Infertility is a relatively common problem that affects 12-18% of all couples in the United States. Experts attribute one-third of all fertility problems to female factors, one-third to male factors, and one-third to either unknown factors or a combination of male and female factors.

For women, infertility is often linked to hormonal abnormalities leading to ovulation problems and can even be the result of chronic stress and poor dietary habits, especially when associated with being underweight.

Many of the women we see here at Global Fertility & Genetics in Midtown East, New York are surprised to learn that being overweight or underweight can also dramatically influence their ability to become pregnant.

If you’ve been trying unsuccessfully to become pregnant, and you suspect that your body weight may be part of the problem, read on to learn how weight affects fertility, and what you can do about it.   

Body weight and fertility

It may be harder to conceive if you’re significantly overweight or underweight, because both conditions can interfere with normal ovulation, or the monthly release of an egg from one of your ovaries.  

Besides causing anovulation, obesity can also negatively affect quality of eggs and their capability to normally fertilize by semen. As a 2017 study published in Systems Biology in Reproductive Medicine notes, “obesity appears to negatively influence female reproductive function at multiple levels of the hypothalamic-pituitary-ovarian (HPO) axis, and also at the level of embryo development and the endometrium.”

It’s also generally acknowledged that obesity increases the chance of miscarriage.

In women who underwent in-vitro-fertilization (IVF) treatment, being obese lowered their pregnancy success rate: “Obese women who undergo… IVF using autologous oocytes have reduced clinical intrauterine pregnancy rates, increased miscarriage rates, and lower live birth rates compared to their normal-weight peers, after controlling for age.”

Your body fat helps control the release of leptin, a hormone that affects not only appetite and metabolism, but also reproduction. If you don’t consume enough calories, or if you don’t have enough fat stores to support a pregnancy, leptin plays a role in decreasing fertility.

Moreover, a low body weight caused by significant weight loss, “especially when associated with strenuous physical activity and/or heightened cortisol secretion in women, causes hypothalamic dysfunction, with decreased GnRH pulsatility and impaired gonadotropin secretion, subsequently leading to arrested follicle development, oligo-anovulation and prolonged amenorrhea.” Oligo-anovulation is ovulation that occurs less than six times per year, and prolonged amenorrhea refers to extended periods of time with no menstrual period.

The body mass index gauge

Body mass index (BMI) is a quick, easy way to assess your level of body fat and get a better understanding of where you need to be to optimize your chances of conceiving and maintaining a healthy pregnancy.

Your BMI, which is calculated with a simple formula that uses your height and weight, is an indicator of fat levels, but not a direct measure of body fat.

You’re considered underweight if your BMI is less than 18.5, overweight if your BMI is between 25 and 29.9, and obese if you have a BMI of 30 or higher.

By this standard, a woman who is 5’9” tall is considered underweight if she weighs 124 pounds or less, overweight if she weighs more than 169 pounds, and obese if she weighs 203 pounds or more.

Although having a healthy body weight — or a BMI between 18.5 and 24.9 — is ideal for conception and carrying pregnancy, you don’t necessarily need to gain or lose a substantial amount of weight from your baseline to increase your chances of having a baby.

Reaching a healthy body weight

If you’re overweight or obese, simply losing 5-10% of your body weight can be enough to put conception and a healthy pregnancy within reach.

Fortunately, the best strategies for achieving a healthy pre-pregnancy body weight are the same strategies you should use to stay healthy throughout your pregnancy to give your baby a healthy head-start.

Physical activity should be a part of most, if not all, days of the week. That may mean you take a short walk after each meal, swim at the local pool, find a fitness class you’d like to attend, or start a workout program with a trainer. In addition to helping you shed excess pounds, regular exercise will also increase your strength, energy, and stamina — all of which are invaluable during labor and delivery.

