士0.4721周5.22士0.4215.62士1.843.64士0.4022周5.45士0.5716.70士2.233.82士0.4723周5.80士0.4417.90士1.854.21士0.4124周6.05士0.5018.74士2.234.36士0.5125周6.39士0.7019.64士2.204.65士0.4226周6.68士0.6121.62士2.304.87士0.4127周6.98士0.5721.81士2.125.10士0.4128周7.24士0.6522.86士2.415.35士0.5529周7.50士0.6523.71士1.505.61士0.4430周7.83士0.6224.88士2.035.77士0.4731周8.06士0.6025.78士2.326.03士0.3832周8.17士0.6526.20士2.336.43士0.4933周8.50士0.4727.78士2.306.52士0.4634周8.61士0.6327.99士2.556.62士0.4335周8.70士0.5528.74士2.886.71士0.4536周8.81士0.5729.44士2.836.95士0.4737周9.00士0.6330.14士2.177.10士0.5238周9.08士0.5930.63士2.837.20士0.4339周9.21士0.5931.34士3.127.34士0.5340周9.28士0.5031.49士2.797.40士0.53