Use smaller plates to help reduce portion sizes, and opt for a whole-foods diet that includes plenty of vegetables, fruit, whole grains, nuts and seeds, lean proteins, and healthy fats. Swap sugary drinks (and alcohol) for water, and limit the amount of fast food, processed food, and sugar-rich food you consume.

If you’re underweight, you’ll still want to find time for regular physical activity. You’ll also want to swap out any unhealthy foods and beverages for healthier options.

Most underweight women only need to gain a few pounds to optimize their chances of becoming pregnant. To gain weight in a way that supports optimal health, fill your plate with whole foods, and increase your portions at every meal. Try making healthy fats — including nuts and seeds, olive oil, avocado, and salmon — a part of most meals.

And remember, whether you’re trying to lose weight or gain a few pounds, the team at Global Fertility & Genetics in New York City is always ready to help.  

Women’s fertility starts to decline after age 30; by 40, a woman has only a 5% chance each month of getting pregnant as compared to a 20% chance for a 30-year-old. Sadly, by age 40 woman’s fertility has decreased to half.

As you get older, your egg inventory, or ovarian reserve, decrease in quantity (the size of egg pool) and quality.The lowered egg quality with aging relates to the high rate of chromosomal abnormalities of eggs that decreases an egg’s capability to normally fertilize and increases the risk of miscarriage. Moreover, with aging the risks of other medical issues that may impair fertility increase including uterine fibroids, tubal disease, endometriosis, and adenomyosis. Fortunately, there are many ways the fertility specialists at Global Fertility & Genetics in New York City can help women in their 40s overcome their ovarian reserve obstacles and increase their odds of getting pregnant.

In vitro fertilization (IVF)

In an IVF procedure, a woman’s eggs and a man’s sperm are combined in a laboratory to create fertilized eggs, embryos. The specialists at Global Fertility & Genetics first test their patients to ensure that they are candidates for IVF. If so, the first step in the procedure is stimulating a woman’s egg production with fertility drugs to help create multiple mature eggs.

Through careful monitoring, the specialist determines the right time to retrieve the maximum number of eggs, which are then mixed with sperm to create embryos.

If desired, those embryos then undergo preimplantation genetic screening (PGS) to identify normal embryos that have the highest chance of implanting and creating a pregnancy. This testing increases the odds of a woman carrying a healthy baby and it also decreases the risks of having a miscarriage due to chromosomal abnormalities, so commonly encountered in women over 40.  

Egg donation

Egg donation, also called third-party reproduction, is a great option for women who don’t have a viable ovarian reserve. With egg donation, the donor first undergoes a thorough exam that includes blood tests to check for sexually transmitted infections, drug use, and genetic conditions, as well as a psychological exam.

If the donor is deemed a healthy and suitable candidate, she takes fertility medications to stimulate the growth of multiple eggs and her eggs are then retrieved in the same fashion as in an IVF procedure. Freshly harvested eggs or frozen/thawed eggs are combined with a partner’s or donor’s sperm in an IVF lab. The high-quality embryos are selected for transfer into the woman’s uterus. The pregnancy success rate with donor eggs is related to the egg donor’s age provided that the recipient woman has a normal receptive uterus.

Gestational surrogacy

Gestational surrogacy, another form of third-party reproduction, is a viable option to build a family when woman’s uterus is not receptive for embryo implantation, or she has a medical condition endangering her and baby’s health or post-hysterectomy. Gestational surrogacy process is complicated from a legal standpoint and therefore assistance from an experienced lawyer is always recommended. In this type of surrogacy, the woman who is seeking a child still produces viable eggs that can be retrieved and combined with the father’s sperm. The embryo is then implanted in the uterus of the gestational carrier or gestational surrogate, who carries and delivers the baby

Global Fertility & Genetics is a top reproductive endocrinology and infertility center in New York City. Their specialists have helped couples from around the world overcome infertility through assisted reproductive technologies (ART) including IVF, egg donation, and surrogacy. Call or make an appointment online to find out how they can help you have a baby.